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.
oxyphencyclimine [ oxyphencyclimine hydrochloride,oxyphencyclimine monohydrochloride,oxyphencyclimine, (+-)-isomer ] minor descriptor (65-85); on-line & Index Medicus search PYRIMIDINES (65-85); RN given refers to parent cpd without isomeric designation