Patents by Inventor Hidetoshi Kaga

Hidetoshi Kaga 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).

  • 2,3-diketopiperazine derivatives or their salts
    Patent number: 6153613
    Abstract: The present invention relates to a 2,3-diketopiperazine derivative or a salt thereof, which has inhibitory effect on platelet aggregation because of glycoprotein IIb/IIIa receptor antagonism and hence is useful as a prophylactic and therapeutic agent for diseases associated with platelet aggregation.General formula ##STR1## wherein R.sup.1 represents a protected or unprotected amidino group; R.sup.2 represents a hydrogen atom or a carboxyl-protecting group; A represents a substituted or unsubstituted lower alkylene group; B represents --O--, --CONH--, --NHCO-- or --SO.sub.2 NH--; Y represents a substituted or unsubstituted lower alkylene group; and the broken line represents a single bond or a double bond.
    Type: Grant
    Filed: October 29, 1998
    Date of Patent: November 28, 2000
    Assignee: Toyoma Chemical Co., Ltd.
    Inventors: Satoshi Ono, Tetsuo Yamafuji, Hirohiko Yamamoto, Hiroyuki Egawa, Yousuke Furuta, Hidetoshi Kaga
  • 2,3-diketopiperazine derivatives or their salts
    Patent number: 5877174
    Abstract: The present invention relates to a 2,3-diketopiperazine derivative or a salt thereof, which has inhibitory effect on platelet aggregation because of glycoprotein IIb/IIIa receptor antagonism and hence is useful as a prophylactic and therapeutic agent for diseases associated with platelet aggregation. General formula: ##STR1## wherein R.sup.1 represents a protected or unprotected amidino group; R.sup.2 represents a hydrogen atom or a carboxyl-protecting group; A represents a substituted or unsubstituted lower alkylene group; B represents --O--, --CONH--, --NHCO--or --SO.sub.2 NH--; Y represents a substituted or unsubstituted lower alkylene group; and the broken line represents a single bond or a double bond.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: March 2, 1999
    Assignee: Toyama Chemical Co., Ltd.
    Inventors: Satoshi Ono, Tetsuo Yamafuji, Hirohiko Yamamoto, Hiroyuki Egawa, Yousuke Furuta, Hidetoshi Kaga