Anti-HIV-1 Constituents from Leaves and Twigs of Cratoxylum arborescens

Abstract

Two new xanthones, 1,3,8-trihydroxy-2,4-dimethoxyxanthone (1) and 1,7-dihydroxy-2,8-dimethoxyxanthone (2), along with twelve known compounds 3 - 14 were isolated from leaves and twigs of Cratoxylum arborescens. Compound 1, euxanthone (4), betulinic acid (8), lup-20(29)-ene-3β,30-diol (9), 3β-hydroxylup-20(29)-en-30-oic acid (10) and 3,4-dihydroxybenzoic acid (11) displayed anti-HIV-1 activities in the syncytium assay using ^{Δ Tat/Rev}MC99 virus and the 1A2 cell line system (EC₅₀ values between 3.9 and 32.2 μg/mL with TI ranging from 1.5 to 11.7), while 1,3,7-trihydroxy-6-methoxy-4,5-diisoprenylxanthone (3), 4, and 8 - 10 inhibited HIV-1 reverse transcriptase with IC₅₀ values between 8.7 and 84.9 μg/mL.