Light-Induced Trans to Cis Conversion of β-d-Glucosyl o-Hydroxycinnamic Acid in Melilotus alba Leaves

Abstract

The indicated conversion was studied in steamed and unsteamed leaflets of sweetclover (Melilotus alba) of the CuCuBB genotype, in aqueous leaf extracts, and in aqueous solutions of the 2 glucosides. Ultraviolet light (peak near 360 m[mu]), cool white fluorescent lamps, and variously filtered sunlight were used as sources of illumination. Results of the experiments support the conclusion that in sweetclover leaves this conversion is a nonenzymic photochemical reaction effected by light of wavelengths shorter than 360 m[mu].