title: Quantitative thin-layer chromatography of pyrimethamine and related diaminopyrimidines in body fluids and tissues.
abstract: Several 2,4-diaminopyrimidines which inhibit the enzyme dihydrofolate reductase are quantitated following extraction and separation on silica gel thin-layer chromatographic plates. These compounds are candidates for the treatment of brain tumors and meningeal leukemia, because they have the ability to cross the blood-brain barrier. The ultraviolet absorption of the pyrimidine ring at 275 nm is utilized to quantitate these compounds on thin-layer chromatographic plates with a scanning instrument. This method offers the advantages of speed, specificity, versatility and sensitivity, and has proven to be satisfactory for the measurement of as little as 10 ng/ml of these compounds in biological fluids.
mesh_terms: D000042:Absorption; D001322:Autoanalysis; D002855:Chromatography, Thin Layer; D005493:Folic Acid Antagonists / Q000032:analysis; D005782:Gels; D011739:Pyrimethamine / Q000031:analogs & derivatives / Q000032:analysis* / Q000097:blood / Q000652:urine; D011743:Pyrimidines / Q000032:analysis* / Q000097:blood / Q000652:urine; D012822:Silicon Dioxide; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014020:Tissue Extracts / Q000032:analysis
chemical_list: D005493:Folic Acid Antagonists; D005782:Gels; D011743:Pyrimidines; D014020:Tissue Extracts; D012822:Silicon Dioxide; D011739:Pyrimethamine