Quantitative structure-activity relationship study of N-(3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carbonyl)guanidines as potent Na/H exchange inhibitors.
We have previously reported that N-(4-isopropyl-2,2-dimethyl-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-car bonyl)guanidine (4b) methanesulfonate salt (KB-R9032) is a potent and highly water-soluble Na/H exchange inhibitor. In a series of studies on Na/H exchange inhibitors, we designed and synthesized N-(3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carbonyl)guanidines (5) as more potent inhibitors with high water-solubility. The design strategy for 5 was based on a quantitative structure-activity relationship (QSAR) study, involving the proportional relationship between the biological activity and hydrophobicity of the ring structure of compounds 4. As expected, compounds 5 showed more potent activity than 4. It was found by using the QSAR analysis that 5 were about five-fold more potent than 4. The increase in potency of compounds 5 well agreed with our previous QSAR analysis result. The most potent derivative was the methanesulfonate salt 5d of the 4-isopropyl derivative (IC50=0.0091 microM). And in addition to the in vitro study, 5d showed significant protective activity against a rat acute myocardial infraction model.
Yamamoto
T
T
R&D Laboratories, Nippon Organon K.K., Osaka, Japan. Yamamoto.Takeshi@organon.co.jp
Hori
M
M
Watanabe
I
I
Harada
K
K
Ikeda
S
S
Ohtaka
H
H
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000517:prevention & control; D006146:Guanidines / Q000737:chemistry* / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D017923:Sodium-Hydrogen Exchangers / Q000138:chemical synthesis* / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D006146:Guanidines; D017923:Sodium-Hydrogen Exchangers