Isolasi dan Identifikasi Golongan Senyawa Flavonoida dari Kulit Batang Eukaliptus (Eucalyptus grandis W. Hill ex Maiden)

Abstract

The isolation and identification of flavonoid compounds obtained from the bark of eucalyptus tree (Eucalyptus grandis W. Hill ex Maiden) was carried out using several methods, namely maceration extraction with methanol as the solvent, partition extraction with ethyl acetate and n-hexane, yielding an ethyl acetate extract. The concentrated ethyl acetate extract was then analyzed using Thin Layer Chromatography (TLC) and subsequently separated by column chromatography using a stationary phase of silica gel and n-hexane : ethyl acetate (90:10; 80:20; 70:30; 60:40; 50:50; 40:60; 30:70; 20:80; 10:90) v /v as the mobile phase. Fraction three were purified using preparative TLC with chloroform : ethyl acetate (40:60) v /v as the mobile phase. The isolated compound was a 4 mg brown amorphous solid with an Rf value of 0.48 using chloroform:ethyl acetate (40:60) v /v as the eluent. Furthermore, UV-Visible spectrophotometric analysis showed two absorption bands, the first at 315 nm and the second at 257 nm. Analysis with the Infrared spectrophotometric (FT-IR) an O–H functional group with an stretching vibration at a wavenumber 3408.22 cm⁻¹, C=O ketone with an stretching at a wavenumber 1689.64 cm⁻¹, and C–O–C symmetric stretching at 1029.99 cm⁻¹. The ¹H-NMR spectrum, a characteristic proton signal for H-2 at δ 8.54 ppm, which is typical for isoflavone compounds. Based on the spectroscopic data, the isolated compound was identified as a flavonoid belonging to the isoflavone class.