Triterpene Glycosides from the Sea Cucumber Eupentacta fraudatrix. Structure and Cytotoxic action of Cucumarioside D with a Terminal 3-O-Me-Glucose Residue Unique for this Species

Abstract

New minor triterpene glycoside, cucumarioside D (1) identified earlier as a candidate to new glycoside using LC-ESI QTOF-MS has been isolated from the sea cucumber Eupentacta fraudatrix as individual substance. The structure of the glycoside was elucidated using 2D NMR spectroscopy and MS. The glycoside has non-sulfated pentasaccharide carbohydrate chain branched by the second sugar (quinovose) and having 3-O-methylglucose as a terminal monosacharide residue that is an unique structural feature of sea cucumber triterpene glycosides from this species. A moderate cytotoxic activity of the glycoside 1 against the ascyte form of Echlich carcinoma cells and hemolytic activity has been found.