ALPHA GLUCOSIDASE INHIBITORY ACTIVITY FROM SOME PARTS OF GYMNANTHEMUM AMYGDALINUM (DELILE) SCH. BIP. AND ISOLATION OF ITS BIOACTIVE COMPOUNDS

• Main Author: Vonia, Sheppriola
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/54341
• Institution: Institut Teknologi Bandung

Background and purposes: Diabetes mellitus is becoming one of the biggest health problems in the 21 st century. Maintaining postprandial glucose level by inhibiting alpha glucosidase activity becomes one of the good strategies in diabetes treatment. Traditionally, G. amygdalinum is used for diabetes treatment. The purposes of this study was to determine inhibition activity of alpha glucosidase of roots, stem barks, leaves and flowers of G. amygdalinum, to isolate the active compound and determine the bioactive compound level in extract and fraction. Methods: the inhibition activity of alpha glucosidase was determined by Microplate Reader, using acarbose as the positive control. The separation and purification of the bioactive compound were done by column chromatography. Results: Four extracts inhibited alpha glucosidase. IC50 value of flower methanol extract and ethyl acetate fraction are 47,29 ± 1,12 µg/mL and 19,24 ± 0,12 µg/mL. IC50 value of acarbose is 73,36 ± 3,05 µg/mL. Isolated compound was isolated from ethyl acetate fraction. Based on UV spectrum 1 H NMR and 13 C NMR isolated compound B1 is proposed as 3’,4’,5,6 tetrahydroxy flavone or luteolin. Meanwhile, based on UV spectrum, 1 H NMR, 13 C NMR and HSQC NMR, isolated compound B2 is proposed as 3-o-methyl quercetin. Luteolin and 3-o-methyl quercetin have inhibition activity of alpha glucosidase with IC50 value is 6,53 ± 0,16 µg/mL and 39,95 ± 1,59 µg/mL, respectively. Determination of luteolin level showed G. amygdalinum flower has 32,4 ± 0,8 mg (3,2%) luteolin in 1 g extract and 68,9 ± 3,37 mg (6,9%) luteolin in 1 g ethyl acetate fraction. Conclusion: G. amygdalinum flower has the highest inhibiting activity of alpha glucosidase than root, stem bark and leaf. In vitro study showed extract, fraction and isolated compound had higher inhibition activity of alpha glucosidase than acarbose as positive control. Luteolin and 3-o-methyl quercetin are bioactive compound in G. amygdalinum flower inhibiting activity of alpha glucosidase.