Cyclic Steroid Glycosides from the Starfish Echinaster luzonicus: Structures and Immunomodulatory Activities

Abstract

Five new steroid glycosides, luzonicosides B-E (2-5), belonging to a rare structure group of marine glycosides, containing carbohydrate moieties incorporated into a macrocycle, and a related open carbohydrate chain steroid glycoside, luzonicoside F (6), were isolated from the starfish Echinaster luzonicus along with the previously known cyclic steroid glycoside luzonicoside A (1). The structures of compounds 2-6 were established by extensive NMR and ESIMS techniques as well as chemical transformations. Luzonicoside A (1) at concentrations of 0.01-0.1 μM was shown to be potent in lysosomal activity stimulation, intracellular ROS level elevation, and NO synthesis up-regulation in RAW 264.7 murine macrophages. Luzonicoside D (4) was less active in these biotests.

Achievements in the Study of Marine Low‐Molecular Weight Biologically Active Metabolites from the Vietnamese Territorial Waters as a Result of Expeditions aboard the Research Vessel ‘Akademik Oparin’ (2004–2017)

“…Luzonicoside D (164) was less active in these assays. [59] In addition, the anticancer effects of luzonicosides A (161) and D (164) against human melanoma RPMI-7951 and SK-Mel-28 line cells were investigated. These compounds suppressed in vitro melanoma cell proliferation by arrest-ing the cell cycle in the G2/M phase and inhibiting colony formation and SK-Mel-28 cell migration.…”

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

“…Immunomodulatory activity was estimated as described earlier . For this purpose, RAW 264.7 murine macrophages were plated into 96‐well microplates and incubated at 37° with 5% CO 2 for 24 h. After adhesion, cells were incubated with test compounds (0.01 – 10.0 μ m ) for another 24 h. LPS from E .…”

Ion mobility mass spectrometry of saponin ions

“…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 . Nevertheless, as for other natural products, the principal issues to the industrial/medicinal application of saponins remain their challenging purification as well as their in‐depth structural characterization.…”

“…A complete saponin characterization also represents a prerequisite to assess their structure/activity relationships. 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 .…”

“…The apolar part is constructed around a sterol or a triterpenoid base. 1,2 Those biomolecules are present in numerous plants [3][4][5][6] but also in different classes of echinoderms, in particular in sea stars [7][8][9][10][11] and sea cucumbers. [12][13][14][15][16][17] 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.…”