New acylated flavonoid glycosides from flowers of Aerva javanica.

Chromatographic purification of ethyl acetate soluble fraction of the methanolic extract of the flowers ofAerva javanicayielded three new acylated flavone glycosides: kaempferol-3-O-β-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-galactoside (1), kaempferol-3-O-β-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-(3″-E-p-coumaroyl)galactoside (2), and kaempferol-3-O-β-d-[4‴-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-(4″-E-p-coumaroyl)galactoside (3), along withp-coumaric acid (4), caffeic acid (5), gallic acid (6), eicosanyl-trans-p-coumarate (7), hexadecyl ferulate (8), and hexacosyl ferulate (9). The compounds1–9were characterized using 1D (1H,13C) and 2D NMR (HMQC, HMBC, and COSY) spectroscopy and mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) and in comparison with the reported data in the literature. Compound1showed weak inhibitory activity against enzymes, such as acetylcholinesterase, butyrylcholinesterase, and lipoxygenase with IC50values 205.1, 304.1, and 212.3 μM, respectively, whereas compounds2and3were only weakly active against the enzyme acetylcholinesterase. [ABSTRACT FROM PUBLISHER]