Wakamoto Pharmaceutical Co., Ltd.

Mitsuzi Agata

Masayoshi Goto

Shohei Sawaki

Yasuhiro Ootake

Yoshihiro Horio

Sinji Inukai

Takeo Ohmura

Kiyoshi Akiba

Jun Matsumoto

Toshie Takahashi

Hatsunori Toyofuku

Manami Umezawa

Masakazu Ebie

Naomi Sasada

A 1,2,4-oxadiazole derivative is represented by the following general formula (I): ##STR1## wherein R.sup.1 represents a lower alkyl or cycloalkyl group, a lower alkyl group substituted with a halogen atom, a lower alkylamino group or a phenyl group; R.sup.2 represents a hydrogen atom, a lower dialkylamino group, a cyclic alkylamino group, a cyclic amino group having an oxygen or nitrogen atom in the ring, a phenyl group which may be substituted with a halogen atom, a pyridyl group, an imidazolyl group, an alkylimidazolyl group, a benzimidazolyl group or a 2-oxopyrrolidinyl group; and n is 1, 2 or 3. The derivative has excellent monoamine oxidase-inhibitory activity and is effective as a medicine for treating Parkinson's disease.

1,2,4-oxadiazole derivatives having monoamine oxidase B

A tetrazoleacetic acid derivative represented by the following general formula (I): ##STR1## [in Formula (I), R.sub.1 represents a hydrogen atom or a lower alkyl group; R.sub.2, R.sub.3 and R.sub.4 are the same or different from each other and are selected from the group consisting of hydrogen, lower alkyl, halogen, lower haloalkyl, hydroxy and lower alkoxy; and tetrazol group is substituted at 1- or 2-position of naphthyl group] except for [5-(1-naphthyl)tetrazol-1-yl]acetic acid and ethyl ester thereof, or a salt thereof.

Tetrazoleacetic acid derivatives having aldose reductase inhibitory

A tetrazoleacetic acid derivative represented by the following general formula (I): ##STR1## [in Formula (I), R.sub.1 represents a hydrogen atom or an alkyl group; R.sub.2 represents a hydrogen atom, an alkyl group, an aralkyl group, a halogen atom, a haloalkyl group, a hydroxyl group, an alkoxy group, an alkoxyalkyl group, an amino group, an aryl group, an alkyl or aryl thio group, an alkyl or aryl carbonylamino group, an alkyl or aryl sulfonylamino group, an alkyl or aryl aminosulfonyl group, an alkyl or aryl sulfonyl group or an alkyl or aryl sulfinyl group; and X represents --O-- or --S--] except for [5-(2-thienyl)tetrazol-1-yl] acetic acid, [5-(2-furyl)tetrazol-1-yl] acetic acid and ethyl esters thereof, or a salt thereof shows excellent aldose reductase inhibitory activity, has low toxicity to organisms and is quite effective as an essential component of a preventive medicine and/or remedy for diabetic complications.

Tetrazoleacetic acid derivatives and use for aldose reductase inhibitory

The present invention relates to an aldose reductase inhibitor having the following formula: ##STR1## R.sub.1 is a hydrogen atom or --A--COOR.sub.5 (A is an alkylene group having 1 to 4 carbon atoms and R.sub.5 is a hydrogen atom or a lower alkyl group), and R.sub.2, R.sub.3 and R.sub.4 are the same as or different from each other and selected from the group consisting of a hydrogen atom, a hydroxy group, a halogen atom, a carboxyl group, an alkyl group, an amide group, an amino group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an alkylsulfinyl group, an alkylsulfonyl group, a nitro group, --NHCOCOOR.sub.6 (R.sub.6 is a hydrogen atom or a lower alkyl group), a mono- or dialkylaminosulfonyl group, and a residual group having the following formula: ##STR2## (A and R.sub.5 are the same as in the above). The compounds defined in the above are excellent in aldose reductase inhibitory activity and low in toxicity. Therefore, those compounds are useful as a preventive agent and/or a remedy for diabetic complications such as neuropathy, retinopathy, nephropathy, cataracts and keratopathy.

Tetrazole derivatives and aldose reductase inhibition therewith

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Kanagawa, Japan

Mitsuzi Agata