Methyl 13-D- and 13-L-hydroxydocosanoates have been synthesized from 9-D- and 9-L-hydroxy-octadecanoic acids. Comparison of these esters with the methyl ester of 13-hydroxydocosanoic acid, produced by Candida bogoriensis, shows that the natural product has the L-configuration. The known 2-D-octadecanol has been prepared from 17-hydroxyoctadecanoic acid, produced by Torulopsis apicola, showing that this acid also has the L-configuration. Most naturally occurring long-chain hydroxy acids, however, have the D-configuration.
When cultured in stirred fermentors the yeast Candida bogoriensis produces extracellular glycolipids in yields of 0.5 to 1 g/l. The principal component of these is a crystalline sophorosyl hydroxy fatty acid, the structure of which has been established as 13-[(2′-O-β-D-glucopyranosyl-β-D-glucopyranosyl)-oxy]docosanoic acid 6′,6″-diacetate. The hydroxy acid portion of the molecule probably has the L-configuration. A monoacetyl glycolipid is also present as a minor component.