New Neuritogenic Steroid Glycosides from the Vietnamese Starfish Linckia Laevigata

Abstract

Two new steroid glycosides, linckosides L1 (1) and L2 (2), were isolated, along with the previously known echinasteroside C (3) from the ethanolic extract of the Vietnamese blue starfish, Linckia laevigata. The structures of the new compounds were elucidated by spectroscopic methods (mainly 2D NMR) and chemical transformations. Lifetime observations and analyses of silver impregnated preparations on the culture of neuroblastoma C-1300 cells showed that glycosides 1, 2, and 3 are capable of inducing neuronal differentiation similar to that of neurotrophins and of enhancing substantially the neuritogenic activity of NGF.

Neuritogenic and Neuroprotective Effects of Polar Steroids from the Far East Starfishes Patiria pectinifera and Distolasterias nipon

“…The neuritogenic activity of starfish polar steroids in living NB cells can be detected beginning at the second day of cultivation, as we have described previously [11,12,13]. Previous results have demonstrated that a series of polar steroids, including 1 – 3 , manifested significant and nearly identical neuritogenic effects at doses of 2–20 μM, but these effects were slight or even absent at higher concentrations of approximately 40 μM [11].…”

“…The assays for neuritogenic activity in live cells were performed according to previously described methods [11,12,13]. For experiments involving silver impregnation, the cells were seeded in 6-well plastic plates (2 × 10 4 cells per well) with glass coverslips.…”

“…Neuritogenic activity of steroid glycosides from the Okinawan blue starfish Linckia laevigata was revealed for the first time by Qi, Han and co-authors [4,9,10] on pheochromocytoma PC12 cells. In our previous work, we demonstrated that polar steroids (polyhydroxysteroids and related glycosides) from various species of starfish could induce neurite outgrowth in mouse neuroblastoma C-1300 cell culture [11,12,13]. The present research is devoted to more detailed study of neurotrophic activities of six starfish steroid compounds: asterosaponin Р 1 , (25 S )-5α-cholestane-3β,4β,6α,7α,8,15α,16β,26-octaol, and (25 S )-5α-cholestane-3β,6α,7α,8,15α,16β,26-heptaol, designated as PP1, PP2, and PP3 ( 1 – 3 ), from Patiria (= Asterina ) pectinifera [14], and distolasterosides D 1 –D 3 , designated as D1, D2, and D3 ( 4 – 6 ), from Distolasterias nipon [13] (Figure 1).…”

Four New Steroidal Glycosides, Protolinckiosides A – D, from the Starfish Protoreaster lincki

“…The coupling constant (7.4 Hz) of the anomeric H‐atom corresponded to a β ‐configuration of the glycosidic bond. The C‐ and H‐atom signals and the corresponding coupling constants of monosaccharide unit coincided well with those of the terminal 2‐ O ‐methyl‐ β ‐xylopyranosyl residue . Acid hydrolysis of glycoside 1 with 2 m aqueous CF 3 COOH was carried out to ascertain a stereochemical series of its monosaccharide unit.…”

“…lincki was subjected to the sequential separation by chromatography on columns with Polychrom‐1 , silica gel, and Florisil , followed by HPLC on semipreparative Diasfer‐110‐C18 , Discovery C 18 , and analytical Diasfer‐110‐C18 columns to yield the four new steroidal glycosides 1 – 4 and the four previously known glycosides 5 – 8 . The known compounds were identified by comparison of their 1 H‐ and 13 C‐NMR, and MS spectra with those reported for linckoside L1 ( 5 , (3 β ,4 β ,5 α ,6 β ,15 α ,24 S )‐4,6,8,15,24‐pentahydroxycholestan‐3‐yl 2‐ O ‐methyl‐ β ‐ d ‐xylopyranoside) from Linckia laevigata , granulatoside A ( 6 , (3 β ,4 β ,5 α ,6 β ,15 α ,24 S )‐4,6,8,15‐tetrahydroxy‐3‐[(2‐ O ‐methyl‐ β ‐ d ‐xylopyranosyl)oxy]cholestan‐24‐yl α ‐ l ‐arabinofuranoside) from Choriaster granulatus , leviusculoside D ( 7 , sodium (3 β ,6 β ,15 α ,16 β ,22 E ,24 R )‐6,8,16,28‐tetrahydroxy‐3‐[(2‐ O ‐methyl‐ β ‐ d ‐xylopyranosyl)oxy]ergosta‐4,22‐dien‐15‐yl sulfate) from Henricia leviuscula , and echinasteroside B ( 8 , sodium (3 β ,6 β ,15 α ,16 β ,24 R )‐6,8,16,29‐tetrahydroxy‐3‐[(2‐ O ‐methyl‐ β ‐ d ‐xylopyranosyl)oxy]stigmast‐4‐en‐15‐yl sulfate) from Echinaster sepositus .

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