title: Mycalosides B-I, eight new spermostatic steroid oligoglycosides from the sponge Mycale laxissima.
abstract: New steroidal oligoglycosides mycalosides B-I (2-9) have been isolated from the polar extract of the Caribbean sponge Mycale laxissima, and their structures have been elucidated by 1D and 2D NMR ((1)H, (13)C, DEPT, COSY-45, COSY-RCT, HSQC, HMBC, and NOESY spectra) and MALDI-TOF mass spectrometry. Mycalosides B (2) and C (3) were shown to be 27- and 28-nor derivatives of the previously known tetraoside mycaloside A (1). Mycaloside D (4) differs from 1 only in the presence of an additional acetyl group in the carbohydrate moiety. Mycaloside E (5) was structurally identified as a 28-nor-4-dehydroxy derivative of 1. Mycalosides F-H (6-8), differing from each other by the structures of their side chains and nonacetylated (7, 8) or acetylated (6) tetrasaccharide carbohydrate moieties, have new 5(6)-unsaturated 3 beta,4 beta,21-trihydroxy-15-keto-steroidal aglycons. Mycaloside I (9) is a tetraoside of a new 7,24(28)-diunsaturated 3beta,15 beta,29-trihydroxystigmastane aglycon. It was established that the total fraction of the mycalosides as well as mycalosides A (1) and G (7) inhibit the fertilization of eggs by sperm of the sea urchin Strongylocentrotus nudus preincubated with these compounds.
authors.affiliation: Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospect 100 let Vladivostoku, 690022 Vladivostok, Russian Federation.
authors.forename: Alexandr S
authors.initials: AS
authors.lastname: Antonov
authors.forename: Shamil Sh
authors.initials: SSh
authors.lastname: Afiyatullov
authors.forename: Anatoly I
authors.initials: AI
authors.lastname: Kalinovsky
authors.forename: Ludmila P
authors.initials: LP
authors.lastname: Ponomarenko
authors.forename: Pavel S
authors.initials: PS
authors.lastname: Dmitrenok
authors.forename: Dmitry L
authors.initials: DL
authors.lastname: Aminin
authors.forename: Irina G
authors.initials: IG
authors.lastname: Agafonova
authors.forename: Valentin A
authors.initials: VA
authors.lastname: Stonik
mesh_terms: D000818:Animals; D003462:Cuba; D005306:Fertilization / Q000187:drug effects*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008297:Male; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011161:Porifera / Q000737:chemistry*; D012617:Sea Urchins / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects; D013237:Stereoisomerism; D013256:Steroids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D006027:Glycosides; D013256:Steroids