in vitro Metabolism Pathway of Effective Component of Bletilla striata as Militarine in Liver Microsomes and Kinetics Char- acteristics of Enzyme-catalyzed Reactions
- VernacularTitle:白及有效成分Militarine在肝微粒体中的体外代谢途径及其酶促动力学特征
- Author:
Tao XIA
1
,
2
;
Changquan WANG
2
;
Hao CHEN
2
;
Lin ZHENG
1
;
Zipeng GONG
1
;
Yueting LI
1
;
Yongjun LI
3
;
Yong HUANG
1
;
Jie PAN
3
Author Information
1. Guizhou Provincial Key Lab of Pharmaceutics/State Key Lab of Efficacy and Utilization of Medicinal Plants，Guiyang 550004，China
2. School of Pharmacy，Guizhou Medical University，Guiyang 550004，China
3. Engineering Research Center for the Development and Application of Ethnic Medicine and TCM，Ministry of Education，Guiyang 550004，China
- Publication Type:Journal Article
- Keywords:
Bletilla striata;
Militarine;
Liver microsomes;
Metabolism pathway;
Kinetics of enzyme- catalyzed reactions
- From:
China Pharmacy
2019;30(10):1316-1320
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE： To study in vitro metabolism pathway of effective component of Bletilla striata as Militarine in liver microsomes and kinetics characteristics of enzyme-catalyzed reactions. METHODS： The in vitro incubation system of rat and human liver microsomes was established， and incubation reaction of Militarine was performed. UPLC-QTOF-MS was used to identify the structure of its metabolites in combination with UNIFI database and references. Using puerarin as internal standard， UPLC-Triple Quad-MS was used to quantitatively analyze metabolic transformation of Militarine in rat liver microsomes. The kinetic parameters （vmax， km， CLint） of Militarine enzyme-catalyzed reactions with/without reducing coenzyme Ⅱ （NADPH） were calculated by fitting the curves with GraphPad Prism 5.0 software. RESULTS： After incubation in rat and human liver microsomes， Militarine produced a chemical formula C21H29O11， which was presumed to be a metabolite of Militarine ester bond hydrolysis. The kinetic study of enzyme-catalyzed reactions showed that vmax of Militarine enzyme-catalyzed reactions with/without NADPH were 1.955， 2.129 nmol/（h·mg）； km were 8.601， 9.854 nmol/mL； CLint were 0.227 3， 0.216 1 mL/（h·mg）； there was no significant difference between with NADPH and without NADPH. CONCLUSIONS： The main metabolic pathway of Militarine in liver microsomes is the hydrolysis of C1 and C4 ester bonds. Its metabolism does not depend on the pathway of cytochrome P450 enzymes initiated by NADPH.
