DOI: https://doi.org/10.55373/mjchem.v26i1.265

Keywords: Piperaceae; Piper ornatum; constituent; flavonoid; amide

Abstract

Plants of the genus Piper have long been used as medicinal herbs. The chemistry of Piper species has been widely investigated, and phytochemicals investigations led to the isolation of a number of physiologically active compounds. This study was carried out to investigate the phyto-chemicals isolated from the leaf and stem extracts of Piper ornatum. Cold extraction of the dried powdered leaf and stem was employed to extract the phytochemicals according to the polarity gradient of hexane, ethyl acetate, and methanol. The phytochemicals were obtained using chromatography techniques (column chromatography and prep-TLC) and their structures were confirmed by spectroscopic analysis (IR, NMR and MS) and comparison with literature. The isolation was successfully led to the identification of 5,7-dimethoxyflavone (1), 4',7-dihydroxy-3',5',5-trimethoxyflavone (2), 4'-hydroxy-3',5',5,7-tetramethoxyflavone (5) and 3',4',5,5',7-pentamethoxyflavone (6), together with piperine (3) and β-sitosterol (4). Compounds (2) and (3) showed significant activity towards DPPH radical scavenging (concentration 1,000 μg/mL) with percentage inhibition of 47.5% and 41.5%, respectively. This study may provide valuable and useful information and indications for further exploring the potential nutraceutical and pharmaceutical applications of the Piper species.