Flavonoids from Acacia pennata and their Cyclooxygenase (COX-1 and COX-2) Inhibitory Activities

Abstract

Two new flavonoids quercetin 4′-O-α-L-rhamnopyranosyl-3-O-ß-D-allopyranoside (1) and apigenin 6-C-[2′′-O-(E)-feruloyl-β-D-glucopyranosyl]-8-C-β-glucopyranoside (2), along with the known isorhamnetin 3-O-α-L-rhamnopyranoside (3), kaempferol 3-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside (4), and isovitexin (5) were isolated from the leaves of Acacia pennata Willd. (Mimosaceae) and tested for their anti-inflammatory activity. Their structures were determined by 1D and 2D NMR and mass spectrometry. They were tested for an inhibitory effect on COX-1 and COX-2, showing 60 - 90 % inhibition at 10 ^{- 4} g/mL and 5 - 14 % inhibition at 10 ^{- 4} g/mL, respectively.