Innovating Botanical Extraction through Application of Microwaves for the Efficient Extraction of Ursolic Acid from Ocimum sanctum Leaves

The present work is based on the optimization of a microwave based technique for the extraction of a potent bioactive compound ursolic acid from the leaves of Ocimum sanctum, popularly known as "Tulsi". Different extraction parameters namely, microwave power, extraction time, aqueous methanol composition and preleaching time were optimized in an organized manner using a scientific microwave extractor. Ursolic acid was quantified using HPTLC. The following optimum conditions for the maximum yield of ursolic evolved after the systematic optimization study: 40% (320 W) microwave power, 6 min extraction time (two cycles), 90% v/v methanol as the extraction solvent, 10 min preleaching time and 25: 1 ml/gm as the loading ratio. A detailed comparison of the proposed technique with convention methods revealed that microwave assisted extraction (MAE) has significantly higher degree of precision and reproducibility thus making it a perfect model for complete automization. Recovery study of target analytes also ensured thermal safety.