IDENTIFIKASI SERTA UJI AKTIVITAS ANTIBAKTERI SENYAWA FLAVONOID EKSTRAK DAUN SRIKAYA (Annona squamosa Linn)

Abstract

One of the plants containing flavonoid compounds, commonly used as traditional medicine in Indonesia, is srikaya (Annona squamosa Linn). Isolation, identification and antibacterial activity test of flavonoid compounds from srikaya leaf extract against Staphylococcus aureus and Escherichia coli by using diffusion well method have been done in this research. Srikaya leaf powder with 8% moisture content was macerated with methanol then evaporated until concentrated extract of 113.85 grams was obtained. The extract was partitioned with n-hexane, ethyl acetate and n-butanol solvents and produced 3.43 grams of n-hexane extract, 2.30 grams of ethyl acetate extract and 3.85 grams of n-butanol extract. The phytochemical test showed that the ethyl acetate extract positively contained flavonoids with the highest total flavonoid levels of 26,117.4 mg QE/100 grams. Isolate F5, as the result of separation and purification of ethyl acetate extract, was positive containing flavonoids and resulting relatively pure isolate, analyzed by thin layer chromatography. Identification of isolate F5 using spectrophotometer UV-Visible and Fourier-Transform Infrared (FTIR) showed two absorption bands at ? max of 376.40 nm (band I) and 256.40 nm (band II) as well as contained functional groups of flavonoid which was OH, C=C aromatic, C-H aliphatic, C-H aromatic, C-O ether and C-O alcohol. These isolates were able to inhibit the growth of Staphylococcus aureus and Escherichia coli at the concentration of 15% (w/v) with inhibitory diameter of 7.75 and 7.25 mm, respectively. These results indicated that flavonoids isolated from srikaya leaf extract were suspected 5,3’,4’-trihydroxyflavonol and had antibacterial activity with moderate inhibitory ability. Keywords: antibacterial, flavonoid isolation, srikaya leaf (Annona squamosa Linn),5,3’,4'-trihydroxyflavonol.