Abstract: Disclosed is an anti-foot-and-mouth disease virus agent for an animal belonging to the Family Suidae, which comprises 3-oxo-3,4-dihyro-2-pyrazincarboxamide or a salt thereof. The agent is extremely useful for the prevention or treatment of food-and-mouth disease in an animal belonging to the Family Suidae. Also disclosed is an anti-foot-and-mouth disease virus agent for sheep, which comprises 3-oxo-3,4-dihyro-2-pyrazincarboxamide or a salt thereof. The agent is extremely useful for the prevention, therapy or the like of food-and-mouth disease in sheep.

Abstract: The present invention relates to a 2,3-diketopiperazine derivative or a salt thereof, which has inhibitory effect on platelet aggregation because of glycoprotein IIb/IIIa receptor antagonism and hence is useful as a prophylactic and therapeutic agent for diseases associated with platelet aggregation.General formula ##STR1## wherein R.sup.1 represents a protected or unprotected amidino group; R.sup.2 represents a hydrogen atom or a carboxyl-protecting group; A represents a substituted or unsubstituted lower alkylene group; B represents --O--, --CONH--, --NHCO-- or --SO.sub.2 NH--; Y represents a substituted or unsubstituted lower alkylene group; and the broken line represents a single bond or a double bond.

Abstract: This invention relates to a novel aminothiazole intermediate for production of a cephalosporin of antibiotic activity.