Abstract
Procyanidins and catechins were found in high amounts in the methanol extract of the bark of the mangrove tree Xylocarpus granatum. The procyanidins showed a consistent structural pattern with catechin as the starter and epicatechin as the extender units. Four limonoids with a tetranortriterpenoid structure, previously identified in X. granatum, were isolated as well. Catechins, procyanidins, limonoids and plant extracts were evaluated for DPPH radical scavenging and 15-lipoxygenase (15-LO) inhibiting effects. Catechins and procyanidins demonstrated high activity, and the procyanidin of the pentamer type was found to be most potent (IC50; DPPH: 3.3 ± 0.3 μM, 15-LO: 9 ± 1 μM). Extracts were also found to have antibacterial activity.
