Chalcone Isomerase Isozymes with Different Substrate Specificities towards 6′-Hydroxy- and 6′-Deoxychalcones in Cultured Cells of Glycyrrhiza echinata, a Leguminous Plant Producing 5-Deoxyflavonoids

Three chalcone isomerase isozymes in Glycyrrhiza echinata (Fabaceae) were separated by chromatofocusing and partially purified to examine their substrate specificities. Two isozymes, one of which was elicitor-inducible, acted on both 6'-hydroxychalcone and 6'-deoxychalcone and presumably are involved in the legume-specific 5-deoxyflavonoid pathway, while another acted on only 6'-hydroxychalcone.