Source:http://linkedlifedata.com/resource/umls/id/C0034140
MSH: A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.,CSP: bicyclic ring structure consisting of fused imidazole and pyrimidine rings, with nitrogen atoms at the 1,3,7, and 9 positions; the basic structure of adenine, guanine, and other biologically important bases.