2002 Volume 7 Issue 2 Pages 55-61
Novel tris-quaternary ammonium compounds (tris-QACs), 4, 4', 4''-(1, 2, 3-propylenetrithio)- tris (1-alkylpyridinium iodide)s (4TP-n: alkyl chain length, n= 4, 6, 8, 10, 12 or 14) were synthesized and characterized. The chemical structure of 4TP-n is a tris-structure that is composed of three N-alkyl-4-thiopyridinium iodides attached to propane positions 1, 2 and 3. Its antimicrobial characteristics were compared to those of 4, 4';-(1, 6-hexamethylenedithio) bis (1-alkylpyridinium iodide) (4DTBP-6, n), a bis-quaternary ammonium compound (bis-QAC), and N-alkylpyridinium iodide (P-n), a mono-quaternary ammonium compound (mono-QAC), for both of which there are previous reports on their syntheses and antimicrobial characteristics. Moreover, 4TP-n was also compared to benzyldimethyldodecylammonium chloride (BAC) and 2-(4-thiazolyl) benzimidazole (TBZ) as antibacterial and antifungal agents that are widely used in various industries. Both the bacteriostaticactivity and the bactericidal activity of 4TP-n were higher than those of P-n and were similar to those of 4DTBP-6, n, and were scarcely affected by the length of the alkyl chain unlike the typical mono-QAC, P-n. 4TP-8 exhibited a more wide-ranging and more effective antimicrobial activity against bothbacteria and fungi in comparison with P-12, BAC and TBZ although the antifungal activity of 4TP-8was lower than that of 4DTBP-6, 8. While the bactericidal activity was influencedby pH and temperature, 4TP-n showed a higher bactericidal activity in the ranges of pH 5 to 8.5 and 10 to 40°C than P-12.
