10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 1 2013 (January - March) Antioxidant effects of the Petroleum ether extracts of the leaves of lessThan i greaterThan Calotrois procera lessThan /i greaterThan were tested on the basis of scavenging activity of the free radical DPPH (1, 1-diphenyl-2-picryl-hydrazyl), reducing power and inhibition of nitric oxide radical . The Petroleum Ether extracts of lessThan i greaterThan C .procera lessThan /i greaterThan showed the highest antioxidant activity and the activity of the extract increased with increasing concentration. The total phenolic content of the leaf extract was found to be 38.23 µg pyrocatechol equivalents. Qualitative determination of 10 polyphenols (Gallic acid, 3,4 Dihy droxy B-acid, Epi_GC Gallate, p-Coumaric acid, Ellagic acid, Quercetin, Apigenin, Hesperitin, Luteoline, Kaempherol) was made using UPLC . M. REMYA,R. ANANTHAN AND SUBHA SIVASANKAR Antioxidant activity, Calotropis procera, DPPH scavenging, reducing power, Inhibition of Nitric oxide radical, UPLC 920-926