ISOLATION OF ?-GLUCOSIDASE ENZYME INHIBITOR ACTIVE COMPOUNDS FROM ETHANOL EXTRACT OF LEMPUYANG GAJAH RHIZOME (ZINGIBER ZERUMBET (L.) ROSCOE EX SMITH)

• Main Author: Saumi Destianti, Dinda
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76535
• Institution: Institut Teknologi Bandung

Lempuyang gajah (Zingiber zerumbet (L.) Roscoe ex Smith) is a plant from Zingiberaceae family which is widely used in traditional medicine, one of which is in lowering blood glucose levels. Diabetes mellitus is a disease caused by metabolic disorders resulting in abnormalities in insulin secretion which causes glucose to not be metabolized normally in the body. There are several types of diabetes mellitus treatment, one of which is by using ?-glucosidase enzyme inhibitors. According to research, lempuyang gajah rhizome has the potential to inhibit ?-glucosidase enzyme activity due to the presence of compounds belonging to the flavonoid and sesquiterpene group. This study aims to determine the potential of the ethanol extract of the rhizome, fractions, and isolates of the lempuyang gajah rhizome in inhibiting the ?-glucosidase enzyme and to characterize the isolates that have been obtained. Lempuyang gajah rhizome simplicia was extracted using 96% ethanol and then fractionated using the liquid-liquid extraction method using n-hexane, ethyl acetate, and water. The inhibition activity test of extracts and fractions was carried out in vitro by measuring the absorbance of the samples using a microplate reader at a wavelength of 405 nm. The IC50 values obtained for the ethanol extract, n-hexane fraction, ethyl acetate fraction, water fraction, and acarbose were 444,93 ± 19,54; 616.45 ± 43.33; 44.36 ± 2.87; 2072.22 ± 67.46; and 60.75 ± 5.54 µg/mL. The ethyl acetate fraction was continued to the subfractionation method using classical column chromatography. The subfraction was then purified by using classical column chromatography and preparative thin layer chromatography to obtain three isolates. The IC50 values of isolate 1, isolate 2, and isolate 3, and acarbose were 436.89 ± 19.28; 37.53 ± 6.98; 166.3 ± 20.21, and 54.22 ± 6.71 µg/mL. Based on the results of characterization using a specific spray reagent, UVVisible spectrophotometry, and two-dimensional paper chromatography, it is known that isolates 1 and 3 are compounds of flavonoid group belonging to the flavonol subgroup and isolate 2 is a compound of flavonoid group belonging to the isoflavone subgroup.