RESUMO
Objective To investigate the diterpenes from the stem bark of Euphorbia neriifolia L. and their anti-HIV-1 activity. Methods The chemical constituents were isolated and purified by column chromatography over silica gel, ODS, MCI CHP-20P, Sephadex LH-20, and preparative HPLC. Their structures were identified by the analysis of their physicochemical properties and the spectral data of NMR and MS. The anti-HIV-1 activity of the compounds was tested by cell detection models established by HIV-1 NL4-3 infected MT-4 cells. Results Nine compounds were isolated from the stem bark of the plant, namely 12α-acetoxy- 3β,7α-dihydroxy-8α-methoxyingol (1), 3β,8α,12α-triacetoxy-7α-benzoyloxyingol (2), 3β,8α,12α-triacetoxy-7α-tigloyloxyingol (3), ent-3-oxoatis-16α,17-acetonide (4), 13β-hydroxy-3,15-dioxoatis-16-ene (5), ent-3β,(13S)-dihydroxyatis-16-en-14-one (6), atis-16- en-14-oxo-3β,13(S)-diol (7), ent-(13S),18-dihydroxyatis-16-ene-3,14-dione (8), 4,13β-dihydroxy-14-oxo-3,4-secoatis-16-en-3-oic acid methyl ester (9). Conclusion Compound 1 is a new natural product. Compounds 2-4, and 6-8 are isolated from the plant for the first time. Furthermore, compound 4 exhibited moderate anti-HIV-1 activities, with EC50 values of 8.7 μg/mL (SI = 1.92).