Free sterols from the holothurians Synapta maculata, Cladolabes bifurcatusand Cucumaria sp.

Free sterol fractions from the holothurians (sea cucumbers) Synapta maculat a Cladolabes bifurcatus and Cucumaria sp. have been isolated and studied by HPLC, GLC, GLC-MS and NMR methods. Forty seven sterols were identified, in cluding several rare ones. In contrast with previously studied holothurians , the presence of a minor amount of Delta (7) sterols was indicated in the sterols of S. maculata. This animal contains predominantly Delta (9(11))ste rols as well as an abnormally high concentration of Delta (5) sterols. In C , bifurcatus and Cucumaria sp., 14 alpha -methyl and 4 alpha ,14 alpha -dim ethyl-Delta (9(11))sterols were found to be the main sterol constituents. P eculiarities of sterol distribution and the relationship between sterol com positions and taxonomic positions, ecology and toxicity of the correspondin g sea cucumbers were discussed. (C) 2001 Elsevier Science Inc. All rights r eserved.