Bioassay-guided Fractionation of the Anti-diabetic Constituents of Star Apple Leaves

Abstract

Background and Objectives: The Philippines is one of the world's emerging diabetes hotspots. In 2014, there were 3.2 million Filipinos diagnosed with diabetes. By 2030, incidence is projected to increase by up to 7.8 million. This study aimed to determine the potential α-glucosidase inhibiting activity of the fractions of the ethanolic extract obtained from Chyrsophyllum cainito L. leaves.

Methodology: The research employed thin layer chromatography (TLC) and flash column chromatography techniques for the fractionation, and α-glucosidase inhibition test for the assessment of the activity.

Results and Conclusion: TLC optimization resulted to 15:65:10:10 hexane, ethyl acetate, methanol, and acetic acid as the mobile phase, with silica gel GF254 as the stationary phase. The plates were viewed under white light, UV (254 & 366 nm), and vanillin-sulfuric acid spray. Three different pools of fractions based on TLC Rf values were collected from the flash column chromatography using a gradient mix of hexane, ethyl acetate, methanol, and acetic acid with a flow rate of 3.9 mL per minute. These fractions exhibited higher percent inhibition than Quercetin standard at 30, 70, and 150 μg/mL, with Fraction 2 having the highest activity, followed by Fraction 1, then Fraction 3. Phytochemical tests suggest the presence of Anthraquinone glycosides on the three pooled fractions.