N,S-DI(2,4-DNP)-L-CYSTEINE N-S-di-2-4-dnp-L-cysteine crystalline n,s-di(2,4-dinitrophenyl)-l-cysteine n,s-di(dnp)-l-cysteine 2-(2,4-dinitroanilino)-3-(2,4-dinitrophenyl)sulfanylpropanoic acid 2-(2,4-dinitroanilino)-3-[(2,4-dinitrophenyl)thio]propionic acid 2-[(2,4-dinitrophenyl)amino]-3-(2,4-dinitrophenyl)sulfanyl-propanoic acid (R)-2-((2,4-Dinitrophenyl)aMino)-3-((2,4-dinitrophenyl)thio)propanoic acid