Senju Pharmaceutical Co., Ltd.

Kazuhiko Ito

Kazumi Ogata

Takahiro Sakaue

Hidetoshi Nakao

Shinya Ogino

Masahito Iemura

Sachiko Inoue

Yutaka Inoue

Yuuichi Isowaki

A novel &#x3b1;-lipoic acid derivative represented by the following formula (I). It has a tyrosinase inhibiting activity, melanin production inhibitory activity, and elastase inhibiting activity. (I) (In the formula, M represents a metal and A denotes an amino acid residue bonded through the nitrogen atom.). 

Method of suppressing melanin production by metal chelates of lipoyl amino acid derivatives

The present invention provides novel vitamin E derivatives represented by the following formula (I) wherein: R and R are the same or different and each denotes hydrogen or methyl, R denotes an S-linked SH compound (glutathione, &ggr;-glutamylcysteine, cysteine, penicillamine, an ester thereof or cysteamine), and R denotes hydroxyl, a N-substituted amino acid (glycine, &bgr;-alanine, &ggr;-aminobutyric acid, 5-aminovaleric acid, &egr;-aminocaproic acid, anthranilic acid, tranexamic acid, proline, an ester thereof, aminoethylsulfonic acid , aminoethylsulfinic acid) or serotonin, or a pharmacologically acceptable salt thereof, which are useful as hepatopathy suppressing agents, anticataract agents, cerebral metabolism improving agents, antioxidants and cosmetic components.

Vitamin E derivatives

Hydroquinone derivatives

Urocanic acid derivatives useful as antiallergic agents represented by the following formula (I) or a pharmacologically acceptable salt thereof:

Urocanic acid derivatives

The present invention provides a piperazine derivative of the following formula or a pharmacologically acceptable salt thereof ##STR1## wherein R.sub.1 represents a benzene ring, naphthalene ring, quinoline ring, indole ring or chroman ring that may be substituted by lower alkyl, lower alkoxy and/or hydroxy; R.sub.2 and R.sub.3 independently represent hydrogen or lower alkyl. The compound of the present invention has potent antiallergic activity and can therefore be used with advantage in the treatment of various allergic diseases.

Piperazine derivative

This invention provides a benzylpiperazine derivative of formula (I) and a pharmacologically acceptable salt thereof ##STR1## wherein R.sub.1 represents a pyridine ring or a group of either formula (IV) or formula (V); R.sub.2 represents hydrogen or lower alkyl ##STR2## wherein R.sub.3 represents hydrogen, lower alkyl, a pyridine ring or a benzene ring which may be substituted by halogen; X represents halogen ##STR3## wherein R.sub.4 and R.sub.5 may be the same or different and each represents hydrogen, lower alkyl, lower alkoxy, halogen or carboxy.

Benzylpiperazine derivative

This invention provides a novel steroid derivative having the structure of an ester between the carboxyl group of a quinolonecarboxylic acid and the alcoholic hydroxyl group in 21-position of asteroid compound, which has the following formula (I) (wherein R is a hydrogen atom, a methyl group or a hydroxyl group) or a pharmacologically acceptable salt thereof. ##STR1## The compound of this invention has high antibacterial activity and antiinflammatory activity.

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Hyogo, Japan

Kazuhiko Ito