ISOLATION OF THE ACTIVE COMPOUNDS OF SYZYGIUM JAMBOS (L.) ALSTON) LEAVES AND INHIBITORY ACTIVITIES OF ?-GLUCOSIDASE ENZYME

• Main Author: Meilani, Lani
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/62929
• Institution: Institut Teknologi Bandung

Background and purpose: Diabetes mellitus (DM) is a disease that causes the biggest death in Indonesia and even in the world. Management of DM is very important, especially type 2 DM, which can be done by inhibiting the postprandial intestinal ?-glucosidase enzyme limiting glucose levels by delaying the process of carbohydrate hydrolysis and glucose absorption so that it can control blood sugar levels. Synthetic drugs that inhibit the ?-glucosidase enzyme cause some side effects, therefore other alternatives are needed to treat diabetes, one of which is herbal treatment from plants. Several species of the genus Syzygium including Syzygium cumini and Syzygium syzygioides have been known to have ?-glucosidase inhibitory activity, but research on the ?-glucosidase activity of Syzygium jambos is still very limited. Several studies have shown Syzygium jambos has various activities such as antimicrobial, antioxidant, hepatoprotective and cytotoxic. Therefore, the purpose of this study was to test the activity of S. jambos leaves against ?-glucosidase inhibition and isolate the active compound. Methods: Extraction was carried out by maceration method using 96% ethanol. Fractionation, subfractionation and isolation were carried out by liquid-liquid extraction, liquid-vacuum chromatography, classical column chromatography, medium pressure liquid chromatography (MPLC) and radial chromatography with a guided activity test against ?-glucosidase inhibition. The purity test was carried out using TLC with three mobile phases with different polarities, two-dimensional TLC and densitometric TLC. Characterization and identification of isolates were carried out using ultraviolet, infrared, mass and NMR spectroscopy ( 1 H and 13 C). The activity test for the ?-glucosidase enzyme was carried out by measuring the absorbance of the test sample using a microplate reader. Results: S. jambos leaf extract and fraction had inhibitory activity against ?-glucosidase enzyme with IC50 extract 1.22 + 0.03 µg/ml and n-hexane, ethyl acetate and water fractions yielded IC50 41.53 + 0.56; 0.31 + 0.01 dan 1.21 + 0.08 µg/ml. Subfraction KCV no 15 of the ethyl acetate fraction, had the highest percentage inhibition of 43.78 + 10% at a concentration of 8 µg/ml. Two compounds were obtained from the purification results namely isolates A and B which had IC50 65.63 + 1.36 and 188.96 + 2.85 ppm. The identification results showed that isolate A was quercetin 3-O-xylosyl(1 ? 2)-rhamnoside (C26H28O15) and isolate B was myricetin 3-O-xylosyl-(1 ? 2)- rhamnoside (C26H28O16). Conclusion: The compound that was isolated from the leaves (S. jambos) with a guide to the inhibition of the ?-glucosidase enzyme was a flavonoid compound of the flavonol type, namely quercetin 3-O-xylosyl-(1 ? 2)- rhamnoside (C26H28O15) with IC50 65.63 + 1.36 ppm and myrisetin 3-O-xylosyl(1 ? 2)-rhamnoside (C26H28O16) with IC50 188.96 + 2.85 ppm.