In vitro α- glucosidase inhibitory and antioxidant activities of extract, fractions and isolated compounds from Tetracera macrophylla vall leaf

Opeyemi Roheem, Fatimah and Mat So'ad, Siti Zaiton and Ahmed, Qamar Uddin and Latip, Jalifah and Alhassan, Muhammad (2017) In vitro α- glucosidase inhibitory and antioxidant activities of extract, fractions and isolated compounds from Tetracera macrophylla vall leaf. In: University Kebangsaan Malaysia-Universiti Riau, Indonesia-Universitas Islam Indonesia-Prince of Songkla University, Thailand Joint Seminar 2017 (UKM-UR-UII-PSU Joint Seminar 2017), 20th-22nd November 2017, Bangi, Selangor. (Unpublished)

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Abstract

Tetracera macrophylla vall. (Dilleniaceae), has been a neglected species from Tetracera genus despite its usefulness in the traditional herbal medicines. T. macrophylla leaves crude ethanol (95%) extract (ETM) and its different fractions obtained through liquid-liquid partitioning strategy were screened for their total phenolics and flavonoids contents and then investigated using in vitro models for their inhibitory activity on α-glucosidase. Free radical scavenging techniques including 2, 2diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-3-ethylbenzothiazine-6-sulfonic acid (ABTS) were used to examine the antioxidant capacity. ETM was found to be rich in both phenolic and flavonoid contents (417.90 ± 20.16, 5.86 ± 0.51 µg gallic acid (GA) and quercetin (QU) equivalent/mg dry weight) and exhibited good radical scavenging activity on DPPH and ABTS radicals ( 78.00% and 79.0%, respectively). Ethyl acetate fraction exhibited highest phenolic and flavonoid contents (206.34 ± 4.86, 14.01± 1.20 µg GA and QU equivalent/mg dry weight, respectively), and it was also observed to exhibit highest scavenging capacity on DPPH and ABTS radicals viz., 96.73%, 76.51% respectively. Both ETM and ethyl acetate fraction showed a promising and concentration-dependent α-glucosidase inhibitory activity. Bioassay guided silica gel column chromatography purification of ethyl-acetate fraction afforded a triterpenoid (12 mg), and a flavonoid (10 mg) characterized as betullinic acid and 5,7-dihydroxy-8-methoxy flavone based on spectroscopic analysis (IR, NMR). These compounds displayed promising radical scavenging activity against DPPH and ABTS radicals with moderate inhibitory activity on α-glucosidase enzymes.

Item Type:	Conference or Workshop Item (Slide Presentation)
Additional Information:	5652/61450
Uncontrolled Keywords:	Tetracera macrophylla, DPPH, ABTS, α-glucosidase, triterpenoid, flavonoid
Subjects:	Q Science > Q Science (General) Q Science > QD Chemistry
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Pharmacy > Department of Pharmaceutical Chemistry
Depositing User:	Dr Qamar Uddin Ahmed
Date Deposited:	18 Jan 2018 09:17
Last Modified:	18 Jan 2018 09:17
URI:	http://irep.iium.edu.my/id/eprint/61450

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