(R-(R*,R*))-3,3'-Dithiobis(2-amino-N-(4-nitrophenyl)propionamide) 34199-07-0 Cystine-bis-4-nitroanilide EINECS 251-872-6 Propanamide, 3,3'-dithiobis(2-amino-N-(4-nitrophenyl)-, (R-(R*,R*))-