Patents by Inventor Masahiko Nagakura

Masahiko Nagakura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4898876
    Abstract: A benzopylpiperazine ester of the following formula: ##STR1## wherein A represents a single bond or an alkylene group, vinylene group, --O--alkylene group or methine group, R.sub.1 represents a bicyclic carbon ring residue which may be substituted with a lower alkyl group, lower alkoxy group, oxo group or nitro group or a halogen atom, or may be partially saturated; a fluorene residue which may contain an oxo group; a fluorenylidene group; an anthracene residue; a phenanthrene residue which may be substituted with a lower alkyl group, or may be partially saturated; a benzofuran residue or thianaphthene residue which may be substituted with a lower alkyl group or lower alkoxy group; a benzopyran residue or benzoazine residue which may be substituted with an oxo group or phenyl group and partially saturated; a phthalimide residue; a benzodiazine residue; an isozazole residue which may be substituted with a lower alkyl group or phenyl group; or an alkylene dioxybenzene residue or xanthene residue; and R.sub.
    Type: Grant
    Filed: November 12, 1985
    Date of Patent: February 6, 1990
    Assignee: Kowa Co., Ltd.
    Inventors: Setsuro Fujii, Eizou Hattori, Mitsuteru Hirata, Koichiro Watanabe, Kazuhiro Onogi, Masahiko Nagakura
  • Patent number: 4755383
    Abstract: A pharmaceutical composition is disclosed which comprises a physiologically active substance possessing peptide bonds in its structure and being inactivable by digestive enzymes, the active substances being other than insulin, and a synthetic chymotrypsin inhibitor. The composition is particularly suitable for intestinal absorption of the active substance.
    Type: Grant
    Filed: June 30, 1986
    Date of Patent: July 5, 1988
    Assignee: Kowa Co., Ltd.
    Inventors: Setsuro Fujii, Touru Yokoyama, Kouji Ikegaya, Nobuo Yokoo, Masahiko Nagakura
  • Patent number: 4746737
    Abstract: Novel benzoyl esters of the following formula (I), and acid addition salts thereof, ##STR1## in which R.sub.1 and R.sub.2 are the same or different and represent a hydrogen atom or a lower alkoxy group, A represents a single bond, a linear or branched lower alkylene group, a lower alkenylene group, R.sub.3 and R.sub.4 are the same or different and represent a hydrogen atom or a lower alkyl group, or R.sub.3 and R.sub.4 join together to form a lower alkylene group, R.sub.5 represents a group of the formula, --X--(CO).sub.
    Type: Grant
    Filed: July 16, 1986
    Date of Patent: May 24, 1988
    Assignee: Kowa Co., Ltd.
    Inventors: Setsuro Fujii, Eizou Hattori, Mitsuteru Hirata, Koichiro Watanabe, Tomio Ohta, Nobuo Yokoo, Masahiko Nagakura
  • Patent number: 4639435
    Abstract: A pharmaceutical composition is disclosed which comprises a physiologically active substance possessing peptide bonds in its structure and being inactivable by digestive enzymes, the active substance being other than insulin, and a synthetic chymotrypsin inhibitor. The composition is particularly suitable for intestinal absorption of the active substance.
    Type: Grant
    Filed: June 27, 1984
    Date of Patent: January 27, 1987
    Assignee: Kowa Co., Ltd.
    Inventors: Setsuro Fujii, Touru Yokoyama, Kouji Ikegaya, Nobuo Yokoo, Masahiko Nagakura
  • Patent number: 4482562
    Abstract: A compound represented by the following formula ##STR1## wherein A represents a direct bond or the bond --O--CH.sub.2 --,B represents a C.sub.1 -C.sub.11 alkylene group bonded to a carbon atom of the aromatic ring D either directly or through --O--, --S--, --SO-- or --NH--,W represents a carbon or nitrogen atom,R.sub.1 represents a C.sub.3 -C.sub.7 alkyl group, a hydroxy-C.sub.1 -C.sub.6 alkyl group, or a phenyl- or diphenyl-alkyl group with the alkyl group having 1 to 4 carbon atoms,R.sub.2 represents a member selected from the group consisting of hydrogen, halogen, OH, C.sub.1 -C.sub.4 alkyl, NO.sub.2, C.sub.1 -C.sub.4 alkoxy, acetyl, allyloxy, carbamoyl and sulfamoyl, and when two or more R.sub.2 groups exist, they may be identical or different, andn represents 1, 2 or 3 and m represents 1 or 2, provided that n+m.gtoreq.4;and an acid addition salt thereof; a process for producing the same; and a pharmaceutical composition comprising aforesaid compound.
    Type: Grant
    Filed: September 3, 1982
    Date of Patent: November 13, 1984
    Assignee: Kowa Company, Ltd.
    Inventors: Masami Shiratsuchi, Noboru Shimizu, Hiromichi Shigyo, Yoshinori Kyotani, Hisashi Kunieda, Kiyoshi Kawamura, Seiichi Sato, Toshihiro Akashi, Masahiko Nagakura, Naotoshi Sawada, Yasumi Uchida
  • Patent number: 4394382
    Abstract: A benzopyran compound represented by the following ##STR1## wherein A represents a direct bond or the bond --CH.sub.2 --O--,R.sub.1 represents a member selected from the group consisting of a C.sub.3 -C.sub.5 alkyl group, a hydroxy-(C.sub.3 -C.sub.5 alkyl) group, a lower alkylamino-lower alkyl group, a nitrato-(C.sub.3 -C.sub.5 alkyl) group and a phenyl-(C.sub.1 -C.sub.5) alkyl group, provided that the phenyl may be substituted by a lower alkoxy group, R.sub.2 represents a member selected from the group consisting of hydrogen, halogen, OH, NO.sub.2, a carbamoyl group, a lower alkyl group, a lower alkoxy group, a lower alkyleneoxy group and acetyl group,R.sub.3 represents hydrogen or NO.sub.2,B represents a direct bond, a C.sub.1 -C.sub.7 alkylene group, a --O-lower alkylene group or a --CONH-lower alkylene group, andn represents 1 or 2;and an acid addition salt thereof and a pharmaceutical composition comprising aforesaid compound.
    Type: Grant
    Filed: June 9, 1981
    Date of Patent: July 19, 1983
    Assignee: Kowa Company, Ltd.
    Inventors: Masami Shiratsuchi, Noboru Shimizu, Hiromichi Shigyo, Yoshinori Kyotani, Hisashi Kunieda, Kiyoshi Kawamura, Seiichi Sato, Toshihiro Akashi, Masahiko Nagakura, Naotoshi Sawada, Yasumi Uchida
  • Patent number: 4382142
    Abstract: A compound represented by the formula, ##STR1## wherein R.sub.1 represents a hydrogen atom, and R.sub.2 represents a lower alkyl group, an aryl group, an aralkyl group, a lower alkylthio lower alkyl group, a lower alkyl group substituted by a carboxyl or hydroxyl group, or a 3-indolymethyl group, or wherein R.sub.1 and R.sub.2 define in combination an alkylene group, or a pharmaceutically acceptable acid addition salt thereof, is an anti-tumor agent for leukemia and malignant tumors.
    Type: Grant
    Filed: November 3, 1980
    Date of Patent: May 3, 1983
    Assignee: Kowa Co., Ltd.
    Inventors: Kichitaro Takatori, Takashi Yamaguchi, Masahiko Nagakura
  • Patent number: 4374840
    Abstract: A compound represented by the following formula ##STR1## wherein A represents a direct bond or the bond --0--CH.sub.2--,B represents a C.sub.1 -C.sub.11 alkylene group bonded to a carbon atom of the aromatic ring D either directly or through --O--, --S--, --SO-- or --NH--,W represents a carbon or nitrogen atom,R.sub.1 represents a C.sub.3 -C.sub.7 alkyl group, a hydroxy-C.sub.1 -C.sub.6 alkyl group, or a phenyl- or diphenyl-alkyl group with the alkyl group having 1 to 4 carbon atoms,R.sub.2 represents a member selected from the group consisting of hydrogen, halogen, OH, C.sub.1 -C.sub.4 alkyl, NO.sub.2, C.sub.1 -C.sub.4 alkoxy, acetyl, allyloxy, carbamoyl and sulfamoyl, and when two or more R.sub.2 groups exist, they may be identical or different, andn represents 1, 2 or 3 and m represents 1 or 2, provided that n+m.gtoreq.4;and an acid addition salt thereof; a process for producing the same; and a pharmaceutical composition comprising aforesaid compound.
    Type: Grant
    Filed: February 11, 1981
    Date of Patent: February 22, 1983
    Assignee: Kowa Company, Ltd.
    Inventors: Masami Shiratsuchi, Noboru Shimizu, Hiromichi Shigyo, Yoshinori Kyotani, Hisashi Kunieda, Kiyoshi Kawamura, Seiichi Sato, Toshihiro Akashi, Masahiko Nagakura, Naotoshi Sawada, Yasumi Uchida
  • Patent number: 4335247
    Abstract: The specification describes a nitrosourea derivative having the general formula: Cl--(CH.sub.2).sub.2 --N(NO)CO--NHR, wherein --NHR represents a 2-(1,3,4-thiadiazolyl)amino group, an amino residue of a neutral .alpha.-amino acid, or an amino residue of a neutral .alpha.-amino acid whose carboxyl group is amidated with 2-(1,3,4-thiadiazolyl)amine, or a pharmaceutically acceptable acid addition salt thereof. The above nitrosourea derivative and its salt are useful as antitumor drugs. The above nitrosourea derivative may be prepared either by nitrosating a urea derivative of the general formula: Cl--(CH.sub.2).sub.2 NHCONHR or by reacting N-(2-chloroethyl)-N-nitrosocarbamic acid or a reactive derivative thereof with an amino compound of the general formula: R--NH.sub.2.
    Type: Grant
    Filed: February 23, 1981
    Date of Patent: June 15, 1982
    Assignee: Kowa Co., Ltd.
    Inventors: Kichitaro Takatori, Takashi Yamaguchi, Masahiko Nagakura
  • Patent number: 4290954
    Abstract: A tetrahydroxanthone derivative represented by the general formula: ##STR1## wherein R is a hydrogen atom, a hydroxyl, cyano, lower alkyl, lower alkoxy, lower acyloxy, benzoyloxy or tetrazolyl group, or ##STR2## (R.sub.3 is a hydrogen atom, R.sub.4 is a hydrogen atom, a phenyl group which may be optionally substituted, or a tetrazolyl group; or R.sub.3 and R.sub.4 commonly form a ring together with the adjacent nitrogen atom and another nitrogen atom or an oxygen atom); R.sub.1 is a hydrogen or halogen atom, a lower alkyl, cyano, carboxyl or tetrazolyl group, or ##STR3## (R.sub.5 is a hydrogen atom, R.sub.6 is a phenyl group which may be optionally substituted, or a tetrazolyl group; or R.sub.5 and R.sub.6 commonly form a ring together with the adjacent nitrogen atom and an oxygen atom); and R.sub.2 is a hydrogen or halogen atom, or a lower alkyl group; with the proviso that neither R nor R.sub.1 is a hydrogen atom; when R is --CONH.sub.2, R.sub.1 and R.sub.
    Type: Grant
    Filed: October 30, 1979
    Date of Patent: September 22, 1981
    Assignee: Kowa Company Limited
    Inventors: Kazuhiro Onogi, Hisashi Kunieda, Kiyoshi Kawamura, Masami Shiratsuchi, Masahiko Nagakura, Naoki Machida, deceased, by Takayasu Miwa, heir
  • Patent number: 4217284
    Abstract: A novel monoester of cis-cyclopentenediol of the following formula ##STR1## wherein ##STR2## is an optically active acyl moiety. The monoester can be prepared by reacting cis-2-cyclopentene-1,4-diol with an optically active carboxylic acid of the following formula ##STR3## wherein ##STR4## is the same as defined above, or its reactive derivative, and separating the resulting reaction product into the two individual diastereomers. Lactones can be prepared from the monoesters selectively and with commercial advantage.
    Type: Grant
    Filed: June 30, 1978
    Date of Patent: August 12, 1980
    Assignee: Kowa Company Ltd.
    Inventors: Shun-ichi Yamada, Shiro Terashima, Masahiko Nagakura, Munehiko Nara
  • Patent number: 4216225
    Abstract: Methylmethioninesulfonium compounds of the formula ##STR1## wherein X.crclbar. represents an anion;R.sup.1 represents a hydrogen atom or an acyl group of the formula -COR.sup.3 in which R.sup.3 represents an alkyl group with 1 to 20 carbon atoms, the group --CH.sub.2).sub.2 COOH or the group ##STR2## in which Z represents a direct bond or a methylene or vinylene linkage, Y represents C or N, R.sup.4 represents a member selected from the class consisting of a hydrogen atom, lower alkyl groups, lower alkoxy groups, di-lower-alkylamino groups and a sulfamoyl group, n is a number of 1 to 3, and two or more R.sup.4 groups may be identical or different; andR.sup.2 represents the group --COOR.sup.5 in which R.sup.5 represents a hydrogen atom, an alkyl group with 1 to 5 carbon atoms or a metal- or metal complex-forming moiety, or the group ##STR3## in which R.sup.6 groups may be identical or different, and each represent a hydrogen atom or an alkyl group with 1 to 5 carbon atoms, with the proviso that when R.sup.
    Type: Grant
    Filed: May 16, 1978
    Date of Patent: August 5, 1980
    Assignee: Kowa Company, Ltd.
    Inventors: Masami Shiratsuchi, Kiyoshi Kawamura, Hisashi Kunieda, Naoki Machida, Toshihiro Akashi, Masahiko Nagakura
  • Patent number: 4170596
    Abstract: A novel monoester of cis-cyclopentenediol of the following formula ##STR1## wherein ##STR2## is an optically active acyl moiety. The monoester can be prepared by reacting cis-2-cyclopentene-1,4-diol with an optically active carboxylic acid of the following formula ##STR3## wherein ##STR4## is the same as defined above, or its reactive derivative, and separating the resulting reaction product into the two individual diastereomers. Lactones can be prepared from the monoesters selectively and with commercial advantage.
    Type: Grant
    Filed: October 4, 1977
    Date of Patent: October 9, 1979
    Assignee: Kowa Company, Ltd.
    Inventors: Shun-Ichi Yamada, Shiro Terashima, Masahiko Nagakura, Munehiko Nara