Abstract

Novel fluorous and non-fluorous surfactants have been synthesized and examined for their potential as microbicides compared with nonoxynol-9 (N-9) by testing their effects on Candida albicans (C. albicans) and Escherichia coli (E. coli). These compounds include nonionic surfactants consisting of F5-triethylene glycol (F5-TEG), F7-triethylene glycol (F7-TEG), C5-triethylene glycol (C5-TEG), C7-triethylene glycol (C7-TEG), and anionic surfactants consisting of F5-propane sultone (F5-PS), and F7-propane sultone (F7-PS).  In this study, we investigated the possible effects of fluorous and non-fluorous surfactants on the growth of C. albicans and E. coli cultured in vitro, which were treated individually with different concentrations of these novel surfactants and nonoxynol-9 (N-9). Then, each sample was incubated for 3, 6, 24 and 48 h at 35°C for C. albicans and 37°C for E. coli. After incubation, C. albicans and E. coli colonies were evaluated compared with the control. N-9 and F5-PS had only small effects (25% growth inhibition or lower) on C. albicans but F7-PS, F7-TEG, F5-TEG, and C5-TEG notably inhibited C. albicans growth, and had potential to control their population. C. albicans cells treated with 10% F7-TEG, F5-TEG, or C5-TEG showed no growth; especially, C5-TEG gave the maximum growth inhibition of C. albicans. For E. coli, N-9 had no growth inhibition but F7-PS, F5-TEG, C5-TEG, C7-TEG, and F7-TEG inhibited E. coli growth. Interestingly, F7-TEG showed the maximum inhibition for E. coli starting at a concentration of 1%. Therefore, these surfactants might have potential for prevention or treatment of genital and urinary tract infection from C. albicans and E. coli. 

Key words: Candida albicans, Escherichia coli, nonoxynol-9, fluorous surfactants, non-fluorous surfactants.