Prostaglandin has a prostanoic acid structure indicated by the formula:
and there are many prostaglandins expressing a variety of therapeutic effects.
11-deoxy-prostaglandin compounds such as 11-deoxy-15-keto-16,16-difluoro prostaglandin E1:

are useful for the improvement of central nerves system dysfunction as well as peripheral circular dysfunction (WO2006/093348 and WO2006/080549, the cited references are herein incorporated by reference).