Dialysis sampling on-line coupled with high-performance liquid chromatography for simultaneous investigation of the interactions between multi-components in herbs and the albumin.

An on-line dialysis sampling method coupled with high-performance liquid chromatography was developed for simultaneous investigation of the interactions between multiple bioactive compounds contained in herbal medicines and proteins. The system was used to estimate the interactions of components in danshen (Salvia miltiorrhiza) injection with bovine serum albumin. The results showed that the binding actions of five water-soluble compounds in danshen injection could be simultaneously investigated. The binding parameters of caffeic acid, ferulic acid, danshensu, protocatechuic acid and protocatechuic aldehyde were obtained and the interaction mechanisms were explored. The association constant evaluated for caffeic acid agreed well with literature values. The proposed approach should be beneficial for examining the holistic combined action of herbal medicine with proteins and help facilitate the discovery process of drug candidates.