Emission of 2-phenylethanol from its β-D-glucopyranoside and the biogenesis of these compounds from[2H8] L-phenylalanine in rose flowers

The hydrolysis of 2-phenylethyl beta-D-glucopyranoside (3) was found to be partially inhibited by feeding with 2-phenyl-N-glucosyl-acetamidiumbromide (8), a beta-glucosidase inhibitor, resulting in a decrease in the diurnal emission of 2-phenylethanol (2) from Rosa damascena Mill. flowers. Detection of [1,1,2,2',3,4',5',6'-H-2(8)]-2 and [1,2,2',3,4,5',6'-H-2(7)]-2 from R. 'Hoh-Jun' flowers fed with [1,1,2,2',3',4',5',6'-H-2(8)]-3 suggested that beta-glucosidase, alcohol dehydrogenase, and reductase might be involved in scent emission. Comprehensive GC-SIM analyses revealed that [1,2,2,2',3',4',5',6'-H-2(8)]-2 and [1,2,2,2',3',4',5',6'-H-2(8)]-3 must be biosynthesized from [1,2,2,2',3',4',5'6'-H-2(8)] L-phenylalanine ([H-2(8)]-1) with a retention of the deuterium atom at alpha-position of [H-2(8)]-1. (C) 2004 Elsevier Ltd. All rights reserved.