Inhibitory effects on HIV-1 protease of tri-p-coumaroylspermidine from Artemisia caruifolia and related amides

From a methanol extract of Artemisia caruifolia, which showed a moderate inhibitory activity on HIV-1 protease in a preliminary screening, N-1,N-5,N-10-tri-p-coumaroylspermidine and three dicaffeoylquinic acids were isolated. The former compound was found to appreciably inhibit HIV-1 protease. Of related amides which were chemically synthesized, N-1,N-5,N-10,N-14-tetra-p-coumaroylspermine and N-1,N-4,N-7,N-10,N-13-penta-p-coumaroyltetraethylenepentamine inhibited HIV-1 protease more potently than N-1,N-5,N-10-tri-p-coumaroylspermidine.