@article{Jothy_Saito_Kanwar_Kavitha_Herng_Chen_Yin-Hui_Sasidharan_2017, title={Bioassay-Guided Isolation and Antioxidant Evaluation of Rutin from Leaf of <i>Polyalthia longifolia </i>}, volume={5}, url={https://ajouronline.com/index.php/AJAS/article/view/4246}, abstractNote={&lt;p&gt;Medicinal plants are sources of antioxidant compounds that have been reported to protect the human body from the adverse effects of free radicals. Therefore, the present study was intended to identify the DPPH (2, 2-diphenyl-1-picrylhydrazyl) free-radical scavenging constituent from the methanol extract of Polyalthia longifolia leaf using bioassay-guided fractionation. On the basis of DPPH radical scavenging assay-guided isolation, the leaf extract of P. longifolia was separated by employing a solvent partition of methanol leaf extract followed by Medium Pressure Liquid Chromatography (MPLC) and High-Performance Liquid Chromatography (HPLC) fractionation. The ethyl acetate fraction (EtOAc) revealed a strong antioxidant activity, compared to other fractions through in vitro DPPH radical-scavenging assay. The repeated fractionation of active EtOAc by MPLC separation and elution procedure yielded a sub-fraction EtOAc_F007 with strong antioxidant potential. The results indicated that the ethyl acetate sub-fraction EtOAc_F007 has noticeable effects on DPPH radical compared with other sub fractions. The sub fraction EtOAc_F007 was further purified using a preparative HPLC system. Subsequent Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) analysis of the purified constituent from sub-fraction EtOAc-F007 led to the identification of rutin as the antioxidant agent in P. longifolia leaf extract. The results obtained suggested that extracts from P. longifolia leaf have potential use as a bioactive source of natural antioxidants by contributing valuable health effects.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;}, number={1}, journal={Asian Journal of Applied Sciences}, author={Jothy, Subramanion Lachumy and Saito, Tamio and Kanwar, Jagat Rakesh and Kavitha, Subramaniam and Herng, Leow Chiuan and Chen, Yeng and Yin-Hui, Leong and Sasidharan, Sreenivasan}, year={2017}, month={Feb.} }