Glycosidic Conjugates of C13 Norisoprenoids, Monoterpenoids, and Cucurbates in Boronia megastigma (Nees)

Analysis of a methanolic extract of marc from Boronia megastigma (Nees) using LC-MS (APCI, nominal mass)provided strong evidence for the presence of both glycosides and malonyl glycosides of methyl cucurbates, C13 norisoprenoids including megastigmanes, and monoterpene alcohols. Subsequent fractionation of an extract from the marc using XAD-2 and LH 20 chromatography followed by LC-UV/MS-SPE-NMR and accurate mass LC-MS resulted in the isolation and identification of (1R,4R,5R)-3,3,5-trimethyl-4-[(1E)-3-oxobut-1-en-1-yl]cyclohexyl â-D-glucopyranoside (3-hydroxy-5,6-dihydro-â-ionone-â-Dglucopyranoside); 3,7-dimethylocta-1,5-diene-3,7-diol-3-O-â-D-glucopyranoside; and a methyl {(1R)-3-(â-D-glucopyranosyloxy)- 2-[(2Z)-pent-2-en-1-yl]cyclopentyl}acetate stereoisomer (a methyl cucurbate-â-D-glucopyranoside); and provided evidence for 3,7-dimethylocta-1,5-diene-3,7-diol-3-O-(60-O-malonyl)-â-D-glucopyranoside in boronia flowers.