Enzymic Dehydrogenation of p-Coumaryl Alcohol. : III. Analysis of Dilignols by Gas Chromatography and NMR Spectrometry

Abstract

p-Coumaryl alcohol was dehydrogenated with peroxidase and H_2O_2 system. Five dilignols, p-coumarylresinol (I), dehydrodi-p-coumaryl alcohol (II), p-hydroxyphenyl-glycerol-β-coumaryl ether (III), monoepoxylignan (IV) and 5-5'-dilignol (V) were identified and determined by both gas chromatography and NMR spectrometry, and the ratio of the amounts of the three main dilignols (I, II and III) was 31 : 49 : 20. The dilignol (V) was trace in amount (0.6%), and 1, 2-diarylpropane-l, 3-diol (VI) could not be found. The ratio of the racemoid and mesoid couplings at C-β and C-β' carbons was about 9.4 : 1, and the dilignol (III) was a mixture consisting of erythro and threo isomers (1:4.7) whose ratio was determined by gas chromatography. From these results, it was concluded that coniferyl and p-coumaryl alcohols had almost the same reactivity on enzymic dehydrogenation.