Comparative Evaluation of Extraction Techniques and HPLC-Based Quantification of Luteolin from Mentha piperita Leaves

Abstract

Background: Efficient extraction of bioactive flavonoids is critical for their downstream research and industrial applications.
Objective: This work systematically investigates the influence of extraction procedures and solvent polarity on the separation of Luteolin from Mentha piperita leaves.
Methods: Dried and powdered leaves were treated to maceration, reflux, and Soxhlet extraction using solvents of increasing polarity—methanol, ethanol, chloroform, and ethyl acetate. Extract yield and Luteolin content were quantitatively evaluated by High-performance liquid chromatography (HPLC) utilising a Lichrospher C18 column and a methanol–acetic acid mobile phase.
Results: The results indicated a substantial reliance of Luteolin recovery on both the extraction process and solvent employed. Among all combinations, reflux extraction with methanol provided the highest Luteolin concentration (5.57% w/w) and purity (98.97%). In comparison, the maceration and Soxhlet techniques generated relatively lower concentrations and purity levels. In general, methanol was the most effective solvent and reflux extraction was the optimum procedure.
Conclusion: The results might be used as a robust and optimised technique for the Luteolin extraction from M. piperita, facilitating its effective utilisation in phytochemical studies and industrial applications.