Preparation of baicalein using thermophilic and sugar-tolerant beta-glucosidase.
- Author:
Shi-ping LI
;
Jian-hui WEN
;
Yi-wu ZHAO
;
Wen-zhe HUANG
;
Jian-jun PEI
;
Zhen-zhong WANG
;
Lin-guo ZHAO
;
Wei XIAO
- Publication Type:Journal Article
- MeSH:
Biocatalysis;
Enzyme Stability;
Flavanones;
chemistry;
Flavonoids;
chemistry;
Glucose;
chemistry;
Hot Temperature;
Hydrolysis;
Kinetics;
beta-Glucosidase;
chemistry
- From:
China Journal of Chinese Materia Medica
2015;40(23):4616-4622
- CountryChina
- Language:Chinese
-
Abstract:
The reaction conditions of baicalin hydrolyzed into baicalein by a kind of thermophilic and sugar-tolerant beta-glucosidase were studied in this paper. The beta-glucosidase could catalyze baicalin into baicalein well in the acetic acid-sodium acetate buffer. The optimal enzyme activity was at 85 degrees C and pH 5.5. The enzyme was stable at the temperature less than 85 degrees C and pH range of 5-7.5. The maximum reaction rate V. and michaelis constant K. were 0.41 mmol x L(-1) x min(-1) and 3.31 mmol x L(-1) respectively. Different metal ions had different effects on the activity of enzyme. Na+ existing in acetic acid-sodium acetate buffer had an activation effect on enzyme. The enzyme activity was enhanced by the concentrations of glucose below 0.6 mol x L(-1), and was gradually inhibited when monosaccharide concentration was over 0.6 mol x L(-1). When the monosaccharide concentration reached 1.2 mol x L(-1), the inhibition rate of enzyme activity was about 50%, which showed good glucose tolerance. The good reaction conditions through the experiment have been determined as follows, the substrate: enzyme dose was 1 g: 0.2 mL, acetic acid-sodium acetate buffer pH 5.5, reaction temperature 85 degrees C, reaction time 10 h, and the enzymatic hydrolyzation ratio could reach 97%.
