International Congress on Biotechnology and Food Sciences
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Accepted Abstracts

Isolation, Characterization and Anti-Diabetic Potentials of Oleanolic Acid from the Leaves of Aspilia africana (Pers) C.D Adams (Asteraceae)

EC Johnson1, 2,*, M Ilyas1, OA Eseyin1, EI Etim1, AS Udobre1, AE Udoh1, EO Edem1
1 University of Uyo, Nigeria
2 Ahmadu Bello University, Nigeria


Citation: Johnson EC*,  Ilyas M, Eseyin OA, Etim EI, Udobre AS et al (2020) Isolation, Characterization and Anti-Diabetic Potentials of Oleanolic Acid from the Leaves of Aspilia africana (Pers) C.D Adams (Asteraceae). SciTech BioTech-Food Sciences 2020

Received: May 31, 2020         Accepted: June 04, 2020         Published: June 04, 2020

Abstract

The objective of this research work was to isolate the anti-diabetic principle of the leaves of Aspilia africana through bioassay guided phytochemical investigation. The methanol extract previously screened for anti-diabetic activity was partitioned successively with n-Hexane, CH2Cl2, EtOAc and n-BuOH. The butanol fraction, the only fraction that responded positively to in-vitro anti-diabetic tests (like the crude methanol extract) was treated with diethyl ether to precipitate the saponins. The crude saponin was hydrolyzed with 4M HCl and the organic part subjected to silica gel chromatography which on further purification through gel filtration and prep TLC afforded a compound which was identified using melting point determination, extensive nuclear magnetic resonance spectroscopy (1D, 2D, COSY, HMBC, HQMC), Fourier Transform- Infra-red (FT-IR) spectroscopy and basic chemical reactions. The isolated compound was identified as 2-hydroxyolean-12-en-28-oic acid or oleanolic acid. The in vitro anti-diabetic assays showed inhibition of α-amylase and α-glucosidase with the following IC50: in α-amylase assay: crude methanol 96.40±0.2 mg/mL, butanol fraction 72.50±0.65 mg/mL, isolated compound 25.45±0.45 μg/mL, compared to the reference drug (acarbose) 46.31±0.58 μg/mL; in the α-glucosidase assay crude methanol 95.10±0.20 mg/mL, butanol fraction 72.65±3.20 mg/mL, isolated compound 47.57±0.40 μg/mL, compared to the reference drug (acarbose), 48.10±0.13 μg/mL. Based on these findings the compound responsible for the anti-diabetic activity of Aspilia africana is 2-hydroxyolean-12-en-28-oic acid.