Abstract: The present invention provides compounds and medicines effective for prophylaxis and therapy of various diseases by controlling or inhibiting cell-adhesion. Especially, the compounds of this invention perform platelet aggregation action without remarkable elongation of hemorrhagic period and can be used as a safe and long-acting antithrombotic drug as compared with known substances showing the same activity.

Abstract: (1) a compound represented by the following formula (I): ##STR1## wherein R represents a hydrocarbon group or heterocyclic group which may be substituted; the ring A represents a pyridine ring having a substituent or a thiazole ring which may be substituted; or a pharmaceutically acceptable salt thereof, and a method of its production, and(2) an endothelin receptor antagonist, an cathepsin B inhibitor or a bone resorption suppressor having as an active ingredient a compound represented by the following formula (I'): ##STR2## wherein R has the same definition as in term (1); the ring A' represents a pyridine ring or thiazole ring which may be substituted; or a pharmaceutically acceptable salt thereof.