GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC STUDIESOF LONG CHAIN HYDROXY ACIDS .I. CONSTITUENT CUTIN ACIDS OF APPLE CUTICLE

The constituent cutin acids of apple cuticle have been determined by preparative TLC of the methyl esters followed by combined gas chromatography-mass spectrometry of the TMSi ethers of the methyl esters. This method may be applied to small amounts of cutin and has allowed the detection of a variety of hitherto unreported cutin acids. The principle cutina cids are 10,16-dihydroxyhexadecanoic acid, threo and erythro-9, 10,18-trihydroxyoctadecanoic, 16-hydroxyhexadecanoic, 18-hydroxyoctadec-9-enoic and 18-hydroxyoctadeca-9,12-dienoic. The location of the double bonds in the unsaturated compounds was determined by a novel method involving hydroxylation followed by GC-MS of the trimethylsilyl ethers of the resulting vic-dihydroxy compounds. © 1968.