Cultivation of locust associated rare actinobacteria, Amycolatopsis sp. HCa4, has provided five unusual macrolactams rifamorpholines A–E. Their structures were determined by interpretation of spectroscopic and crystallographic data. Rifamorpholines A–E possess an unprecedented 5/6/6/6 ring chromophore, representing a new subclass of rifamycin antibiotics. The biosynthetic pathway for compounds 1–5 involves a key 1,6-cyclization for the formation of the morpholine ring. Compounds 2 and 4 showed potent activities against methicillin-resistant Staphylococcus aureus (MRSA) with MICs of 4.0 and 8.0 μM, respectively.

The present study was designed to examine the anti-hyperuricemic and anti-inflammatory effects and possible mechanisms of vaticaffinol, a resveratrol tetramer isolated from ethanol extracts of Dipterocarpus alatus, in oxonate-induced hyperuricemic mice. At 1 h after 250 mg·kg−1 potassium oxonate was given, vaticaffinol at 20, 40, and 60 mg·kg−1 was intragastrically administered to hyperuricemic mice once daily for seven consecutive days. Vaticaffinol significantly decreased serum uric acid levels and improved kidney function in hyperuricemic mice. It inhibited hepatic activity of xanthine dehydrogenase (XDH) and xanthine oxidase (XOD), regulated renal mRNA and protein levels of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), organic anion transporter 1 (OAT1), organic cation transporter 1 (OCT1), OCT2, organic cation/carnitine transporter 1 (OCTN1), and OCTN2 in hyperuricemic mice. Moreover, vaticaffinol markedly down-regulated renal protein levels of NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like (ASC), and Caspase-1, resulting in the reduction of interleukin (IL)-1β, IL-18, IL-6 and tumor necrosis factor-α (TNF-α) levels in this animal model. Additionally, HPLC and LC-MS analyses clearly testified the presence of vaticaffinol in the crude extract. These results suggest that vaticaffinol may be useful for the prevention and treatment of hyperuricemia with kidney inflammation.

•Five new aromatic polyketides were isolated from a caterpillar associated fungus.•We obtained crystals of compound 1 and compound 3.•Compounds 4 and 5 showed weak cytotoxic activities.Five new aromatic polyketides, alternaphenols A–E (1–5), and two known compounds (6–7) were isolated from a liquid culture of Alternaria sp. (strain no. NF2198), a caterpillar associated fungus. Their structures were determined by extensive spectroscopic analysis and single crystal X-ray crystallography. Compounds 1–7 were evaluated for their cytotoxic activities against a human skin melanoma A-375 cell line. Only compounds 4 and 5 showed weak cytotoxic activities.Download high-res image (65KB)Download full-size image

The conversion from triene- to diene-typed ansamycins is clarified step by step in Streptomyces seoulensis IFB-A01. Such an intertype convertibility is adopted to establish for the first time the simultaneous mutasynthesis of both types of C17-benzene ansamycins (C17BAs). Three of the newly generated unnatural compounds showed potent cytotoxicity.

Ten new sesquiterpenoids including six brasilane-type sesquiterpenoids, diaporols J–O (1–6), a 3,6-cycloprecapnellane sesquiterpenoid, diaporol P (7), and three drimane sesquiterpenoids, diaporols Q–S (8–10) were isolated from Diaporthe sp., an endophytic fungus associated with the leaves of Rhizophora stylosa collected in Hainan Province, China. The structures of these compounds were elucidated by extensive analysis of NMR, MS, CD spectra and single crystal X-ray diffraction. Among them, compound 9 exhibited moderate cytotoxicity against the SW480 cell line with an IC50 value of 8.72 ± 1.32 μM.

Seven new compounds, pleosporallins A–G (1–7), were isolated from Pleosporales sp., a fungus derived from a marine alga Enteromorpha clathrata. The structures of these compounds were elucidated by an extensive analysis of NMR, MS, CD spectra, and single crystal X-ray diffraction. Compounds 4 and 5 showed antimicrobial activity with their MIC values of 9.48 μg/ml and 7.44 μg/ml against Clavibacter michiganense subsp. Sepedonicus and Candida albicans, respectively. Compounds 1–3 exhibited moderate inhibitory activities against the lipopolysaccharide (LPS)-induced intracellular IL-6 production of murine macrophage cell line RAW264.7.

Five new stilbenolignans, hopeachinols E–I (1–5), and two new stilbenoids, hopeachinols J and K (6 and 7), together with the known resveratrol trimer, vaticanol A (8), were isolated from the stem bark of Hopea chinensis. The structures and relative configurations of these natural products were elucidated by using spectroscopic and spectrometric methods. The (8R) absolute configuration of 1 was assigned by using the modified Mosher ester method. Hopeachinols E–I (1–5) possess unprecedented stilbenolignan skeletons, in which a stilbene trimer is linked with a phenylpropanoid unit through a pyran bridge. Hopeachinols J and K (6 and 7) have new skeletons in which a stilbene trimer is connected by an additional two-carbon unit through a furan moiety. An evaluation of the cytotoxicities against HCT116, MDA-MB-231, SMMC-7721, and HepG2 cell lines of the new hopeachinols showed that 1, 2, 4, and 6 have moderate activities with IC50 values in the 10.39–18.72 μM range.

Six new p-terphenyl derivatives, named 4″-deoxy-3-hydroxyterphenyllin (1), 4″-deoxy-5′-desmethyl-terphenyllin (2), 5′-desmethylterphenyllin (3), 4″-deoxycandidusin A (4), 4,5-dimethoxycandidusin A (5), and terphenolide (6), four new diterpenoids with norcleistanthane (aspergiloid A (12) and aspergiloid B (13)), cleistanthane (aspergiloid C (14)), and isopimarane (aspergiloid D (15)) type skeletons, and five known p-terphenyl compounds (7–11) were isolated from the fermentation broth of the plant endophytic fungus Aspergillus sp. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison of their NMR data with those reported in the literature. Compounds 4, 6, 7, and 9 displayed moderate neuraminidase inhibitory activity with IC50 values ranging from 4.34 to 9.17 μM.

A new sesquiterpenoid, diaporol A (1), possessing a unique tricyclic lactone framework, eight new drimane sesquiterpenoids, diaporols B–I (2–9), and the known compounds 10 and 11 were isolated from a culture of the mangrove-derived endophyte Diaporthe sp. The absolute configurations of 1–5 were determined by low-temperature (100 K) single-crystal X-ray diffraction with Cu Kα radiation. The compounds were evaluated for cytotoxic activity; however, no compound showed significant cytotoxicity against the tested cell lines at a concentration of 20 μM.

One new angucyclinone derivative, amycomycin A (1), and one new angucycline, amycomycin B (2), along with 5 known compounds (3–7), were isolated from an actinobacterium Amycolatopsis sp. HCa1 associated with the grasshopper, Oxya chinensis. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR spectra. Compounds 1–7 were tested in vitro for their cytotoxic effects on five cell lines including human gastric adenocarcinoma cell line (BGC823), human hepatocarcinoma cell line (HepG2), human melanoma cell line (A375), human oral squamous carcinoma cell line (KB), and ghost cell line (Ghost-R5X4). Cell viability assays showed that compound 7 was active in four cell lines with IC50 values less than 18.0 μM except in KB showing no activity up to 100 μM.One new angucyclinone derivative, amycomycin A (1), and one new angucycline, amycomycin B (2), and 5 known compounds (3–7), were isolated from an actinobacterium Amycolatopsis sp. HCa1 associated with the grasshopper, Oxya chinensis.

Six flavonoids named cryptogiones A–F, and nine known compounds were isolated from an ethanol extract of stems of Cryptocaryachingii. The structures of the compounds were elucidated by interpretation of comprehensive spectroscopic data and X-ray analysis. A majority of these flavonoids contained an acetic acid/lactone moiety, a possible taxonomic marker. Anti-inflammatory effects of the compounds were evaluated using in vitro assays. At 20 μM concentration, three compounds significantly inhibited TNFα-induced NF-кB activation and LPS-induced IL-1β expression.Graphical abstractSix new flavonoids, cryptoginone A–F, together with nine known compounds were isolated from the ethanol extract of stems of Cryptocaryachingii. Compounds 7–9 showed significant anti-inflammatory activities at 20 μM.Highlights► The phytochemical constituents of Cryptocaryachingii have been investigated. ► Six flavonoids and 9 known compounds have been isolated. ► An acetic acid/lactone moiety in the majority of the compounds can be a possible taxonomic marker. ► The anti-inflammatory effects of the compounds have been evaluated. ► Three compounds show activity against TNF and LPS induced proinflammatory responses.

Phytochemical examination of the branches and twigs of the tropical plant Vatica mangachapoi resulted in the isolation of three novel oligostilbenes named vaticahainols A–C (1–3) along with seventeen known oligostilbenes (4–20). The structures of the new compounds were elucidated on the basis of extensive spectroscopic data analysis, modified Mosher's method, and quantum chemical computation. All of the isolated phytochemicals were screened for their xanthine oxidase (XO) and acetylcholinesterase (AChE) inhibitory activities.

Cultivation of locust associated rare actinobacteria, Amycolatopsis sp. HCa4, has provided five unusual macrolactams rifamorpholines A–E. Their structures were determined by interpretation of spectroscopic and crystallographic data. Rifamorpholines A–E possess an unprecedented 5/6/6/6 ring chromophore, representing a new subclass of rifamycin antibiotics. The biosynthetic pathway for compounds 1–5 involves a key 1,6-cyclization for the formation of the morpholine ring. Compounds 2 and 4 showed potent activities against methicillin-resistant Staphylococcus aureus (MRSA) with MICs of 4.0 and 8.0 μM, respectively.