Fitodisponibilidade de metais, composição química e ensaios biológicos no óleo de Bauhinia ungulata L. (Fabaceae)

Abstract

The Bauhinia ungulate species, belongs to the Bauhinia genus, popularly known as Pata de vaca, which is among the species of medicinal use in Brazil, it is widely used in the treatment of diabetes. This work had as main objective the determination of the volatile chemical constituents and biological activity of the essential oil from the leaves of B. ungulata in the North in Boa Vista, Roraima. In chemical analyzes, we tested the qualitative and quantitative aspects of the volatile components by gas chromatography (GC-FID and CGMS) and metals present in the essential oil by ICPOES method. Biological activities were carried out with Artemia salina microcrustacean for evaluating the cytotoxicity, inhibition test acetylcholinesterase enzyme and antimicrobial testing of four bacteria which two Gram negative bacteria: Salmonella typhimurium (ST) ATCC 13311 and Citrobacter freundii (ATCC8090), two gram-positive bacteria Staphylococcus aureus (SA) ATCC 25923 and Bacillus cereus (BC) ATCC 11778 and fungus (yeast) Candida albicans (CA) ATCC 18804. The chromatographic analysis revealed 18 components, of which the majority were the β-caryophyllene (15, 9%), caryophyllene oxide (9.2%), α-humulene (8.1%), epi-γ-eudesmol (7.5%), α-bisabolol (4.7%), copaene (3.5%), nerolidol (3.3%), α-bisabolol oxide B (2.5%) and spathulenol (2.1%). In qualitative analysis of metal elements have been identified with a concentration below 1 ppm, which are Ag, Al, B, Ba, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, Pb, Sr, Zn and between 1 and 100 ppm, Ca, Na, P and S and up to 100 ppm silicon element (Si). Among the elements mentioned above it was determined the concentration to the elements, Ca with 8.77 ppm, P with 11.06 ppm, Na with 25.58 ppm, S with 30.47 ppm, with the highest content Si with 149.2 ppm. The essential oil showed high cytotoxicity forward to testing with A. salina. In tests for evaluation of enzyme acetylcholinesterase inhibitory essential oil obtained inhibition 95.96%. Microorganisms were presented antimicrobial inhibiting C. albicans (85%), B. cereus (65.5%), S. aureus (66.4%) and S. typhimurium (68.7%), and the C. freundii, showed 46.1% inhibition of less than 50 %. Given these results, it can be considered that the oil of this species has great potential to obtain natural or synthetic products of interest in the pharmaceutical industry.