Variegatusides: New Non-Sulphated Triterpene Glycosides from the Sea Cucumber Stichopus variegates Semper

Abstract

Four new triterpene glycosides, variegatusides C–F (1–4), together with three structurally known triterpene glycosides, variegatusides A and B (5, 6), and holothurin B (7), were isolated from the sea cucumber Stichopus variegates Semper (Holothuriidae), collected from the South China Sea. Their structures were elucidated on the basis of extensive spectral analysis (nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESIMS)) and chemical evidence. Variegatusides C–F exhibit the same structural feature consisting of the presence of a 23-hydroxyl group at the holostane-type triterpene aglycone side chain. Variegatuside C (1) has a double bond (24, 25) in this same chain, while variegatuside D (2) exhibits a 8(9)-ene bond in the holostane-type triterpene aglycone, which has not been extracted from other sea cucumber species. Compound 4 is a native compound from the sea cucumber S. variegates Semper, which has been reported to be desacetylstichloroside B1. Except for holothurin B, these glycosides have no sulfate group in their sugar chain and show potent antifungal activities in vitro biotests.

Three New Cytotoxic Polyhydroxysteroidal Glycosides from Starfish Craspidaster hesperus

“…Steroidal metabolites from starfish, especially steroidal oligoglycosides, were reported to show a broad spectrum of biological activities, including cytotoxic, hemolytic, antiviral, antibacterial, antibiofouling, neuritogenic, and antifungal effects [1,7,8,9,10]. As a continuation of our previous studies on biologically active compounds from echinoderms [11,12,13,14], we collected starfish Craspidaster hesperus from the South China Sea, and evaluated biological activity of the steroidal glycosides from this starfish. To our knowledge, the polyhydroxysteroidal glycosides from C. hesperus remains unknown, although some polyhydroxysteroidal glycosides from other starfish (e.g., Anthenea chinensis ) , were reported [15].…”

Triterpene Glycosides of Sea Cucumbers (Holothuroidea, Echinodermata) as Taxonomic Markers

“…The report of the isolation of holothurin B from Stichopus variegatus [32] is probably another example of work with biological materials that had been incorrectly identified because all the samples of this species collected in different regions of the Indo-West Pacific did not contain this type of glycoside [1,[33][34][35]. The taxonomic name of the animal in this article is also erroneously given as "variegates".…”

“…The related problem is erroneous elucidation of glycosidic structures. In our opinion, the article cited above also describes erroneous elucidation of structures of a series of so called "variegatusides", the glycosides isolated from Stichopus variegatus [32]. This species was studied earlier [33][34][35].…”

Antimicrobial lead compounds from marine plants

“…Melophlus sponge shows the presence of a tetramic acid glycoside -Aurantoside K with wide spectrum antifungal action against C. albicans strains, yeast Cryptococcus neoformans, Aspergillus niger, Penicillium sp., Rhizopus sporangia and Sordaria sp [112]. Variegatusides -Triterpene glycosides from Holothuriida, Stichopus variegatus sea cucumber shows antifungal activity [113].…”