Inhibitory effects of Cordia spinescens extracts and their constituents on reverse transcriptase and protease from human immunodeficiency virus

By bioactive‐guided fractionation of a water extract of Cordia spinescens, magnesium lithospermate (1), calcium rosmarinate (2) and magnesium rosmarinate (3) were isolated as potent inhibitory substances against HIV‐1 reverse transcriptase (RT) with IC50 values of 0.8, 5.8 and 3.1 μM, respectively. However, they were weak HIV‐1 protease (PR) inhibitors with IC50>100 μM. The RT inhibition by these compounds was noncompetitive with respect to dTTP substrate. © 1997 John Wiley & Sons, Ltd.