| dc.description.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. | en_US |
