Microbial Glycosylation of Daidzein, Genistein and Biochanin A: Two New Glucosides of Biochanin A

Abstract

Biotransformation of daidzein, genistein and biochanin A by three selected filamentous fungi was investigated. As a result of biotransformations, six glycosylation products were obtained. Fungus <i>Beauveria bassiana</i> converted all tested isoflavones to 4″-<i>O</i>-methyl-7-<i>O</i>-glucosyl derivatives, whereas <i>Absidia coerulea</i> and <i>Absidia glauca</i> were able to transform genistein and biochanin A to genistin and sissotrin, respectively. In the culture of <i>Absidia coerulea</i>, in addition to the sissotrin, the product of glucosylation at position 5 was formed. Two of the obtained compounds have not been published so far: 4″-<i>O</i>-methyl-7-<i>O</i>-glucosyl biochanin A and 5-<i>O-</i>glucosyl biochanin A (isosissotrin). Biotransformation products were obtained with 22%-40% isolated yield.