Qualitative confirmation of flavonoids in Moringa oleifera leaf extract and evaluation of antioxidant potential

Abstract

Background: Moringa oleifera Lam. leaves are widely recognized as a medicinal plant and a high-nutrition source, with their biological activities supported by the content of phytochemical compounds. The Flavonoid group is the main class of polyphenol compounds known to confer potent antioxidant activity. Objective: This study aimed to verify the qualitative presence of flavonoids in the Moringa oleifera leaf extract and evaluate the associated free-radical scavenging capacity. Methods: Bioactive compounds were extracted using a suitable polar solvent, specifically 96% ethanol. The qualitative test for Flavonoids was performed using the Shinoda method, which employs Magnesium powder (Mg) and concentrated Hydrochloric Acid (HCI) as reagents. A positive result is confirmed by a characteristic color change (e.g., orange, red, or magenta) in the solution, indicating the reduction of the flavonoid's benzopyrone nucleus. Subsequently, the extract's antioxidant activity was qualitatively evaluated in vitro using the DPPH spot test method. Results: The qualitative screening showed a clear positive reaction for the Flavonoid group, characterized by the expected color change after the addition of Mg and HCl reagents. The confirmed presence of flavonoids correlates directly with the antioxidant evaluation, which demonstrated a strong radical scavenging ability by the extract. Conclusion: The Moringa oleifera leaf extract is qualitatively proven to contain flavonoids. These findings provide scientific validation that flavonoids are significant contributors to the plant's notable antioxidant potential, supporting its development as a natural nutraceutical source.

Keywords

• Moringa oleifera
• flavonoids
• antioxidant
• shinoda test
• qualitative screening