Antibacterial activity, toxicity and phytochemical analysis of fractions obtained from Caesalpinia paraguariensis tincture

BARRERA, M.L.; SGARIGILA, M. A.; SOBERÓN , J.R.; MALDONADO, G.E.; VATTUONE M.A.

Tafí del Vale - Tucumán

Congreso; XXXV Annual Scientific Meeting of Tucuman Biology Society; 2018

Tucuman Biology Society

Previous works reported about antimicrobial activities of Caesalpinia paraguariensis Burk. extracts. The tincture shown also toxicity, but the bioactive constituents were not identified yet. Objectives: to fractionate components of C. paraguariensis bark tincture and to determine its antibacterial (AB) activity and toxicity. To analyze the secondary metabolites profile of the bioactive fraction/s (fr). Tincture (5) was obtained by percolation, was dried and suspended in water, and Liq-Liq. extractions were applied with CH2Cl2 (1) y AcOEt. (2); soluble (3) and insoluble (4) components from aqueous fr were separated by centrifugation. All frs were dried, weighed and dissolved in methanol, then were loaded between 50-500 ug in sterile discs. The AB activity was determined against ATCC strains at 108ufc/mL, E. coli 25922, Ps. aeruginosa 27853, St. aureus 25923, E. faecalis 29912, by disc diffusion on solid MH medium. Ciprofloxacin was (+) control, and all plates were incubated at 37 °C, 24 h. Toxicity was determine by Brine shrimp test (10-1000 ug/ml), using DMSO and anthracene as controls. Frs were analyzed by TLC (silicagel; Toluene/AcOEt/Formic/Methanol 3:4:1:2) and revealed under UV 254/365 nm light, NP/PEG, p-AS and Dragendoff reagents. 1, 2 and 3 frs were active against St. aureus (Ø: 8-13 mm, 500 ug); 2 and 3 frs were active against E. faecalis (Ø: 7-10 mm, 250 ug). Lethal concentrations 50% (ug/ml) were: 131.82 (5), 892.25 (1), 131.82 (2), 478.63 (3), 100.00 (anthracene). Bioactive Frs. (1 y 2) revealed different profiles of phenolic and triterpenoid compounds. These results justify the purification of 2 in order to separate their AB constituents from toxics.