Enzymatic deglycosylation of isoflavones and polydatin by ULTRAFLO TM L and NOVOZYM TM188L into Genistein, Daidzein and Resveratrol

Enzymatic deglycosylation of isoflavones and polydatin by ULTRAFLO^âL and NOVOZYM^â 188L into Genistein, Daidzein and Resveratrol

Abstract

Isoflavones are naturally present in soybean and other leguminous plants and reported to have an effect against cancer, as well as other health benefits. The aglycone forms of isoflavones are better absorbed by animals and human beings.

ULTRAFLO^â L and NOVOZYM^â 188 L, two commercial enzyme preparations from NOVOZYMES A/S, Krogshoejvej 36, DK-2880 Bagsvaerd, Denmark, can deglycosylate isoflavone and resveratrol glucoside into the respective aglycones at a high efficiency under gentle conditions.

ULTRAFLO^â L is a heat-stable multi-active beta-glucanase preparation obtained from a strain of Humicola insolens. The most important activities are beta-glucosidase,cellulase, xylanase, pentosanase and arabanase.

NOVOZYM^â 188 L is obtained by submerged fermentation of a strain of Aspergillus niger and contains cellobiase (beta-1,4-glucosidase) activity.

Cellobiase polypeptides described in PCT patent application no. PCT/DK/0200325 filed on May 17, 2002 and claiming priority of DK patent application 2001 00798 of May 18, 2001, are also capable of deglycosylating the compounds described herein. One example of such polypeptide is the cellobiase derived from Aspergillus oryzae strain IFO4177.

Background

Glycoside is a kind of secondary metabolism product of plant (herb) material linked with sugar group, such as glucose and glucuronide. The type of sugar and its position can play an important role in its biological function. For some glycosides, partly or totally removing sugars (deglycosylation) will improve its biological activity or change its physical, chemical or active properties completely.

Isoflavonoids are natural products found in soybeans and leguminous plants and are currently under intensive study regarding their application to cancer prevention and other potential health benefits. Isoflavones absorption in the form of aglycones has been found to increase availability of isoflavones in the blood stream. This suggests that ingestion of aglycones can increase the availability of the isoflavones compared with glycosides.

Resveratrol is a phenolic compound which has been reported to reduce the risk of coronary heart disease, cancer and other degenerative disorders such as Alzeimer’s disease or dementia. Resveratrol exists in grapes and wine, but the quantity is very small. Piceid, the glucosides of� resveratrol, is the bio-active component of the polygonum cuspidatum root, used in traditional Chinese medicine. Resveratrol can be commercially produced by deglycosylating piceid.

The method for deglycosylation include acid hydrolyzing, enzymatic hydrolyzing and microbial fermentation. Compare with acid method, enzyme and microbial reactions are more selective hydrolysis, and they are taken under more gentle conditions and give higher yield of the transformation. Microbial method is often used in the fermentat...