Natural Glycosides Containing Allopyranose from the Passion Fruit Plant and Circular Dichroism of Benzaldehyde Cyanohydrin Glycosides1

Leaves of the edible passion fruit plant, Passiflora edulis, contain benzylic β-d-allopyranosides 1 and 2, representatives of a rare class of natural glycosides with d-allose as the only sugar constituent. The glycoside 1 is the first known cyanogenic glycoside containing a sugar different from d-glucose attached directly to the cyanohydrin center. Asymmetric perturbation of the 1Lb transition of the benzene chromophore was shown to be useful for determination of absolute configuration of the cyanohydrin center of aromatic cyanogenic glycosides.