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.
ICI D2788 [ 4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino)pyrimidinium chloride,ICI-D2788,ZD 7288,ZD-7288,ZD7288,ZENECA ZD7288 ] a sinoatrial node modulator; may be of use in treatment of ischaemic heart disease by increasing heart rate without impairing cardiac function