Synthesis and pharmacological investigation of some novel 2-methyl-3-(substituted methylamino)-(3H)-quinazolin-4-ones as histamine H1-receptor blockers.
A series of 2-methyl-3-(substituted methylamino)-(3H)-quinazolin-4-ones were synthesized from 3-amino-2-methyl-(3H)-quinazolin-4-one. Their structures were confirmed by spectral data (IR, NMR and MS) and the purity was ascertained by microanalysis. When tested for H1-receptor blocking activity on isolated guinea pig ileum all the test compounds inhibited histamine induced contraction whereas compound 5 (IC50 0.22 x 10(3) ng/ml) was found to be four times more potent than chlorpheniramine maleate (IC50 1 x 10(3) ng/ml) and it showed lesser sedation (8%) than the standard (32%).
Alagarsamy
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Medicinal Chemistry Laboratory, J.S.S. College of Pharmacy, Mysore, India. samy_veera@yahoo.com
D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000138:chemical synthesis* / Q000494:pharmacology*; D006993:Hypnotics and Sedatives / Q000138:chemical synthesis / Q000494:pharmacology; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D051379:Mice; D011799:Quinazolines / Q000138:chemical synthesis* / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship
D006634:Histamine H1 Antagonists; D006993:Hypnotics and Sedatives; D011799:Quinazolines