Isolasi dan Identifikasi Golongan Senyawa Flavonoida dari Kulit Batang Jeruk Bali Putih (Citrus Grandis L Osbeck)

Abstract

The flavonoid compounds had been from the bark of the white Bali orange plant (Citrus grandis L. Osbeck). Isolation was carried out by maceration extraction mrthod with mrthanol and methanol extract was re-extracted with ethyl acetate repetedly until nrgative to FeCl3 5%. The concentrated ethyl acetate extract was dissolved in methanol and partitioned with n-hexane. The methanol layer was evaporated until all methanol was removed. The concentrated methanol extract was analyzed by TLC, then separated by column chromatography with silica gel as the stationary phase and n-hexane:ethyl acetate (90:10, 80:20, 70:30, 60:40) v/v as the mobile phase. The pure compound obtained was in the form of an amorphous yellow solid, mass = 4 mg with Rf = 0.6 using eluent chloroform:ethyl acetate (80:20) v/v. Based on UV-Vis spectroscopic analysis with methanol solvent, two absorption peaks with wavelengths (λmax) of 310 nm and 273 nm were observed. The FT-IR spectrum showed the presence of O-H, C-H sp3, C=O ketones, C=C aromatic, C-H, C-O, and C-O-C groups, sequentially at wave numbers 3439.09; 2926.01; 1724.36; 1411.89; 1039.63; 1126.43 cm-1. Proton Nuclear Magnetic Resonance Spectrum (1H-NMR) indicated the existence of H-3, H-3' & H-5' and H-2' & H-6' protons. Spectroscopic data indicated that the isolated compound belonged to the flavone group.