title: [Kinetics of the bacteriostatic activity of natural and synthetic chalcones on a strain of Staphylococcus aureus].
abstract: The bacteriostatic action exerted by natural chalcones (2',4'-dihydroxychalcone and 2'-hydroxy-4'-methoxychalcone) and by synthetic chalcones (chalcone, 2'-hydroxychalcone, 2'4-dihydroxychalcone and 2'-hydroxy-4-methoxychalcone) on Staphylococcus aureus (ATCC 25 923 Strain) was investigated. In addition, the influence of the concentration, nature and position of the substituents of the mentioned drugs on the specific growth rate of the germ was determined. Qualitative tests made on nutritive agar plates showed the inhibitory action of chalcone and its dihydroxyl derivatives. Quantitative experiments were made in nutritive broth at 33 degrees C, with permanent stirring (200 rpm), measuring the microbial growth by turbidimetry at 720 nm. The results distinguish the strong bacteriostatic effect of 2',4'-dihydroxychalcone and 2',4-dihydroxychalcone, which at low concentrations caused complete inhibition of microorganism growth, from the other chalcones studies which only reduced the up to a limiting value. The presence of an hydroxyl group in the A or B ring of 2'-hydroxychalcone increases its bacteriostatic activity, being this effect stronger at position 4' (ring A) than at position 4 (ring B). The introduction of a methoxy group into the 2'-hydroxychalcone structure causes a decrease of its inhibitory power.
mesh_terms: D002599:Chalcone / Q000138:chemical synthesis / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D011427:Propiophenones / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*; D013329:Structure-Activity Relationship
chemical_list: D011427:Propiophenones; D002599:Chalcone
vernacular_title: Cinética de la acción bacteriostática de chalconas naturales y de síntesis sobre una cepa de Staphylococcus aureus.