Nitrotyrosine ethyl ester

Formula :
CAS : 53497-45-3 

Inactivates yeast 3-phosphoglycerate kinase.

Nitrous acid

Formula : H-N-O2
CAS : 7782-77-6 

Nitrous acid (HNO2). A weak acid that exists only in solution. It can form water-soluble nitrites and stable esters. (From Merck Index, 11th ed)