LC-ESI MS/MS profiling of polar steroid metabolites of the Far Eastern starfish Patiria (=Asterina) pectinifera

Abstract

Profiling of asterosaponins, polyhydroxysteroids and glycosides of polyhydroxysteroids of the common in the Far Eastern sea waters starfish Patiria (=Asterina) pectinifera was performed by LC-ESI MS and LC-APPI MS. The 72 polar steroid metabolites, including 35 asterosaponins, 22 polyhydroxysteroids and 15 sulfated glycosides of polyhydroxysteroids, were detected and identified using the LC–MS and LC–MS/MS spectra. The steroid metabolome of P. pectinifera is characterized by large number of sulfated and non-sulfated highly oxidized compounds with cholestane, ergostane and stigmastane skeleton systems of aglycones. Some peculiarities of biosynthesis of the starfish polar steroids were discussed. It was suggested that biosynthesis of asterosaponins from diet sterols is executed in a mosaic type manner with transformations in aglycone moieties and elongation of carbohydrate chains proceeding independently from each other and simultaneously.