Patents by Inventor Itaru Tsukada

Itaru Tsukada 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: 8252294
    Abstract: The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite P. falciparum. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.
    Type: Grant
    Filed: March 4, 2011
    Date of Patent: August 28, 2012
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Katsura Hata, Kaoru Ogawa, Itaru Tsukada, Kazutaka Nakamoto, Koji Sagane, Keigo Tanaka, Kappei Tsukahara, Toshihiro Horii
  • Publication number: 20110201816
    Abstract: The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite P. falciparum. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.
    Type: Application
    Filed: March 4, 2011
    Publication date: August 18, 2011
    Applicant: EISAI R&D MANAGEMENT CO., LTD
    Inventors: Katsura Hata, Kaoru Ogawa, Itaru Tsukada, Kazutaka Nakamoto, Koji Sagane, Keigo Tanaka, Kappei Tsukahara, Toshihiro Horii
  • Patent number: 7999090
    Abstract: The present invention provides isolated DNA encoding a GWT1 protein having activity to confer resistance of a fungus against a compound of formula Ia, and wherein a defect of a function of the GWT1 protein leads to a decrease in the amount of a glycosylphosphatidylinositol (GPI)-anchored protein in the cell wall of a fungus.
    Type: Grant
    Filed: April 15, 2008
    Date of Patent: August 16, 2011
    Assignee: Eisai Co., Ltd
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20110195999
    Abstract: The present invention provides an antifungal agent represented by the formula: wherein A1 represents a 3-pyridyl group which may have a substituent, a quinolyl group which may have a substituent, or the like; X1 represents a group represented by the formula —NH—C(?O)—, a group represented by the formula —C(?O)—NH—, or the like; E represents a furyl group, a thienyl group, a pyrrolyl group, a phenyl group, a pyridyl group, a tetrazolyl group, a thiazolyl group or a pyrazolyl group; with the proviso that A1 may have 1 to 3 substituents, and E has one or two substituents.
    Type: Application
    Filed: March 14, 2011
    Publication date: August 11, 2011
    Inventors: Kazutaka NAKAMOTO, Itaru Tsukada, Keigo Tanaka, Masayuki Matsukura, Toru Haneda, Satoshi Inoue, Norihiro Ueda, Shinya Abe, Katsura Hata, Naoaki Watanabe
  • Patent number: 7932272
    Abstract: The present invention provides an antifungal agent represented by the formula: [wherein A1 represents a 3-pyridyl group which may have a substituent, a quinolyl group which may have a substituent, or the like; X1 represents a group represented by the formula —NH—C(?O)—, a group represented by the formula —C(?O)—NH—, or the like; E represents a furyl group, a thienyl group, a pyrrolyl group, a phenyl group, a pyridyl group, a tetrazolyl group, a thiazolyl group or a pyrazolyl group; with the proviso that A1 may have 1 to 3 substituents, and E has one or two substituents].
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: April 26, 2011
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kazutaka Nakamoto, Itaru Tsukada, Keigo Tanaka, Masayuki Matsukura, Toru Haneda, Satoshi Inoue, Norihiro Ueda, Shinya Abe, Katsura Hata, Naoaki Watanabe
  • Patent number: 7928215
    Abstract: The present inventors succeeded in isolating GWT1 (PfGWT1), which is one of the enzymes involved in GPI biosynthesis in the malaria parasite P. falciparum. In addition, the inventors revealed that degenerate mutant DNAs, with a lower AT content than the DNA encoding the PfGWT1 protein, can complement the phenotype of GWT1-deficient yeast. Based on the findings, the present invention provides the GWT1 protein of malaria parasites and the use of the protein in methods of screening for antimalarial drugs. The present invention also provides degenerate mutant DNAs encoding proteins involved in GPI biosynthesis, and which have a lower AT content than the original DNAs. The present invention also provides methods of screening for antimalarial drugs which use the degenerate mutant DNAs.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: April 19, 2011
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Katsura Hata, Kaoru Ogawa, Itaru Tsukada, Kazutaka Nakamoto, Koji Sagane, Keigo Tanaka, Kappei Tsukahara, Toshihiro Horii
  • Patent number: 7928209
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: April 19, 2011
    Assignee: Eisai R & D Management Co. Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7910712
    Abstract: The present invention provides isolated DNA encoding a GWT1 protein having activity to confer resistance of a fungus against a compound of formula Ia, and wherein a defect of a function of the GWT1 protein leads to a decrease in the amount of a glycosylphosphatidylinositol (GPI)-anchored protein in the cell wall of a fungus.
    Type: Grant
    Filed: April 15, 2008
    Date of Patent: March 22, 2011
    Assignee: Eisai R&D Management Co., Ltd
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7897387
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: March 1, 2011
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20090325228
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 15, 2008
    Publication date: December 31, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Oba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20090227799
    Abstract: Disclosed is an antimalarial agent containing a compound represented by the formula: [wherein A1 represents a 3-pyridyl group that may have a substituent, a 6-quinolyl group that may have a substituent, or the like; X1 represents a group represented by the formula —C(?O)—NH— or the like; E represents a furyl group, a thienyl group or a phenyl group; with the proviso that A1 may have one to three substituents, and E has one of two substituents] or a salt thereof or hydrates thereof.
    Type: Application
    Filed: August 8, 2005
    Publication date: September 10, 2009
    Inventors: Kazutaka Nakamoto, Masayuki Matsukura, Keigo Tanaka, Satoshi Inoue, Itaru Tsukada, Toru Haneda, Norihiro Ueda, Shinya Abe, Koji Sagane
  • Publication number: 20090215795
    Abstract: A cyclic amidine derivative represented by the formula: [wherein R1, R2 and R3 represent hydrogen, C1-6 alkyl, aryl-C1-6 alkyl, etc.; R4, R5 and R7 represent hydrogen, C1-6 alkyl, etc.; Z represents 0 or 1; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; n represents 1 or 2; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; Ar represents hydrogen, a group represented by the formula: [wherein R10-R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc., and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocycle], etc.] or a salt thereof.
    Type: Application
    Filed: July 17, 2008
    Publication date: August 27, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD.
    Inventors: Shuichi Suzuki, Makoto Kotake, Mitsuaki Miyamoto, Tetsuya Kawahara, Akiharu Kajiwara, Ieharu Hishinuma, Kazuo Okano, Syuhei Miyazawa, Richard Clark, Fumihiro Ozaki, Nobuaki Sato, Masanobu Shinoda, Atsushi Kamada, Itaru Tsukada, Fumiyoshi Matsuura, Yoshimitsu Naoe, Taro Terauchi, Yoshiaki Oohashi, Osamu Ito, Hiroshi Tanaka, Takashi Musha, Motoji Kogushi, Tsutomu Kawata, Toshiyuki Matsuoka, Hiroko Kobayashi, Ken-ichi Chiba, Akifumi Kimura, Naoto Ono
  • Patent number: 7541332
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: June 2, 2009
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20090117586
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 1, 2008
    Publication date: May 7, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD.
    Inventors: KAPPEI TSUKAHARA, KATSURA HATA, KOJI SAGANE, KAZUTAKA NAKAMOTO, MAMIKO TSUCHIYA, NAOAKI WATANABE, FUMINORI OHBA, ITARU TSUKADA, NORIHIRO UEDA, KEIGO TANAKA, JUNKO KAI
  • Publication number: 20090098636
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 15, 2008
    Publication date: April 16, 2009
    Applicant: EISAI R&D MANAGEMENT CO., LTD
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20080261272
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: April 15, 2008
    Publication date: October 23, 2008
    Applicant: EISAI R&D MANAGEMENT CO., LTD
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Publication number: 20080166765
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Application
    Filed: December 17, 2007
    Publication date: July 10, 2008
    Applicant: Eisai R&D Management, Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Oba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7375204
    Abstract: A reporter system reflecting the transport process that transports GPI-anchored proteins to the cell wall was constructed and compounds inhibiting this process were discovered. Further, fungal genes conferring resistance to the above compounds were identified and methods of screening for compounds that inhibit the activity of the proteins encoded by these genes were developed. These genes encode proteins participating in fungal cell wall synthesis. Therefore, through the novel compounds, the present invention showed that antifungal agents having a novel mechanism, i.e. inhibiting the process that transports GPI-anchored proteins to the cell wall, could be achieved.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: May 20, 2008
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Kappei Tsukahara, Katsura Hata, Koji Sagane, Kazutaka Nakamoto, Mamiko Tsuchiya, Naoaki Watanabe, Fuminori Ohba, Itaru Tsukada, Norihiro Ueda, Keigo Tanaka, Junko Kai
  • Patent number: 7304083
    Abstract: A 2-iminoimidazole derivative represented by the formula: {wherein R1, R2 and R3 represent hydrogen, optionally substituted C1-6 alkyl, etc.; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; and Ar represents hydrogen, a group represented by the formula: [wherein R10–R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc., and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocycle], etc.}or salt thereof.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: December 4, 2007
    Assignee: Eisai R&D Management Co., Ltd.
    Inventors: Shuichi Suzuki, Makoto Kotake, Mitsuaki Miyamoto, Tetsuya Kawahara, Akiharu Kajiwara, Ieharu Hishinuma, Kazuo Okano, Syuhei Miyazawa, Richard Clark, Fumihiro Ozaki, Nobuaki Sato, Masanobu Shinoda, Atsushi Kamada, Itaru Tsukada, Fumiyoshi Matsuura, Yoshimitsu Naoe, Taro Terauchi, Yoshiaki Oohashi, Osamu Ito, Hiroshi Tanaka, Takashi Musha, Motoji Kogushi, Tsutomu Kawata, Toshiyuki Matsuoka, Hiroko Kobayashi, Ken-ichi Chiba, Akifumi Kimura, Naoto Ono
  • Patent number: 7244730
    Abstract: A 2-iminopyrrolidine derivative represented by the formula: {wherein ring B represents a benzene ring, pyridine ring, etc.; R101–R103 represent hydrogen, halogen, C1-6 alkyl, etc.; R5 represents hydrogen, C1-6 alkyl, C1-6 alkoxy-C1-6 alkyl, etc.; R6 represents hydrogen, C1-6 alkyl, C1-6 alkyloxycarbonyl, etc.; Y1 represents a single bond, —CH2—, etc.; Y2 represents a single bond, —CO—, etc.; and Ar represents hydrogen, a group represented by the formula: [wherein R10—R14 represent hydrogen, C1-6 alkyl, hydroxyl, C1-6 alkoxy, etc.; and R11 and R12 or R12 and R13 may bond together to form a 5- to 8-membered heterocyclic ring], etc.}, or a salt thereof.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: July 17, 2007
    Assignee: Eisai Co., Ltd
    Inventors: Shuichi Suzuki, Makoto Kotake, Mitsuaki Miyamoto, Tetsuya Kawahara, Akiharu Kajiwara, Ieharu Hishinuma, Kazuo Okano, Syuhei Miyazawa, Richard Clark, Fumihiro Ozaki, Nobuaki Sato, Masanobu Shinoda, Atsushi Kamada, Itaru Tsukada, Fumiyoshi Matsuura, Yoshimitsu Naoe, Taro Terauchi, Yoshiaki Oohashi, Osamu Ito, Hiroshi Tanaka, Takashi Musya, Motoji Kogushi, Tsutomu Kawada, Toshiyuki Matsuoka, Hiroko Kobayashi, Ken-ichi Chiba, Akifumi Kimura, Naoto Ono