Showing papers by "Patrizia Brigidi published in 1995"

Cosmetic preservation and structure-activity relationships of 4-diazo-pyrazole-5-carboxamides.

Abstract: Summary Diazoles have attracted considerable attention for a long time owing to their potentially interesting chemical, biochemical, and medicinal properties. We have reported the synthesis and in vitro antibacterial activity of a new series of (N-substituted)-3-methyl-4-diazo-5-pyrazolecarboxamides 1a-n along with their quantitative structureactivity study. There was a trend towards a better Gram-negative activity with decreasing molecular refraction values of the substituents on the carboxamidic moiety and a better Gram-positive activity with increasing values of IR carbonyl shift. The compounds which displayed the broadest antibacterial spectrum were 3-methyl-4-diazo-5-pyrazolecarboxamides substituted with 2-pyridinyl and 3-isoxazolyl moieties, making evident the structural requirement of a heterocyclic substituent with aminic function located in the ortho position with respect to heteroatom(s). The introduction of new substituents with different lipophilic properties in place of the C3-methyl group such as cyano, methoxy, ethoxy, benzyloxy substituents have been examined followed by application of these materials to the cosmetic formulations. An emulsion utilizing the 2-pyridinyl compound at 0.2% and 0.4% has been prepared, and their specific antimicrobial activity has been evaluated. Preliminary antimicrobial challenge studies indicated the excellent preservative activity of this compound in cosmetic formulations. Resume Les diazoles sont l'objet d'un interet particulier depuis longtemps. dua leurs proprietes potentielles en chimie, biochimie et medicine. Nous avions presente la synthese et l'etude de l'activite antibacterienne in-vitro d'une nouvelle serie de (N-substitues)-3-methyl-4-diazo-5-pyrazole carboxamides 1a-n, ainsi que l'etude quantitative de leurs relations structure-activite [1,2]. On pouvait alors constater que l'activite Gram- s'ameliorait avec la diminution des valeurs de refraction moleculaire des substituants de la partie carboxamidique, et que l'activite Gram+ s'ameliorait avec des valeurs croissantes du deplacement en IR du groupement carbonyl. Les composes qui avaient montre le spectre antibacterien le plus large etaient les 3-methyl-4-diazo-5-pyrazole carboxamides, substitues avec des radicaux 2-pyridinyl et 3-isoxazolyl. Ce fait semblait prouver l'utilite d'un substituant heterocyclque ayant une fonction aminee, en ortho par rapport aux heteroatomes. Nous avons depuis etudie l'introduction de substituants a la place du methyl en C3, avec des proprietes lipophiles diverses: cyano, methoxy, ethoxy et benzyloxy. Ces produits ont par la suite ete introduits dans des formulations cosmetiques. L'ttude de I'activitk antimicrobienne d'une emulsion contenant le compose 2-pyridinyl a 0.2% et 0.4% a ete mente en particulier; des ttudes comparatives prtliminaires avaient en effet prouvt I'excellente activite prtservatrice de ce compost dans les formulations cosmttiques.