title: Steroidal monoglycosides from the Far Eastern starfish Hippasteria kurilensis and hypothetic pathways of polyhydroxysteroid biosynthesis in starfish.
abstract: Five new steroidal monoglycosides, kurilensosides E (1), F (2), G (3), H (4) and 15-O-sulfate of echinasteroside C (5) were isolated along with the previously known echinasteroside C (6) from the alcoholic extract of the Far Eastern starfish Hippasteria kurilensis collected near Kuril Islands. Compounds 1-3 were determined to contain unusual polyhydroxysteroidal aglycons lacking 6-hydroxy group. Aglycon moiety of kurilensoside H (4) was shown to be the first case of marine polar steroids containing 4,5-epoxy functionality. Hypothetic pathways of the biosynthesis of polyhydroxysteroids and related glycosides in starfish and the existence of the late C-6 oxidation pathway in H. kurilensis are discussed.
authors.affiliation: Pacific Institute of Bioorganic Chemistry, Far East Branch of the Russian Academy of Sciences, Pr. 100-let Vladivostoku 159, 690022 Vladivostok, Russia.
authors.forename: Alla A
authors.initials: AA
authors.lastname: Kicha
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Ivanchina
authors.forename: Anatoly I
authors.initials: AI
authors.lastname: Kalinovsky
authors.forename: Pavel S
authors.initials: PS
authors.lastname: Dmitrenok
authors.forename: Valentin A
authors.initials: VA
authors.lastname: Stonik
mesh_terms: D000818:Animals; D006027:Glycosides / Q000737:chemistry*; D006914:Hydroxysteroids / Q000378:metabolism*; D010084:Oxidation-Reduction; D011108:Polymers / Q000378:metabolism*; D013215:Starfish / Q000737:chemistry* / Q000378:metabolism*; D013256:Steroids / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D006027:Glycosides; D006914:Hydroxysteroids; D011108:Polymers; D013256:Steroids