title: Determination of dissociation constants of aristolochic acid I and II by capillary electrophoresis with carboxymethyl chitosan-coated capillary.
abstract: Aristolochic acid-I and aristolochic acid-II have been proved to be the main bioactive and toxic component in Aristolochia plants. As a result, the determination of their dissociation constants, which are important property parameters for weak acids, is highly desired for related pharmacological and toxicological studies. In this work, the dissociation constant values of aristolochic acid-I and aristolochic acid-II were determined by capillary electrophoresis using carboxymethyl chitosan-coated capillary, based on their electrophoretic mobilities by using nonlinear regression as well as linear regression, showing that the two models give comparable results. The data were also compared with those obtained by capillary electrophoresis with polybrene-coated capillary, and no conspicuous difference was observed. The correlation coefficients were all higher than 0.998 for both linear and nonlinear regression model. The pKa values were found to be 3.3±0.1 for aristolochic acid-I and 3.2±0.1 for aristolochic acid-II.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Fu
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Yiping
authors.initials: Y
authors.lastname: Liao
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D034341:Aristolochic Acids / Q000032:analysis* / Q000737:chemistry; D048271:Chitosan / Q000031:analogs & derivatives; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D014116:Toxicology / Q000379:methods
chemical_list: D034341:Aristolochic Acids; C514968:carboxymethyl-chitosan; D048271:Chitosan; C000228:aristolochic acid I; C042310:aristolochic acid II