Synthesis of novel 2-benzothiopyran and 3-benzothiepin derivatives and their stimulatory effect on bone formation.
In a search for therapeutic agents for the treatment of osteoporosis and bone fracture, we found that 2-benzothiopyran-1-carboxamide derivatives 1, derived from ipriflavone as a lead compound, increase cellular alkaline phosphatase activity in cultures of rat bone marrow stromal cells. Further modification of 1 has led to the discovery of more potent 3-benzothiepin-2-carboxamide derivatives 2. Of these, 3-benzothiepin derivatives bearing a 4-(dialkoxyphosphorylmethyl)phenyl group on the 2-carboxamide moiety such as 2h and 2q exhibited significant improvement of activity compared to ipriflavone. Asymmetric synthesis of 2h and 2q revealed that the (-)-isomers possessed activities superior to those of the (+)-isomers. Further evaluation of these compounds using the mouse osteoblastic cell line MC3T3-E1 revealed that (-)-2q enhanced the effect of bone morphogenetic protein. In addition, application of a sustained-release agent containing 2q increased the area of newly formed bone in a rat skull defect model. Based on these findings, (-)-2q was selected for further investigation as a new drug stimulating bone formation. Synthesis and structure-activity relationships for this novel series of 2-benzothiopyran and 3-benzothiepin derivatives are detailed.
Oda
T
T
Pharmaceutical Research Division, Takeda Chemical Industries, Ltd., 17-85, Jusohonmachi 2-chome, Yodogawa-ku, Osaka 532-8686, Japan.
Notoya
K
K
Gotoh
M
M
Taketomi
S
S
Fujisawa
Y
Y
Makino
H
H
Sohda
T
T
D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001582:Benzothiepins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001846:Bone Development / Q000187:drug effects*; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D002478:Cells, Cultured; D018360:Crystallography, X-Ray; D004353:Drug Evaluation, Preclinical; D008297:Male; D051379:Mice; D009943:Organophosphorus Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000187:drug effects / Q000293:injuries; D013237:Stereoisomerism; D017154:Stromal Cells / Q000187:drug effects / Q000201:enzymology; D013329:Structure-Activity Relationship
D001582:Benzothiepins; C117668:N-(4-(diethoxyphosphorylmethyl)phenyl)-1,2,4,5-tetrahydro-4-methyl-7,8-methylenedioxy-5-oxo-3-benzothiepin-2-carboxamide; D009943:Organophosphorus Compounds; D000469:Alkaline Phosphatase