Source:http://linkedlifedata.com/resource/umls/id/C0022203
MSH: The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed),CSP: substances that have the same chemical composition but differ in structural form.,NCI: One of two or more compounds that have the same chemical formula but different arrangements of the atoms within the molecules and that may have different physical/chemical properties.