STRUCTURAL MODIFICATIONS OF 4,4'-DIMETHYL STEROLS DURING THE HYDROGENATION OF EDIBLE VEGETABLE-OILS

The structural changes induced by the hydrogenation of dietary vegetab le oils affect not only fatty acids but sterolic components too, espec ially C-24-methylene and C-24-ethylidene sterols. The main alterations found in the triterpene alcohols involve 24-methylene-cycloartenol an d, to a lesser extent, cycloartenol. Of the three potential hydrogenat ion-induced reactions to affect these compounds, i.e. hydrogenation of the double ethylene bonds, the opening of the cyclopropane ring and t he isomerization of the double bonds in the side chain, the latter is predominant. Cyclobranol and cyclosadol from 24-methylene cycloartanol and 9beta,19-cyclo-5alpha-lanost-25-en-3beta-ol from cycloartenol acc ount for most of the structural isomers formed.