Abstract: Novel pyrrolidine derivatives, being useful as chymase inhibitor or intermediate for synthesis of the active compounds, which has the formula (I): wherein R1 is cycloalkyl, substituted or unsubstituted phenyl or naphthyl, indanyl, thienyl, furyl, substituted or unsubstituted indolyl, benzofuryl, substituted or unsubstituted benzothienyl, etc.; R2 is H, alkyl, phenyl-lower alkyl, cycloalkyl or cycloalkyl-lower alkyl; R3 is (i) substituted or unsubstituted monocyclic heterocyclic group, (ii) substituted or unsubstituted benzene- or pyridine-fused heterocyclic group, or (iii) a group (a): R4 and R5 are independently H or OH, but R4 and R5 are not simultaneously H, or both form oxo; n is 0, 1, 2 or 3; or a salt thereof.

Abstract: Novel pyrrolidine derivatives, being useful as chymase inhibitor or intermediate for synthesis of the active compounds, which has the formula (I): wherein R1 is cycloalkyl, substituted or unsubstituted phenyl or naphthyl, indanyl, thienyl, furyl, substituted or unsubstituted indolyl, benzofuryl, substituted or unsubstituted benzothienyl, etc.; R2 is H, alkyl, phenyl-lower alkyl, cycloalkyl or cycloalkyl-lower alkyl; R3 is (i) substituted or unsubstituted monocyclic heterocyclic group, (ii) substituted or unsubstituted, benzene- or pyridine-fused heterocyclic group, or (iii) a group (a): R4 and R5 are independently H or OH, but R4 and R5 are not simultaneously H, or both form oxo; n is 0, 1, 2 or 3; or a salt thereof.

Abstract: A novel prostaglandin I.sub.2 derivative selected from a prostaglandin I.sub.2 having a halogen atom on the carbon atom corresponding to the 7-position of natural prostaglandin I.sub.2 and having a cycloalkylene group in the .alpha.-chain, and its esters and salts.

Abstract: Tetrahydropyrrolo[1,2-a]pyrazine-4-spiro-3'-pyrrolidine derivatives of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are independently hydrogen, halogen, trifluoromethyl, alkyl having 1 to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms, or nitro, and R.sup.3 is hydrogen, halogen or alkyl having 1 to 6 carbon atoms, and pharmaceutically acceptable salts thereof, processes for preparation thereof, and pharmaceutical composition containing the same. Said compounds and their salts show excellent aldose reductase inhibitory activity and are useful for the prevention and treatment of diabetic complications.

Abstract: A 6-fluoroprostaglandin having the formula: ##STR1## wherein A is a carbonyl group or a hydroxymethylene group, R.sup.1 is a substituted or unsubstituted C.sub.1 -C.sub.10 alkyl group or a substituted or unsubstituted 5- or 6-membered cycloalkyl group, R.sup.2 is a hydrogen atom or a C.sub.1 -C.sub.10 alkyl group, each of R.sup.3 and R.sup.4 which may be the same or different is a hydrogen atom or a protecting group, R.sup.5 is a hydrogen atom or a hydroxyl group, and is a single bond or a double bond, and its salt when R.sup.2 is a hydrogen atom.