EpicentRx Word of the Week: SNO

Jul 24, 2023

“The meek shall inherit the… words of the week.”



Abbreviation: SNO stands for S-nitrosothiol. This is an organic compound that contains a nitroso (-NO) group attached to a sulfur.

Example sentences:

“Nibrozetone (RRx-001) releases a “SNO storm” in tumors.”

“Nitric oxide (NO) modifies cysteine (Cys) residues to form S-nitrosothiols (SNOs) that regulate the activity and stability of many proteins. SNO protects nitric oxide from inactivation and thus stabilizes and regulates the activity of nitric oxide.”


S-nitrosothiols are nitric oxide donors. When nibrozetone (RRx-001) encounters an ischemic or hypoxic environment, it decomposes into several metabolites including NO or nitric oxide, which combines with thiols to form SNOs that impact different disease processes like cancer, neurodegeneration, and heart disease.

About the word:

S-nitrosothiols have the general formula R−S−N=O, where R denotes an organic group. The S in nitrosothiols stands for Sulfur. Nitroso refers to a functional group in which the nitric oxide (−N=O) group attaches to a carbon or nitrogen atom. A nitrite is a nitroso group attached to an oxygen atom. Compounds that contain a nitric oxide group are called nitrosyl compounds. A thiol refers to any compound that contains the group —SH.