Abstract
The antimicrobial activity, hydrophobicity and toxicity of tri(n-alkyl)sulfoniums (TASs) and tris{4-(n-alkylphenyl)}sulfoniums (TAPSs), and their relationships were investigated. The antimicrobial activity against the tested strains tended to increase with the increase in the sulfonium ClogP between 7 and approximately 12 and beyond that decreased with the increase in the ClogP in both sulfoniums. The antimicrobial activities of the most TAPSs were higher than those of the TASs at similar ClogP values. The mutagenicity of the TASs and the TAPSs was judged to be negative. The acute oral toxicity decreased with the increase in the ClogP in the both sulfoniums. The skin irritation/corrosion increased with the increase in the ClogP between approximately 7 and 12, and beyond that decreased or similar with the increase in the ClogP in both sulfoniums. It is noted that the acute toxicity and the skin irritation/corrosion of the TAPSs were clearly higher than those of the TASs at a similar ClogP. In comparing the sulfoniums to representative quaternary ammonium compounds (QACs), the antimicrobial activities of the some sulfoniums were higher than those of QACs and the toxicity was lower. Therefore, some sulfoniums could be utilized in many fields instead of the presently and widely-used QACs.
