2,5-Dioxopyrrolidin-1-yl docosanoate is the N-hydroxysuccinimide (NHS) ester of docosanoic acid (behenic acid), a reactive lipid reagent. It is primarily used in bioconjugation chemistry to covalently attach a C22 alkyl chain to primary amines on proteins, peptides, antibodies, and other biomolecules. This lipidation increases hydrophobicity, enables membrane anchoring, and enhances stability in liposomal or nanoparticle formulations. Key applications include targeted drug delivery systems, improving solubility, bioavailability, and efficacy of therapeutics. Its biocompatibility and selective reactivity make it ideal for biomedical research and pharmaceutical development.