Unlocking the antioxidant and antimicrobial potential of flavone and amide-rich fractions from Conchocarpus macrocarpus (Rutaceae) leaves

Abstract

Conchocarpus macrocarpus (Rutaceae) is an endemic species in Brazil, whose chemical and biological properties are poorly understood. This study aimed to evaluate the antioxidant and antimicrobial potential of the butanolic partition phase extracted from C. macrocarpus leaves collected in Espírito Santo, Brazil. In vitro antioxidant assays, including DPPH radical scavenging and Folin–Ciocalteu assay, and cytotoxicity and antioxidant activity in RAW cells using the MTT method were performed. Additionally, antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was investigated. Results showed that the flavone-rich fraction exhibited the strongest antioxidant activity, as observed for the PF-BuOH G2.1 fraction that showed values of 237.2 ± 1.4 mg TE/g of extract and 118.2 ± 1.6 mg GAE/g of extract. However, the samples did not show protective effects against hydrogen peroxide. Furthermore, the flavones and amides present in the PF-BuOH G2.1 fraction displayed antimicrobial activity against C. albicans, showing a minimum inhibitory concentration of 1.25 mg/mL at the highest microbial load (1.5 × 105 CFU/mL). Our findings provide insights into the chemical composition and biological potential of C. macrocarpus and highlight the promising applications of the BuOH partition phase and its fractions.