Abstract: Aminophenol derivatives represented by the following formula (1): ##STR1## wherein X is O or S; A is alkylene, R.sup.1 is phenyl, etc., R.sup.2 and R.sup.3 are H or alkyl; R.sup.4 is substituted carbamoylalkyl, etc.; R.sup.5 is substituted amino, etc.; their salts, and optical isomers of the derivatives and salts. Also disclosed are gastrin receptor antagonists, cholecystokinin receptor antagonists, and medicines for digestive diseases. The compounds have strong binding inhibition against gastrin receptor or CCK-A receptor and also they have higher selectivity to either group of CCK-A receptor or gastrin receptor, and therefore, the compounds are useful for preventing and treating gastrointestinal diseases including peptic ulcers as well as central nervous system diseases.

Abstract: An optically action pyridobenzoxazine derivative, a process for preparing the same and a novel intermediate useful for preparing the optically active pyridobenzoxazine derivative are disclosed. The optically active pyridobenzoxazine derivative possesses increased antimicrobial activity and reduced toxicity. The intermediate is useful for preparing such optically active pyridobenzoxazine derivatives such as Ofloxacin and anolog compounds.

Abstract: A compound represented by the following formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom, an alkyl group or a cyclic alkyl group;R.sub.2 represents a hydroxyl group, an alkoxy group which may have one to three substituents in the alkyl group moiety, an arylthio group which may have one or more substituents in the aryl group moiety, an aryloxy group which may have one or more substituents in the aryl group moiety, an amino group, an alkylamino group or a cyclic amino group which may contain other hetero atoms as ring atoms selected from a nitrogen atom, an oxygen atom and a sulfur atom;R.sub.

Abstract: An optically action pyridobenzoxazine derivative, a process for preparing the same and a novel intermediate useful for preparing the optically active pyridobenzoxazine derivative are disclosed. The optically active pyridobenzoxazine derivative possesses increased antimicrobial activity and reduced toxicity. The intermediate is useful for preparing such optically active pyridobenzoxazine derivatives such as Ofloxacin and anolog compounds.

Abstract: An optically action pyridobenzoxazine derivative, a process for preparing the same and a novel intermediate useful for preparing the optically active pyridobenzoxazine derivative are disclosed. The optically active pyridobenzoxazine derivative possesses increased antimicrobial activity and reduced toxicity. The intermediate is useful for preparing such optically active pyridobenzoxazine derivatives such as Ofloxacin and anolog compounds.

Abstract: Novel tricyclic triazolopyrimidine compounds represented by formula (I) shown in the specification and physiologically acceptable salts thereof are disclosed. These compounds have an excellent anti-allergic activity and are useful for treatment and prophylaxis of allergic diseases.

Abstract: Novel 4-oxoguinoline-3-carboxylic acid derivatives having the formula ##STR1## wherein X.sup.1 represents a halogen or hydrogen atom, X.sup.2 represents a halogen or hydrogen atom, X.sup.3 represents a halogen atom, and R.sup.1, R.sup.2 and R.sup.3 each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and physiologically acceptable salts thereof, are disclosed. These compounds have excellent antibacterial activity against gram-positive and gram-negative bacteria and beneficial pharmacokinetic properties.