Phytochemical Characterization of <i>Pouteria guianensis</i>: Optimized Flavonoid Extraction and HPLC Method Validation

Plant biodiversity of Brazil offers significant potential for the development of phytotherapeutics, highlighting the <i>Pouteria</i> spp. genus. Despite traditional use and ethnopharmacological support, <i>Pouteria</i> species remain underexplored in scientific literature. This study aims to explore the flavonoids class, by optimizing flavonoid extraction from <i>Pouteria guianensis</i> (Aubl.) leaves through response surface methodology and by developing and validating a high-performance liquid chromatography (HPLC) method. Parameters reported in the literature as important for the extraction of this genus were optimized using parametric statistical analysis. Extraction optimization was achieved evaluating key parameters, including extraction time (5,10 and 15 min), drug-to-solvent ratio (1:5, 1:10 and 1:15), temperature (20, 30 and 40 °C), and the number of extraction cycles (1, 2 and 3). The developed HPLC method was validated using myricitrin as the primary analytical marker and quercetin was chosen as external standard for quantitative purposes. Temperature was found to play a pivotal role in metabolite extraction from the plant raw material and the optimized condition consisted of two extraction cycles, each lasting 8 min, at 21 °C, with a drug-to-solvent ratio of 1:8. The optimized <i>P. guianensis</i> extract (10 mg/mL) was analyzed by HPLC using methanol as the diluent, with quercetin (29.5 μg/mL) as an external marker. The myricitrin content in the plant was determined to be 2.96 mg/g (0.30%). This study provides the first detailed characterization of a chemical marker for the <i>P. guianensis</i> species using an optimized extraction process that can be useful for other species of the genus in the future.