Synthesis and antimicrobial activity of quaternary ammonium silane coupling agents.

Fourteen novel silane coupling agents with a quaternary ammonium group introduced into the molecule, [CH(2)=CHCH(2)N(+)(CH(3))(C(n)H(2n+1))(CH(2))(3)Si(OCH(3))(3)]X(-) (n-X, n=10-18, X=Cl, Br, or I), were synthesized with the aim of using these agents to make material surfaces antimicrobial for a long period of time. Measurements of the minimum inhibitory concentrations (MIC) against 12 kinds of fungi and bacteria revealed that the coupling agent with a C(10) alkyl chain and Cl- or Br- counter-ion (10-Cl or 10-Br) has the highest antimicrobial activity among the n-X agents synthesized, but 14-Cl and 14-Br showed the highest activity on a modified porcelain plate.

Chemo-enzymatic synthesis and properties of novel optically active cationics containing carbonate linkages.

Novel optically active carbonate-type cationics were designed and synthesized via a green method. A series of n-alkyl N,N-dimethylaminoalkyl carbonates was prepared via a two-step successive carbonate exchange reaction of diphenyl carbonate with 1-alkanol followed by the reaction of the optically active or racemic amino alcohol in the presence of triethylamine. The quaternarization of the N,N-dimethylamino group was carried out using methyl iodide.

Synthesis and antibacterial activity of quaternary ammonium salt-type antibacterial agents with a phosphate group.

Quaternary ammonium salts are frequently used as antibacterial agent that disrupts cell membrane through the binding of their ammonium cations to anionic sites in the outer layer tissue of bacteria. This article describes the synthesis of quaternary ammonium salt-type antibacterial agents with a phosphate group that strongly binds to hydroxyapatite and bromide ion as counterion. Evaluation of the antibacterial activity of the synthesized compounds in terms of minimum inhibitory concentration (MIC test) showed that the compounds exhibit an excellent antibacterial activity on a variety of bacteria including Gram-positive and Gram-negative bacteria, yeast, and fungi.

Synthesis and properties of biodegradable and chemically recyclable cationic surfactants containing carbonate linkages.

Novel biodegradable and chemically recyclable carbonate-type cationic surfactants consisting of a long chain alkyl group and a quaternary ammonium propyl group were designed and synthesized as a green surfactant. These carbonate-type cationics showed better surface activities in an aqueous solution when compared to the conventional cationics. Novel cationics containing both the carbonate linkage and n-dodecyl group showed strong antimicrobial properties, enzymatic degradabilities for chemical recycling and rapid biodegradabilities by activated sludge.