Soxhlet Extraction and Quantification of Gallic Acid and Quercetin from Moringa oleifera Leaves by HPLC

Abstract

Moringa oleifera is a nutritionally and medicinally important plant widely recognized for its rich phytochemical composition, particularly phenolic acids and flavonoids. The present study aimed to evaluate extraction efficiency and quantify major antioxidant markers, gallic acid and quercetin, in methanolic and aqueous leaf extracts. Soxhlet extraction was carried out using methanol and distilled water, and both solvents yielded measurable extractable fractions. The total phenolic content (TPC), determined using the Folin–Ciocalteu method, was higher in the methanolic extract compared to the aqueous extract. Similarly, the total flavonoid content (TFC), measured by the aluminum chloride assay, was also greater in the methanolic extract than in the aqueous extract. High-Performance Liquid Chromatography (HPLC) analysis confirmed the presence of gallic acid and quercetin in both extracts. The methanolic extract exhibited higher concentrations of these compounds compared to the aqueous extract. Retention times showed close agreement with standard references, confirming chromatographic accuracy and specificity. Overall, the findings demonstrate that methanolic extraction is more efficient than aqueous extraction for isolating phenolic and flavonoid compounds from Moringa oleifera leaves. These results highlight the strong antioxidant potential of Moringa oleifera, supporting its application in nutraceutical, herbal, and pharmaceutical formulations.