Isolasi dan Identifikasi Golongan Senyawa Flavonoida dari Buah Tumbuhan Arbei (Rubus Rosifolius Sm)

Abstract

Isolation and identification of flavonoid coumpounds from Arbei fruit (Rubus rosifolius Sm) have been made through the maceration extraction step whit methanol solvent. The concentrated methanol extract was reextracted using ethyl acetate was concentrated until it was negatife for FeCl3 5%. The ethyl acetate extract was separated and redissolved whit methanol and the partitioned whith n-heksane until the n-heksane layer was clear. Concentrated methanol extract then analyzed TlC, then separated by column chromatography whit silica gel as a stationary phase and chloroform: ethyl asetate (90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, 10:90) v/v as the mobile phase. The coumpounds obtained from fraction 65-125 was purifed using preparative thin layer chromatography whit chlorofom:ethyl asetate (30:30) v/v as the eluent to obtain was brick red amorphous solid, weight 6,5 mg. The isolate amourphous solids then analyzed TLC whit eluent chlorofom:ethyl asetate (30:30) v/v Rf value 0,57 and eluent acetone:benzene (50:50) v/v Rf value 0,68. Based on the UV-Vis spectrophotometer, it shows that there are two absorption (ʎmaks) of 378 nm and 256 nm. FT-IR spectrum showed the presence of OH stretch, C-H stretch, C=O keton, C=C aromatic, C-H bend, O-H bend, C-O-C stretch asymmetrical, C-O-C stretch symmetrical,C-H bend out of plane dan O-H in plane successively at wave number 3427,51 cm-1, 2922,16 cm-1 , 1608,63 cm-1, 1460,11 cm-1 and 1406,11 cm-1, 1319,3 cm-1,1382,96 cm-1, 1267,23 cm-1-1203,58 cm-1, 1016,49 cm-1, 869,90-794,67 cm-1 and 723,31 cm-1. 1H-NMR spectrum showed the presence of H-6, H-8, H-5', H- 2', H-6', CH2 from 3'-OCH2CH3, and CH3 from 3'-OCH3CH3. Based on the data obtained it shows that the isolated compound are flavonoid of the flavonols group.