Context: HIV-1 integrase (HIV-1 IN) is a key enzyme involved in the replication cycle of the retrovirus. Any new knowledge on inhibitors of this enzyme could provide essential clues for the development of anti-HIV drugs. Objective: To evaluate anti-HIV-1

The leaf extract from M. elengi had the strongest anti-HIV-1 IN activity with an IC₅₀ value of 62.1 µg/mL. A bioassay-guided isolation of the active compounds from M. elengi leaf extract resulted in the isolation of active compounds, identified as a mixture of gallocatechin and epigallocatechin. This mixture of gallocatechin and epigallocatechin showed satisfactory anti-HIV-1 IN activity with an IC₅₀ value of 35.0 µM. A flavanol glycoside, mearnsitrin was also isolated but was inactive at a concentration of 100 µM.

Abstract4-Hydroxy-4,7-dimethyl-a-tetralone (1), 4,5-dihydroblumenol A (2), N-trans-feruloyltyramine (3), and 24-methylenelanosta-7, 9(11)-dien-3-b, 15a-diol (4) were isolated from the stem bark of Polyalthia jucunda (Piere) Finet & Gagnep (Annonaceae). All the compounds were evaluated for their effects on growth of four human tumor cell lines [ER(þ) MCF-7, ER(À) MDA-MB-23, SF 268, and NCI-H460] and of a non-tumor cell line (MRC-5). Only compound 4 exhibited a dose-dependent growth inhibitory effect against both tumor and non-tumor cell lines but with less effect on the latter. Using the TUNEL assay, it was found that the inhibitory effect of compound 4 on NCI-H460 cells was probably caused by apoptosis.

A reverse-phase high-performance liquid chromatographic method was described for the determination of proanthocyanidin A2 in Pometia pinnata leaf extracts. The method utilized a Phenominex® Luna 5u Hilic column with a mixture of 2% acetic acid and acetonitrile (step gradient elution as follows: 0-4 min, 5:95; 5-9 min, 10:90; 10-14 min, 80:20 v/v) as the mobile phase at a flow rate of 1 mL/min, and UV detection at 280 nm. The parameters of linearity, precision, accuracy, specificity and sensitivity of the method were evaluated. The extraction methods for proanthocyanidin A2 were also examined. Proanthocyanidin A2 was eluted within 7 min with a satisfactory peak resolution. The recovery of the HPLC method was 96-98% with a good linearity (r2≥ 0.9999) for proanthocyanidin A2 in the concentration range of 7.7 - 250 µg/mL. A high degree of specificity as well as repeatability and reproducibility (RSD values less than 5%) were also achieved. The limits of detection and quantification were 1.25 and 2.50 µg/mL, respectively. This eatablished specific, precise, accurate, rapid and reproducible HPLC method was successfully used to quantify the active principle, proanthocyanidin A2 in P. pinnata leaf extracts. Proanthocyanidin A2 was found to be a major constituent in the crude methanol extract of P. pinnata leaves, at 33.8 ± 0.4 mg/g dried extract. Microwave-assisted extraction (MAE) was selected as the best extraction method for proanthocyanidin A2. The optimized MAE method increased the amount of proanthocyanidin A2 extracted from the dried leaf powder up to 36.6 %w/w.

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