Molecular Networking-Based Analysis of Cytotoxic Saponins from Sea Cucumber .

The saponin composition of a specimen of black sea cucumber, collected in the Persian Gulf was studied by a combined approach including LC-MS/MS, Molecular Networking, pure compound isolation, and NMR spectroscopy. The saponin composition of turned out to be more complex than previously reported. The most abundant saponins in the extract (⁻) were isolated and characterized by 1D- and 2D-NMR experiments. Compound was identified as a new triterpene glycoside saponin, holothurin A5. The side chain of the new saponin , unprecedented among triterpene glycosides, is characterized by an electrophilic enone function, which can undergo slow water or methanol addition under neutral conditions. The cytotoxic activity of compounds ⁻, evaluated on the human cervix carcinoma HeLa cell line, was remarkable, with IC values ranging from 1.2 to 2.5 µg/mL.