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Antioxidant and α-Glucosidase Inhibitory Activities of Isolated Compounds from Ipomoea aquatica

Umar Lawal, Khozirah Shaari, Intan Safinar Ismail, Alfi Khatib and Faridah Abas

Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

Laboratory of Natural Products, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, International Islamic University Malaysia, 25200 Kuantan, Malaysia

Abstract:Ipomoea aquatica Forsk is a green leafy vegetable that is a rich source of amino acids and vitamins. Antioxidant and α-glucosidase inhibitory activities of the hexane (IAHE) and methanol (IAME) fractions of the vegetable portion of I. aquatica were investigated. The IAME fraction exhibited a strong scavenging effect of the 2,2-diphenyl-2-picryl hydrazyl (DPPH) free radicals, and this fraction contained the highest phenolic contents. Phytochemical investigation of the IAME fraction yielded three known compounds, namely 3,5-di-O-caffeoylquinic acid (1), 4,5-di-O-caffeoylquinic acid (2) and quercetin 3-O-β-D-glucoside (3). The structures were unambiguously elucidated based on 1D and 2D-NMR analyses (1H, 13C, COSY, HSQC, HMBC) and mass spectrometry data. Compound 3 was isolated for the first time from this plant.

 Keywords: Antioxidant activity; total phenolic content; α-glucosidase inhibition, spectral analysis . © 2016 ACG Publications. All rights reserved.