“Flavonoids from Pterocaulon alopecuroides with antibacterial activity”

ALARCÓN, R.; CARRIZO FLORES, R.A.; OCAMPO, S.; LUCATTI, A.; FLORES GALLEGILLO, L.; TONN, C.E.; SOSA, V.

PLANTA MEDICA

Thieme

Lugar: Stuttgart; Año: 2008 p. 1463 - 1467

0032-0943

Abstract : Three flavonoids, (2R,3R)-5,4′-dihydroxy-3′-Omethyl-7-(ã,ã-dimethylallyloxy)dihydroflavonol 1, (2R,3R)-5,7,4′-trihydroxy-3′-O-methyl-6-(á,á-dimethylallyl) dihydroflavonol 2, and (2R,3R)-5,7,4′-trihydroxy-6-(á,á-dimethylallyl)dihydroflavonol 3, together with three known flavonoids (4–6), were isolated from the aerial parts of Pterocaulon alopecuroides. The structures of the compounds were determined by mass and by 1 D and 2 D NMR spectroscopy. Screening of the antibacterial activity of all six compounds was conducted by a disc diffusion test against Bacillus cereus, Bacillus subtilis, Salmonella typhimurium and Proteus mirabilis. The minimum inhibitory concentration (MIC) of the active compounds (2, 3, 4, 6) was determined by a microdilution assay. These compounds were active only against both Gram (+) bacteria with MIC values ≤ 200 ìg/mL.