Natural Products Society of the Philippines Poster Paper Presentation PP-22 Villaber, RAP, JVV Tongco, JG Gado, & LM Lapoot. (2013). Free Radical Scavenging Activity, Quantification of Total Phenolic and Flavonoid Contents and Phytochemical Screening of Paco [Diplazium esculentum (Retz) Sw.] Abstract. Proceedings of the 18th Annual Convention of the Natural Products Society of the Philippines. De La Salle University - Manila, December 6, 2013. ISSN: 2094-375X Free Radical Scavenging Activity, Quantification of Total Phenolic and Flavonoid Contents and Phytochemical Screening of Paco [Diplazium esculentum (Retz) Sw.] Ronald Arlet P. Villaber*, Jovale Vincent V. Tongco, Jeric G. Gado, Lloyd M. Lapoot Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Baños College, Laguna, 4031 Philippines Email: rapvillaber1990@yahoo.com Abstract Indigenous plants play a very significant role in the economic spectra of a particular area. In the Philippines, most of the people relies more on indigenous plant especially as food. Unfortunately, due to the biodiverse nature of Philippines’ plant kingdom, still many of its indigenous species are understudied, yet it is being patronized by the masses. Paco, or vegetable fern, [Diplazium esculentum (Retz.)Sw.] is an indigenous edible fern in the Philippines. The versatility of its taste makes it a good pick for Filipino salads. But still, less is known regarding to the research and development of this plant species in the Philippine setting, thus, paco [Diplazium esculentum (Retz.)Sw.] is the main subject of this study. Ethanolic and aqueous extracts of paco were subjected for phytochemical screening, free radical scavenging activity and quantification of total phenolic and flavonoid contents using standard methods to assess its potential health benefits. Results show that both extracts contain alkaloids, carbohydrates as reducing sugars, anthranol glycosides, cyanidin, hydrolysable phenols, saponins and proteins. Furthermore, ethanolic extract contains leukoanthocyanins, phytosterols and terpenes (diterpenes and triterpenes). The ethanolic and aqueous paco extracts, together with gallic acid, were also evaluated for its percent free radical scavenging activity on 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DOPH), a free radical, in 5 different concentrations in ppm (10, 50, 100, 200 and 400). Aqueous paco extract scavenge 52.9% of the radical at 400 ppm, while ethanolic extract scavenge 48.1% of the radical on the same concentration which is 28.0% and 34.6% lower than the %FRSA of gallic acid at the same concentration respectively. Lastly, for total phenolic content, results are presented as gallic acid equivalence while for total flavonoid content is quercetin equivalence. Ethanolic paco extract gives a total phenolic content of 125.60 ± 13.44 mg GAE/100g dried sample and a total flavonoid content of 110.80 ± 11.16 mg QE/100g dried sample while aqueous paco extract gives total phenolic content of 11.65 ± 0.87 mg GAE/100g dried sample and total flavonoid content of 16.21 ± 0.72 mg QE/100 g dried sample. The results may suggest that with proper utilization of solvents, paco could be a great source of phytochemicals that has potential free radical scavenging activity and other potential health benefits. Keywords: Fern, phytochemical screening, phenolics, flavonoids, antioxidant References 1. Kaur, G., H. Kaur, M. Kaur, B. Kumar, and P. Tiwari. Phytochemical Screening and Extraction: A Review. Internationale Pharmaceutica Sciencia, 2011, Vol. 1, Issue. 1 2. Croteau, R., T.M. Kutchan and N.G. Lewis. Natural Products (Secondary Metabolites). Biochemistry & Molecular Biology of Plants. Am. Soc. Plant Biologists, Rockvillle, MD, USA, 2000, 1250-1318.