10(S)-hydroxy-8(E)-octadecenoic acid, an intermediate in the conversion ofoleic acid to 7,10-dihydroxy-8(E)-octadecenoic acid

The new microbial isolate Pseudomonas aeruginosa (PR3) has been reported to produce from oleic acid a new compound, 7,10-dihydroxy-8(E)-octadecenoic a cid (DOD), with 10-hydroxy-8-octadecenoic acid (HOD) being a probable inter mediate. The production of DOD involves the introduction of two hydroxyl gr oups at carbon numbers 7 and 10, and a rearrangement of the double bond fro m carbons 9-10 to 8-9. It has been shown that the 8-9 unsaturation of HOD w as possibly in the cis configuration. Now we report that the rearranged dou ble bond of HOD is trans rather than cis, as determined by spectral data. A lso, it was found that the 10-hydroxyl was in the S-con figuration as deter mined by gas chromatographic separation of R- and S-isomers after preparati on of the (-)-menthoxycarbonyl derivative of the hydroxyl group followed by oxidative cleavage of the double bond and methyl esterification. This latt er result coincides with our recent finding that the main final product, DD D, is in the 7(S),10(S)-dihydroxy configuration. In addition, a minor isome r of HOD (about 3 %) with the 10(R)-hydroxyl configuration was also detecte d. From the data obtained herein, we concluded that 10(S)-hydroxy-8(E)-octa decenoic acid is the probable intermediate in the bioconversion of oleic ac id to 7(S),10(S)-dihydroxy-8(E)-octadecenoic acid by PR3.