Co-reporter:William H. Gerwick
Journal of Natural Products September 22, 2017 Volume 80(Issue 9) pp:2583-2583
Publication Date(Web):September 8, 2017
DOI:10.1021/acs.jnatprod.7b00624
Recent technological advances in mass spectrometry and NMR spectroscopy have enabled new approaches for the rapid and insightful profiling of natural product mixtures. MALDI-MS with the provision of biosynthetic heavy-isotope-labeled precursors can be a powerful method by which to interrogate a natural product metabolome and to gain insight into its unique constituents; this is illustrated herein by the detection, isolation, and characterization of cryptomaldamide. MS/MS-based Molecular Networks, facilitated by the Global Natural Products Social (GNPS) platform, is rapidly changing the way in which we dereplicate known natural products in mixtures, find new analogues in desired structure classes, and identify fundamentally new chemical entities. This method can be linked to genomic information to assist in genome-driven natural products discovery and is illustrated here with the characterization of the columbamides. Similarly, algorithmic interpretation of NMR data is facilitating the automatic identification or classification of new natural products. We developed such a tool named the Small Molecule Accurate Recognition Technology (SMART), which employs a convolutional neural network to classify HSQC spectra of organic molecules using pattern recognition principles. The discovery and rapid classification of several new peptides from a marine cyanobacterium as members of the viequeamide class provides an example of its utility in natural products research. These three illustrations represent different methods by which to look at the external features of a chemical substance and derive valuable insights into its identity or, as described herein, the “face of a molecule”.
Co-reporter:C. Benjamin Naman, Ramandeep Rattan, Svetlana E. Nikoulina, John Lee, Bailey W. Miller, Nathan A. Moss, Lorene Armstrong, Paul D. Boudreau, Hosana M. Debonsi, Frederick A. Valeriote, Pieter C. Dorrestein, and William H. Gerwick
Journal of Natural Products March 24, 2017 Volume 80(Issue 3) pp:625-625
Publication Date(Web):January 5, 2017
DOI:10.1021/acs.jnatprod.6b00907
Integrating LC-MS/MS molecular networking and bioassay-guided fractionation enabled the targeted isolation of a new and bioactive cyclic octapeptide, samoamide A (1), from a sample of cf. Symploca sp. collected in American Samoa. The structure of 1 was established by detailed 1D and 2D NMR experiments, HRESIMS data, and chemical degradation/chromatographic (e.g., Marfey’s analysis) studies. Pure compound 1 was shown to have in vitro cytotoxic activity against several human cancer cell lines in both traditional cell culture and zone inhibition bioassays. Although there was no particular selectivity between the cell lines tested for samoamide A, the most potent activity was observed against H460 human non-small-cell lung cancer cells (IC50 = 1.1 μM). Molecular modeling studies suggested that one possible mechanism of action for 1 is the inhibition of the enzyme dipeptidyl peptidase (CD26, DPP4) at a reported allosteric binding site, which could lead to many downstream pharmacological effects. However, this interaction was moderate when tested in vitro at up to 10 μM and only resulted in about 16% peptidase inhibition. Combining bioassay screening with the cheminformatics strategy of LC-MS/MS molecular networking as a discovery tool expedited the targeted isolation of a natural product possessing both a novel chemical structure and a desired biological activity.
Co-reporter:Jehad Almaliti, Karla L. Malloy, Evgenia Glukhov, Carmenza Spadafora, Marcelino Gutiérrez, and William H. Gerwick
Journal of Natural Products June 23, 2017 Volume 80(Issue 6) pp:1827-1827
Publication Date(Web):May 23, 2017
DOI:10.1021/acs.jnatprod.7b00034
A family of 2,2-dimethyl-3-hydroxy-7-octynoic acid (Dhoya)-containing cyclic depsipeptides, named dudawalamides A–D (1–4), was isolated from a Papua New Guinean field collection of the cyanobacterium Moorea producens using bioassay-guided and spectroscopic approaches. The planar structures of dudawalamides A–D were determined by a combination of 1D and 2D NMR experiments and MS analysis, whereas the absolute configurations were determined by X-ray crystallography, modified Marfey’s analysis, chiral-phase GCMS, and chiral-phase HPLC. Dudawalamides A–D possess a broad spectrum of antiparasitic activity with minimal mammalian cell cytotoxicity. Comparative analysis of the Dhoya-containing class of lipopeptides reveals intriguing structure–activity relationship features of these NRPS–PKS-derived metabolites and their derivatives.
Co-reporter:C. Benjamin Naman, Jehad Almaliti, Lorene Armstrong, Eduardo J. Caro-Díaz, Marsha L. Pierce, Evgenia Glukhov, Amanda Fenner, Carmenza Spadafora, Hosana M. Debonsi, Pieter C. Dorrestein, Thomas F. Murray, and William H. Gerwick
Journal of Natural Products August 25, 2017 Volume 80(Issue 8) pp:2328-2328
Publication Date(Web):August 7, 2017
DOI:10.1021/acs.jnatprod.7b00367
A recent untargeted metabolomics investigation into the chemical profile of 10 organic extracts from cf. Symploca spp. revealed several interesting chemical leads for further natural product drug discovery. Subsequent target-directed isolation efforts with one of these, a Panamanian marine cyanobacterium cf. Symploca sp., yielded a phenethylamide metabolite that terminates in a relatively rare gem-dichlorovinylidene moiety, caracolamide A (1), along with a known isotactic polymethoxy-1-alkene (2). Detailed NMR and HRESIMS analyses were used to determine the structures of these molecules, and compound 1 was confirmed by a three-step synthesis. Pure compound 1 was shown to have in vitro calcium influx and calcium channel oscillation modulatory activity when tested as low as 10 pM using cultured murine cortical neurons, but was not cytotoxic to NCI-H460 human non-small-cell lung cancer cells in vitro (IC50 > 10 μM).
Co-reporter:Gregory M. LaMonte, Jehad Almaliti, Betsaida Bibo-Verdugo, Lena Keller, Bing Yu Zou, Jennifer Yang, Yevgeniya Antonova-Koch, Pamela Orjuela-Sanchez, Colleen A. Boyle, Edgar Vigil, Lawrence Wang, Gregory M. Goldgof, Lena Gerwick, Anthony J. O’Donoghue, Elizabeth A. Winzeler, William H. Gerwick, and Sabine Ottilie
Journal of Medicinal Chemistry August 10, 2017 Volume 60(Issue 15) pp:6721-6721
Publication Date(Web):July 11, 2017
DOI:10.1021/acs.jmedchem.7b00671
Naturally derived chemical compounds are the foundation of much of our pharmacopeia, especially in antiproliferative and anti-infective drug classes. Here, we report that a naturally derived molecule called carmaphycin B is a potent inhibitor against both the asexual and sexual blood stages of malaria infection. Using a combination of in silico molecular docking and in vitro directed evolution in a well-characterized drug-sensitive yeast model, we determined that these compounds target the β5 subunit of the proteasome. These studies were validated using in vitro inhibition assays with proteasomes isolated from Plasmodium falciparum. As carmaphycin B is toxic to mammalian cells, we synthesized a series of chemical analogs that reduce host cell toxicity while maintaining blood-stage and gametocytocidal antimalarial activity and proteasome inhibition. This study describes a promising new class of antimalarial compound based on the carmaphycin B scaffold, as well as several chemical structural features that serve to enhance antimalarial specificity.
Co-reporter:Karin Kleigrewe, Lena Gerwick, David H. Sherman and William H. Gerwick
Natural Product Reports 2016 vol. 33(Issue 2) pp:348-364
Publication Date(Web):13 Jan 2016
DOI:10.1039/C5NP00097A
Covering: 2010 to July 2015. Previous review: Nat. Prod. Rep., 2010, 27, 1048-1065
Cyanobacteria are a prolific source of structurally unique and biologically active natural products that derive from intriguing biochemical pathways. Advancements in genome sequencing have accelerated the identification of unique modular biosynthetic gene clusters in cyanobacteria and reveal a wealth of unusual enzymatic reactions involved in their construction. This article examines several interesting mechanistic transformations involved in cyanobacterial secondary metabolite biosynthesis with a particular focus on marine derived modular polyketide synthases (PKS), nonribosomal peptide synthetases (NRPS) and combinations thereof to form hybrid natural products. Further, we focus on the cyanobacterial genus Moorea and the co-evolution of its enzyme cassettes that create metabolic diversity. Progress in the development of heterologous expression systems for cyanobacterial gene clusters along with chemoenzymatic synthesis makes it possible to create new analogs. Additionally, phylum-wide genome sequencing projects have enhanced the discovery rate of new natural products and their distinctive enzymatic reactions. Summarizing, cyanobacterial biosynthetic gene clusters encode for a large toolbox of novel enzymes that catalyze unique chemical reactions, some of which may be useful in synthetic biology.
Co-reporter:Nathan A. Moss;Matthew J. Bertin
Journal of Industrial Microbiology & Biotechnology 2016 Volume 43( Issue 2-3) pp:313-324
Publication Date(Web):2016 March
DOI:10.1007/s10295-015-1705-7
Filamentous marine cyanobacteria produce bioactive natural products with both potential therapeutic value and capacity to be harmful to human health. Genome sequencing has revealed that cyanobacteria have the capacity to produce many more secondary metabolites than have been characterized. The biosynthetic pathways that encode cyanobacterial natural products are mostly uncharacterized, and lack of cyanobacterial genetic tools has largely prevented their heterologous expression. Hence, a combination of cutting edge and traditional techniques has been required to elucidate their secondary metabolite biosynthetic pathways. Here, we review the discovery and refined biochemical understanding of the olefin synthase and fatty acid ACP reductase/aldehyde deformylating oxygenase pathways to hydrocarbons, and the curacin A, jamaicamide A, lyngbyabellin, columbamide, and a trans-acyltransferase macrolactone pathway encoding phormidolide. We integrate into this discussion the use of genomics, mass spectrometric networking, biochemical characterization, and isolation and structure elucidation techniques.
Co-reporter:Matthew J. Bertin, Ozlem Demirkiran, Gabriel Navarro, Nathan A. Moss, John Lee, Gregory M. Goldgof, Edgar Vigil, Elizabeth A. Winzeler, Fred A. Valeriote, William H. Gerwick
Phytochemistry 2016 Volume 122() pp:113-118
Publication Date(Web):February 2016
DOI:10.1016/j.phytochem.2015.11.011
•Bioassay guided isolation gave three γ-pyrones from a marine cyanobacterium.•Kalkipyrone B was determined by NMR and Mosher’s ester analysis.•Kalkipyrone A was cytotoxic while kalkipyrone A and B were equipotent antifungals.•16S rRNA analysis identified the producing strain to be a Leptolyngbya species.Bioassay-guided fractionation of two marine cyanobacterial extracts using the H-460 human lung cancer cell line and the OVC-5 human ovarian cancer cell line led to the isolation of three related α-methoxy-β, β′-dimethyl-γ-pyrones each containing a modified alkyl chain, one of which was identified as the previously reported kalkipyrone and designated kalkipyrone A. The second compound was an analog designated kalkipyrone B. The third was identified as the recently reported yoshinone A, also isolated from a marine cyanobacterium. Kalkipyrone A and B were obtained from a field-collection of the cyanobacterium Leptolyngbya sp. from Fagasa Bay, American Samoa, while yoshinone A was isolated from a field-collection of cyanobacteria (cf. Schizothrix sp.) from Panama. One-dimensional and two-dimensional NMR experiments were used to determine the overall structures and relative configurations of the kalkipyrones, and the absolute configuration of kalkipyrone B was determined by 1H NMR analysis of diastereomeric Mosher’s esters. Kalkipyrone A showed good cytotoxicity to H-460 human lung cancer cells (EC50 = 0.9 μM), while kalkipyrone B and yoshinone A were less active (EC50 = 9.0 μM and >10 μM, respectively). Both kalkipyrone A and B showed moderate toxicity to Saccharomyces cerevisiae ABC16-Monster strain (IC50 = 14.6 and 13.4 μM, respectively), whereas yoshinone A was of low toxicity to this yeast strain (IC50 = 63.8 μM).Bioassay-guided fractionation of the lipophilic extract of a field collection of cyanobacteria from American Samoa resulted in the isolation and structure characterization of kalkipyrone B.
Co-reporter:Dr. Matthew J. Bertin;Dr. Alexra Vulpanovici; Emily A. Monroe; Anton Korobeynikov; David H. Sherman;Lena Gerwick; William H. Gerwick
ChemBioChem 2016 Volume 17( Issue 2) pp:164-173
Publication Date(Web):
DOI:10.1002/cbic.201500467
Abstract
Phormidolide is a polyketide produced by a cultured filamentous marine cyanobacterium and incorporates a 16-membered macrolactone. Its complex structure is recognizably derived from a polyketide synthase pathway, but possesses unique and intriguing structural features that prompted interest in investigating its biosynthetic origin. Stable isotope incorporation experiments confirmed the polyketide nature of this compound. We further characterized the phormidolide gene cluster (phm) through genome sequencing followed by bioinformatic analysis. Two discrete trans-type acyltransferase (trans-AT) ORFs along with KS-AT adaptor regions (ATd) within the polyketide synthase (PKS) megasynthases, suggest that the phormidolide gene cluster is a trans-AT PKS. Insights gained from analysis of the mode of acetate incorporation and ensuing keto reduction prompted our reevaluation of the stereochemistry of phormidolide hydroxy groups located along the linear polyketide chain.
Co-reporter:Jung-Rae Rho, Gurusamy Subramaniam, Hyukjae Choi, Eun-Hee Kim, Sok Peng Ng, K. Yoganathan, Siewbee Ng, Antony D. Buss, Mark S. Butler, and William H. Gerwick
Organic Letters 2015 Volume 17(Issue 6) pp:1377-1380
Publication Date(Web):February 27, 2015
DOI:10.1021/acs.orglett.5b00068
Gargantulide A (1), an extremely complex 52-membered macrolactone, was isolated from Streptomyces sp. A42983 and displayed moderate activity against MRSA. The planar structure of 1 was determined using 2D NMR, and its stereochemistry was partially established on the basis of NOESY correlations, J-based configuration analysis, and Kishi’s universal NMR database.
Co-reporter:Gabriel Navarro, Susie Cummings, John Lee, Nathan Moss, Evgenia Glukhov, Frederick A. Valeriote, Lena Gerwick, and William H. Gerwick
Environmental Science & Technology Letters 2015 Volume 2(Issue 7) pp:166-170
Publication Date(Web):June 15, 2015
DOI:10.1021/acs.estlett.5b00116
The polycavernosides make up a unique class of marine-derived macrolides that were implicated in the poisoning of 49 people in the South Western Pacific resulting in 11 deaths. The original source ascribed to these environmental toxins was from the edible red alga Polycavernosa tsudai (also known as Gracilaria edulis); however, the inability to reisolate these metabolites from the alga, along with structural resemblance to several marine cyanobacterial natural products, suggested that these compounds derive from these latter photosynthetic prokaryotes. In this study, we identified a new analogue “polycavernoside D” from an environmental sample of the marine cyanobacterium Okeania sp., thus providing the first experimental evidence that these lethal toxins are in fact cyanobacterial secondary metabolites. Moreover, the new metabolite was obtained from a Caribbean cyanobacterial collection, thus suggesting this toxin family to be of broader environmental occurrence than previously realized, and raising concerns about unrecognized human exposure in diverse tropical marine environments.
Co-reporter:Matthew J. Bertin, Sarah L. Schwartz, John Lee, Anton Korobeynikov, Pieter C. Dorrestein, Lena Gerwick, and William H. Gerwick
Journal of Natural Products 2015 Volume 78(Issue 3) pp:493-499
Publication Date(Web):February 10, 2015
DOI:10.1021/np5009762
Spongosine (1), deoxyspongosine (2), spongothymidine (Ara T) (3), and spongouridine (Ara U) were isolated from the Caribbean sponge Tectitethya crypta and given the general name “spongonucleosides”. Spongosine, a methoxyadenosine derivative, has demonstrated a diverse bioactivity profile including anti-inflammatory activity and analgesic and vasodilation properties. Investigations into unusual nucleoside production by T. crypta-associated microorganisms using mass spectrometric techniques have identified a spongosine-producing strain of Vibrio harveyi and several structurally related compounds from multiple strains.
Co-reporter:Chang-Lun Shao, Roger G. Linington, Marcy J. Balunas, Argelis Centeno, Paul Boudreau, Chen Zhang, Niclas Engene, Carmenza Spadafora, Tina S. Mutka, Dennis E. Kyle, Lena Gerwick, Chang-Yun Wang, and William H. Gerwick
The Journal of Organic Chemistry 2015 Volume 80(Issue 16) pp:7849-7855
Publication Date(Web):July 29, 2015
DOI:10.1021/acs.joc.5b01264
Bastimolide A (1), a polyhydroxy macrolide with a 40-membered ring, was isolated from a new genus of the tropical marine cyanobacterium Okeania hirsuta. This novel macrolide was defined by spectroscopy and chemical reactions to possess one 1,3-diol, one 1,3,5-triol, six 1,5-diols, and one tert-butyl group; however, the relationships of these moieties to one another were obscured by a highly degenerate 1H NMR spectrum. Its complete structure and absolute configuration were therefore unambiguously determined by X-ray diffraction analysis of the nona-p-nitrobenzoate derivative (1d). Pure bastimolide A (1) showed potent antimalarial activity against four resistant strains of Plasmodium falciparum with IC50 values between 80 and 270 nM, although with some toxicity to the control Vero cells (IC50 = 2.1 μM), and thus represents a potentially promising lead for antimalarial drug discovery. Moreover, rigorous establishment of its molecular arrangement gives fresh insight into the structures and biosynthesis of cyanobacterial polyhydroxymacrolides.
Co-reporter:Daniela B.B. Trivella, Alban R. Pereira, Martin L. Stein, Yusuke Kasai, Tara Byrum, Frederick A. Valeriote, Dean J. Tantillo, Michael Groll, William H. Gerwick, Bradley S. Moore
Chemistry & Biology 2014 Volume 21(Issue 6) pp:782-791
Publication Date(Web):19 June 2014
DOI:10.1016/j.chembiol.2014.04.010
•Example of enzyme inhibition by hydroamination•Proteasome interaction with enone warheads revealing a two-step reaction mechanism•Reaction involves a 1,2-addition followed by an unanticipated hydroamination•The newly established enone warhead leads to a slow irreversible inhibitorHydroamination reactions involving the addition of an amine to an inactivated alkene are entropically prohibited and require strong chemical catalysts. While this synthetic process is efficient at generating substituted amines, there is no equivalent in small molecule-mediated enzyme inhibition. We report an unusual mechanism of proteasome inhibition that involves a hydroamination reaction of alkene derivatives of the epoxyketone natural product carmaphycin. We show that the carmaphycin enone first forms a hemiketal intermediate with the catalytic Thr1 residue of the proteasome before cyclization by an unanticipated intramolecular alkene hydroamination reaction, resulting in a stable six-membered morpholine ring. The carmaphycin enone electrophile, which does not undergo a 1,4-Michael addition as previously observed with vinyl sulfone and α,β-unsaturated amide-based inhibitors, is partially reversible and gives insight into the design of proteasome inhibitors for cancer chemotherapy.Figure optionsDownload full-size imageDownload high-quality image (438 K)Download as PowerPoint slide
Co-reporter:Emily Mevers ; F. P. Jake Haeckl ; Paul D. Boudreau ; Tara Byrum ; Pieter C. Dorrestein ; Frederick A. Valeriote ;William H. Gerwick
Journal of Natural Products 2014 Volume 77(Issue 4) pp:969-975
Publication Date(Web):March 3, 2014
DOI:10.1021/np401051z
A collection of the tropical marine cyanobacterium Symploca sp., collected near Kimbe Bay, Papua New Guinea, previously yielded several new metabolites including kimbeamides A–C, kimbelactone A, and tasihalide C. Investigations into a more polar cytotoxic fraction yielded three new lipopeptides, tasiamides C–E (1–3). The planar structures were deduced by 2D NMR spectroscopy and tandem mass spectrometry, and their absolute configurations were determined by a combination of Marfey’s and chiral-phase GC-MS analysis. These new metabolites are similar to several previously isolated compounds, including tasiamide (4), grassystatins (5, 6), and symplocin A, all of which were isolated from similar filamentous marine cyanobacteria.
Co-reporter:Bailey Miller, Aaron J. Friedman, Hyukjae Choi, James Hogan, J. Andrew McCammon, Vivian Hook, and William H. Gerwick
Journal of Natural Products 2014 Volume 77(Issue 1) pp:92-99
Publication Date(Web):December 23, 2013
DOI:10.1021/np400727r
A number of marine natural products are potent inhibitors of proteases, an important drug target class in human diseases. Hence, marine cyanobacterial extracts were assessed for inhibitory activity to human cathepsin L. Herein, we have shown that gallinamide A potently and selectively inhibits the human cysteine protease cathepsin L. With 30 min of preincubation, gallinamide A displayed an IC50 of 5.0 nM, and kinetic analysis demonstrated an inhibition constant of ki = 9000 ± 260 M–1 s–1. Preincubation–dilution and activity-probe experiments revealed an irreversible mode of inhibition, and comparative IC50 values display a 28- to 320-fold greater selectivity toward cathepsin L than closely related human cysteine cathepsin V or B. Molecular docking and molecular dynamics simulations were used to determine the pose of gallinamide in the active site of cathepsin L. These data resulted in the identification of a pose characterized by high stability, a consistent hydrogen bond network, and the reactive Michael acceptor enamide of gallinamide A positioned near the active site cysteine of the protease, leading to a proposed mechanism of covalent inhibition. These data reveal and characterize the novel activity of gallinamide A as a potent inhibitor of human cathepsin L.
Co-reporter:Jacob R Winnikoff, Evgenia Glukhov, Jeramie Watrous, Pieter C Dorrestein and William H Gerwick
The Journal of Antibiotics 2014 67(1) pp:105-112
Publication Date(Web):November 27, 2013
DOI:10.1038/ja.2013.120
Untargeted liquid chromatography-MS (LC-MS) is used to rapidly profile crude natural product (NP) extracts; however, the quantity of data produced can become difficult to manage. Molecular networking based on MS/MS data visualizes these complex data sets to aid their initial interpretation. Here, we developed an additional visualization step for the molecular networking workflow to provide relative and absolute quantitation of a specific compound in an extract. The new visualization also facilitates combination of several metabolomes into one network, and so was applied to an MS/MS data set from 20 crude extracts of cultured marine cyanobacteria. The resultant network illustrates the high chemical diversity present among marine cyanobacteria. It is also a powerful tool for locating producers of specific metabolites. In order to dereplicate and identify culture-based sources of known compounds, we added MS/MS data from 60 pure NPs and NP analogs to the 20-strain network. This dereplicated six metabolites directly and offered structural information on up to 30 more. Most notably, our visualization technique allowed us to identify and quantitatively compare several producers of the bioactive and biosynthetically intriguing lipopeptide malyngamide C. Our most prolific producer, a Panamanian strain of Okeania hirsuta (PAB10FEB10-01), was found to produce at least 0.024 mg of malyngamide C per mg biomass (2.4%, w/dw) and is now undergoing genome sequencing to access the corresponding biosynthetic machinery.
Co-reporter:Emily Mevers;Teatulohi Matainaho;Marco Allara’;Vincenzo Di Marzo
Lipids 2014 Volume 49( Issue 11) pp:1127-1132
Publication Date(Web):2014 November
DOI:10.1007/s11745-014-3949-9
Bioassay-guided fractionation of a collection of Moorea bouillonii from Papua New Guinea led to the isolation of a new alkyl amide, mooreamide A (1), along with the cytotoxic apratoxins A–C and E. The planar structure of 1 was elucidated by NMR spectroscopy and mass spectrometry analysis. Structural homology between mooreamide A and the endogenous cannabinoid ligands, anandamide, and 2-arachidonoyl glycerol inspired its evaluation against the neuroreceptors CB1 and CB2. Mooreamide A was found to possess relatively potent and selective ligand binding activity to CB1 (K1 = 0.47 µM) versus CB2 (K1 > 25 µM). This represents the most potent marine-derived CB1 ligand described to date and adds to the growing family of marine metabolites that exhibit cannabinomimetic activity.
Co-reporter:Emily Mevers, Tara Byrum, and William H. Gerwick
Journal of Natural Products 2013 Volume 76(Issue 9) pp:1810-1814
Publication Date(Web):September 17, 2013
DOI:10.1021/np400347f
Two new marine cyanobacterial natural products, parguerene (1) and precarriebowmide (2), were isolated from a collection of Moorea producens obtained from La Parguera, Puerto Rico. The planar structures of both were deduced by 2D NMR spectroscopy and mass spectrometry. Parguerene is a modified acyl amide with some structural similarity to the bacterial metabolite stipiamide (3), whereas precarriebowmide is a lipopeptide and represents a minor modification compared to two other known metabolites, carriebowmide (4) and carriebowmide sulfone (5). The identification of 2 led to an investigation into whether carriebowmide and carriebowmide sulfone were true secondary metabolites or isolation artifacts.
Co-reporter:Emily M. Trentacoste;Roshan P. Shrestha;Sarah R. Smith;Corine Glé;Aaron C. Hartmann;Mark Hildebrand;William H. Gerwick;
Proceedings of the National Academy of Sciences 2013 110(49) pp:19748-19753
Publication Date(Web):November 18, 2013
DOI:10.1073/pnas.1309299110
Biologically derived fuels are viable alternatives to traditional fossil fuels, and microalgae are a particularly promising
source, but improvements are required throughout the production process to increase productivity and reduce cost. Metabolic
engineering to increase yields of biofuel-relevant lipids in these organisms without compromising growth is an important aspect
of advancing economic feasibility. We report that the targeted knockdown of a multifunctional lipase/phospholipase/acyltransferase
increased lipid yields without affecting growth in the diatom Thalassiosira pseudonana. Antisense-expressing knockdown strains 1A6 and 1B1 exhibited wild-type–like growth and increased lipid content under both
continuous light and alternating light/dark conditions. Strains 1A6 and 1B1, respectively, contained 2.4- and 3.3-fold higher
lipid content than wild-type during exponential growth, and 4.1- and 3.2-fold higher lipid content than wild-type after 40
h of silicon starvation. Analyses of fatty acids, lipid classes, and membrane stability in the transgenic strains suggest
a role for this enzyme in membrane lipid turnover and lipid homeostasis. These results demonstrate that targeted metabolic
manipulations can be used to increase lipid accumulation in eukaryotic microalgae without compromising growth.
Co-reporter:William H. Gerwick;Amanda M. Fenner
Microbial Ecology 2013 Volume 65( Issue 4) pp:800-806
Publication Date(Web):2013 May
DOI:10.1007/s00248-012-0169-9
The marine environment has been a source of more than 20,000 inspirational natural products discovered over the past 50 years. From these efforts, 9 approved drugs and 12 current clinical trial agents have been discovered, either as natural products or as molecules inspired from the natural product structure. To a significant degree, these have come from collections of marine invertebrates largely obtained from shallow-water tropical ecosystems. However, there is a growing recognition that marine invertebrates are oftentimes populated with enormous quantities of “associated” or symbiotic microorganisms and that microorganisms are the true metabolic sources of these most valuable of marine natural products. Also, because of the inherently multidisciplinary nature of this field, a high degree of innovation is characteristic of marine natural product drug discovery efforts.
Co-reporter:Marcy J. Balunas, Manuel F. Grosso, Francisco A. Villa, Niclas Engene, Kerry L. McPhail, Kevin Tidgewell, Laura M. Pineda, Lena Gerwick, Carmenza Spadafora, Dennis E. Kyle, and William H. Gerwick
Organic Letters 2012 Volume 14(Issue 15) pp:3878-3881
Publication Date(Web):July 13, 2012
DOI:10.1021/ol301607q
Four unsaturated polyketide lactone derivatives, coibacins A–D, were isolated from a Panamanian marine cyanobacterium, cf. Oscillatoria sp. The two different types of termini observed in these co-occurring metabolites, either a methyl cyclopropyl ring as seen in curacin A or a methyl vinyl chloride similar to that observed in the jamaicamides, suggest an intriguing flexibility in the “beta branch” forming biosynthetic process. The coibacins possess selective antileishmanial activity as well as potent anti-inflammatory activity.
Co-reporter:Eun Ji Kim, Jong Hyun Lee, Hyukjae Choi, Alban R. Pereira, Yeon Hee Ban, Young Ji Yoo, Eunji Kim, Je Won Park, David H. Sherman, William H. Gerwick, and Yeo Joon Yoon
Organic Letters 2012 Volume 14(Issue 23) pp:5824-5827
Publication Date(Web):November 13, 2012
DOI:10.1021/ol302575h
Heterologous expression of the barbamide biosynthetic gene cluster, obtained from the marine cyanobacterium Moorea producens, in the terrestrial actinobacterium Streptomyces venezuelae, resulted in the production of a new barbamide congener 4-O-demethylbarbamide, demonstrating the potential of this approach for investigating the assembly and tailoring of complex marine natural products.
Co-reporter:Hyukjae Choi, Samantha J. Mascuch, Francisco A. Villa, Tara Byrum, Margaret E. Teasdale, Jennifer E. Smith, Linda B. Preskitt, David C. Rowley, Lena Gerwick, William H. Gerwick
Chemistry & Biology 2012 Volume 19(Issue 5) pp:589-598
Publication Date(Web):25 May 2012
DOI:10.1016/j.chembiol.2012.03.014
Honaucins A−C were isolated from the cyanobacterium Leptolyngbya crossbyana which was found overgrowing corals on the Hawaiian coast. Honaucin A consists of (S)-3-hydroxy-γ-butyrolactone and 4-chlorocrotonic acid, which are connected via an ester linkage. Honaucin A and its two natural analogs exhibit potent inhibition of both bioluminescence, a quorum-sensing-dependent phenotype, in Vibrio harveyi BB120 and lipopolysaccharide-stimulated nitric oxide production in the murine macrophage cell line RAW264.7. The decrease in nitric oxide production was accompanied by a decrease in the transcripts of several proinflammatory cytokines, most dramatically interleukin-1β. Synthesis of honaucin A, as well as a number of analogs, and subsequent evaluation in anti-inflammation and quorum-sensing inhibition bioassays revealed the essential structural features for activity in this chemical class and provided analogs with greater potency in both assays.Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (420 K)Download as PowerPoint slideHighlights► Honaucins A−C were isolated from the cyanobacterium Leptolyngbya crossbyana ► Honaucins A−C displayed potent anti-inflammatory and QS inhibitory activities ► SAR study revealed crucial structural features for bioactivity of the honaucins ► 4′-Bromohonaucin A is a potent modulator of inflammation and quorum sensing
Co-reporter:William H. Gerwick, Bradley S. Moore
Chemistry & Biology 2012 Volume 19(Issue 1) pp:85-98
Publication Date(Web):27 January 2012
DOI:10.1016/j.chembiol.2011.12.014
Marine life forms are an important source of structurally diverse and biologically active secondary metabolites, several of which have inspired the development of new classes of therapeutic agents. These success stories have had to overcome difficulties inherent to natural products-derived drugs, such as adequate sourcing of the agent and issues related to structural complexity. Nevertheless, several marine-derived agents are now approved, most as “first-in-class” drugs, with five of seven appearing in the past few years. Additionally, there is a rich pipeline of clinical and preclinical marine compounds to suggest their continued application in human medicine. Understanding of how these agents are biosynthetically assembled has accelerated in recent years, especially through interdisciplinary approaches, and innovative manipulations and re-engineering of some of these gene clusters are yielding novel agents of enhanced pharmaceutical properties compared with the natural product.
Co-reporter:William H. Gerwick, Bradley S. Moore
Chemistry & Biology 2012 Volume 19(Issue 12) pp:1631
Publication Date(Web):21 December 2012
DOI:10.1016/j.chembiol.2012.12.004
Co-reporter:Paul D. Boudreau, Tara Byrum, Wei-Ting Liu, Pieter C. Dorrestein, and William H. Gerwick
Journal of Natural Products 2012 Volume 75(Issue 9) pp:1560-1570
Publication Date(Web):August 27, 2012
DOI:10.1021/np300321b
The viequeamides, a family of 2,2-dimethyl-3-hydroxy-7-octynoic acid (Dhoya)-containing cyclic depsipeptides, were isolated from a shallow subtidal collection of a “button” cyanobacterium (Rivularia sp.) from near the island of Vieques, Puerto Rico. Planar structures of the two major compounds, viequeamide A (1) and viequeamide B (2), were elucidated by 2D-NMR spectroscopy and mass spectrometry, whereas absolute configurations were determined by traditional hydrolysis, derivative formation, and chromatography in comparison with standards. In addition, a series of related minor metabolites, viequeamides C–F (3–6), were characterized by HRMS fragmentation methods. Viequeamide A was found to be highly toxic to H460 human lung cancer cells (IC50 = 60 ± 10 nM), whereas the mixture of B–F was inactive. From a broader perspective, the viequeamides help to define a “superfamily” of related cyanobacterial natural products, the first of which to be discovered was kulolide. Within the kulolide superfamily, a wide variation in biological properties is observed, and the reported producing strains are also highly divergent, giving rise to several intriguing questions about structure–activity relationships and the evolutionary origins of this metabolite class.
Co-reporter:Karla L. Malloy, Takashi L. Suyama, Niclas Engene, Hosana Debonsi, Zhengyu Cao, Teatulohi Matainaho, Carmenza Spadafora, Thomas F. Murray, and William H. Gerwick
Journal of Natural Products 2012 Volume 75(Issue 1) pp:60-66
Publication Date(Web):December 12, 2011
DOI:10.1021/np200611f
Credneramides A (1) and B (2), two vinyl chloride-containing metabolites, were isolated from a Papua New Guinea collection of cf. Trichodesmium sp. nov. and expand a recently described class of vinyl chloride-containing natural products. The precursor fatty acid, credneric acid (3), was isolated from both the aqueous and organic fractions of the parent fraction as well as from another geographically and phylogenetically distinct cyanobacterial collection (Panama). Credneramides A and B inhibited spontaneous calcium oscillations in murine cerebrocortical neurons at low micromolar concentrations (1, IC50 4.0 μM; 2, IC50 3.8 μM).
Co-reporter:Joshawna K. Nunnery, Niclas Engene, Tara Byrum, Zhengyu Cao, Sairam V. Jabba, Alban R. Pereira, Teatulohi Matainaho, Thomas F. Murray, and William H. Gerwick
The Journal of Organic Chemistry 2012 Volume 77(Issue 9) pp:4198-4208
Publication Date(Web):April 9, 2012
DOI:10.1021/jo300160e
Five new vinylchlorine-containing metabolites, the lipoamides janthielamide A and kimbeamides A–C and the ketide-extended pyranone kimbelactone A, have been isolated from collections of marine cyanobacteria made in Curaçao and Papua New Guinea. Both janthielamide A and kimbeamide A exhibited moderate sodium channel blocking activity in murine Neuro-2a cells. Consistent with this activity, janthielamide A was also found to antagonize veratridine-induced sodium influx in murine cerebrocortical neurons. These lipoamides represent the newest additions to a relatively rare family of marine cyanobacterial-derived lipoamides and a new structural class of compounds exhibiting neuromodulatory activities from marine cyanobacteria.
Co-reporter:Dr. Alban R. Pereira;Andrew J. Kale;Dr. Andrew T. Fenley;Tara Byrum;Dr. Hosana M. Debonsi;Dr. Michael K. Gilson;Dr. Frederick A. Valeriote;Dr. Bradley S. Moore;Dr. William H. Gerwick
ChemBioChem 2012 Volume 13( Issue 6) pp:810-817
Publication Date(Web):
DOI:10.1002/cbic.201200007
Abstract
Two new peptidic proteasome inhibitors were isolated as trace components from a Curaçao collection of the marine cyanobacterium Symploca sp. Carmaphycin A (1) and carmaphycin B (2) feature a leucine-derived α,β-epoxyketone warhead directly connected to either methionine sulfoxide or methionine sulfone. Their structures were elucidated on the basis of extensive NMR and MS analyses and confirmed by total synthesis, which in turn provided more material for further biological evaluations. Pure carmaphycins A and B were found to inhibit the β5 subunit (chymotrypsin-like activity) of the S. cerevisiae 20S proteasome in the low nanomolar range. Additionally, they exhibited strong cytotoxicity to lung and colon cancer cell lines, as well as exquisite antiproliferative effects in the NCI60 cell-line panel. These assay results as well as initial structural biology studies suggest a distinctive binding mode for these new inhibitors.
Co-reporter:Hyukjae Choi, Philip J. Proteau, Tara Byrum, William H. Gerwick
Phytochemistry 2012 Volume 73() pp:134-141
Publication Date(Web):January 2012
DOI:10.1016/j.phytochem.2011.09.014
An investigation of the oxylipin chemistry of the temperate brown alga Cymathere triplicata led to the isolation of several secondary metabolites, cymatherelactone (1) and cymatherols A−C (2–4), the latter as their methyl ester derivatives (5–7), which contained cyclopentyl, cyclopropyl, epoxide and lactone rings. Their structures were elucidated using a combination of spectroscopic techniques and synthetic chemistry. Cymatherelactone (1), as well as R- and S-Mosher’s esters of its seco acid, exhibited moderate sodium channel blocking activity.Graphical abstractcymatherelactone and methyl cymatherols A–C, cyclopropyl and cyclopentene oxide containing oxylipins, were isolated from Cymathere triplicata and showed moderate sodium channel blocking activities.Highlights► Four oxylipins were isolated from the marine brown alga Cymathere triplicata. ► The structures were elucidated by spectroscopic data analyses and derivatization. ► These metabolites are cyclopentyl- and cyclopropyl-containing oxylipins. ► Cymatherelactone and synthetic derivatives showed Na+ channel blocking activities.
Co-reporter:Hyukjae Choi, Philip J. Proteau, Tara Byrum, Alban R. Pereira, William H. Gerwick
Phytochemistry 2012 Volume 78() pp:197
Publication Date(Web):June 2012
DOI:10.1016/j.phytochem.2012.01.016
Co-reporter:Adam C. Jones, Emily A. Monroe, William H. Gerwick
Chemistry & Biology 2011 Volume 18(Issue 3) pp:281-283
Publication Date(Web):25 March 2011
DOI:10.1016/j.chembiol.2011.03.001
Hormaomycin, an NRPS-produced bacterial metabolite involved in microbial signaling, possesses several remarkable structural features. The study by Höfer et al. (2011) employed a range of methodologies to explore and ultimately understand the elaborate biosynthesis of this complex natural product.
Co-reporter:Alban R. Pereira, Lena Etzbach, Niclas Engene, Rolf Müller, and William H. Gerwick
Journal of Natural Products 2011 Volume 74(Issue 5) pp:1175-1181
Publication Date(Web):April 7, 2011
DOI:10.1021/np200106b
Molluscicides can play an important role in the control of schistosomiasis because snails of the genus Biomphalaria act as intermediate hosts for the parasite. Schistosomiasis is one of 13 neglected tropical diseases with high morbidity and mortality that collectively affect one billion of the world’s poorest population, mainly in developing countries. Thiopalmyrone (1) and palmyrrolinone (2), metabolites isolated from extracts of a Palmyra Atoll environmental assemblage of two cyanobacteria, cf. Oscillatoria and Hormoscilla spp., represent new and potent molluscicidal chemotypes against Biomphalaria glabrata (LC50 = 8.3 and 6.0 μM, respectively). A slight enhancement in molluscicidal effect (LC50 = 5.0 μM) was observed when these two natural products were utilized as an equimolar binary mixture.
Co-reporter:Emily Mevers, Wei-Ting Liu, Niclas Engene, Hosein Mohimani, Tara Byrum, Pavel A. Pevzner, Pieter C. Dorrestein, Carmenza Spadafora, and William H. Gerwick
Journal of Natural Products 2011 Volume 74(Issue 5) pp:928-936
Publication Date(Web):April 13, 2011
DOI:10.1021/np200077f
A family of cancer cell cytotoxic cyclodepsipeptides, veraguamides A−C (1−3) and H−L (4−8), were isolated from a collection of cf. Oscillatoria margaritifera obtained from the Coiba National Park, Panama, as part of the Panama International Cooperative Biodiversity Group program. The planar structure of veraguamide A (1) was deduced by 2D NMR spectroscopy and mass spectrometry, whereas the structures of 2−8 were mainly determined by a combination of 1H NMR and MS2/MS3 techniques. These new compounds are analogous to the mollusk-derived kulomo’opunalide natural products, with two of the veraguamides (C and H) containing the same terminal alkyne moiety. However, four veraguamides, A, B, K, and L, also feature an alkynyl bromide, a functionality that has been previously observed in only one other marine natural product, jamaicamide A. Veraguamide A showed potent cytotoxicity to the H-460 human lung cancer cell line (LD50 = 141 nM).
Co-reporter:Marcelino Gutiérrez, Alban R. Pereira, Hosana M. Debonsi, Alessia Ligresti, Vincenzo Di Marzo, and William H. Gerwick
Journal of Natural Products 2011 Volume 74(Issue 10) pp:2313-2317
Publication Date(Web):October 14, 2011
DOI:10.1021/np200610t
NMR-guided fractionation of two independent collections of the marine cyanobacteria Lyngbya majuscula obtained from Papua New Guinea and Oscillatoria sp. collected in Panama led to the isolation of the new lipids serinolamide A (3) and propenediester (4). Their structures were determined by NMR and MS data analysis. Serinolamide A (3) exhibited a moderate agonist effect and selectivity for the CB1 cannabinoid receptor (Ki = 1.3 μM, >5-fold) and represents the newest addition to the known cannabinomimetic natural products of marine origin.
Co-reporter:Karla L. Malloy, Francisco A. Villa, Niclas Engene, Teatulohi Matainaho, Lena Gerwick, and William H. Gerwick
Journal of Natural Products 2011 Volume 74(Issue 1) pp:95-98
Publication Date(Web):December 14, 2010
DOI:10.1021/np1005407
A Papua New Guinea collection of the marine cyanobacterium cf. Lyngbya sordida yielded three known compounds as well as a new PKS-NRPS-derived malyngamide with anti-inflammatory and cytotoxic activity. Malyngamide 2 features an extensively oxidized cyclohexanone ring. Resolution of the ring core as a 6,8,9-triol rather then a 7,8,9-triol and relative configuration was based on chemical shift and bond geometry modeling in conjunction with homonuclear and heteronuclear coupling constants, NOE and ROE correlations, and other structural information. Malyngamide 2 exhibited anti-inflammatory activity in LPS-induced RAW macrophage cells (IC50 = 8.0 μM) with only modest cytotoxicity to the mammalian cell line.
Co-reporter:Niclas Engene ; Hyukjae Choi ; Eduardo Esquenazi ; Tara Byrum ; Francisco A. Villa ; Zhengyu Cao ; Thomas F. Murray ; Pieter C. Dorrestein ; Lena Gerwick ;William H. Gerwick
Journal of Natural Products 2011 Volume 74(Issue 8) pp:1737-1743
Publication Date(Web):July 13, 2011
DOI:10.1021/np200236c
The evolutionary relationships of cyanobacteria, as inferred by their SSU (16S) rRNA genes, were used as predictors of their potential to produce varied secondary metabolites. The evolutionary relatedness in geographically distant cyanobacterial specimens was then used as a guide for the detection and isolation of new variations of predicted molecules. This phylogeny-guided isolation approach for new secondary metabolites was tested in its capacity to direct the search for specific classes of new natural products from Curaçao marine cyanobacteria. As a result, we discovered ethyl tumonoate A (1), a new tumonoic acid derivative with anti-inflammatory activity and inhibitory activity of calcium oscillations in neocortical neurons.
Co-reporter:Carla S. Jones, Eduardo Esquenazi, Pieter C. Dorrestein, William H. Gerwick
Bioorganic & Medicinal Chemistry 2011 Volume 19(Issue 22) pp:6620-6627
Publication Date(Web):15 November 2011
DOI:10.1016/j.bmc.2011.06.005
Scytonemin is a dimeric indole phenolic pigment found in the sheaths of many cyanobacteria. This pigment absorbs UV radiation protecting subtending cyanobacterial cells from harmful effects. Based on scytonemin’s unique chemical structure, the pathway to its biosynthesis is uncertain, thus motivating the current investigation. Herein, we report the incorporation of both tyrosine and tryptophan into scytonemin, and provide in vivo data supporting the tryptophan origin of the ketone carbon involved in the condensation of the two biosynthetic precursors. This study also reports on the new use of a small-scale, MALDI-TOF mass spectrometry technique to monitor the incorporation of isotopically labeled tyrosine during scytonemin biosynthesis.Graphical abstract
Co-reporter:Joshawna K. Nunnery, Takashi L. Suyama, Roger G. Linington, William H. Gerwick
Tetrahedron Letters 2011 Volume 52(Issue 23) pp:2929-2932
Publication Date(Web):8 June 2011
DOI:10.1016/j.tetlet.2011.03.126
An efficient synthetic methodology for 3-hydroxy-2,2-dimethyloctynoic acid (DHOYA) and several variants, which are increasingly common fragments encountered in bioactive marine cyanobacterial metabolites, was developed. These fragments were obtained in three steps via a tertiary aldol reaction utilizing an Evans’ chiral auxiliary to afford the desired stereochemistry at the β-hydroxy carbon. Thus far, this methodology has been successfully applied in determination of the absolute stereochemistry of eight cyanobacterial natural products, including the VGSC activator palymramide A.
Co-reporter:Eduardo Esquenazi;Adam C. Jones;William H. Gerwick;Tara Byrum;Pieter C. Dorrestein
PNAS 2011 Volume 108 (Issue 13 ) pp:5226-5231
Publication Date(Web):2011-03-29
DOI:10.1073/pnas.1012813108
Sessile marine organisms are prolific sources of biologically active natural products. However, these compounds are often
found in highly variable amounts, with the abiotic and biotic factors governing their production remaining poorly understood.
We present an approach that permits monitoring of in vivo natural product production and turnover using mass spectrometry
and stable isotope (15N) feeding with small cultures of various marine strains of the natural product-rich cyanobacterial genus Lyngbya. This temporal comparison of the amount of in vivo 15N labeling of nitrogen-containing metabolites represents a direct way to discover and evaluate factors influencing natural
product biosynthesis, as well as the timing of specific steps in metabolite assembly, and is a strong complement to more traditional
in vitro studies. Relative quantification of 15N labeling allowed the concurrent measurement of turnover rates of multiple natural products from small amounts of biomass.
This technique also afforded the production of the neurotoxic jamaicamides to be more carefully studied, including an assessment
of how jamaicamide turnover compares with filament growth rate and primary metabolism and provided new insights into the biosynthetic
timing of jamaicamide A bromination. This approach should be valuable in determining how environmental factors affect secondary
metabolite production, ultimately yielding insight into the energetic balance among growth, primary production, and secondary
metabolism, and thus aid in the development of methods to improve compound yields for biomedical or biotechnological applications.
Co-reporter:Adam C. Jones, Emily A. Monroe, Eli B. Eisman, Lena Gerwick, David H. Sherman and William H. Gerwick
Natural Product Reports 2010 vol. 27(Issue 7) pp:1048-1065
Publication Date(Web):04 May 2010
DOI:10.1039/C000535E
Covering: up to January 2010
Co-reporter:Alban R. Pereira, Zhengyu Cao, Niclas Engene, Irma E. Soria-Mercado, Thomas F. Murray, and William H. Gerwick
Organic Letters 2010 Volume 12(Issue 20) pp:4490-4493
Publication Date(Web):September 16, 2010
DOI:10.1021/ol101752n
Palmyrolide A (1) is a new neuroactive macrolide isolated from a marine cyanobacterial assemblage composed of Leptolyngbya cf. and Oscillatoria spp. collected from Palmyra Atoll. It features a rare N-methyl enamide and an intriguing t-butyl branch; the latter renders the adjacent lactone ester bond resistant to hydrolysis. Consistent with its significant suppression of calcium influx in cerebrocortical neurons (IC50 = 3.70 μM), palmyrolide A (1) showed a relatively potent sodium channel blocking activity in neuro-2a cells (IC50 = 5.2 μM), without appreciable cytotoxicity.
Co-reporter:Marcy J. Balunas, Roger G. Linington, Kevin Tidgewell, Amanda M. Fenner, Luis-David Ureña, Gina Della Togna, Dennis E. Kyle and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 1) pp:60-66
Publication Date(Web):December 23, 2009
DOI:10.1021/np900622m
Tropical parasitic and infectious diseases, such as leishmaniasis, pose enormous global health threats, but are largely neglected in commercial drug discovery programs. However, the Panama International Cooperative Biodiversity Group (ICBG) has been working to identify novel treatments for malaria, Chagas’ disease, and leishmaniasis through an investigation of plants and microorganisms from Panama. We have pursued activity-guided isolation from an extract of Lyngbya majuscula that was found to be active against leishmaniasis. A new modified linear peptide from the dragonamide series was isolated, dragonamide E (1), along with two known modified linear peptides, dragonamide A (2) and herbamide B (3). Dragonamides A and E and herbamide B exhibited antileishmanial activity with IC50 values of 6.5, 5.1, and 5.9 μM, respectively. Spectroscopic and stereochemical data for dragonamide E (1) and herbamide B (3; the spectroscopic and stereochemical data for this substance is incomplete in the literature) are presented as well as comparisons of biological activity within the dragonamide compound family. Biosynthetic differences among marine compounds with a terminal free amide are also discussed.
Co-reporter:Alban R. Pereira, Tara Byrum, Grant M. Shibuya, Christopher D. Vanderwal and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 2) pp:279-283
Publication Date(Web):January 25, 2010
DOI:10.1021/np900672h
Malhamensilipin A (2), a bioactive chlorosulfolipid initially reported in 1994 from the freshwater alga Poterioochromonas malhamensis, was reinvestigated for its structural and stereochemical features. HRESIMS data revealed that 2 possesses two sulfate groups rather than the one originally reported. A combination of J-based configurational and Mosher’s analyses led us to assign its absolute configuration as 11R, 12S, 13S, 14R, 15S, and 16S. Finally, comparison of 1H and 13C NMR chemical shifts with synthetic standards confirmed that malhamensilipin A (2) possesses a terminal double bond of E configuration.
Co-reporter:Alban R. Pereira, Christine F. McCue and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 2) pp:217-220
Publication Date(Web):February 4, 2010
DOI:10.1021/np9008128
Over the last 50 years, molluscicides have played a critical role in the control of schistosomiasis transmission. Cyanolide A (2), isolated from extracts of a Papua New Guinea collection of Lyngbya bouillonii, is a new and highly potent molluscicidal agent against the snail vector Biomphalaria glabrata (LC50 = 1.2 μM). The structure of cyanolide A (2) was elucidated through extensive NMR spectroscopic analyses, yielding a symmetrical dimer that represents the newest addition to the family of glycosidic macrolides from cyanobacteria.
Co-reporter:Masatoshi Taniguchi, Joshawna K. Nunnery, Niclas Engene, Eduardo Esquenazi, Tara Byrum, Pieter C. Dorrestein and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 3) pp:393-398
Publication Date(Web):October 19, 2009
DOI:10.1021/np900428h
Bioassay-guided fractionation of the extract of a consortium of a marine cyanobacterium and a red alga (Rhodophyta) led to the discovery of a novel compound, palmyramide A, along with the known compounds curacin D and malyngamide C. The planar structure of palmyramide A was determined by one- and two-dimensional NMR studies and mass spectrometry. Palmyramide A is a cyclic depsipeptide that features an unusual arrangement of three amino acids and three hydroxy acids; one of the hydroxy acids is the rare 2,2-dimethyl-3-hydroxyhexanoic acid unit (Dmhha). The absolute configurations of the six residues were determined by Marfey’s analysis, chiral HPLC analysis, and GC/MS analysis of the hydrolysate. Morphological and phylogenetic studies revealed the sample to be composed of a Lyngbya majuscula−Centroceras sp. association. MALDI-imaging analysis of the cultured L. majuscula indicated that it was the true producer of this new depsipeptide. Pure palmyramide A showed sodium channel blocking activity in neuro-2a cells and cytotoxic activity in H-460 human lung carcinoma cells.
Co-reporter:Marcelino Gutiérrez, Kevin Tidgewell, Todd L. Capson, Niclas Engene, Alejandro Almanza, Jörg Schemies, Manfred Jung and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 4) pp:709-711
Publication Date(Web):February 16, 2010
DOI:10.1021/np9005184
Fractionation of the extract of the marine cyanobacterium Lyngbya majuscula collected from Panama led to the isolation of malyngolide dimer (1). The planar structure of 1 was determined using 1D and 2D NMR spectroscopy and HRESI-TOFMS. The absolute configuration was established by chemical degradation followed by chiral GC-MS analyses and comparisons with an authentic sample of malyngolide seco-acid (4). Compound 1 showed moderate in vitro antimalarial activity against chloroquine-resistant Plasmodium falciparum (W2) (IC50 = 19 μM) but roughly equivalent toxicity against H-460 human lung cell lines. Furthermore, because the closely related cyanobacterial natural product tanikolide dimer (5) was a potent SIRT2 inhibitor, compound 1 was evaluated in this assay but found to be essentially inactive.
Co-reporter:Hyukjae Choi, Niclas Engene, Jennifer E. Smith, Linda B. Preskitt and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 4) pp:517-522
Publication Date(Web):February 19, 2010
DOI:10.1021/np900661g
Periodically, the marine cyanobacterium Leptolyngbya crossbyana forms extensive blooms on Hawai’ian coral reefs and results in significant damage to the subtending corals. Additionally, corals near mats of this cyanobacterium, but not directly overgrown, have been observed to undergo bleaching. Therefore, samples of this cyanobacterium were chemically investigated for bioactive secondary metabolites that might underlie this toxicity phenomenon. 1H NMR spectroscopy-guided fractionation led to the isolation of four heptabrominated polyphenolic ethers, crossbyanols A−D (1−4). Structure elucidation of these compounds was made challenging by their very low proton to carbon (H/C) ratio, but was completed by combining standard NMR and MS data with 2 Hz-optimized HMBC data. Derivatization of crossbyanol A as the diacetate assisted in the assignment of its structure. Crossbyanol B (2) showed antibiotic activity with an MIC value of 2.0−3.9 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA) and relatively potent brine shrimp toxicity (IC50 2.8 ppm).
Co-reporter:Hyukjae Choi, Alban R. Pereira, Zhengyu Cao, Cynthia F. Shuman, Niclas Engene, Tara Byrum, Teatulohi Matainaho, Thomas F. Murray, Alfonso Mangoni and William H. Gerwick
Journal of Natural Products 2010 Volume 73(Issue 8) pp:1411-1421
Publication Date(Web):August 5, 2010
DOI:10.1021/np100468n
Two related peptide metabolites, one a cyclic depsipeptide, hoiamide B (2), and the other a linear lipopeptide, hoiamide C (3), were isolated from two different collections of marine cyanobacteria obtained in Papua New Guinea. Their structures were elucidated by combining various techniques in spectroscopy, chromatography, and synthetic chemistry. Both metabolites belong to the unique hoiamide structural class, characterized by possessing an acetate extended and S-adenosyl methionine modified isoleucine unit, a central triheterocyclic system comprised of two α-methylated thiazolines and one thiazole, and a highly oxygenated and methylated C-15 polyketide unit. In neocortical neurons, the cyclic depsipeptide 2 stimulated sodium influx and suppressed spontaneous Ca2+ oscillations with EC50 values of 3.9 μM and 79.8 nM, respectively, while 3 had no significant effects in these assays.
Co-reporter:Kevin Tidgewell Dr.;Niclas Engene;Tara Byrum;Joseph Media;Takayuki Doi Dr.;Fred A. Valeriote Dr.;William H. Gerwick Dr.
ChemBioChem 2010 Volume 11( Issue 10) pp:1458-1466
Publication Date(Web):
DOI:10.1002/cbic.201000070
Abstract
A collection of Lyngbya bouillonii from Palmyra Atoll in the Central Pacific, a site several thousand kilometers distant from all previous collections of this chemically prolific species of cyanobacterium, was found to contain two new cancer cell cytotoxins of the apratoxin family. The structures of the new compounds, apratoxins F and G, were determined by 1D and 2D NMR techniques in combination with mass spectrometric methods. Stereochemistry was explored by using chromatographic analyses of the hydrolytically released fragments in combination with NMR and optical rotation comparisons with known members of the apratoxin family. Apratoxins F and G add fresh insights into the SAR of this family because they incorporate an N-methyl alanine residue at a position where all prior apratoxins have possessed a proline unit, yet they retain high potency as cytotoxins to H-460 cancer cells with IC50 values of 2 and 14 nM, respectively. Additional assays using zone inhibition of cancer cells and clonogenic cells give a comparison of the activities of apratoxin F to apratoxin A. Additionally, the clonogenic studies in combination with maximum tolerated dose (MTD) studies provided insights as to dosing schedules that should be used for in vivo studies, and preliminary in vivo evaluation validated the predicted in vivo efficacy for apratoxin A. These new apratoxins are illustrative of a mechanism (the modification of an NRPS adenylation domain specificity pocket) for evolving a biosynthetic pathway so as to diversify the suite of expressed secondary metabolites.
Co-reporter:Harald Gross, Kerry L. McPhail, Douglas E. Goeger, Frederick A. Valeriote, William H. Gerwick
Phytochemistry 2010 Volume 71(14–15) pp:1729-1735
Publication Date(Web):October 2010
DOI:10.1016/j.phytochem.2010.07.001
Two epimers of malyngamide C, 8-O-acetyl-8-epi-malyngamide C (1) and 8-epi-malyngamide C (3) have been isolated along with known compounds 6-O-acetylmalyngamide F (5), H (6), J (7) K (8), and characterized from a Grenada field collection of the marine cyanobacterium Lyngbya majuscula. The structures of these compounds were deduced by 1D and 2D NMR spectroscopic and mass spectral data interpretation. Absolute configurations were determined by a combination of CD-spectroscopy, chemical degradation and the variable temperature Mosher’s method. Compounds 1–5, 7 and 8 displayed moderate cytotoxicity to NCI-H460 human lung tumor and neuro-2a cancer cell lines, with IC50 values ranging between 0.5 and 20 μg/mL.Two cancer cell cytotoxins were structurally described as epimers of malyngamide C.
Co-reporter:Pedro N. Leão;Alban R. Pereira;Wei-Ting Liu;Pavel A. Pevzner;Pieter C. Dorrestein;Gabriele M. König;Vitor M. Vasconcelos;William H. Gerwick;Julio Ng
PNAS 2010 Volume 107 (Issue 25 ) pp:11183-11188
Publication Date(Web):2010-06-22
DOI:10.1073/pnas.0914343107
The ability of cyanobacteria to produce complex secondary metabolites with potent biological activities has gathered considerable
attention due to their potential therapeutic and agrochemical applications. However, the precise physiological or ecological
roles played by a majority of these metabolites have remained elusive. Several studies have shown that cyanobacteria are able
to interfere with other organisms in their communities through the release of compounds into the surrounding medium, a phenomenon
usually referred to as allelopathy. Exudates from the freshwater cyanobacterium Oscillatoria sp. had previously been shown to inhibit the green microalga Chlorella vulgaris. In this study, we observed that maximal allelopathic activity is highest in early growth stages of the cyanobacterium, and
this provided sufficient material for isolation and chemical characterization of active compounds that inhibited the growth
of C. vulgaris. Using a bioassay-guided approach, we isolated and structurally characterized these metabolites as cyclic peptides containing
several unusually modified amino acids that are found both in the cells and in the spent media of Oscillatoria sp. cultures. Strikingly, only the mixture of the two most abundant metabolites in the cells was active toward C. vulgaris. Synergism was also observed in a lung cancer cell cytotoxicity assay. The binary mixture inhibited other phytoplanktonic
organisms, supporting a natural function of this synergistic mixture of metabolites as allelochemicals.
Co-reporter:Adam C Jones, Liangcai Gu, Carla M Sorrels, David H Sherman, William H Gerwick
Current Opinion in Chemical Biology 2009 Volume 13(Issue 2) pp:216-223
Publication Date(Web):April 2009
DOI:10.1016/j.cbpa.2009.02.019
Cyanobacteria, among Earth's oldest organisms, have evolved sophisticated biosynthetic pathways to produce a rich arsenal of bioactive natural products. In consequence, cyanobacterial secondary metabolites have been an incredibly fruitful source of lead compounds in drug discovery efforts. Investigations into the biochemistry responsible for the creation of these compounds, complemented by genome sequencing efforts, are revealing unique enzymatic mechanisms not described or rarely described elsewhere in the natural world. Herein, we discuss recent advances in understanding the biosynthesis of three cyanobacterial classes of natural product: mixed polyketide synthase/non ribosomal peptide synthetase (PKS/NRPS) metabolites, aromatic amino acid-derived alkaloids, and ribosomally encoded cyclic peptides. The unique biosynthetic mechanisms employed by cyanobacteria are inspiring new developments in heterologous gene expression and biotechnology.
Co-reporter:Irma E. Soria-Mercado, Alban Pereira, Zhengyu Cao, Thomas F. Murray and William H. Gerwick
Organic Letters 2009 Volume 11(Issue 20) pp:4704-4707
Publication Date(Web):September 15, 2009
DOI:10.1021/ol901438b
Alotamide A (1), a structurally intriguing cyclic depsipeptide, was isolated from the marine mat-forming cyanobacterium Lyngbya bouillonii collected in Papua New Guinea. It features three contiguous peptidic residues and an unsaturated heptaketide with oxidations and methylations unlike those found in any other marine cyanobacterial metabolite. Pure alotamide A (1) displays an unusual calcium influx activation profile in murine cerebrocortical neurons with an EC50 of 4.18 μM.
Co-reporter:Alban Pereira, Zhengyu Cao, Thomas F. Murray, William H. Gerwick
Chemistry & Biology 2009 Volume 16(Issue 8) pp:893-906
Publication Date(Web):28 August 2009
DOI:10.1016/j.chembiol.2009.06.012
Hoiamide A, a novel bioactive cyclic depsipeptide, was isolated from an environmental assemblage of the marine cyanobacteria Lyngbya majuscula and Phormidium gracile collected in Papua New Guinea. This stereochemically complex metabolite possesses a highly unusual structure, which likely derives from a mixed peptide-polyketide biogenetic origin, and includes a peptidic section featuring an acetate extended and S-adenosyl methionine modified isoleucine moiety, a triheterocyclic fragment bearing two α-methylated thiazolines and one thiazole, and a highly oxygenated and methylated C15-polyketide substructure. Pure hoiamide A potently inhibited [3H]batrachotoxin binding to voltage-gated sodium channels (IC50 = 92.8 nM), activated sodium influx (EC50 = 2.31 μM) in mouse neocortical neurons, and exhibited modest cytotoxicity to cancer cells. Further investigation revealed that hoiamide A is a partial agonist of site 2 on the voltage-gated sodium channel.
Co-reporter:T. Luke Simmons, Lisa M. Nogle, Joseph Media, Frederick A. Valeriote, Susan L. Mooberry and William H. Gerwick
Journal of Natural Products 2009 Volume 72(Issue 6) pp:1011-1016
Publication Date(Web):June 2, 2009
DOI:10.1021/np9001674
Cytotoxicity-guided fractionation of the organic extract from a Fijian Lyngbya majuscula led to the discovery of desmethoxymajusculamide C (DMMC) as the active metabolite. Spectroscopic analysis including 1D and 2D NMR, MS/MS, and chemical degradation and derivatization protocols were used to assign the planar structure and stereoconfiguration of this new cyclic depsipeptide. DMMC demonstrated potent and selective anti-solid tumor activity with an IC50 = 20 nM against the HCT-116 human colon carcinoma cell line via disruption of cellular microfilament networks. A linear form of DMMC was generated by base hydrolysis, and the amino acid sequence was confirmed by mass spectrometry. Linearized DMMC was also evaluated in the biological assays and found to maintain potent actin depolymerization characteristics while displaying solid tumor selectivity equivalent to DMMC in the disk diffusion assay. A clonogenic assay assessing cytotoxicity to HCT-116 cells as a function of exposure duration showed that greater than 24 h of constant drug treatment was required to yield significant cell killing. Therapeutic studies with HCT-116 bearing SCID mice demonstrated efficacy at the highest dose used (%T/C = 60% at 0.62 mg/kg daily for 5 days).
Co-reporter:Eduardo Esquenazi;Pieter C. Dorrestein;William H. Gerwick
PNAS 2009 Volume 106 (Issue 18 ) pp:7269-7270
Publication Date(Web):2009-05-05
DOI:10.1073/pnas.0902840106
Co-reporter:Marcelino Gutiérrez, Takashi L. Suyama, Niclas Engene, Joshua S. Wingerd, Teatulohi Matainaho and William H. Gerwick
Journal of Natural Products 2008 Volume 71(Issue 6) pp:1099-1103
Publication Date(Web):April 30, 2008
DOI:10.1021/np800121a
Cancer cell toxicity-guided fractionation of extracts of the Papua New Guinea marine cyanobacteria Lyngbya majuscula and Lyngbya sordida led to the isolation of apratoxin D (1). Compound 1 contains the same macrocycle as apratoxins A and C but possesses the novel 3,7-dihydroxy-2,5,8,10,10-pentamethylundecanoic acid as the polyketide moiety. The planar structures and stereostructures of compound 1 were determined by extensive 1D and 2D NMR and MS data analyses and by comparison with the spectroscopic data of apratoxins A and C. Apratoxin D (1) showed potent in vitro cytotoxicity against H-460 human lung cancer cells with an IC50 value of 2.6 nM.
Co-reporter:Roger G. Linington, Daniel J. Edwards, Cynthia F. Shuman, Kerry L. McPhail, Teatulohi Matainaho and William H. Gerwick
Journal of Natural Products 2008 Volume 71(Issue 1) pp:22-27
Publication Date(Web):December 29, 2007
DOI:10.1021/np070280x
Investigation of a Symploca sp. from Papua New Guinea has led to the isolation of symplocamide A (1), a potent cancer cell cytotoxin, which also inhibits serine proteases with a 200-fold greater inhibition of chymotrypsin over trypsin. The complete stereostructure of symplocamide A was determined by detailed NMR and MS analysis as well as chiral HPLC analysis of the component amino acid residues. The presence of several unusual structural features in symplocamide A provides new insights into the pharmacophore model for protease selectivity in this drug class and may underlie the potent cytotoxicity of this compound to H-460 lung cancer cells (IC50 = 40 nM) as well as neuro-2a neuroblastoma cells (IC50 = 29 nM).
Co-reporter:T. Luke Simmons, Niclas Engene, Luis David Ureña, Luz I. Romero, Eduardo Ortega-Barría, Lena Gerwick and William H. Gerwick
Journal of Natural Products 2008 Volume 71(Issue 9) pp:1544-1550
Publication Date(Web):August 21, 2008
DOI:10.1021/np800110e
Parallel chemical and phylogenetic investigation of a marine cyanobacterium from Panama led to the isolation of two new PKS-NRPS-derived compounds, viridamides A and B. Their structures were determined by NMR and mass spectroscopic methods, and the absolute configurations assigned by Marfey’s method and chiral HPLC analysis. In addition to six standard, N-methylated amino and hydroxy acids, these metabolites contained the structurally novel 5-methoxydec-9-ynoic acid moiety and an unusual proline methyl ester terminus. Morphologically, this cyanobacterium was identified as Oscillatoria nigro-viridis, and its 16S rDNA sequence is reported here for the first time. Phylogenetic analysis of these sequence data has identified O. nigro-viridis strain OSC3L to be closely related to two other marine cyanobacterial genera, Trichodesmium and Blennothrix. Viridamide A showed antitrypanosomal activity with an IC50 of 1.1 μM and antileishmanial activity with an IC50 of 1.5 μM.
Co-reporter:Benjamin R. Clark, Niclas Engene, Margaret E. Teasdale, David C. Rowley, Teatulohi Matainaho, Frederick A. Valeriote and William H. Gerwick
Journal of Natural Products 2008 Volume 71(Issue 9) pp:1530-1537
Publication Date(Web):August 13, 2008
DOI:10.1021/np800088a
A Papua New Guinea field collection of the marine cyanobacterium Blennothrix cantharidosmum was investigated for its cytotoxic constituents. Bioassay-guided isolation defined the cytotoxic components as the known compounds lyngbyastatins 1 and 3. However, six new acyl proline derivatives, tumonoic acids D−I, plus the known tumonoic acid A were also isolated. Their planar structures were defined from NMR and MS data, while their stereostructures followed from a series of chiral chromatographies, degradation sequences, and synthetic approaches. The new compounds were tested in an array of assays, but showed only modest antimalarial and inhibition of quorum sensing activities. Nevertheless, these are the first natural products to be reported from this genus, and this inspired a detailed morphologic and 16S rDNA-based phylogenetic analysis of the producing organism.
Co-reporter:T. Luke Simmons;R. Cameron Coates;Benjamin R. Clark;Niclas Engene;David Gonzalez;Eduardo Esquenazi;Pieter C. Dorrestein;William H. Gerwick
PNAS 2008 Volume 105 (Issue 12 ) pp:4587-4594
Publication Date(Web):2008-03-25
DOI:10.1073/pnas.0709851105
In all probability, natural selection began as ancient marine microorganisms were required to compete for limited resources.
These pressures resulted in the evolution of diverse genetically encoded small molecules with a variety of ecological and
metabolic roles. Remarkably, many of these same biologically active molecules have potential utility in modern medicine and
biomedical research. The most promising of these natural products often derive from organisms richly populated by associated
microorganisms (e.g., marine sponges and ascidians), and often there is great uncertainty about which organism in these assemblages
is making these intriguing metabolites. To use the molecular machinery responsible for the biosynthesis of potential drug-lead
natural products, new tools must be applied to delineate their genetic and enzymatic origins. The aim of this perspective
is to highlight both traditional and emerging techniques for the localization of metabolic pathways within complex marine
environments. Examples are given from the literature as well as recent proof-of-concept experiments from the authors' laboratories.
Co-reporter:Harald Gross, Virginia O. Stockwell, Marcella D. Henkels, Brian Nowak-Thompson, Joyce E. Loper, William H. Gerwick
Chemistry & Biology 2007 Volume 14(Issue 1) pp:53-63
Publication Date(Web):January 2007
DOI:10.1016/j.chembiol.2006.11.007
With the increasing number of genomes sequenced and available in the public domain, a large number of orphan gene clusters, for which the encoded natural product is unknown, have been identified. These orphan gene clusters represent a tremendous source of novel and possibly bioactive compounds. Here, we describe a “genomisotopic approach,” which employs a combination of genomic sequence analysis and isotope-guided fractionation to identify unknown compounds synthesized from orphan gene clusters containing nonribosomal peptide synthetases. Analysis of the Pseudomonas fluorescens Pf-5 genome led to the identification of an orphan gene cluster predicted to code for the biosynthesis of a lipopeptide natural product. Application of the genomisotopic approach to isolate the product of this gene cluster resulted in the discovery of orfamide A, founder of a group of bioactive cyclic lipopeptides.
Co-reporter:Aishwarya V. Ramaswamy, Carla M. Sorrels and William H. Gerwick
Journal of Natural Products 2007 Volume 70(Issue 12) pp:1977-1986
Publication Date(Web):November 15, 2007
DOI:10.1021/np0704250
Cyanobacteria, or blue-green algae, are a rich source of novel bioactive secondary metabolites that have potential applications as antimicrobial or anticancer agents or useful probes in cell biology studies. A Jamaican collection of the cyanobacterium Lyngbya majuscula has yielded several unique compounds including hectochlorin (1) and the jamaicamides A−C (5–7). Hectochlorin has remarkable antifungal and cytotoxic properties. In this study, we have isolated the hectochlorin biosynthetic gene cluster (hct) from L. majuscula to obtain details regarding its biosynthesis at the molecular genetic level. The genetic architecture and domain organization appear to be colinear with respect to its biosynthesis and consists of eight open reading frames (ORFs) spanning 38 kb. An unusual feature of the cluster is the presence of ketoreductase (KR) domains in two peptide synthetase modules, which are predicted to be involved in the formation of the two 2,3-dihydroxyisovaleric acid (DHIV) units. This biosynthetic motif has only recently been described in cereulide, valinomycin, and cryptophycin biosynthesis, and hence, this is only the second such report of an embedded ketoreductase in a cyanobacterial secondary metabolite gene cluster. Also present at the downstream end of the cluster are two cytochrome P450 monooxygenases, which are likely involved in the formation of the DHIV units. A putative halogenase, at the beginning of the gene cluster, is predicted to form 5,5-dichlorohexanoic acid.
Co-reporter:Takashi L. Suyama, Zhengyu Cao, Thomas F. Murray, William H. Gerwick
Toxicon (February–March 2010) Volume 55(Issues 2–3) pp:204-210
Publication Date(Web):1 February 2010
DOI:10.1016/j.toxicon.2009.07.020
Primary fractions from the extract of a tropical red alga mixed with filamentous cyanobacteria, collected from Papua New Guinea, were active in a neurotoxicity assay. Bioassay-guided isolation led to two natural products (1,2) with relatively potent calcium ion influx properties. The more prevalent of the neurotoxic compounds (1) was characterized by extensive NMR, mass spectrometry, and X-ray crystallography, and shown to be identical to a polybrominated diphenyl ether metabolite present in the literature, but reported with different NMR properties. To clarify this anomalous result, we synthesized a candidate isomeric polybrominated diphenyl ether (3), but this clearly had different NMR shifts than the reported compound. We conclude that the original isolate of 3,4,5-tribromo-2-(2,4-dibromophenoxy)phenol was contaminated with a minor compound, giving rise to the observed anomalous NMR shifts. The second and less abundant natural product (2) isolated in this study was a more highly brominated species. All three compounds showed a low micromolar ability to increase intracellular calcium ion concentrations in mouse neocortical neurons as well as toxicity to zebrafish. Because polybrominated diphenyl ethers have both natural as well as anthropomorphic origins, and accumulate in marine organisms at higher trophic level (mammals, fish, birds), these neurotoxic properties are of environmental significance and concern.
Co-reporter:Joshawna K Nunnery, Emily Mevers, William H Gerwick
Current Opinion in Biotechnology (December 2010) Volume 21(Issue 6) pp:787-793
Publication Date(Web):1 December 2010
DOI:10.1016/j.copbio.2010.09.019
Marine cyanobacteria are a rich source of complex bioactive secondary metabolites which derive from mixed biosynthetic pathways. Recently, several marine cyanobacterial natural products have garnered much attention due to their intriguing structures and exciting anti-proliferative or cancer cell toxic activities. Several other recently discovered secondary metabolites exhibit insightful neurotoxic activities whereas others are showing pronounced anti-inflammatory activity. A number of anti-infective compounds displaying activity against neglected diseases have also been identified, which include viridamides A and B, gallinamide A, dragonamide E, and the almiramides.
Co-reporter:Karin Kleigrewe; Jehad Almaliti; Isaac Yuheng Tian; Robin B. Kinnel; Anton Korobeynikov; Emily A. Monroe; Brendan M. Duggan□; Vincenzo Di Marzo; David H. Sherman◊; Pieter C. Dorrestein□; Lena Gerwick;William H. Gerwick□
Journal of Natural Products () pp:
Publication Date(Web):
DOI:10.1021/acs.jnatprod.5b00301
An innovative approach was developed for the discovery of new natural products by combining mass spectrometric metabolic profiling with genomic analysis and resulted in the discovery of the columbamides, a new class of di- and trichlorinated acyl amides with cannabinomimetic activity. Three species of cultured marine cyanobacteria, Moorea producens 3L, Moorea producens JHB, and Moorea bouillonii PNG, were subjected to genome sequencing and analysis for their recognizable biosynthetic pathways, and this information was then compared with their respective metabolomes as detected by MS profiling. By genome analysis, a presumed regulatory domain was identified upstream of several previously described biosynthetic gene clusters in two of these cyanobacteria, M. producens 3L and M. producens JHB. A similar regulatory domain was identified in the M. bouillonii PNG genome, and a corresponding downstream biosynthetic gene cluster was located and carefully analyzed. Subsequently, MS-based molecular networking identified a series of candidate products, and these were isolated and their structures rigorously established. On the basis of their distinctive acyl amide structure, the most prevalent metabolite was evaluated for cannabinomimetic properties and found to be moderate affinity ligands for CB1.
![Carbamic acid, N-[(1S)-3-methyl-1-(2-methylpropyl)-2-oxobutyl]-, 1,1-dimethylethyl ester](/data/chemimg/3768100/1708967-98-9.png)
![Carbamic acid, N-[(1S)-3-methyl-1-(2-methylpropyl)-2-oxobutyl]-, 1,1-dimethylethyl ester](/data/chemimg/3768100/1708967-98-9_b.png)
![Tert-butyl N-[(2s)-4-methyl-1-[(2r)-2-methyloxiran-2-yl]-1-oxopentan-2-yl]carbamate](http://img.cochemist.com/ccimg/247100/247068-82-2.png)
![Tert-butyl N-[(2s)-4-methyl-1-[(2r)-2-methyloxiran-2-yl]-1-oxopentan-2-yl]carbamate](http://img.cochemist.com/ccimg/247100/247068-82-2_b.png)
![N-[(4-AMINOPHENYL)METHYL]-1-METHYLPIPERIDIN-4-AMINE;DIHYDROCHLORIDE](http://img.cochemist.com/data/images/144408-86-6.png)
![N-[(4-AMINOPHENYL)METHYL]-1-METHYLPIPERIDIN-4-AMINE;DIHYDROCHLORIDE](http://img.cochemist.com/data/images/144408-86-6_b.png)
![Phenylalanine,N-[[[1-[[[1-[[[[dihydro-3-hydroxy-5-(tetrahydro-2,4-dioxo-1(2H)-pyrimidinyl)-2(3H)-furanylidene]methyl]amino]carbonyl]-2-[methyl[(1,2,3,4-tetrahydro-6-hydroxy-3-isoquinolinyl)carbonyl]amino]propyl]amino]carbonyl]-3-(methylthio)propyl]amino]carbonyl]-3-hydroxy-](http://img.cochemist.com/ccimg/144400/144379-26-0.png)
![Phenylalanine,N-[[[1-[[[1-[[[[dihydro-3-hydroxy-5-(tetrahydro-2,4-dioxo-1(2H)-pyrimidinyl)-2(3H)-furanylidene]methyl]amino]carbonyl]-2-[methyl[(1,2,3,4-tetrahydro-6-hydroxy-3-isoquinolinyl)carbonyl]amino]propyl]amino]carbonyl]-3-(methylthio)propyl]amino]carbonyl]-3-hydroxy-](http://img.cochemist.com/ccimg/144400/144379-26-0_b.png)
![(1s,4s,7z,10s,16e,21r)-7-ethylidene-4,21-di(propan-2-yl)-2-oxa-12,13-dithia-5,8,20,23-tetrazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone](http://img.cochemist.com/ccimg/128600/128517-07-7.png)
![(1s,4s,7z,10s,16e,21r)-7-ethylidene-4,21-di(propan-2-yl)-2-oxa-12,13-dithia-5,8,20,23-tetrazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone](http://img.cochemist.com/ccimg/128600/128517-07-7_b.png)
![Butanamide,N-[[[1-carboxy-2-(3-hydroxyphenyl)ethyl]amino]carbonyl]methionyl-N-[[5-(3,4-dihydro-2,4-dioxo-1(2H)-pyrimidinyl)dihydro-4-hydroxy-2(3H)-furanylidene]methyl]-N3-methyl-N3-[(1,2,3,4-tetrahydro-6-hydroxy-3-isoquinolinyl)carbonyl]-D-2,3-diamino-(9CI)](http://img.cochemist.com/ccimg/126100/126049-03-4.png)
![Butanamide,N-[[[1-carboxy-2-(3-hydroxyphenyl)ethyl]amino]carbonyl]methionyl-N-[[5-(3,4-dihydro-2,4-dioxo-1(2H)-pyrimidinyl)dihydro-4-hydroxy-2(3H)-furanylidene]methyl]-N3-methyl-N3-[(1,2,3,4-tetrahydro-6-hydroxy-3-isoquinolinyl)carbonyl]-D-2,3-diamino-(9CI)](http://img.cochemist.com/ccimg/126100/126049-03-4_b.png)
![Butanamide,N-[[[1-carboxy-2-(3-hydroxyphenyl)ethyl]amino]carbonyl]methionyl-N-[[5-(3,4-dihydro-2,4-dioxo-1(2H)-pyrimidinyl)dihydro-4-hydroxy-2(3H)-furanylidene]methyl]-N3-(N-glycyl-3-hydroxyphenylalanyl)-N3-methyl-D-2,3-diamino-(9CI)](http://img.cochemist.com/ccimg/114800/114797-06-7.png)
![Butanamide,N-[[[1-carboxy-2-(3-hydroxyphenyl)ethyl]amino]carbonyl]methionyl-N-[[5-(3,4-dihydro-2,4-dioxo-1(2H)-pyrimidinyl)dihydro-4-hydroxy-2(3H)-furanylidene]methyl]-N3-(N-glycyl-3-hydroxyphenylalanyl)-N3-methyl-D-2,3-diamino-(9CI)](http://img.cochemist.com/ccimg/114800/114797-06-7_b.png)
![2-[[1-[[3-[[2-AMINO-3-(3-HYDROXYPHENYL)PROPANOYL]-METHYLAMINO]-1-[[5-(2,4-DIOXO-1,3-DIAZINAN-1-YL)-4-HYDROXYOXOLAN-2-YLIDENE]METHYLAMINO]-1-OXOBUTAN-2-YL]AMINO]-4-METHYLSULFANYL-1-OXOBUTAN-2-YL]CARBAMOYLAMINO]-3-(3-HYDROXYPHENYL)PROPANOIC ACID](http://img.cochemist.com/ccimg/114800/114797-05-6.png)
![2-[[1-[[3-[[2-AMINO-3-(3-HYDROXYPHENYL)PROPANOYL]-METHYLAMINO]-1-[[5-(2,4-DIOXO-1,3-DIAZINAN-1-YL)-4-HYDROXYOXOLAN-2-YLIDENE]METHYLAMINO]-1-OXOBUTAN-2-YL]AMINO]-4-METHYLSULFANYL-1-OXOBUTAN-2-YL]CARBAMOYLAMINO]-3-(3-HYDROXYPHENYL)PROPANOIC ACID](http://img.cochemist.com/ccimg/114800/114797-05-6_b.png)
![(2E)-3-[(4S)-2,2-DiMethyl-1,3-dioxolan-4-yl]-2-Methyl-2-propenoic acid ethyl ester](http://img.cochemist.com/ccimg/82000/81997-76-4.png)
![(2E)-3-[(4S)-2,2-DiMethyl-1,3-dioxolan-4-yl]-2-Methyl-2-propenoic acid ethyl ester](http://img.cochemist.com/ccimg/82000/81997-76-4_b.png)
![Thiazole,4,5-dihydro-4-[(1Z,5E,7E,11R)-11-methoxy-8-methyl-1,5,7,13-tetradecatetraen-1-yl]-2-[(1R,2S)-2-methylcyclopropyl]-,(4R)-](http://img.cochemist.com/ccimg/155300/155233-30-0.png)
![Thiazole,4,5-dihydro-4-[(1Z,5E,7E,11R)-11-methoxy-8-methyl-1,5,7,13-tetradecatetraen-1-yl]-2-[(1R,2S)-2-methylcyclopropyl]-,(4R)-](http://img.cochemist.com/ccimg/155300/155233-30-0_b.png)