title: Quantitative structure-activity relationship of 5-(X-benzyl)-2,4-diaminopyrimidines inhibiting bovine liver dihydrofolate reductase.
abstract: The inhibitory effect for a set of 23 5-(X-benzyl)-2,4-diaminopyrimidines acting on bovine liver dihydrofolate reductase (DHFR) had led to the following quantitative structure-activity relationship (QSAR): log 1/C = 0.62pi3 + 0.33epsilon sigma + 4.99, where r = 0.931 and s = 0.146. C in this expression is the molar concentration of inhibitor producing 50% inhibition, pi3 is the hydrophobic parameter for substituents on the 3 position of the phenyl moiety, and epsilon sigma is the the sum of the Hammett sigma constants for the 3, 4, and 5 substituents of the phenyl ring.
mesh_terms: D000818:Animals; D002417:Cattle; D005493:Folic Acid Antagonists; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008954:Models, Biological; D011743:Pyrimidines / Q000138:chemical synthesis / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D005493:Folic Acid Antagonists; D011743:Pyrimidines