HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC ANALYSIS OF ISOFLAVONES AGLYCONE IN INDONESIAN SOYBEAN

Soybean is one of the highest isoflavones source. Isoflavones are one type of phytoestrogen that have a chemical structure similar to estradiol, that’s why it can be used not only to inhibite but also to prevent many symptoms related deficiency of estrogen. However in the small intestine, isoflavones like genistin will be hydrolyzed by β-glucosidase and produce aglycone like genistein, this process can be optimized by hydrolysis with enzyme or chemical. The aim of this study was to obtain the extract of soybean that hydrolysed by hydrochloric acid and to obtain scientific data about the content of genistein in the extract by High Performance Liquid Chromatography (HPLC). Analysis of samples by HPLC using C18 reverse phased column. Genistein standard with a concentration 8 ppm, 10 ppm, 12 ppm respectively diluted with methanol: water (8:2) as much as 5 ml. Soybean extract, weighed as much as 3 mg and dissolved in 10 ml of methanol: water (8: 2). Standard and sample then analyzed with the mobile phase used was methanol: water (7:3), a flow rate of 1 ml/min with a temperature of 28 °C, at a wavelength of 254 nm. From the results, show that average of genistein levels contained in the extract of soybean hydrolyzed for Glycine max is 0.5% and Glycine soja is 1.1%.