In organic chemistry, S-nitrosothiols, also known as thionitrites, are organic compounds or functional groups containing a nitroso group attached to the sulfur atom of a thiol.[1] S-Nitrosothiols have the general formula R−S−N=O, where R denotes an organic group.
S-Nitrosothiols have received much attention in biochemistry because they serve as donors of both the nitrosonium ion NO+ and of nitric oxide and thus best rationalize the chemistry of NO-based signaling in living systems, especially related to vasodilation.[2] Red blood cells, for instance, carry an essential reservoir of S-nitrosohemoglobin and release S-nitrosothiols into the bloodstream under low-oxygen conditions, causing the blood vessels to dilate.[3]