title: Synthesis and biological activities of new 2-substituted 1,4-benzoxazine derivatives.
abstract: A series of new 1,4-benzoxazine derivatives (XI, XII) possessing (4-phenyl-1-piperazinyl)alkyl moieties at the 2-position and related compounds (XIII) were synthesized and tested for calcium antagonistic, calmodulin antagonistic and antihypertensive activities. Various compounds had in vitro calmodulin antagonistic activity superior or comparable to that of trifluoperazine. Among these compounds, tetrahydronaphtho[2,3-b] [1,4]oxazine derivatives such as 51, 53, 54, 58, 59, 60, 73 and 75 showed potent antihypertensive effects in spontaneously hypertensive rats. Optical isomers of 51 were also synthesized and evaluated biologically. No differences in biological activities were seen between the enantiomers.
authors.affiliation: Chemistry Research Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kajino
authors.forename: Y
authors.initials: Y
authors.lastname: Shibouta
authors.forename: K
authors.initials: K
authors.lastname: Nishikawa
authors.forename: K
authors.initials: K
authors.lastname: Meguro
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000138:chemical synthesis*; D002121:Calcium Channel Blockers / Q000138:chemical synthesis*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D066298:In Vitro Techniques; D008297:Male; D010078:Oxazines / Q000138:chemical synthesis* / Q000494:pharmacology; D010879:Piperazines / Q000138:chemical synthesis* / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains
chemical_list: D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D002147:Calmodulin; D010078:Oxazines; D010879:Piperazines