title: Determination of dissociation constants of pharmacologically active xanthones by capillary zone electrophoresis with diode array detection.
abstract: In this article, the dissociation constants (pKa) of 10 pharmacologically active xanthones isolated from herbal medicine Securidaca inappendiculata were determined by capillary zone electrophoresis with diode array detection. The pKa values determined by the method based on the electrophoretic mobilities (calculated from migration times) have been proved by the method based on UV absorbance calculated from the online spectra corresponding peaks. No conspicuous difference was observed between the two methods with acceptable reproducibility. Two pKa values (pKa1 and pKa2) were found for four xanthones while generally the 10 compounds possess the pKa values ranging from 6.4 to 9.2.
authors.affiliation: 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: Xiaomu
authors.initials: X
authors.lastname: Wu
authors.forename: Suxuan
authors.initials: S
authors.lastname: Gong
authors.forename: Tao
authors.initials: T
authors.lastname: Bo
authors.forename: Yiping
authors.initials: Y
authors.lastname: Liao
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D044004:Xanthones / Q000032:analysis*
chemical_list: D044004:Xanthones