Aglobo, Jastine S. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2015-05)
The crude ethanolic extract of Dalanghita (Citrus nobilis) was studied for their antibacterial activity, antioxidant and phytochemical properties. The DPPH free radical scavenging assay of extracts with varying concentrations showed strong antioxidant activity with a maximum % inhibition of 92.30 at 80.70 ug/mL concentration. The IC50 was calculated to be 26.26 pg/mL against 12.48 ug/mL for Ascorbic acid, the positive control. The antibacterial activity of the extract was determined against Escherichia coli and Staphylococcus aureus by measuring the mean zones of inhibition using the paper disc diffusion assay at different concentration of crude ethanolic extract. The crude ethanol extract at 100% concentration yielded the highest inhibition for E. coli at 21.50±0.50 mm which is comparable to tetracycline, the positive control. The presence of phytochemicals in the extract were evaluated and the phytochemicals identified were: alkaloids, flavonoids, saponins, steroids, tannins, and terpenes.
