First isolation of geranyl disaccharides from ginger and their relations to aroma formation.

Abstract Three geraniol glycosides were isolated from immature fresh ginger rhizomes (Zingiber officinale Roscoe). Their structures were identified as geranyl 6-O-α-L-arabinopyranosyl-β-D-glucopyranoside (1), geranyl 6-O-β-D-apiofuranosyl-β-D-glucopyranoside (2) and geranyl 6-O-β-D-xylopyranosyl-β-D-glucopyranoside (3) by spectrometric analyses. After incubating each glycoside with a crude enzyme solution prepared from ginger, geraniol was liberated in all of those fractions. This result indicates that the glycosides are related to the formation of geraniol-related compounds in ginger aroma.