Effect of the amino chain length and the transformation into citric acid salts of aryl-diphenyl-butenes and ferrocenyl-diphenyl-butenes bearing two dimethylaminoalkyl chains on their antimicrobial activities

In a previous work we have demonstrated the antimicrobial activity of ferrocenyl or phenyl derivatives of diphenyl butene series. This finding has opened a new area of applications of organometallic compounds. In order to improve these activities, we have synthesized new organic and organometallic diaryl butene compounds with different lengths of their amino chains. These new compounds, and also their ammonium salts, were tested against man pathogenic microorganisms Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442), Staphylococcus aureus (ATCC 6538) and Enterococcus hirae (ATCC 10541). It emerged from the tests that the Gram+ bacteria are more sensitive to the compounds than Gram-, and the compounds with 3 carbon amino chains have a better antimicrobial activity than the one having a chain of 2 or 4 carbons. The transformation of compounds to citrate salts was accompanied by a significant regression of antibacterial activity against Pseudomonas aeruginosa, for both organic and ferrocenic molecules. This resistance problem has been solved using hydrochlorides salts rather than citrates one.