The structure activity relationship of saikosaponins and glycyrrhizin derivatives for Na+, K+-ATPase inhibiting action

Abstract

The study on structure-activity relationship of saikosaponins and glycyrrhizin derivatives for Na+, K+-ATPase inhibiting action has been made in vitro. The results showed that the order of potency of inhibitory effect of saikosaponins on Na+, K+-ATPase is as follows: b1 > d > b2 > b4 > a > b3 > e > c. The chemical structure C23-OH, C16-OH and the C11, C13 conjugated double diene of saikosaponins are important for its inhibitory activity. The inhibitory potency of glycyrrhizin (GL), glycyrrhetinic acid (GA) and carbenoxolone (CX) for Na+, K+-ATPase activity is as follows : GA≥CX>GL. In addition, the inhibitory effect of saikosaponin d on Na+, K+-ATPase was found to be non-competitive.