Comparative binding affinities of flavonoid phytochemicals with bovine serum albumin

Dietary flavonoids show beneficial effects in the prevention of chronic diseases. However, flavonoid bioavailability is poor, probably due to their interaction with serum albumins. In the current work, the binding interactions of eight related flavonoids, sharing a similar core structure, with bovine serum albumin [BSA] were investigated by fluorescence spectroscopy. The binding affinities of the flavonoids with BSA were in the order hesperetin [KA=5.59 × 10[5]] > quercetin [4.94 × 10[5]] > naringenin [3.04 × 10[5]] > isoquercitrin [4.66 × 10[4]] > icariin [3.60 × 10[4]] > rutin [1.65 × 10[4]] > hesperidin [2.50 × 10[3]] > naringin [8.70 × 10[2]]. The associations of specific structural components of the flavonoids with their binding properties to BSA were also explored and hydrophobicity, functional group substituents, steric hindrance effects and the spatial arrangements of substituents seem to be the key factors for the affinities of flavonoids towards BSA. The results from the current work contribute to a better understanding of the transport of flavonoids in plasma and helping predict their physiological functions based on their intrinsic structures

Microorganisms of special herb-glycosidases and their fermentation, enzyme properties / 生物工程学报

Herb-glycosides are main active elements of Zhongcaoyao (Chinese traditional medicines, Chinese medical herbs). However, the herb-glycoside structures are not optimal active structure for the human bodies. After orally taken up, the herb-glycosides of Zhongcaoyao could be changed into other more active structures by the digestive system such as enzymes and intestinal microorganisms; then degraded and absorbed in the human body and play the real role of pharmic effect; but only a small amount could be changed and controlled by circadian state of the human body. If this biochange of herb-glycosides to more active structures in vivo was finished in vitro, it is very useful for the development of the Chinese traditional medicines, new plant medicines, health food, and function cosmetics. To biotransformate herb-glycosides to more active structure, this paper introduced the studies of author's team on the new microorganism isolation of the special herb-glycosidases and enzyme fermentation, the special enzyme purification and characterization.