Definition: A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They include several nucleic acid constituents (CYTOSINE; THYMINE; and URACIL) and form the basic structure of the barbiturates.
tasosartan [ ANA 756,5,8-dihydro-2,4-dimethyl-8-((2'-(1H-tetrazol-5-yl)(1,1'-biphenyl)-4-yl)methyl)pyrido(2,3-d)pyrimidin-7(6H)-one,ANA-756,ANA756,taso-sartan ] angiotensin II antagonist; structure given in first source