抄録
As a part of series of studies on the interaction of thiol-type thiamines with SH or S-S groups of proteins, the interaction of thiamine as well as L-cysteine with keratin has been investigated through the observations of the permanent waving action on human hair under various conditions. It was found that L-cysteine can be used as an effective cold waving agent in aqueous solution at pH from 8.8 to 9.4,concentration ranging from 5 to 15% and at 30℃ for 15-25 minutes. A less but significant hair waving effect of thiamine hydrochloride was observed at the condition of pH 9.2-9.8,concentration from 15 to 25% and 30℃ for 25-40 minutes. It was also observed that ammonia or monoethanolamine was one of the most effective alkaline agents among various alkalies and that the waving power was significantly increased by the combined use of protein denaturants such as urea and guanidine hydrochloride with L-cysteine or thiamine. From these results, it is plausible that the main action of thiol-type thiamine or L-cysteine on the hair waving is concerned with thiol-disulfide interaction between mercaptide ion of these thiols and S-S linkages of keratin.
