Study On The Interaction Between Four Active Components Of Chinese Herb And Human Serum Album By High-performance Affinity Chromatography

The interaction of drugs and protein in blood can influence drug transportation, distribution, metabolism, and excretion. In addition, the direct or indirect competition between two or more drugs for the same binding proteins has been know as a source of drug-drug interaction, which can possibly affect the disposition of several drugs, and result in many physiological consequences. Therefore, the study of drug-protein is of great significance. Human serum albumin(HSA) and a1-acid glycoprotein(AGP) are the most important plasma proteins to act as drug carrier, and often used to study the binding information for drug. In this text, high-performance affinity chromatography was used to investigate the binding of four drugs to immobilized HSA column by frontal analysis and zonal elution experiments under the condition of pH of 7.4 and temperature of 37℃,that is regarded as physical condition.The obtained conclusion are1. HSA was immobilized onto the aminopropyl silica under a mild condition. The HSA column was proved to bond on the surface of silica with chiral compound as a test.2. Frontal analysis was performed to determine the adsorptive capacity of four drugs paeonol, ferulic acid, chlorogenic acid and vanillic acid on HSA column. The experiment data were analysed by using one-site model, two-site model and double-reciprocal frontal analysis plot respectively. The results showed that only one major binding site on HSA molecular was provided for the interaction of paeonol, ferulic acid and vanillic acid with HSA, but chlorogenic acid gave a better fit to the two-site model, it indicated that chlorogenic acid had more than one binding site on HSA.3. Competition studies based on zonal elution between paeonol, ferulic acid, chlorogenic acid, vanillic acid and four probe compounds were carried out to investigate binding sites of the four drugs on HSA. The four probe compounds used in competition studies were warfarin, L-tryptophan, clomiphene, digitoxin, which have been known to interact with several major and minor sites on HSA respectively. Paeonol, ferulic acid, chlorogenic acid, vanillic acid were found to have direct competition with L-tryptophan, indicating that the four drugs interacted with sudlow site II (the indole-benzodiazepine site) on HSA. However, the competition experiment of digitoxin with chlorogenic acid, vanillic acid as a mobile phase additive showed that the zonal elution plot of 1/k (digitoxin) vs. [chlorogenic acid] and [vanillic acid] possessed good linear relation with a negative slop. But, it had been proved that the allosteric effects between chlorogenic acid, vanillic acid and digitoxin. were not occurring. Therefore, depth analysis and studies should be carried on to look for the reasons.