Pyrimidines are heterocyclic six-membered nitrogen-containing carbon ring structures with uracil cytosine and thymine being the basal structures of ribose-containing nucleosides (uridine cytidine and thymidine respectively) or deoxyribose-containing deoxynucleosides and their corresponding ribonucleotides or deoxyribonucleotides.

Orotirelin(CG 3509), a thyrotropin-releasing hormone analog, reversed pentobarbital-induced sleep time.Orotirelin may be beneficial in animals with focal cerebral ischemia.

CPI-360 is a potent, selective, and SAM-competitive EZH1 inhibitor with IC50 of 102.3 nM, >100-fold selectivity over other methyltransferases.