Provided is a compound represented by the formula (1): wherein R 1 and R 2 are each independently a hydrogen atom or a straight chain alkyl group having a carbon number of 1-3, R 3 is a hydrogen atom, an alkyl group having a carbon number of 1 -4, an alkoxyalkyl group, an aryl group, a halogen atom or a haloalkyl group, or a pharmaceutically acceptable salt thereof, which has, unlike known PGI 2 analogs, a selective EP4 agonist action, and a medicament containing the compound, which is useful for the prophylaxis and/or treatment of immune diseases, diseases of the digestive tract, cardiovascular diseases, cardiac diseases, respiratory diseases, neurological diseases, ophthalmic diseases, renal diseases, hepatic diseases, bone diseases, skin diseases and the like.
1. A compound represented by the formula (1):
wherein R 1 and R 2 are each independently a hydrogen atom or a straight chain alkyl group having a carbon number of 1 to 3, and R 3 is a hydrogen atom, an alkyl group having a carbon number of 1 to 4, an alkoxyalkyl group, an aryl group, a halogen atom or a haloalkyl group, or a pharmaceutically acceptable salt thereof.
2. The compound according to claim 1 , wherein R 1 is a methyl group, or a pharmaceutically acceptable salt thereof.
3. The compound according to claim 1 , wherein R 3 is a methyl group, or a pharmaceutically acceptable salt thereof.
4. The compound according to claim 1 , wherein R 2 is a hydrogen atom, or a pharmaceutically acceptable salt thereof.
5. The compound according to claim 1 , wherein R 1 is a methyl group, and R 2 is a hydrogen atom, or a pharmaceutically acceptable salt thereof.
6. The compound according to claim 1 , wherein R 3 is an m-methyl group, or a pharmaceutically acceptable salt thereof.
7. The compound according to claim 1 , wherein R 1 is a methyl group, R 2 is a hydrogen atom, and R 3 is a methyl group, or a pharmaceutically acceptable salt thereof.
8. The compound according to claim 1 , wherein R 1 is a hydrogen atom, R 2 is a methyl group, and R 3 is a methyl group, or a pharmaceutically acceptable salt thereof.
9. The compound according to claim 1 , which is 4-[(Z)-(1S,5R,6R,7R)-6-[(1E,3R,4RS)-3-hydroxy-4-(m-tolyl)-1-pentenyl]-7-hydroxy-2-oxa-4,4-difluoro-bicyclo[3.3.0]octan-3-ylidene]-1-(tetrazol-5-yl)butane, 4-[(Z)-(1S,5R,6R,7R)-6-[(1E,3R,4R)-3-hydroxy-4-(m-tolyl)-1-pentenyl]-7-hydroxy-2-oxa-4,4-difluoro-bicyclo[3.3.0]octan-3-ylidene]-1-(tetrazol-5-yl)butane, 4-[(Z)-(1S,5R,6R,7R)-6-[(1E,3R,4S)-3-hydroxy-4-(m-tolyl)-1-pentenyl]-7-hydroxy-2-oxa-4,4-difluoro-bicyclo[3.3.0]octan-3-ylidene]-1-(tetrazol-5-yl)butane, or a pharmaceutically acceptable salt thereof.
10. A pharmaceutical composition comprising (a) the compound according to claim 1 , or a pharmaceutically acceptable salt thereof as an active ingredient, and (b) a pharmaceutically acceptable carrier.
11. A method of treating a disease of the digestive tract in a subject. comprising administering an effective amount of the compound according to claim 1 , or a pharmaceutically acceptable salt thereof, as an active ingredient to the subject, thereby treating a disease of the digestive tract in the subject, wherein the disease of the digestive tract is an inflammatory disease or ulcerative disease of the digestive tract.
12. The method according to claim 11 , wherein the inflammatory disease of the digestive tract is an inflammatory bowel disease.
13. The method according to claim 12 , wherein the inflammatory bowel disease is ulcerative colitis or Crohn's disease.
14. The method according to claim 12 , wherein the inflammatory bowel disease is intestinal Behcet's disease or simple ulcer.
15. The method according to claim 11 , wherein the ulcerative disease of the digestive tract is esophagitis, esophageal ulcer, gastritis or gastric ulcer.
16. The method according to claim 15 , wherein the gastritis or gastric ulcer is drug-induced gastritis or gastric ulcer.
17. The method according to claim 16 , wherein the drug-induced gastritis or gastric ulcer is induced by a non-steroidal anti-inflammatory drug.
18. The method according to claim 15 , wherein the gastritis or gastric ulcer is induced by alcohol.
19. The method according to claim 11 , wherein the ulcerative disease of the digestive tract is small intestinal ulcer.
20. The method according to claim 19 , wherein the small intestinal ulcer is a drug-induced small intestinal ulcer.
21. The method according to claim 20 , wherein the drug-induced small intestinal ulcer is induced by a non-steroidal anti-inflammatory drug,
22. The method according to claim 19 , wherein the small intestinal ulcer is induced by alcohol.
23. A method of treating a disease whose symptons can be mitigated by a selective EP4 agonist action in a subject, comprising administering an effective amount of the compound according to claim 1 , or a pharmaceutically acceptable salt thereof, as an active ingredient to the subject, thereby treating a disease whose symptoms can be mitigated by a selective EP4 agonist action in the subject, wherein the disease whose symptoms can be mitigated by a selective EP4 agonist action is glaucoma, ocular hypertension, glomerulonephritis, diabetic nephropathy, IgA nephropathy, renal ischemia-reperfusion injury, hepatitis, hepatopathy, or hepatic ischemia-reperfusion injury.
24. The method according to claim 23 , wherein the disease whose symptoms can be mitigated by a selective EP4 agonist action is glaucoma or ocular hypertension.
25. The method according to claim 23 , wherein the disease whose symptoms can be mitigated by a selective EP4 agonist action is glomerulonephritis, diabetic nephropathy, IgA nephropathy or renal ischemia-reperfusion injury.
26. The method according to claim 23 , wherein the disease whose symptoms can be mitigated by a selective EP4 agonist action is hepatitis, hepatopathy or hepatic ischemia-reperfusion injury.