Identification of a cytochrome P450 cDNA encoding (2S)‐flavanone 2‐hydroxylase of licorice (Glycyrrhiza echinata L.; Fabaceae) which represents licodione synthase and flavone synthase II1

The microsome of insect cells expressing CYP Ge-5 (CYP93B1), a cytochrome P450 cDNA of licorice (Glycyrrhiza echinata L.), catalyzed the formation of 14Clicodione and 14C2-hydroxynaringenin from (2S)-14Cliquiritigenin and (2S)-14Cnaringenin, respectively. On acid treatment, the products were converted to 14C-labeled 7,4'-dihydroxyflavone and apigenin. Eriodictyol was also converted to luteolin by the reaction with the microsome of yeast expressing CYP93B1 and subsequent acid treatment. CYP93B1 was thus shown to encode (2S)-flavanone 2-hydroxylase, which has previously been designated to licodione synthase and flavone synthase II depending on the substrates employed.