Used as a heterobifunctional crosslinker in bioconjugation, this NHS (N-hydroxysuccinimide) ester compound features a pyridyl disulfide group. The NHS moiety activates carboxylic acids to form stable active esters that react efficiently with primary amines to create amide bonds, ideal for peptide synthesis and protein labeling with minimal racemization. The pyridin-2-yldisulfaneyl group enables thiol-disulfide exchange, allowing site-specific conjugation of thiols on biomolecules to other molecules or surfaces.

It is particularly valuable in solid-phase peptide synthesis, preparation of complex organic molecules, and advanced applications such as targeted drug delivery systems and antibody-drug conjugates (ADCs), where precise linkage of drugs to targeting proteins is required. Its selective reactivity ensures compatibility with various functional groups in biomolecules.