Cyclooxygenase-2 inhibitory compounds from the leaves of glycosmis pentaphylla (Retz.) A. DC. Chemical and in silico studies

Glycosmis pentaphylla is traditionally used for treating many diseases in Bangladesh. Anti-inflammatory and analgesic effects of Glycosmis pentaphylla have been reported prominently but no bioactive element has been identified so far. In order to explore its analgesic and anti-inflammatory compound(s), phytochemical analysis was conducted. Nine compounds were isolated from the methanol extract of leaves of Glycosmis pentaphylla whose structures were solved as arborinine (1), vanillic acid (2), 3-hydroxy-4-methoxybenzoic acid (3), benzoic acid (4), p-hydroxybenzoic acid (5), stigmasterol (6), β-amyrin (7), phytol (8) and 3α,16α-dihydroxyolean-12-ene (9) by spectroscopic studies, including high field ¹H NMR analyses as well as co-TLC with authentic samples whenever possible. Among these, compounds 3 and 9 are the first report of their occurrence from G. pentaphylla. in silico docking studies of these metabolites with cyclooxygenase (COX)-2, an enzyme responsible for producing prostaglandins, were conducted. It was found that only arborinine and phytol can bind in the active site of COX-2, which might be considered as the major responsible moieties to cause analgesic and anti-inflammatory activities.