Stereospecific hydration of unsaturated fatty acids by bacteria

Abstract

Abstract Three new 10‐hydroxy fatty acids, all optically active, have been prepared by the anaerobic microbiological hydration of a cis ‐9 double bond. Substrates that formed these new hydroxy fatty acids are linoleic, linolenic, and ricinoleic acids. The hydroxyl group has the D configuration and the methyl esters are levorotatory. Infrared, mass spectral, specific rotation and ultraviolet data on these compounds were determined. There was no migration of the unreated double bonds at C 12 and C 15 in linoleic or linolenic acids. The presence of a double bond in the 10‐hydroxy fatty acids significantly increased the optical rotation of the methyl esters. The hydratase enzyme showed unusual specificity among Δ 9 unsaturated acids. While it hydrates methylene interrupted and hydroxy unsaturated acids, it failed to hydrate either 9‐decenoic, 12,13‐epoxy‐ or 12‐keto‐ cis ‐9‐octadecenoic acids or sterculic acid.