6-hydroxynicotinic acid (6-OHNA) is exploited in the use of NMR spectroscopy or gas chromatography--mass spectrometry for the diagnosis of Pseudomonas aeruginosa in urinary tract infection.

A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.

Cdk4/6 inhibitor IV is a cell-permeable triaminopyrimidine that reversibly blocks Cdk4/cyclin D1 and Cdk6/cyclin D1 activity with IC50 values of 1.5 and 5.6 μM, respectively.