ISOLATION AND CHARACTERIZATION OF ANTIBACTERIAL COMPOUNDS FROM Euphorbia tirucalli

Abstract

Medicinal plants constitute a natural reservoir for medicines worldwide. They serve mainstream therapeutics and are central in folklore medicine. In case of Euphorbia tirucalli belongs to the Euphorbiaceae family and is a very popular herb in traditional herbal medicine. Despite the traditional use of this plant, no scientific report or information was found in the literature regarding neither its biological activity nor its chemical constituents in Vietnam. This study was designed to determine the antimicrobial of different polarities crude extracts as well as the isolation and identification of the chemical constituents of this plant. The extracts and pure compounds of E. tirucalli were tested for antimicrobial activity against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Staphylococcus epi using agar well diffusion method. Compounds were isolated from EtOAC extract of E. tirucalli through column chromatography and their structures were determined by means of NMR. According to the antimicrobial assay, EtOAC extract showed the best antibacterial activity against all of bacteria test was submitted further separation and purification. This led to the isolation of three compounds identified as eriodictyol (1), quercitrin (2) and afzelin (3). Afzelin showed the best antibacterial activity against all of bacteria test with MIC values from 0.125–0.25 mg/mL. Our results revealed that E. tirucalli was a good source of antibacterial and could be used in the study area against enterocolitis and conjunctivitis.

Keywords: Euphorbia tirucalli, chemical constituents, antimicrobial activity, ethyl acetate extract.