Bioactivity flavonoids from roots of Euphorbia tirucalli L.

• Two flavonoids and one ellagic acid derivative were isolated from the roots of Euphorbia tirucalli. • 13 compounds were identified by HPLC-MS/MS analysis. • Ethanol extract from roots of E. tirucalli and the isolated compounds displayed significant antimicrobial activity. Euphorbia tirucalli (Euphorbiaceae) is a species widely utilized for popular medicine in northeast of Brazil because of its innumerable reported medicinal properties. The HPLC-Qtrap-MS/MS analysis from E. tirucalli roots ethanol extract revealed that this species presents 8 flavonoids and 5 shikimate derivative compounds. Chemical studies of these ethanolic extract using chromatographic procedures allowed the isolation of four previously unreported compounds for this species: myricetin, 3,3'-dimethoxy-4- O -α-rhamnopyranoside-ellagic acid, 4- O -methyl-gallic acid and ampelopsin. All structures were determined using 1D and 2D NMR spectroscopy analysis. The ethanol extract and four isolated compounds were evaluated for antimicrobial activity against Staphylococcus aureus , Escherichia coli , Sporothrix brasiliensis and Candida albicans. All the analyzed compounds presented activity against all evaluated bacteria and fungi, with MIC values ranging from 8 to 2048 μg/mL. [ABSTRACT FROM AUTHOR]