Polar steroidal compounds from the Far-Eastern starfish Lethasterias fusca

Abstract

Nine steroidal compounds including three new steroidal glycosides, viz., sodium (24S) 3,24 di O (β D xylopyranosyl) 5α cholestane 3β,6β,8,15α,24 pentol 15 sulfate (fuscaside A), (24S) 3,24 di O (β D xylopyranosyl) 5α cholestane 3β,6β,8,15α,24 pentol (fuscaside B), and (22E,24R) 24 O (β D xylopyranosyl) 5α cholest 22 ene 3β,6α,8,15β,24 pentol (desulfated minutoside A); three previously known glycosides, viz., distolasterosides D 1 and D 2 and pycno podioside A; two previously known polyhydroxysteroids, viz., 5α cholestane 3β, 6α,8,15β,16β,26 hexaol and 5α cholestan 3β,4β,6α,7α,8,15β,16β,26 octol; and the known sodium 24,25 dihydro marthasterone 3 sulfate were isolated from the Far Eastern starfish Lethasterias fusca. The struc tures of these compounds were elucidated by NMR spectroscopy and mass spectrometry.

Four New Sulfated Polar Steroids from the Far Eastern Starfish Leptasterias ochotensis: Structures and Activities

“…The NMR spectra of aglycon side chain indicated the existence of three secondary methyls CH 3 -21 [δ H 0.92 d ( J = 6.7); δ C 19.1], CH 3 -26 [δ H 0.92 d ( J = 6.7); δ C 18.4], and CH 3 -27 [δ H 0.92 d ( J = 6.7); δ C 18.5] and oxygenated CH-24 group (δ H 3.34 m; δ C 86.2) bearing an O -monosaccharide residue. These proton and carbon resonances were similar to those of a 24- O -glycosylated cholestane chain of fuscaside A earlier isolated from the starfish Lethasterias fusca [ 17 ]. The 1 H NMR spectrum exhibited one resonance in the downfield region due to an anomeric proton of monosaccharide unit at δ H 4.06 correlated in the HSQC experiment with a carbon signal at δ C 105.0.…”

“…The coupling constant of the anomeric proton of monosaccharide unit (6.6 Hz) corresponded to the β-configuration of the glycosidic bond. The carbon and proton signals and corresponding coupling constants of monosaccharide unit coincided well with those of the terminal β-xylopyranosyl residue [ 17 ]. Acid hydrolysis of glycoside 1 with 2 M trifluoroacetic acid (TFA) followed by obtaining of chiral derivatives were carried out to ascertain an absolute stereochemistry of its monosaccharide unit.…”

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2007–2008

“…Steroid glycosides TOF, NMR Structural determination (Ivanchina, et al, 2008) Linckia laevigata (Viet Namese starfish)…”

Chemical Constituents and Bioactivities of Starfishes: An Update

“…Compound 73 was isolated from the Pacific starfish Evasterias echinosoma . Compounds 74 and 75 were generated by the Far Eastern starfish Distolasterias nipon whereas compound 76 was produced by Lethasterias fusca . The starfish Asterina pectinifera produced compound 77 , and starfish Asterias amurensis Lutken yielded compound 78 .…”

“…Compound 166 was a triglycoside containing two carbohydrate chains, which are rarely found in starfish . The starfish Lethasterias fusca yielded compounds 167 – 168 and they were a rather scarce structural group of natural glycosylated steroidal polyols containing monosaccharide residues attached to both O‐3 and O‐24 atoms of the aglycon . The starfish Hippasteria kurilensis Fisher produced compounds 169 and 170 – 173 .…”