title: Ring B aromatic steroids from an endophytic fungus, Colletotrichum sp.
abstract: The new (22E,24R)-3-acetoxy-19(10-->6)-abeo-ergosta-5,7,9,22-tetraen-3beta-ol (1) and the known (22E,24R)-19(10-->6)-abeo-ergosta-5,7,9,22-tetraen-3beta-ol (2), two interesting ergosteroids with rare aromatized ring B, together with seven known derivatives, namely (22E,24R)-ergosta-5,7,22-trien-3beta-ol (3), (22E,24R)-ergosta-4,7,22-trien-3-one (4), (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (5), (22E,24R)-5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (6), (22E,24R)-ergosta-7,22-dien-3beta,5alpha,6beta-triol (7), (22E,24R)-6-acetoxy-ergosta-7,22-dien-3beta,5alpha,6beta-triol (8), and (22E,24R)-3,6-diacetoxy-ergosta-7,22-dien-3beta,5alpha,6beta-triol (9), were isolated from Colletotrichum sp., an endophytic fungus isolated from Ilex canariensis from Gomera. The structures of these compounds were elucidated by detailed spectroscopic analysis, comparison with reported data, and chemical interconversion. The isolation of these metabolites not only displays a beautiful array of chemical diversity, but also gives insight into the biosynthetic interconnections. Preliminary studies showed antimicrobial activity of these compounds against the fungus Microbotryum violaceum, the alga Chlorella fusca, and the bacteria Escherichia coli and Bacillus megaterium.
authors.affiliation: Research Center for Marine Drugs, School ofPharmacy, Second Military Medical University, 325 Guo-He Road, Shanghai 200433, PR China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Siegfried
authors.initials: S
authors.lastname: Draeger
authors.forename: Barbara
authors.initials: B
authors.lastname: Schulz
authors.forename: Karsten
authors.initials: K
authors.lastname: Krohn
mesh_terms: D000107:Acetylation; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D002855:Chromatography, Thin Layer; D020231:Colletotrichum / Q000737:chemistry*; D003470:Culture Media; D056890:Eukaryota / Q000187:drug effects; D005658:Fungi / Q000187:drug effects; D030017:Ilex / Q000382:microbiology; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D013256:Steroids / Q000096:biosynthesis / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D013256:Steroids