Structures of new polar steroids from the Far-Eastern starfish Ctenodiscus crispatus

Abstract

A fraction of sulfated polyhydroxylated steroids from the Far Eastern starfish Ctenodiscus crispatus was investigated. The main component of this fraction was identified as (22E,24R,25R) 24 methyl 5α cholest 22 en 3β,5,6β,15α,25,26 hexol 26 O sulfate. For the compound stere oisomeric with respect to the side chain, the (24R,25S) or (24S,25R) relative configurations were assigned to the C(24) and C (25) chiral centers. The structures of two other compounds isolated from the fraction were identified as (22E,24ξ) 26,27 bisnor 24 methyl 5α cholest 22 en 3β,5,6β,15α,25 pentol 25 O sulfate and (22E,24ξ,25ξ) 24 methyl 5α cholest 22 en 3β,5,6β,8,15α,25,26 heptol 26 O sulfate.Polyhydroxysteroids and their glycosides are the most widespread secondary metabolites of starfishes. These compounds are of interest not only because of their un usual chemical structures but also due to their properties, including embriotoxic, fungicidal, bactericidal, antifoul ing, neuritogenic, and other types of physiological activi ties. 1 Earlier, 2 we have isolated four new polyhydroxylated steroids, two of which are sulfates, from the starfish Ctenodiscus crispatus (family Ctenodiscidae, the order Paxillosida) collected in the Japan Sea (the Posiet Bay). As part of continuing investigations of steroid metabolites from Far Eastern starfishes, 2,3 we studied the composi tion of a fraction of sulfated polyhydroxysteroids from this starfish, isolated several new steroids, and established the absolute configuration of the side chain of steroid 1, whose structure has been determined earlier without elu cidation of the stereochemical features of the side chain. Results and DiscussionA fraction of sulfated polyhydroxylated steroids was obtained from an aqueous ethanolic extract of the star fish Ctenodiscus crispatus by reversed phase, gel perme ation, and adsorption chromatography on Amberlite XAD 2, Sephadex LH 20, and silica gel. The following four compounds were isolated from this fraction by HPLC: previously known (22E) 24 methyl 5α cholest 22 en * Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.

Chemical Constituents and Bioactivities of Starfish

“…The side-chain configuration of the known structurally-related sterol 178 [59] was determined as (24R,25R) [60]. Far Eastern starfish Henricia tumida was the source of 179 and 180, and both metabolites exhibited moderate cytostatic activity towards sea urchin eggs [61].…”

Phallusiasterol C, A New Disulfated Steroid from the Mediterranean Tunicate Phallusia fumigata

“…The structure of phallusiasterol C ( 1 ), a new disulfated steroid isolated from the Mediterranean tunicate Phallusia fumigata was elucidated using mass spectrometry and NMR experiments. Phallusiasterol C ( 1 ) is the first example of a sterol with a sulfated (22 E )-26,27-dinor-24-methyl-25-hydroxy side chain from tunicates; up to now, only one sterol with the same side chain has been isolated from the starfish Ctenodiscus crispatus [ 21 ] and only few similar polyhydroxylated steroids containing an analogous, but sulfate-free, side chain from the starfishes and from sea gorgonian have been characterized [ 22 , 23 , 24 , 25 , 26 ]. However, the occurrence of sterols with side chains of the 24-methyl-27-nor- and 24-methyl-26,27-dinorcholestane types in nearly every marine invertebrate phylum is reported and this suggests that these sterols could be of a dietary origin.…”

Steroids from the Cold Water Starfish Ctenodiscus crispatus with Cytotoxic and Apoptotic Effects on Human Hepatocellular Carcinoma and Glioblastoma Cells

“…Three remaining sterols were determined to be (22E,24R, 25R)-24-methyl-5α-cholest-22-en-3β,5,6β,15α,25,26-hexol 26-O-sulfate (2), 6 (25S)-5α-cholestane-3β,5,6β,15α,16β,26-hexaol (4), 10 and Δ7-sitosterol (5) 11 by comparing their NMR and MS data with those reported in the literature (Figure 1).…”

“…Previous investigations on chemical composition of C. crispatus have shown the presence of some polyhydroxylated steroids. 5,6 As a part of our on-going search for bioactive secondary metabolites from marine organisms, this study describes the isolation and identification of five steroids (1)(2)(3)(4)(5) from the cold water starfish C. crispatus.…”