チオールエステルに関する研究 (第3報)

チオールエステルと芳香族アミンとの反応について

抄録

Under the assumption that the antifungal mechanism of thiophenol esters was due to the acylation of SH- or NH₂-group essential for fungal growth, its experimental confirmation in vitro was attempted by a model experiment using aromatic amines, such as aniline, sulfanilamide, and p-anisidine, as the acyl acceptor. The yield of the anilides thereby formed was taken as the reaction rate of the thiol esters in comparing the reactivity of such esters (Table I and II). The reactivity of aniline with antifungal CH₃COSC₆H₅ and non-antifungal CH₃COSC₂H₅ was compared by following the amount of thiols formed with 0.1 N iodine titration (Fig. 1) and the results indicated that the thioesters capable of acylating aromatic amines generally tended to have powerful antifungal activity. An introduction of a methyl group in the para position of the thiophenol ring lessens the rate of transacylation with attendant decrease in antifungal activity. The results shown in Fig. 1 is in agreement with the observation that esters of aliphatic thiols do not possess antifungal activity but those of aromatic thiols do.