Estudo químico e avaliação do potencial biológico das folhas de Cassia bakeriana Craib

Abstract

Cassia bakeriana Craib (Leguminosae family) is native from Thailand, but it was adapted in the Cerrado. The present study aimed to evaluate the antifungal, antioxidant and antidiabetic potential of extracts and partitions of C. bakeriana Craib leaves as well as to identify the chemical constituents of the most active samples. The antifungal activity was performed by broth microdilution method against Candida spp. The most active partitions for C. glabrata were dichloromethane (PD) and ethyl acetate (P-AE) (MIC 93.75 and 187.5 µg mL–1, respectively). The evaluation of the antioxidant activity was performed by the ORAC and DPPH radical method. The ethanolic extract (EE) and the partitions presented high antioxidant activity in the ORAC method with results superior to the positive ascorbic acid control (2498.5 ± 109.6 μmol Troloxeq/gsample). In the DPPH radical method, the n-butanol (PB), P-AE and PD partitions showed higher antioxidant activity (IC50 21.7 ± 3.2, 21.9 ± 4.3 and 31.7 ± 10.9 μg mL–1, respectively). In relation to enzymatic inhibition, the EE showed higher α-amylase inhibition (IC50 5.00 ± 0.85 μg mL–1). The P-D showed greater α-glycosidase inhibition (IC50 359.55 ± 2.90 μg mL–1). The EH showed high inhibition of pancreatic lipase (IC50 25.26 ± 8.77 µg mL–1). In relation to glycation inhibition capacity, P-D and P-AE were also the most active (IC50 37.85 ± 0.49 and 53.25 ± 11.24 μg mL–1, respectively). By fractionation of P-D by semi-preparative CLAE-DAD, the flavonoids canferol (XX) and canferol-3-O-rhamnoside (XVII) were isolated and characterized by NMR and MS-IES. These compounds showed high antioxidant activity in the ORAC method (4198.0 ± 42.6 and 4153.6 ± 3.8 μmol Troloxeq/gsample, respectively), but only compound XX was active by DPPH radial method (IC50 10.2 ± 0.1 μg mL–1). The isolated compounds XX showed high inhibition of α-amylase (IC50 1.5 ± 0.14 μg mL–1). The compounds XX and XVII showed high inhibition of glycation (IC50 64.16 ± 1.53 and 84.27 ± 11.38 μg mL–1, respectively). Through the HPLC-ESI-MS analysis of EE, Fr-D and Fr-AE, some compounds such as phenolics acid, flavonoids, megastigmane, fatty acids and derivatives, sphingolipids, proanthocyanidins, cyanidin and anthraquinones were identified.