Estratégias de identificação e extração de bioativos de plantas da Mata Atlântica do sul da Bahia, Brasil

Abstract

This study presents sustainable strategies for the extraction and characterization of bioactive compounds from plant species remaining in the Atlantic Forest, employing High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD), Fourier-Transform Infrared Spectroscopy (FTIR), and chemometric tools. The research resulted in two complementary scientific articles, integrating the valorization of Brazilian biodiversity with the development of clean and efficient analytical methodologies. The first article, “Strategies for the Identification of Varronia curassavica in Southern Bahia, Brazil,” evaluated samples collected from three sites (P1, P2, and P3) in the municipality of Eunápolis, BA. MIR spectroscopy revealed bands indicative of phenolic, carbonyl, and aromatic groups, while chromatograms showed a predominant peak with a retention time of ~30 minutes, along with significant variations in chemical profiles among sites. Quantification indicated that P2 presented the highest total phenolic contents (708.05 ± 32.50 to 527.59 ± 20.90 μg GAE·g⁻¹) and P1 had the highest flavonoid contents (2642.50 ± 132.13 and 2574.93 ± 128.75 μg QE·g⁻¹). Principal Component Analysis (PCA) separated the samples into three distinct groups, explaining 82.2% of the total variance (PC1 = 51.3%; PC2 = 19.5%; PC3 = 11.4%). Antioxidant assays (DPPH and ABTS) highlighted sample J2S (CE₅₀ DPPH = 2.74 ± 0.08 µg/mL) and I2F (CE₅₀ ABTS = 5.43 ± 2.42 µg/mL) as having the highest antioxidant capacity, reinforcing the species’ therapeutic potential and the influence of environmental and genetic factors on its chemical composition. The second article, “Extracion of bioactives from Eriope blanchetii (Benth.) Harley ” investigated the extraction of bioactive compounds from this species, endemic to the Parque Metropolitano da Lagoa de Abaeté, Salvador, BA, using deep eutectic solvents (DES) based on choline chloride, urea, and malic acid, varying temperature (25 °C and 60 °C) and water content. FTIR analyses confirmed the formation of hydrogen bonds characteristic of DES, and HPLC-DAD identified the chemical composition and differences between peaks, highlighting a major compound. Quantification showed that the 2PA extract (DES 2, aerial parts) presented 1,036.73 ± 17.85 μg QE·g⁻¹ of flavonoids and 25,014.36 ± 2,083.01 μg GAE·g⁻¹ of phenolics, the highest value recorded in the study. Among stem bark samples, 1CC (DES 1) reached 13,286.26 ± 1,807.81 μg GAE·g⁻¹ of phenolics, surpassing by more than 100% the yield obtained with conventional methanol solvent (MCC = 6,041.43 ± 82.02 μg GAE·g⁻¹). For flavonoids, MCC yielded 512.34 ± 61.60 μg QE·g⁻¹, while aerial parts extracted with methanol (MPA) obtained 881.32 ± 17.93 μg QE·g⁻¹. Antioxidant activity by ABTS was lowest (best) for 2PA (9.66 ± 0.32 μg/mL) and 2CC (19.60 ± 0.33 μg/mL), and by DPPH for MPA (14.31 ± 0.96 μg/mL) and 2CC (33.20 ± 1.01 μg/mL). The coefficient of variation for 2PA flavonoids was only 1.72%, indicating high reproducibility. The results demonstrate that the combination of analytical techniques, chemometric approaches, and green solvents is effective for the classification and characterization of plant extracts, enabling the production of standardized products with reduced environmental impact. The proposed methodologies contribute to the advancement of green chemistry, the conservation of native species, and the development of safe and sustainable herbal medicines.