Kinetika Inhibisi Flavonoid Sidaguri (Sida rhombi/alia L.) Terhadap Enzim Xantin Oksidase

Abstract

Sidaguri is one of the traditional medicinal plants that has a potency as antigout. It has been reported that flavonoid from sidaguri could inhibit activity of x~hine oxidase enzyme (causes gout) up to 55,29% (Iswantini & Darusman, 200~ The aim of this research is to investigate the type of sidaguri's flavonoid crud~ extract kinetic inhibition and the effects of purification on inhibitory poterWY that have never been studied. The result of this research showed that sidagWi's extraction has yielded 11,85% flavonoid crude extract (LCso 501,23 ppm)~ith inhibitory effect from 47,71 % until 70,71% (100-800 ppm). Generally, the eSract has a good potential as gout medicine although it was tested in low conc~tration from the extract's toxicity rate. The kinetic inhibition of 200 ppm crudeDextract caused the increment ofKM (1,15 mM or increase 132%) from 0,87 roM i> 2,02 roM and without changed of V max. Based on that, the type of VI inhibinon is competitive inhibition (Webb 1963). Purification yielded 11 fracti~s and the highest activity came from fraction 4 (inhibitory effect of 79,09!'o). The purification has caused low increase of potent inhibitory effect. Fract~n 3 with 100 ppm has a bit higher inhibitory effect (51,58%) compare to the cI!oe extract at same concentration (47,71%) or increase 8,11%. In general the poten1l:linhibitory effect from purification result has lower strength compare to the 100 Ifm crude extract. GC-MS analysis from fraction 4 showed that there were 39 or..gruric compounds with BM estimation of 152-454 glmol. Based on FT-IR and GC-MS analysis, strengthened with phytochemical test we estimate that the potential compound with xanthine oxidase inhibitory activity is flavonoid compound.