Lignans and other constituents from the roots of the Vietnamese medicinal plant Pseuderanthemum palatiferum.

Two new lignans, palatiferin A (1) and palatiferin B (2), were isolated from the roots of Pseuderanthemum palatiferum, together with five known triterpenes, epifriedelanol (3), lupeol (4), lupenone (5), betulin (6), pomolic acid (7), and a dipeptide asperglaucide (8). Their structures were established from 2D NMR and mass spectroscopy. The absolute configuration of 1 and 2 was proposed based on the comparison of their optical rotation activities with those of compounds with similar structures such as wodeshiol and paulownin. The new lignans, palatiferin A (1) and palatiferin B (2) exhibited a moderate cytotoxicity against KB and HepG2 cell lines. However, betulin and lupeol, two abundant compounds from the roots of P. palatiferum, showed cytotoxic and antimicrobial activities.

Chemical constituents and biological activities of the fruits of Knema pachycarpa de Wilde.

The n-hexane extract of Knema pachycarpa fruits (Myristicaceae family), exhibiting strong anti-acetylcholinesterase activity, was investigated by gas chromatography/mass spectrometry and then purified by column chromatography. Guided by GC/MS profiling and bioassay, chromatographic separations led to the isolation of five new compounds: two anacardic acid derivatives 1-2, two cardanol derivatives 3-4 and a cardol derivative 5, along with mixtures of known phenolic lipids 6-9. The chemical structures were determined by various spectroscopic methods. New isolated compounds 1-5 were evaluated for their cytotoxicity and anti-acetylcholinesterase activity. Cardanol 3 and cardol 5 were the most active compounds in the acetylcholinesterase inhibitory assay with IC50 values of 2.60 ± 0.24 µM and 2.46 ± 0.23 µM, respectively. Cardanol 4 and cardol 5 showed moderate cytotoxicity against Hela and MCF-7 cancer cell lines with IC50 values ranging from 31.36 ± 0.41 µM to 41.30 ± 2.49 µM.