Chromatographic determination of optical configuration of 3-hydroxy fatty acids composing microbial surfactants

The chromatographic determination of the optical configuration of 3-hydroxy fatty acids of microbial surfactants was achieved in chiral high pressure liquid chromatography (HPLC) by injecting 3,5-dinitroaniline-derivatives of crude hydrolysates (less than 1 mg). Serrawettin W2, a surface-active cyclodepsipeptide of Serratia marcescens, was shown to contain d-3-hydroxydecanoic acid. Rubiwettin R1 and RG1, surface active glycolipid and linked fatty acids of Serratia rubidaea, were shown to contain d-3-hydroxytetradecanoic acid and d-3-hydroxydecanoic acid. The new method does not require purified sample or authentic optical isomers, and could be useful in the structural analysis of microbial lipids.