Structural Elucidation of Novel Saponins in the Sea Cucumber Holothuria lessoni

Abstract

Sea cucumbers are prolific producers of a wide range of bioactive compounds. This study aimed to purify and characterize one class of compound, the saponins, from the viscera of the Australian sea cucumber Holothuria lessoni. The saponins were obtained by ethanolic extraction of the viscera and enriched by a liquid-liquid partition process and adsorption column chromatography. A high performance centrifugal partition chromatography (HPCPC) was applied to the saponin-enriched mixture to obtain saponins with high purity. The resultant purified saponins were profiled using MALDI-MS/MS and ESI-MS/MS which revealed the structure of isomeric saponins to contain multiple aglycones and/or sugar residues. We have elucidated the structure of five novel saponins, Holothurins D/E and Holothurinosides X/Y/Z, along with seven reported triterpene glycosides, including sulfated and non-sulfated saponins containing a range of aglycones and sugar moieties, from the viscera of H. lessoni. The abundance of novel compounds from this species holds promise for biotechnological applications.

Ion mobility mass spectrometry of saponin ions

“…The apolar part is constructed around a sterol or a triterpenoid base . Those biomolecules are present in numerous plants but also in different classes of echinoderms, in particular in sea stars and sea cucumbers . Thanks to their amphiphilic property and to their broad structural diversity, saponin molecules are considered to be important candidates in the pharmaceutical and food industries as well as in agronomy .…”

“…For many years, saponin structures have been established based on a time‐consuming procedure combining individual saponin isolation and nuclear magnetic resonance (NMR) measurements . Nowadays, mass spectrometry methods are increasingly involved for their structural identification based on accurate mass measurements (high‐resolution mass spectrometry – HRMS) and collision‐induced dissociation (CID) experiments . Mass spectrometry data are almost always interpreted based on NMR results and it is important to remind here that MS alone is unable to distinguish stereoisomers.…”

Cytotoxic Activity and Secondary Metabolite Characteristics of Sea Cucumber Actinopyga sp. Methanolic Extract

“…Saponins are glycosides that consist of polycyclic aglycones, which are steroids or triterpenoids attached to one or more sugar side chains. Triterpenoid saponins consist of aglycones that are composed of 30 carbon atoms (C30), while steroid saponins consist of aglycones that are composed of 27 carbon atoms (C27) (Bahrami et al, 2014). Glycoside saponins are known as self-defense chemical in sea cucumber.…”

“…Sea cucumber was used as traditional medicine by the Chinese and Malaysian to treat hypertension and cancer (Bahrami et al, 2014;Elbandy et al, 2014;Soltani et al, 2014). Its biological activities include antioxidant, anti-microbe, and anticancer (Liu et al, 2012;Slichenko et al, 2012;Salazar et al, 2013).…”

Scabraside D Extracted from Holothuria scabra Induces Apoptosis and Inhibits Growth of Human Cholangiocarcinoma Xenografts in Mice

“…Extracts from sea cucumbers have been reported as anti-cancer agents. Many species of sea cucumber produce triterpene glycosides, a group of saponin, which are poisonous for other organisms and presumably function as a chemical defense against predation (Caulier et al, 2011;Bahrami et al, 2014). This group of substances shows various biological activities, including antifungal, cytotoxic, hemolytic, cytostatic and immunomodulatory effects (Kitagaw et al, 1989;Stonix et al, 1999;Chludil et al, 2002).…”