1949 年 69 巻 4 号 p. 185-188
During the course of investigations into a substance which inhibited “fogging” in photographic emulsions, crude penicillin was found to be effective in this respect. Further observations proved that this substance was a decomposition product of penicillin and in order to observe its effective mechanism, various 4-carboxy-thiazolidine derivatives were synthesized as allied compounds of thiazolidine, one of the component part of penicillin structure. These synthesized compounds showed similar properties. Theses derivatives were found to be unstable against heat and difficult to recrystallize and the aldehydes possessing a double bond were found to be difficult in combining with cystein and even if they did combine, the condition of combination seemed to be different. It is assumed that the tendency to decompose by heat has some relationship to the mechanism of converting from decreased sensitivity to incrersed sensitivity during the ripening of emulsion.