Enzymatic deglycosylation of isoflavones
and polydatin by ULTRAFLOâL and NOVOZYMâ 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.
ULTRAFLOâ L and NOVOZYMâ 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.
ULTRAFLOâ 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.
NOVOZYMâ 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...