title: Caught between triterpene- and steroid-metabolism: 4α-carboxylic pregnane-derivative from the marine alga-derived fungus Phaeosphaeria spartinae.
abstract: Investigation of the fungus Phaeosphaeria spartinae, an endophyte of the marine red alga Ceramium sp., led to the isolation of spartopregnenolone (1), a metabolite whose structure includes features of triterpenes and steroids, i.e. a Δ(8,9) double bond as occurring in lanosterol type triterpenoids, a carboxyl group at C-4 which is characteristic for intermediates on the way from triterpenes to steroids and an acetyl side chain as typical for pregnane type steroids. The unusual structure of compound 1 was established from extensive spectroscopic investigations and is best described as a 4α-carboxy-8,9-pregnene derivative.
authors.affiliation: Institute for Pharmaceutical Biology, University of Bonn, 53115 Bonn, Germany.
authors.forename: Mahmoud Fahmi
authors.initials: MF
authors.lastname: Elsebai
authors.forename: Stefan
authors.initials: S
authors.lastname: Kehraus
authors.forename: Gabriele M
authors.initials: GM
authors.lastname: König
mesh_terms: D001203:Ascomycota / Q000737:chemistry* / Q000378:metabolism; D060026:Endophytes / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011284:Pregnenolone / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D000461:Rhodophyta / Q000382:microbiology; D013237:Stereoisomerism
chemical_list: D011284:Pregnenolone
keywords: Natural products; Phaeosphaeria spartinae; Pregnenolone; Spartopregnenolone