Isolation and Identification of Antioxidant and α-glucosidase Inhibitor Compound from Prospective Extract of Acacia Bark from Indonesia

Abstract

Tropical forests in Indonesia have a great diversity of plants. Among those species, Acacia is a plant that is widely found in Indonesia. The utilization of Acacia in Indonesia increases the amount of bark waste in the harvesting process. The aim of the research was to obtain prospective extracts the bark of A. mangium, A. auriculiformis, and A. crassicarpa based on antioxidant activity, α-glucosidase inhibition assay, and to identify compound in the prospective extract. In this research, the methods used to determine antioxidant were used 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), antioxidant Ferric Reducing power (FRAP), and assays for the total levels of phenolic compounds and flavonoids in each extract. To determine antidiabetic, a test was carried out by examining the α-glucosidase inhibition of the α-glucosidase enzyme from Sachamyce cerevisiae. Then the prospective extracts were identified using Liquid Chromatography-Mass Spectrometry (LC-MS) and Nuclear Magnetic Resonance (NMR) (1H and 13C). Based on the test results, Acacia mangium methanol extract showed the best activity for testing. Separation and further purification of A. mangium extract obtained sub-fraction 6 (isolate 1) which was identified as scopoletin and shows the α-glucosidase inhibition at 96,84%. Based on the results of this research, A. mangium has the potential as a source of medicinal ingredients, and it is suggested to conduct further research to isolate other active compounds.