N,N_-Diacetyl Cystine

N,N'-Diacetyl Cystine is a disulfide-bridged dimer of acetylated cysteine residues, featuring two acetyl groups appended to the ε-amino functionalities of each cysteine unit. This derivative exhibits a fully oxidized disulfide linkage (S-S) and retains the inherent thiol reactivity of cystine in a masked amino state. Structurally, it represents a cystine analog with enhanced thermal stability due to N-acylation, which sterically hinders oxidative degradation pathways. Synthetically, it serves as a critical HPLC reference standard for quantifying acetylation-related impurities in cystine API synthesis.