Contains At Least One Ring Formed Only Through Peptide Links (c07k 5/12b) Patents (Class 930/DIG781)
  • Patent number: 5112944
    Abstract: A cyclic tetrapeptide having the formula (I): ##STR1## wherein n is 4 or 3 and a process for preparing the above cyclic tetrapeptide. The cyclic tetrapeptide of the present invention inhibits transformation of cells caused by oncogenes and possesses activities for recovering to a normal cell and for inhibiting proliferation of carcinoma cells. Therefore, the cyclic tetrapeptide of the present invention is useful for an active ingredient of an antitumor agent.
    Type: Grant
    Filed: June 12, 1990
    Date of Patent: May 12, 1992
    Assignee: Shionogi & Co., Ltd.
    Inventors: Kenji Sugita, Hiroshi Itazaki, Koichi Matsumoto, Yoshimi Kawamura