Chemical constituents and bioactivity studies of artocarpus fulvicortex F. M. Jarret, artocarpus integer var. silvestris corner and artocarpus rigidus blume

Abstract

Investigations on the chemical constituents of A. fulvicortex, A. integer var. silvestris and A. rigidus have been carried out. All the extracts were obtained from maceration method by successive extractions using petroleum ether, dichloromethane, ethyl acetate and methanol as solvents. A total of sixteen compounds were successfully isolated; nine from A. fulvicortex, five from A. integer var. silvestris and two from A. rigidus. Purification of the extract from heartwood of A. fulvicortex led to the isolation of catechin, oxyresveratrol, lupeol-3-acetate and fridelin. 5-Hydroxy-(6:7,3':4')-di(2,2- dimethylpyrano)flavone, carpachromene, norartoarpetin, cycloartocarpesin and fridelin were isolated from the leaves of A. fulvicortex. Purification on the barks extract of A. integer var. silvestris afforded one new pyranoflavone class named as methoxycyclocommunol along with four known flavonoids, heteroflavanone A, artonin F, cudraflavone C and cyclocommunol. Recrystallisation of a fraction from the ethyl acetate barks extract of A. rigidus gave artonin E while purification of the dichloromethane extract yielded cyclorigidol. All the pure compounds except cycloartocarpesin and cyclocommunol were tested for their anti-inflammatory properties using radioimmunoassay method on human whole blood. Compounds that inhibited prostaglandin E2 (PGE2) production greater than 55% were tested in serial concentration to determine the IC50 values. Cudraflavone C exhibited the strongest inhibition toward vasoactive PGE2 with IC50 value of 0.03 µg/mL which is higher than positive control, indomethacin that gave IC50 value of 0.06 µg/mL. Catechin and oxyresveratrol showed significant values of inhibition against butyrylcholinesterase enzyme in dose dependent manner. The IC50 values of catechin and oxyresveratrol are 25.0 mM and 3.13 mM, respectively.