Samir Ross

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Organization: University
Department: National Center for Natural Products Research
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Co-reporter:Ahmad E. Mostafa, Atef A. El-Hela, Abd-Elsalam I. Mohammad, Stephen J. Cutler, Samir A. Ross
Phytochemistry Letters 2016 Volume 17() pp:213-218
Publication Date(Web):September 2016
DOI:10.1016/j.phytol.2016.07.008
⿢Three new triterpenoidal saponins were isolated from Koelreuteria paniculata.⿢First report of tridesmosidic saponin from family Sapindaceae.⿢Two of the isolated compounds showed antimalarial activity.Bioassay guided fractionation and chemical investigation of the ethanolic extract of the aerial parts of Koelreuteria paniculata Laxm. (Sapindaceae), resulted in the isolation and identification of three new triterpenoid saponins 1⿿3 named Paniculatosoid A⿿C, along with eleven known compounds. The structures of the isolated compounds were elucidated using 1D and 2D NMR experiments, HRESIMS, and comparison with literature data. The occurrence of tridesmosidic saponin is reported for the first time from family Sapindaceae, as well as it is rarely found in natural saponins. Compounds 4⿿13 were evaluated for their antibacterial, antifungal, antimalarial and antileishmanial activities. Compound 12 showed weak antibacterial activity against Escherichia coli with an IC50 value of 101 μM. Compounds 12 and 13 showed antimalarial activity against chloroquine-sensitive (D6) Plasmodium falciparum protozoan with IC50 values of 6.46 and 6.95 μM, and against chloroquine-resistant (W2) Plasmodium falciparum protozoan with IC50 values of 9.34 and 4.18 μM.Bioassay guided fractionation of aerial parts of Koelreuteria paniculata Laxm. (Sapindaceae) led to isolation of three new saponins, together with eleven known compounds. The presence of the rare tridesmosidic saponin is reported for the first time from the family.
Co-reporter:Nesma M. Mohamed, Makboul A. Makboul, Salwa F. Farag, Surendra Jain, Melissa R. Jacob, Babu L. Tekwani, Samir A. Ross
Phytochemistry Letters 2016 15() pp: 30-36
Publication Date(Web):March 2016
DOI:10.1016/j.phytol.2015.11.008
•Three new triterpenoids along with nine known compounds were isolated.•Some compounds showed antibacterial activity against some of the tested organisms.•Some compounds showed moderate antileishmanial.•Some compounds showed potent antitrypanosomal activity.Bioassay guided fractionation of the roots of Lantana montevidensis (Verbenaceae) has resulted in the isolation and identification of three new triterpenoids; 13β-hydroxy-3-oxo-olean-11-en-28-oic acid (1), 12β,13β-dihydroxyolean-3-oxo-28-oic acid (2) and 12β,13β,22β-trihydroxyolean-3-oxo-28-oic acid (3) in addition to nine known compounds: oleanonic acid (4), oleanolic acid (5), 3β,25β-dihydroxy-olean-12-en-28-oic acid (6), lantadene A (7), 19α-hydroxy-3-oxo-olean-12-en-28-oic acid (8) pomolic acid (9), camaric acid (10) together with β-sitosterol (11) and β-sitosterol-3-O-β-d-glucoside (12). The structures of the isolated metabolites were elucidated based on comprehensive 1D and 2D NMR spectroscopic data as well as HR-ESI–MS. The extracts and the isolated metabolites were evaluated for their antiprotozoal and antimicrobial activities. Compound 2 showed antibacterial activity against Staphylococcus aureus and methicillin resistant S. aureus with IC50 values against both organisms of 2.1 μM and compound 10 showed activity against same organisms with IC50 values 8.74 and 8.09 μM, respectively, compared to the positive control ciprofloxacin (IC50 = 0.3 μM against S. aureus and MRSA). Compounds 1, 4, 5, 6, and 10 showed moderate antileishmanial activity with IC50 values ranging between (2.54–14.95 μM) and IC90 values ranging between (11.90–19.47 μM), using pentamidine as a control (IC50 values 2.09 ≥ 16.8 μM) and IC90 values ranging between (4.72 ≥ 16.8 μM). These compounds also showed highly potent antitrypanosomal activity with IC50 values ranging between (0.39–7.12 μM) and IC90 values ranging between (1.91–10.51 μM), which are more efficient than the DFMO, the antitrypanosomal drug employed as positive control (IC50 and IC90values 11.82 and 30.82 μM).
Co-reporter:Mohamed M. Radwan; Mahmoud A. ElSohly; Abir T. El-Alfy; Safwat A. Ahmed; Desmond Slade; Afeef S. Husni; Susan P. Manly; Lisa Wilson; Suzanne Seale; Stephen J. Cutler;Samir A. Ross
Journal of Natural Products 2015 Volume 78(Issue 6) pp:1271-1276
Publication Date(Web):May 22, 2015
DOI:10.1021/acs.jnatprod.5b00065
Seven new naturally occurring hydroxylated cannabinoids (1–7), along with the known cannabiripsol (8), have been isolated from the aerial parts of high-potency Cannabis sativa. The structures of the new compounds were determined by 1D and 2D NMR spectroscopic analysis, GC-MS, and HRESIMS as 8α-hydroxy-Δ9-tetrahydrocannabinol (1), 8β-hydroxy-Δ9-tetrahydrocannabinol (2), 10α-hydroxy-Δ8-tetrahydrocannabinol (3), 10β-hydroxy-Δ8-tetrahydrocannabinol (4), 10α-hydroxy-Δ9,11-hexahydrocannabinol (5), 9β,10β-epoxyhexahydrocannabinol (6), and 11-acetoxy-Δ9-tetrahydrocannabinolic acid A (7). The binding affinity of isolated compounds 1–8, Δ9-tetrahydrocannabinol, and Δ8-tetrahydrocannabinol toward CB1 and CB2 receptors as well as their behavioral effects in a mouse tetrad assay were studied. The results indicated that compound 3, with the highest affinity to the CB1 receptors, exerted the most potent cannabimimetic-like actions in the tetrad assay, while compound 4 showed partial cannabimimetic actions. Compound 2, on the other hand, displayed a dose-dependent hypolocomotive effect only.
Co-reporter:Mohamed M. Radwan;Amira S. Wanas;Frank R. Fronczek
Medicinal Chemistry Research 2015 Volume 24( Issue 9) pp:3398-3404
Publication Date(Web):2015 September
DOI:10.1007/s00044-015-1386-9
Bioassay-guided fractionation of the marine sponge Lendenfeldia dendyi and the soft coral Sinularia dura resulted in the isolation of five polybrominated diphenyl ethers (1–5). The structures of the isolated compounds were determined using spectroscopic methods (1D and 2D NMR) and HRMS analyses. The absolute structures of compounds 1 and 2 were confirmed by X-ray analysis. Antimicrobial testing of the isolated compounds along with the acetylated derivative of compound 2 (2a) indicated that they displayed a significant and selective activity against methicillin-resistant Staphylococcus aureus (MRSa) with IC50 values of <0.04–1.18 µM. The antimalarial and antileishmanial activities of the isolated compounds were also evaluated.
Co-reporter:Safwat A. Ahmed, Samir A. Ross, Desmond Slade, Mohamed M. Radwan, Ikhlas A. Khan, Mahmoud A. ElSohly
Phytochemistry 2015 Volume 117() pp:194-199
Publication Date(Web):September 2015
DOI:10.1016/j.phytochem.2015.04.007
•Nine oxygenated cannabinoids were isolated from Cannabis Sativa.•Their chemical structures were determined by 1D and 2D NMR spectroscopic analysis.•The antimicrobial and antimalarial activities of the isolates were evaluated.•Moderate activities were found.Nine oxygenated cannabinoids were isolated from a high potency Cannabis sativa L. variety. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR, HRMS and GC–MS. These minor compounds include four hexahydrocannabinols, four tetrahydrocannabinols, and one hydroxylated cannabinol, namely 9α-hydroxyhexahydrocannabinol, 7-oxo-9α-hydroxyhexa-hydrocannabinol, 10α-hydroxyhexahydrocannabinol, 10aR-hydroxyhexahydrocannabinol, Δ9-THC aldehyde A, 8-oxo-Δ9-THC, 10aα-hydroxy-10-oxo-Δ8-THC, 9α-hydroxy-10-oxo-Δ6a,10a-THC, and 1′S-hydroxycannabinol, respectively. The latter compound showed moderate anti-MRSa (IC50 10.0 μg/mL), moderate antileishmanial (IC50 14.0 μg/mL) and mild antimalarial activity against Plasmodium falciparum (D6 clone) and P. falciparum (W2 clone) with IC50 values of 3.4 and 2.3 μg/mL, respectively.Nine oxygenated cannabinoids (1–9) were isolated from a high potency Cannabis sativa L. variety. Their chemical structures were elucidated using spectroscopic techniques. The antimicrobial, antileishmanial and antimalarial activities were tested.
Co-reporter:Lourin G. Malak ; Mohamed Ali Ibrahim ; Daoud W. Bishay ; Afaf M. Abdel-baky ; Ahmed M. Moharram ; Babu Tekwani ; Stephen J. Cutler ;Samir A. Ross
Journal of Natural Products 2014 Volume 77(Issue 9) pp:1987-1991
Publication Date(Web):August 1, 2014
DOI:10.1021/np5000473
Antileishmanial bioassay guided fractionation of Geosmithia langdonii has resulted in the isolation and identification of two new compounds (1 and 2) together with 10 known compounds (3–12). The structures of the isolated metabolites were elucidated based on comprehensive 1D and 2D NMR spectroscopic data as well as mass spectrometry. The absolute configuration at C4, C5, and C6 of 2 was determined as R using a modified Mosher esterification method and NOESY correlations. The extracts and the isolated metabolites were evaluated for their antileishmanial activities. Compounds 3, 9, 11, and 12 were found to be active against Leishmania donovani with IC50 values of 6.9, 3.3, 8.5, and 9.2 μM, respectively, while compounds 1, 5, and 10 showed lower activities against L. donovani with IC50 values of 13.0, 47.3, and 34.0 μM, respectively.
Co-reporter:Ahmed M. Metwaly, Frank R. Fronczek, Guoyi Ma, Hazem A. Kadry, Atef A. El-Hela, Abd-Elsalam I. Mohammad, Stephen J. Cutler, Samir A. Ross
Tetrahedron Letters 2014 Volume 55(Issue 24) pp:3478-3481
Publication Date(Web):11 June 2014
DOI:10.1016/j.tetlet.2014.04.085
Four new (1–4) and two known (5 and 6) α-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identified to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (1), 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-pyran-2-one (2), 5-(1-hydroxybutyl)-4-methoxy-6-methyl-2H-pyran-2-one (3), 4-methoxy-6-methyl-5-(3-oxobutyl)-2H-pyran-2-one (4), 5-(2-hydroxyethyl)-4-methoxy-6-methyl-2H-pyran-2-one (5), and 5-[(2E)-but-2-en-1-yl]-4-methoxy-6-methyl-2H-pyran-2-one (6). Compounds 2 and 4 showed moderate antileukemic activities against HL60 cells with IC50 values of 2.2 and 0.9 μM and against K562 cells with IC50 values of 4.5 and 1.5 μM, respectively.
Co-reporter:Ahmed M. Metwaly, Hazem A. Kadry, Atef A. El-Hela, Abd-Elsalam I. Mohammad, Guoyi Ma, Stephen J. Cutler, Samir A. Ross
Phytochemistry Letters 2014 Volume 7() pp:1-5
Publication Date(Web):February 2014
DOI:10.1016/j.phytol.2013.09.001
•The phytochemical and biological properties of the endophytic fungus Nigrospora sphaerica were examined. Nigrosphaerin A, a new isochromene derivative, along with nineteen known compounds was isolated and identified. Four compounds showed good in vitro antileukemic activity. Three compounds showed moderate in vitro antileishmanial activity. One compound showed good antifungal activity.Nigrosphaerin A, a new isochromene derivative (1), was isolated from the endophytic fungus Nigrospora sphaerica and chemically identified as 3-(3,4-dihydroxyphenyl)-4,6,8-trihydroxy-1H-isochromen-1-one-6-O-β-d-glucopyranoside. In addition nineteen known compounds (2–20) were isolated from the same fungus and chemically identified. Compounds (1–3, 5, and 7–16) were isolated for the first time from this fungus. In vitro antileukemic, antileishmanial, antifungal, antibacterial and antimalarial activities of (1–20) were examined. Compounds 5, 7, 9 and 10 showed good antileukemic activity against HL60 cells with IC50 values of 0.03, 0.39, 0.2 and 0.4 μg/mL, respectively and against K562 cells with IC50 values of 0.35, 0.35, 0.49 and 0.01 μg/mL, respectively. Compounds 3, 4 and 6 showed moderate antileishmanial activity with IC50 values of 30.2, 26.4 and 36.4 μg/ml, respectively. Compound 7 showed moderate antifungal activity against Cryptococcus neoformans with IC50 value of 14.8 μg/mL.One new isochromene derivative along with nineteen known compounds was isolated from the endophytic fungus Nigrospora sphaerica. Four compounds showed good antileukemic activity. Three compounds showed moderate antileishmanial activity. One compound showed good antifungal activity.
Co-reporter:Ahmad E. Mostafa, Atef A. El-Hela, Abd-Elsalam I. Mohammad, Melissa Jacob, Stephen J. Cutler, Samir A. Ross
Phytochemistry Letters 2014 8() pp: 10-15
Publication Date(Web):
DOI:10.1016/j.phytol.2013.12.008
Co-reporter:Mohammed M. Ghoneim, Khaled M. Elokely, Atef A. El-Hela, Abd-Elsalam I. Mohammad, Melissa Jacob, Mohamed M. Radwan, Robert J. Doerksen, Stephen J. Cutler, Samir A. Ross
Phytochemistry 2014 Volume 105() pp:79-84
Publication Date(Web):September 2014
DOI:10.1016/j.phytochem.2014.06.011
•Five compounds were isolated from Asphodelus microcarpus and their antimicrobial activities evaluated.•Compounds 2–4 showed potent to good activity against (MRSA).•They also exhibited potent activity against Staphylococcus aureus.Bioassay guided fractionation of the ethanolic extract of Asphodelus microcarpus Salzm. et Viv. (Xanthorrhoeaceae or Asphodelaceae) resulted in isolation of five compounds identified as asphodosides A-E (1–5). Compounds 2–4 showed activity against methicillin resistant Staphylococcus aureus (MRSA) with IC50 values of 1.62, 7.0 and 9.0 μg/mL, respectively. They also exhibited activity against Staphylococcus aureus (non-MRSA) with IC50 values of 1.0, 3.4 and 2.2 μg/mL, respectively. The structure elucidation of isolated metabolites was carried out using spectroscopic data (1D and 2D NMR), optical rotation and both experimental and calculated electronic circular dichroism (ECD).Five hitherto unknown compounds (1–5) were isolated from the Asphodelus microcarpus. Secondary metabolites 2–4 showed potent to good activity against both methicillin resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus.
Co-reporter:Gamal A. Mohamed, Sabrin R.M. Ibrahim, Samir A. Ross
Phytochemistry Letters 2013 Volume 6(Issue 3) pp:340-344
Publication Date(Web):August 2013
DOI:10.1016/j.phytol.2013.04.009
•The methanol extract of the rhizomes of Iris germanica L. was investigated.•This work reports the isolation of three new compounds.•Their structures were established by different spectroscopic analyses.•The cytotoxic activity of the isolated compounds was tested against different cancer cell lines.Two new ceramides, irisamides A (1) and B (2), together with a new isoflavone, iridin S (3) have been isolated from the MeOH extract of the rhizomes of Iris germanica L. (Iridaceae). Their structures were established by UV, IR, HRESIMS, 1D and 2D NMR experiments, in addition to comparison with literature data. The isolated compounds were tested for their cytotoxic activity against different cancer cell lines.Two new ceramides, irisamides A (1) and B (2), together with a new isoflavone, iridin S (3) have been isolated from the MeOH extract of the rhizomes of Iris germanica L. (Iridaceae). Their structures were established by UV, IR, HRESIMS, 1D and 2D NMR experiments, in addition to comparison with literature data. The isolated compounds were tested for their cytotoxic activity against different cancer cell lines.
Co-reporter:Fazila Zulfiqar, Samir A. Ross, Desmond Slade, Safwat A. Ahmed, Mohamed M. Radwan, Zulfiqar Ali, Ikhlas A. Khan, Mahmoud A. ElSohly
Tetrahedron Letters 2012 Volume 53(Issue 28) pp:3560-3562
Publication Date(Web):11 July 2012
DOI:10.1016/j.tetlet.2012.04.139
Cannabisol (1), a unique dimer of Δ9-tetrahydrocannabinol (Δ9-THC) with a methylene bridge, was isolated from Cannabis sativa. This is the first example of a C-bridged dimeric cannabinoid. The structure of 1 was unambiguously deduced by HRESIMS, GCMS, and NMR spectroscopy. A plausible biogenesis of 1 is described.
Co-reporter:Mohamed A. El-Shanawany, Gamal A. Mohamed, Alaa M. Nafady, Sabrin R.M. Ibrahim, Mohamed M. Radwan, Samir A. Ross
Phytochemistry Letters 2011 Volume 4(Issue 2) pp:126-128
Publication Date(Web):15 June 2011
DOI:10.1016/j.phytol.2010.12.008
The chloroformic fraction of the roots of Centaurium spicatum L. afforded one new xanthone named 1,5,8-trihydroxy-3,6,7-trimethoxyxanthone (1) together with six known xanthones (2–7), one of them isolated for the first time from a plant source (2). One secoiridoid glucoside (8) was also isolated. The structures of the isolated compounds were established based on 1D and 2D (1H–1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated compounds were tested for their antimicrobial and antiprotozoal activities. Compound 6 displayed moderate antifungal activity against Candida krusei and Cryptococcus neoformans with IC50 values of 12.8 and 17.9 μg/ml respectively.Graphical abstractA new xanthone, 1,5,8-trihydroxy-3,6,7-trimethoxyxanthone (1) together with seven known compounds have been isolated from the roots of Centaurium spicatum. Their chemical structures were established by 1D and 2D (1H–1H COSY, HMQC, and HMBC) NMR spectroscopy. The antimicrobial and antiprotozoal activities of the isolates were evaluated.Research highlights► Seven xanthones from the roots of Centaurium spicatum have been isolated. ► One of them is new from nature and the others are known. ► The antibacterial, antifungal and antiprotozoal activities of the isolated compounds were studied. ► Compound 6 displayed moderate antifungal activity against Candida krusei and Cryptococcus neoformans.
Co-reporter:Zhanar A. Kozhamkulova, Mohamed M. Radwan, Galiya E. Zhusupova, Zharilkasin A. Abilov, Samir A. Ross
Phytochemistry Letters 2011 Volume 4(Issue 3) pp:323-327
Publication Date(Web):September 2011
DOI:10.1016/j.phytol.2011.06.004
Halimodendrin I, a new acylated triterpene glycoside (1), was isolated and chemically characterized as 3β-O-palmitoyl-28-[3′-palmitoyl-β-d-glucopyranosyl]-olean-12-en-28-oic acid from the aerial part of Halimodendron halodendron (Fabaceae) by IR, 1D and 2D NMR, HR-ESI-MS and LR-ESI-MS experiments. In addition, seven known compounds were isolated and identified as: palmitic acid, glycerol-2-linoleneate, glycerol-1,3-dilinoleneate, ferulic acid, 3-O-methylquercetin, β-sitosterol, and β-sitosterol-3-O-β-d-glucopyranoside. Nine fatty acids were identified and quantified in the saponifiable matter of the hexane extract. These fatty acids are: myristic, n-pentadecanoic, palmitoleic, palmitic, linoleic, oleic, stearic, arachidic, and behenic acids. The volatile oil was isolated by hydrodistillation (0.013%, w/w) with unpleasant smell. Twenty-seven components were identified in the oil by GC/MS.Graphical abstractHalimodendrin I, a new acylated triterpene glycoside (1), along with seven known compounds were isolated and identified from the aerial parts of Halimodendron halodendron. The chemical composition of the volatile oil and fatty acids content were also studied.Highlights► Eight compounds have been isolated from the aerial parts of Halimodendron halodendron (Fabaceae). ► One of them is a new acylated triterpene glycoside. ► The chemical composition of the volatile oil as well as fatty acids content were studied.
Co-reporter:Mohamed M. Radwan, Mahmoud A. ElSohly, Desmond Slade, Safwat A. Ahmed, Ikhlas A. Khan and Samir A. Ross
Journal of Natural Products 2009 Volume 72(Issue 5) pp:906-911
Publication Date(Web):April 3, 2009
DOI:10.1021/np900067k
Nine new cannabinoids (1−9) were isolated from a high-potency variety of Cannabis sativa. Their structures were identified as (±)-4-acetoxycannabichromene (1), (±)-3′′-hydroxy-Δ(4′′,5′′)-cannabichromene (2), (−)-7-hydroxycannabichromane (3), (−)-7R-cannabicoumarononic acid A (4), 5-acetyl-4-hydroxycannabigerol (5), 4-acetoxy-2-geranyl-5-hydroxy-3-n-pentylphenol (6), 8-hydroxycannabinol (7), 8-hydroxycannabinolic acid A (8), and 2-geranyl-5-hydroxy-3-n-pentyl-1,4-benzoquinone (9) through 1D and 2D NMR spectroscopy, GC-MS, and HRESIMS. The known sterol β-sitosterol-3-O-β-d-glucopyranosyl-6′-acetate was isolated for the first time from cannabis. Compounds 6 and 7 displayed significant antibacterial and antifungal activities, respectively, while 5 displayed strong antileishmanial activity.
Co-reporter:Mohamed M. Radwan, Raquel Rodriguez-Guzman, Susan P. Manly, Melissa Jacob, Samir A. Ross
Phytochemistry Letters 2009 Volume 2(Issue 4) pp:141-143
Publication Date(Web):19 November 2009
DOI:10.1016/j.phytol.2009.04.002
Bioassay-guided fractionation of the EtOH extract of Artocarpus sepicanus Diels leaves has led to the isolation of a new geranyl flavanone (1), along with the known compounds, afzelechin-3-O-α-l-rhamnopyranoside and β-sitosterol glucoside. The structure of the new compound was established by UV, IR, HRESIMS, 1D and 2D NMR experiments. Antimicrobial testing of the three compounds indicated that 1 displayed a significant selective antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) with IC50 and MIC values of 1.4 and 2.9 μM, respectively.
Co-reporter:Mohamed M. Radwan, Susan P. Manly, Khalid A. El Sayed, Vikram B. Wali, Paul W. Sylvester, Bhushan Awate, Girish Shah and Samir A. Ross
Journal of Natural Products 2008 Volume 71(Issue 8) pp:1468-1471
Publication Date(Web):July 17, 2008
DOI:10.1021/np800208k
Two new diterpenes, sinulodurin A (1) and sinulodurin B (2), along with two known sterols, 24S-methyl cholesterol and 24-methylene cholesterol, were isolated from the Palau soft coral Sinularia dura. The structures of the new metabolites were determined on the basis of spectroscopic methods and by comparison of NMR data with those of related metabolites. Sinulodurin A (1) and sinulodurin B (2) showed antiproliferative activity against highly malignant +SA mammary epithelial cells with an IC50 range of 20−30 μM. They also displayed anti-invasive activity against human highly metastatic prostate cancer PC-3M-CT+ cells in the spheroid disaggregation assay. Furthermore, the antimicrobial activities of the isolates were tested.
Co-reporter:Samir A. Ross, Raquel Rodríguez-Guzmán, Mohamed M. Radwan, Melissa Jacob, Yuanqing Ding, Xing-Cong Li, Daneel Ferreira and Susan P. Manly
Journal of Natural Products 2008 Volume 71(Issue 10) pp:1764-1767
Publication Date(Web):October 11, 2008
DOI:10.1021/np800446g
Bioassay-guided fractionation of a root extract of Sorocea muriculata led to the isolation and identification of two new oxygen heterocyclic Diels−Alder-type adducts, sorocenols G (1) and H (2), along with lupeol-3-(3′R-hydroxytetradecanoate) and oxyresveratrol. The structures of 1 and 2 were elucidated using 1D and 2D NMR spectroscopic and HRMS data and by comparison with reported values. The absolute configurations of 1 and 2 were established by analysis of their experimental and theoretically calculated CD spectra. Compounds 1 and 2 showed significant and selective activity against methicillin-resistant Staphylococcus aureus with IC50 values of 1.5 and 0.5 μM, respectively. Compound 2 also displayed antifungal activity against Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, with IC50 values of 5.4, 5.4, and 10.0 μM, respectively.
Co-reporter:Rita Stanikunaite, Mohamed M. Radwan, James M. Trappe, Frank Fronczek and Samir A. Ross
Journal of Natural Products 2008 Volume 71(Issue 12) pp:2077-2079
Publication Date(Web):December 9, 2008
DOI:10.1021/np800577p
Bioassay-guided fractionation of an EtOH extract of the truffle-mimiking mushroom Astraeus pteridis led to the isolation and identification of three new (3−5) and two known (1, 2) lanostane triterpenes and phenylalanine betaine (6). The structures of the isolates were elucidated on the basis of 1D and 2D NMR spectroscopic data, HRESIMS results, and X-ray crystallographic analysis. Compounds 5 and 1 showed moderate activity against Mycobacterium tuberculosis with MIC values of 34.0 and 58.0 μg/mL, respectively.
Co-reporter:Safwat A. Ahmed, Samir A. Ross, Desmond Slade, Mohamed M. Radwan, Fazila Zulfiqar and Mahmoud A. ElSohly
Journal of Natural Products 2008 Volume 71(Issue 4) pp:536-542
Publication Date(Web):February 28, 2008
DOI:10.1021/np070454a
Eleven new cannabinoid esters, together with three known cannabinoid acids and Δ9-tetrahydrocannabinol (Δ9-THC), were isolated from a high-potency variety of Cannabis sativa. The structures were determined by extensive spectroscopic analyses to be β-fenchyl Δ9-tetrahydrocannabinolate (1), epi-bornyl Δ9-tetrahydrocannabinolate (2), α-terpenyl Δ9-tetrahydrocannabinolate (3), 4-terpenyl Δ9-tetrahydrocannabinolate (4), α-cadinyl Δ9-tetrahydrocannabinolate (5), γ-eudesmyl Δ9-tetrahydrocannabinolate (6), γ-eudesmyl cannabigerolate (7), 4-terpenyl cannabinolate (8), bornyl Δ9-tetrahydrocannabinolate (9), α-fenchyl Δ9-tetrahydrocannabinolate (10), α-cadinyl cannabigerolate (11), Δ9-tetrahydrocannabinol (Δ9-THC), Δ9-tetrahydrocannabinolic acid A (Δ9-THCA), cannabinolic acid A (CBNA), and cannabigerolic acid (CBGA). Compound 8 showed moderate antimicrobial activity against Candida albicans ATCC 90028 with an IC50 value of 8.5 µg/mL. CB-1 receptor assay indicated that the esters, as well as the parent acids, are not active.
Co-reporter:Mohamed M. Radwan, Mahmoud A. ElSohly, Desmond Slade, Safwat A. Ahmed, Lisa Wilson, Abir T. El-Alfy, Ikhlas A. Khan, Samir A. Ross
Phytochemistry 2008 Volume 69(Issue 14) pp:2627-2633
Publication Date(Web):October 2008
DOI:10.1016/j.phytochem.2008.07.010
Six new non-cannabinoid constituents were isolated from a high potency Cannabis sativa L. variety, namely 5-acetoxy-6-geranyl-3-n-pentyl-1,4-benzoquinone (1), 4,5-dihydroxy-2,3,6-trimethoxy-9,10-dihydrophenanthrene (2), 4-hydroxy-2,3,6,7-tetramethoxy-9,10-dihydrophenanthrene (3), 4,7-dimethoxy-1,2,5-trihydroxyphenanthrene (4), cannflavin C (5) and β-sitosteryl-3-O-β-d-glucopyranoside-2′-O-palmitate (6). In addition, five known compounds, α-cannabispiranol (7), chrysoeriol (8), 6-prenylapigenin (9), cannflavin A (10) and β-acetyl cannabispiranol (11) were identified, with 8 and 9 being reported for the first time from cannabis. Some isolates displayed weak to strong antimicrobial, antileishmanial, antimalarial and anti-oxidant activities. Compounds 2–4 were inactive as analgesics.Six new non-cannabinoid constituents (1–6) have been isolated from a high potency Cannabis sativa L. variety, along with five known compounds (7–11). Structure elucidation was accomplished through analysis of 1D and 2D NMR spectroscopic data. All isolates were tested for antimicrobial, antileishmanial, antimalarial and anti-oxidant activities. The analgesic activities of 2–4 in mice were also tested.
Co-reporter:Samir A. Ross;Gazi N. N. Sultana;Mahmoud A. ElSohly;Zlatko Mehmedic;Suman Chra;Chowdhury F. Hossain
Phytochemical Analysis 2005 Volume 16(Issue 1) pp:45-48
Publication Date(Web):24 JAN 2005
DOI:10.1002/pca.809

Chemical investigation of the pollen grain collected from male plants of Cannabis sativa L. resulted in the isolation for the first time of two flavonol glycosides from the methanol extract, and the identification of 16 cannabinoids in the hexane extract. The two glycosides were identified as kaempferol 3-O-sophoroside and quercetin 3-O-sophoroside by spectroscopic methods including high-field two-dimensional NMR experiments. The characterisation of each cannabinoid was performed by GC-FID and GC-MS analyses and by comparison with both available reference cannabinoids and reported data. The identified cannabinoids were Δ9-tetrahydrocannabiorcol, cannabidivarin, cannabicitran, Δ9-tetrahydrocannabivarin, cannabicyclol, cannabidiol, cannabichromene, Δ9-tetrahydrocannabinol, cannabigerol, cannabinol, dihydrocannabinol, cannabielsoin, 6a, 7, 10a-trihydroxytetrahydrocannabinol, 9, 10-epoxycannabitriol, 10-O-ethylcannabitriol, and 7, 8-dehydro-10-O-ethylcannabitriol. Copyright © 2005 John Wiley & Sons, Ltd.

2-(3',5'-dibromo-2'-hydroxyphenoxy)-4,5,6-tribromophenol
(4S,5S)-4,5-dihydroxy-2-methylcyclohex-2-enone
2,2-dimethyl-3(S),5-(4-yloxypent-3-en-1-yl)-7-n-pentylchroman-4-one
5-hydroxy-2,2-dimethyl-3(R)-(3,4-dioxopentyl)-7-n-pentylchroman-4-one
2H-PYRAN-2-ONE, 5-(2E)-2-BUTENYL-4-METHOXY-6-METHYL-
7-OXABICYCLO[4.1.0]HEPTAN-2-ONE, 5-HYDROXY-3-METHYL-, (1S,3S,5R,6S)-
Phenol, 2-[2-(acetyloxy)-3,5-dibromophenoxy]-3,4,5,6-tetrabromo-,acetate
(2E)-3-[4-HYDROXY-3-(3,5,5,8,8-PENTAMETHYL-5,6,7,8-TETRAHYDRO-2-NAPHTHALENYL)PHENYL]ACRYLIC ACID
Stigmasta-4,22-dien-3-one, 6-hydroxy-, (22E)-