the reactions of 2,2'- and 4,4'-dipyridyl disulphide ( 2-py-s-s-2-py and 4-py-s-s-4-py ) with l-ergothioneine ( 2-mercapto-l-histidine betaine ) , 2-mercaptoimidazole , 1-methyl-2-mercaptoimidazole , thiourea , thioacetamide , 2-thiopyridone ( py-2-sh ) and 4-thiopyridone ( py-4-sh ) were investigated spectrophotometrically in the ph range approx .
C0014713
ergothioneine
C0019602
histidine