Patents by Inventor Isamu Saikawa

Isamu Saikawa 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: 4477664
    Abstract: A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and an acid addition salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: October 16, 1984
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Takako Hori, Chosaku Yoshida, Yasuo Kiba, Ryuko Takeno, Joji Nakano, Jun Nitta, Sumiko Kishimoto, Shohachi Murakami, Hisatsugu Tsuda, Isamu Saikawa
  • Patent number: 4477666
    Abstract: A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and an acid addition salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: October 16, 1984
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Takako Hori, Chosaku Yoshida, Yasuo Kiba, Ryuko Takeno, Joji Nakano, Jun Nitta, Sumiko Kishimoto, Shohachi Murakami, Hisatsugu Tsuda, Isamu Saikawa
  • Patent number: 4460774
    Abstract: A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and an acid addition salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: July 17, 1984
    Assignee: Toyama Chemical Company, Limited
    Inventors: Takako Hori, Chosaku Yoshida, Yasuo Kiba, Ryuko Takeno, Joji Nakano, Jun Nitta, Sumiko Kishimoto, Shohachi Murakami, Hisatsugu Tsuda, Isamu Saikawa
  • Patent number: 4459407
    Abstract: A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and a salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.
    Type: Grant
    Filed: February 2, 1982
    Date of Patent: July 10, 1984
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Takako Hori, Chosaku Yoshida, Yasuo Kiba, Ryuko Takeno, Joji Nakano, Jun Nitta, Sumiko Kishimoto, Shohachi Murakami, Hisatsugu Tsuda, Isamu Saikawa
  • Patent number: 4448963
    Abstract: A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and an acid addition salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: May 15, 1984
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Takako Hori, Chosaku Yoshida, Yasuo Kiba, Ryuko Takeno, Joji Nakano, Jun Nitta, Sumiko Kishimoto, Shohachi Murakami, Hisatsugu Tsuda, Isamu Saikawa
  • Patent number: 4444753
    Abstract: A composition comprising a component obtained by deproteinizing an extract from the poison pouch contents of bee has an immunostimulating activity, a carcinostatic activity, an effect of enhancing the antibacterial activity of an antibacterial substance and an effect of enhancing the carcinostatic activity of a carcinostatic substance. This invention is directed to a carcinostatic, immunostimulating and antibacterial agent comprising said composition.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: April 24, 1984
    Assignee: Toyama Chemical Company, Ltd.
    Inventors: Isamu Saikawa, Takashi Yasuda, Shohachi Murakami, Toyoo Maeda, Akira Yotsuji, Masahiro Takahata, Hisatsugu Tsuda, Hidetada Mikami, Hiroshi Sakai, Toshinori Ohashi
  • Patent number: 4436921
    Abstract: A 1-(4-aminobenzyl)-2,3-dioxopiperazine derivative represented by the formula: ##STR1## and an acid addition salt thereof have excellent carcinostatic activity but a low toxicity. Therefore, said compounds are useful as medicines and also as intermediates.
    Type: Grant
    Filed: July 16, 1980
    Date of Patent: March 13, 1984
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Takako Hori, Chosaku Yoshida, Yasuo Kiba, Ryuko Takeno, Joji Nakano, Jun Nitta, Sumiko Kishimoto, Shohachi Murakami, Hisatsugu Tsuda, Isamu Saikawa
  • Patent number: 4428936
    Abstract: An antibacterial composition for medical use comprising a cephalosporin or a pharmaceutically acceptable salt thereof and a .beta.-lactamase-inhibiting compound having a .beta.-lactam ring. The composition exhibits synergistic effect which is much greater than the sum of antibacterial effects of each component used alone.
    Type: Grant
    Filed: September 16, 1980
    Date of Patent: January 31, 1984
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Takashi Yasuda, Masaru Tai, Yutaka Takashita, Hiroshi Sakai, Michiko Mae, Masahiro Takahata, Susumu Mitsuhashi
  • Patent number: 4410522
    Abstract: Novel penicillins and cephalosporins and non-toxic salts thereof, which contain a mono- or di-oxo- or thioxo-piperazino(thio)carbonylamino group in molecule. These compounds are valuable antibacterial compounds for use in mammals including man. This disclosure relates to such compounds and a process for the preparation thereof.
    Type: Grant
    Filed: October 12, 1977
    Date of Patent: October 18, 1983
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Chosaku Yoshida, Okuta Takashima, Kaishu Momonoi, Seietsu Kuroda, Miwako Komatsu, Takashi Yasuda, Yutaka Kodama
  • Patent number: 4395412
    Abstract: A 7.alpha.-methoxycephalosporin represented by the general formula: ##STR1## wherein R.sup.1 represents a hydrogen atom or a carboxyl-protecting group; R.sup.2 represents an organic group linked to the carbon atom through an oxygen or sulfur atom; R.sup.3 represents a lower alkyl group; n is 0, 1 or 2; A represents a hydrogen atom or a substituted or unsubstituted alkyl group; and B represents a substituted or unsubstituted alkyl, cycloalkyl, cycloalkenyl, cycloalkadienyl or heterocyclic group, and a salt thereof. These compounds have a broad antibacterial spectrum, high resistance to .beta.-lactamase produced from bacteria, and an effective antibacterial activity against clinical isolates of bacteria.
    Type: Grant
    Filed: December 31, 1980
    Date of Patent: July 26, 1983
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Hiroyuki Imaizumi, Isamu Takakura, Hirokazu Ochiai, Takashi Yasuda, Hideo Taki, Masaru Tai, Yutaka Kodama
  • Patent number: 4385178
    Abstract: This disclosure relates to a novel process for producing 7-(substituted)amino-3-substituted thiomethyl cephem carboxylic acids which are intermediate products of cephalosporins being valuable antibacterial compounds for use in mammals including man.
    Type: Grant
    Filed: December 17, 1981
    Date of Patent: May 24, 1983
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Kaishu Momonoi, Isamu Takakura, Seietsu Kuroda, Kiyoshi Tanaka, Kenshin Hayashi, Bunei Nagahashi, Chiaki Kutani
  • Patent number: 4379152
    Abstract: Novel penicillins and cephalosporins and non-toxic salts thereof, which contain a mono- or di-oxo- or thioxo-piperazino(thio)carbonylamino group in molecule. These compounds are valuable antibacterial compounds for use in mammals including man. This disclosure relates to such compounds and a process for the preparation thereof.
    Type: Grant
    Filed: May 17, 1979
    Date of Patent: April 5, 1983
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Chosaku Yoshida, Okuta Takashima, Kaishu Momonoi, Seietsu Kuroda, Miwako Komatsu, Takashi Yasuda, Yutaka Kodama
  • Patent number: 4370316
    Abstract: A method for treating a host mammal having a decreased immunity, comprising administering to said host mammal an immunostimulating effective amount of the deproteinized extract from the poison pouch contents of bee B-T, is disclosed.
    Type: Grant
    Filed: May 7, 1980
    Date of Patent: January 25, 1983
    Assignee: Toyama Chemical Company, Ltd.
    Inventors: Isamu Saikawa, Takashi Yasuda, Shohachi Murakami, Toyoo Maeda, Akira Yotsuji, Masahiro Takahata, Hisatsugu Tsuda, Hidetada Mikami, Hiroshi Sakai, Toshinori Ohashi
  • Patent number: 4327097
    Abstract: Novel penicillins and cephalosporins and non-toxic salts thereof, which contain a mono- or di-oxo- or thioxo-piperazino(thio)carbonylamino group have been prepared. These compounds are valuable anti-bacterial compounds for use in mammals including man. A process for the preparation of the compounds has also been discovered.
    Type: Grant
    Filed: June 12, 1979
    Date of Patent: April 27, 1982
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Chosaku Yoshida, Okuta Takashima, Kaishu Momonoi, Seietsu Kuroda, Miwako Komatsu, Takashi Yasuda, Yutaka Kodama
  • Patent number: 4324783
    Abstract: An antibacterial composition for medical use comprising 6-[D(-)-.alpha.-(4-ethyl-2,3-dioxo-1-piperazinylcarbonylamino)phenylacetam ido]penicillanic acid or a pharmaceutically acceptable salt thereof and a .beta.-lactamase-inhibiting penicillin or cephalosporin. The composition exhibits synergistic effect which is much greater than the sum of antibacterial effects of each component used alone.
    Type: Grant
    Filed: January 17, 1980
    Date of Patent: April 13, 1982
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Takashi Yasuda, Masaru Tai, Yutaka Takashita, Hiroshi Sakai, Michiko Mae, Masahiro Takahata, Susumu Mitsuhashi
  • Patent number: 4321265
    Abstract: A 7.alpha.-methoxycephalosporin represented by the general formula: ##STR1## wherein R.sup.1 represents a hydrogen atom or a carboxyl-protecting group; R.sup.2 represents an organic group linked to the carbon atom through an oxygen or sulfur atom; R.sup.3 represents a lower alkyl group; n is 0, 1 or 2; A represents a hydrogen atom or a substituted or unsubstituted alkyl group; and B represents a substituted or unsubstituted alkyl, cycloalkyl, cycloalkenyl, cycloalkadienyl or heterocyclic group, and a salt thereof. These compounds have a broad antibacterial spectrum, high resistance to .beta.-lactamase produced from bacteria, and an effective antibacterial activity against clinical isolates of bacteria.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: March 23, 1982
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Hiroyuki Imaizumi, Isamu Takakura, Hirokazu Ochiai, Takashi Yasuda, Hideo Taki, Masaru Tai, Yutaka Kodama
  • Patent number: 4317907
    Abstract: This disclosure relates to a novel process for producing 7-(substituted)amino-3-substituted thiomethyl cephem carboxylic acids which are intermediate products of cephalosporins being valuable antibacterial compounds for use in mammals including man.
    Type: Grant
    Filed: February 2, 1978
    Date of Patent: March 2, 1982
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Kaishu Momonoi, Isamu Takakura, Seietsu Kuroda, Kiyoshi Tanaka, Kenshin Hayashi, Bunei Nagahashi, Chiaki Kutani
  • Patent number: 4312986
    Abstract: This disclosure relates to a novel process for producing 7-(substituted)-amino-3-substituted thiomethyl-.DELTA..sup.3 -cephem-4-carboxylic acids which are intermediate products of cephalosporins being valuable antibacterial compounds for use in mammals including man.
    Type: Grant
    Filed: July 5, 1979
    Date of Patent: January 26, 1982
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Kaishu Momonoi, Isamu Takakura, Seietsu Kuroda, Kiyoshi Tanaka, Kenshin Hayashi, Bunei Nagahashi, Chiaki Kutani
  • Patent number: 4304909
    Abstract: The N,N-dimethylacetamide adduct of 7-[D(-)-.alpha.-(4-ethyl-2,3-dioxo-1-piperazinecarboxamido)-.alpha.-(4-hyd roxyphenyl)acetamido]-3-[5-(1-methyl-1,2,3,4-tetrazolyl)thiomethyl]-.DELTA. .sup.3 -cephem-4-carboxylic acid, a process for the production thereof, and a process for producing said acid and a pharmaceutically acceptable salt thereof through said adduct.
    Type: Grant
    Filed: August 24, 1979
    Date of Patent: December 8, 1981
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Kaishu Momonoi, Isamu Takakura, Chiaki Kutani, Kiyoshi Tanaka, Kenshin Hayashi
  • Patent number: 4263292
    Abstract: A 7.alpha.-methoxycephalosporin represented by the general formula and a salt thereof: ##STR1## wherein R.sup.1 represents a hydrogen atom or a carboxyl-protecting group; R.sup.2 represents an organic group linked to the carbon atoms through an oxygen or sulfur atom; R.sup.3 represents a lower alkyl group; n is 0, 1 or 2; A represents a hydrogen atom or a substituted or unsubstituted alkyl group; and B represents a substituted or unsubstituted alkyl group. These compounds have a broad antibacterial spectrum and high resistance to .beta.-lactamase produced from bacteria, and are well absorbed in a living body.
    Type: Grant
    Filed: October 4, 1979
    Date of Patent: April 21, 1981
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Isamu Saikawa, Shuntaro Takano, Hiroyuki Imaizumi, Isamu Takakura, Hirokazu Ochiai, Takashi Yasuda, Hideo Taki, Masaru Tai, Yutaka Kodama