High-Performance Thin Layer Chromatography-Effect-Directed Analysis (Hptlc-Eda) of the a-Amylase and a-Glucosidase Inhibitory Activities of Moringa Oleifera Lam. Extracts

Date of Award

5-1-2023

Document Type

Thesis

Degree Name

Master of Science in Chemistry

First Advisor

Fabian M. Dayrit, PhD

Abstract

Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia which can cause the pancreas to malfunction, resulting in insufficient insulin or insulin resistance. The most common form of this disease is type 2 diabetes mellitus (T2DM). T2DM is the result of both insulin resistance and inadequate or impaired insulin secretion of the ß-cells. It is a complex disease for which effective cures are still needed.

Moringa oleifera Lam. has been extensively studied for its antidiabetic property. Although extracts from various parts of M. oleifera have been studied using various antidiabetes assays, the active compounds from the potent extracts have not yet been identified due to the complexity of the extracts and the disease.

In this study, HPTLC-EDA was used to determine the α-amylase and α- glucosidase inhibitory properties of the leaves, petioles, bark, and inner stems of M.oleifera solvent extracts. Components from the extracts which may be active were determined by gas chromatography-mass spectrometry (GC-MS). Results from the α- glucosidase assay show active bands (white bands against violet background) from crude methanol and ethanol extracts and their corresponding fractions: hexane, ethyl acetate, and chloroform of all parts of the plant. The detected compounds from the active zones were: β-sitosterol, n-pentyl acetate, bornyl acetate, n-hexadecane, 2-methylnonadecane, 2-methyleicosane, 2-methyltricosane, n-octadecane, 7-n- hexyleicosane, n-pentadecane, 2-methyloctadecane, n-octacosane, n-nonadecane, n- dotriacontane, n-eicosane, 7-butyldocosane, 11-(1-ethylpropyl)heneicosane. Alkanes are not typically associated with antidiabetic properties, thus, pure compounds known to be present in M. oleifera were also evaluated against α-glucosidase. Pure and combinations of n-docosane, n-eicosane, n-pentadecane, and n-tetracosane also showed activity against the enzyme.

On the other hand, no inhibition was observed against α-amylase from all extracts although M. oleifera extracts were expected to have inhibition based on previous studies. Possible reasons would be due to ineffective compounds present in the separations, and low concentration of active components in the zones to inhibit the enzyme.

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