Protein binding study of catechin hydrate and genistein by high-performance frontal analysis

Abstract

High-performance frontal analysis (HPFA) was used for the protein binding study of catechin hydrate and genistein to human serum albumin (HSA). The experiment was performed on a Develosil 100Diol-5 column, and sodium phosphate buffer (pH 7.4 and ionic strength of 0.17) was used as the mobile phase. The mixtures of the drug-HSA solution were directly injected into the HPFA column, the HSA was eluted first and the unbound drugs were eluted out as a trapezoidal peak with a plateau region. The unbound drug concentration was determined from a plateau height of the plateau region and the experimental data were fitted by Scatchard equation. The binding constants (K) and binding affinities (nK) of the drug to HAS were K=1.32×104 (L mol−1), nK=0.47×104 (L mol−1) for catechin hydrate, and K=5.17×104 (L mol−1), nK=2.14×104 (L mol−1) for genistein.