S Nitroso N acetylpenicillamine

S-Nitroso-N-acetylpenicillamine (SNAP) is the chemical compound with the formula ONSC(CH₃)₂CH(NHAc)CO₂H. SNAP is an S-nitrosothiol and is used as a model for the general class of S-nitrosothiols which have received much attention in biochemistry because nitric oxide and some organic nitroso derivatives serve as signaling molecules in living systems, especially related to vasodilation. SNAP is derived from the amino acid penicillamine. S-Nitrosoglutathione is a related agent.