Amine and ammonium functionalization of chloromethylsilane-ended dendrimers.: Antimicrobial activity studies

Novel amine- and ammonium-terminated carbosilane dendrimers of type Gn-[Si{CH2O-(C6H4)-3-NMe2}](lambda) or Gn-[Si{CH2O-(C6H4)-3-NMe(3)(+)l(-)}](x) have been synthesized and characterized Lip to second generation by phenolysis of (chloromethyl)silyl-terminated dendrimers with 3-dimethylarmine phenol and subsequent quaternization with methyl iodide. Quaternized carbosilane dendrimers are stable in protic solvents and can be solubilised in water after the addition of less than 1% of dimethyl sulfoxide. A study of the antimicrobial activity of these cationic dendrimers of first and second generation against both Gram-positive and Gram-negative bacteria is also described. The results obtained demonstrate that the new ammonium-terminated carbosilane dendrimers can be considered as multivalent biocides.