[The structure activity relationship of saikosaponins and glycyrrhizin derivatives for Na+, K(+)-ATPase inhibiting action].

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 > or = CX > GL. In addition, the inhibitory effect of saikosaponin d on Na+, K(+)-ATPase was found to be non-competitive.