Quantification of Phenolic Compounds and Determination of Antioxidant Potential in Different Medicinal Plants

The study was developed in the context of the search for bioactive compounds of interest present in medicinal plants, among them phenolic compounds, recognized for their func-tional relevance. To this end, the extraction process was optimized using soursop leaves as a model, combining different particle sizes (< 2 mm, 2–6.3 mm, and 6.3–9.5 mm), mac-eration times (12, 24, and 48 h), and ethanol:water ratios (25:75, 50:50, and 75:25), which generated 27 extracts. The optimal process corresponded to an ethanol:water ratio of 50:50, fine particle size (< 2 mm), and 24 h of maceration, reaching 584.64 mg·L⁻¹ of gallic acid equivalents (GAE). Additionally, other plant species were evaluated: horsetail, kiswara, matico, muña, and thyme. Antioxidant capacity was determined using the DPPH method through IC₅₀ val-ues, where soursop, kiswara, and muña recorded the lowest values (0.52, 0.52, and 0.61 mg·L⁻¹), even lower than ascorbic acid (19.10 mg·L⁻¹). Thyme and horsetail showed inter-mediate activity, while matico presented the lowest response. The results indicate that these species have high potential as sources of functional bioac-tive compounds, highlighting the importance of medicinal plants for the development of natural products with antioxidant properties.