Caracterização fitoquímica da Pfaffia glomerata (Spreng)

Abstract

Pfaffia glomerata (Spreng) Pedersen, popularly known as Brazilian Ginseng, is a native plant of Brazil with recognized therapeutic value, being used in the pharmaceutical and food industries. Despite its economic and medicinal potential, the absence of a specific monograph in the Brazilian Pharmacopoeia results in the lack of standardization for its quality control, compromising the safety and efficacy of its products and generating a commercial paradox in which Brazil exports the raw material and imports the finished product. Its biological effects are associated with the presence of compounds such as saponins, ecdysteroids (β-ecdysone), phenolic compounds and flavonoids. The main objective of this study was to evaluate the physicochemical quality of P. glomerata rhizomes and to investigate the efficiency of different solvents in the extraction of its bioactive compounds. Two samples of rhizomes and four extracting solvents (methanol, 70% ethanol (v/v), water and ethanol) were used. The methodology included physical-chemical tests (pH, density, moisture, total ash), qualitative phytochemical screening and spectrophotometric analyses to quantify total phenolic compounds, total flavonoids and antioxidant activity by the DPPH radical scavenging method. The results showed that the storage conditions of the raw material and the choice of the extracting solvent directly influence the levels of bioactive compounds. The sample that was in a better state of preservation (granulated) exhibited higher concentrations of metabolites. Phytochemical screening confirmed the marked presence of saponins (foam index = 500) in both samples, indicated by the high foam index. The 70% (v/v) ethanol solution was the most effective in extracting total phenolic compounds and demonstrated the highest antioxidant activity (444.76 ± 0.018 µmol ET L⁻¹), closely followed by ultra-pure water (439.04 ± 0.018 µmol ET L⁻¹). Statistical analysis (ANOVA and Tukey's test, p < 0.05) confirmed that 70% ethanol and water were significantly superior to 100% methanol and 100% ethanol for the extraction of compounds with antioxidant activity. The study concludes that standardization of post-harvest processing, including drying and storage, is essential to preserve the chemical integrity of P. glomerata. Ethanol 70% (v/v) proved to be the most efficient solvent for the extraction of phenolic compounds with antioxidant activity from the rhizomes. The results of this study reinforce the importance of selecting the type of plant sample and the extracting solvent in obtaining bioactive compounds, as well as the methodological standardization for the quality control of products derived from P. glomerata.