Nitrosation and nitrosylation

Nitrosation and nitrosylation are two names for the process of converting organic compounds or metal complexes into nitroso derivatives, i.e., compounds containing the R−NO functionality. The synonymy arises because the R-NO functionality can be interpreted two different ways, depending on the physico-chemical environment:

  • Nitrosylation interprets the process as adding a nitrosyl radical NO. Nitrosylation commonly occurs in the context of a metal (e.g. iron) or a thiol, leading to nitrosyl iron Fe−NO (e.g., in nitrosylated heme = nitrosylheme) or S-nitrosothiols (RSNOs).
  • Nitrosation interprets the process as adding a nitrosonium ion NO+. Nitrosation commonly occurs with amines (–NH2), leading to a nitrosamine.

There are multiple chemical mechanisms by which this can be achieved, including enzymes and chemical synthesis.