Chemical Profile, Antioxidant and Antimicrobial Activities of Combretum lanceolatum Pohl ex Eichler. (Combretaceae)

Compared to other species, components of Combretum lanceolatum are still with few data reported in the literature. This work describes the compounds identification, antioxidant and antimicrobial activities of C. lanceolatum twigs. Ethanolic extract (EECLT) from C. lanceolatum twigs was submitted to partition obtaining: hexane (HF), diethyl ether (EEF), ethyl acetate (EAF) and hydromethanolic (HMF) fractions. They were analyzed by gas chromatography-mass spectrometry, high performance liquid chromatography coupled to mass spectrometry and direct insertion mass spectrometry and evaluated for antioxidant assay (2,2-diphenyl-1-picrylhydrazyl (DPPH) method) and antimicrobial assay. Fifty-seven compounds were identified in the fractions. In antioxidant assay, EECLT and EAF demonstrated good antioxidant potential (half maximal effective concentration (EC₅₀): 57.9 and 45.4 µg mL^–1, respectively), better than the positive control butylated hydroxytoluene (BHT) (EC₅₀: 69.34 µg mL^–1). For antimicrobial assay, all fractions presented promising minimal inhibitory concentration (MIC). EECLT presented the best values against Staphylococcus aureus (125 µg mL^–1) and Escherichia coli (62.5 µg mL^–1) and better than the positive control fluconazole (8 and 16 µg mL^–1) against Candida albicans (3.9 µg mL^–1) and Candida krusei (15.6 µg mL^–1) strains. This study presents relevant chemical and biological information about C. lanceloatum expanding the knowledge of Brazilian flora.

Keywords:
Combretaceae; Combretum lanceolatum ; phenolic compounds; antioxidant activity; antimicrobial activity