Auroside, a Xylosyl-sterol, and Patusterol A and B, two Hydroxylated Sterols, from two Soft Corals Eleutherobia aurea and Lobophytum patulum

A new sterol glycoside, auroside (1) and two new hydroxylated sterols, patusterol A and B (2, 3) have been isolated from the South African soft coral Eleutherobia aurea and from the Kenyan soft coral Lobophytum patulum. The structure elucidation was achieved from extensive 1D- and 2D- NMR and MS data, and in the case of auroside also by chemical reactions. In addition, from Lobophytum patulum, was also isolated a known nitrogen containing compound (Z)-N-[2-(4-hydroxyphenyl)ethyl]-3-methyldodec-2-enamide, and from Eleutherobia aurea several, earlier reported, diterpenoids. Compound 2 was found to be toxic to brine shrimp embryos with an LC50 value of 2.30 μM.

Forbeside E: a novel sulfated sterol glycoside from Asteriasforbesi

The structure of forbeside E, a minor constituent of the saponin fraction of the starfish Asteriasforbesi, has been identified as the disodium salt of (20R)-5α-pregn-9(11)ene-3β-sulfo-oxy-6α-[O-β-D-4-sulfo-oxyquinovopyranosyl]-20-ol, principally by 2D-COSY, DQ COSY, HCORR, and DEPT experiments. Sodium thornasterol-3-O-sulfate has been isolated as a natural product from the same organism. Keywords: sulfated sterol glycoside, Asteriasforbesi metabolites, sodium thomasterol-3-O-sulfate, asterogenol rearrangement.