title: Determination of active components in rhubarb and study of their hydrophobicity by micellar electrokinetic chromatography.
abstract: A micellar electrokinetic chromatographic (MEKC) method has been developed for the determination of five anthraquinones and one distyrene derivative in rhubarb. The separation conditions were optimized and two kinds of rhubarb plants and rhubarb-containing medicines were analyzed. The negatively charged solutes migrated toward the anode and were retarded by their interaction with the micelle. Hydrophobicity of the solutes was studied by both MEKC with SDS and SDS-free capillary zone electrophoresis in the buffer of 15 mmol/L NaH(2)PO(4)+ 20 mmol/L borax and 15% ethanol (v/v). Linear correlation between log k' and log P(OW) was obtained for the five anthraquinones in SDS micelle system. The capacity factor, k', and free energy differences delta(deltaG) derived from this method provided fundamental information on the interaction between the solutes and the micelle.
authors.affiliation: Department of Chemistry, Graduate School of the University of Science and Technology of China, Academia Sinica, Beijing 100039, PR China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Shang
authors.forename: Zhuobin
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D000880:Anthraquinones / Q000032:analysis / Q000302:isolation & purification; D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods* / Q000592:standards; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D010936:Plant Extracts / Q000032:analysis*; D012250:Rheum / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate; D013329:Structure-Activity Relationship; D013343:Styrenes / Q000032:analysis / Q000302:isolation & purification; D013816:Thermodynamics
chemical_list: D000880:Anthraquinones; D010936:Plant Extracts; D013343:Styrenes; D012967:Sodium Dodecyl Sulfate