Patents by Inventor Kenichiro Nokata

Kenichiro Nokata 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: 5061800
    Abstract: New campotothecin derivatives and a process for preparing same are disclosed, which are represented by the general formula: ##STR1## wherein R.sup.1 represents a lower alkyl group, R.sup.2 represents a hydrogen atom or an amino, hydroxyl, lower acylamino or lower alkoxy group, R.sup.3 represents a hydrogen or halogen atom or a lower alkyl, hydroxyl, lower alkoxy, nitro, amino, cyano or di(lower alkyl)amino group, R.sup.4 represents a hydrogen or halogen atom or a lower alkyl, hydroxyl, lower alkoxy, lower alkylthio, amino, cyano or di(lower alkyl)amino group, and R.sup.5 represents a hydrogen or halogen atom or a hydroxyl or lower alkoxy group, with the proviso that all of the R.sup.2, R.sup.3, R.sup.4 and R.sup.5 substituents should not be a hydrogen atom and also that if any one of the R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is a hydroxyl or lower alkoxy group, all of the other three substituents should not be a hydrogen atom.
    Type: Grant
    Filed: January 19, 1989
    Date of Patent: October 29, 1991
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Takashi Yaegashi, Satoru Okajima, Seigo Sawada, Kenichiro Nokata, Kenichi Tezuka, Hiroshi Nagata, Teruo Yokokura, Tadashi Miyasaka, Tadashi Miyasaka
  • Patent number: 4914205
    Abstract: New camptothecin derivatives, useful as antitumor agents or intermediates therefor, of the general formula (I) ##STR1## wherein X is a lower alkyl group, and R is a hydrogen atom or the grouping -COY where Y is a linear or branched unsubstituted C.sub.1 -C.sub.18 alkyl group; a lower alkyl group substituted by a halogen atom or a lower alkylthio, amino, acylamino, hydroxyl, lower alkoxy, aryloxy or lower alkoxycarbonyl group; a C.sub.3 -C.sub.19 alkenyl, C.sub.3 -C.sub.19 alkynyl or C.sub.3 -C.sub.8 cycloalkyl group; a C.sub.3 -C.sub.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: April 3, 1990
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Seigo Sawada, Kenichiro Nokata, Satoru Okajima, Hisako Nagai, Takashi Yaegashi, Kenichi Tezuka, Tadashi Miyasaka
  • Patent number: 4604463
    Abstract: New camptothecin derivatives possessing high anti-tumor activity with slight toxicity, represented by the general formula: ##STR1## wherein R.sup.1 is a hydrogen atom, a halogen atom or an alkyl group with 1-4 carbon atoms and X is a chlorine atom or --NR.sup.2 R.sup.3 where R.sup.2 and R.sup.3 are the same or different and each represents a hydrogen atom, a substituted or unsubstituted alkyl group with 1-4 carbon atoms or a substituted or unsubstituted carbocyclic or heterocyclic group, with the proviso that when both R.sup.2 and R.sup.3 are the substituted or unsubstituted alkyl groups, they may be combined together with the nitrogen atom, to which they are bonded, to form a heterocyclic ring which may be interrupted with --O--, --S-- and/or >N--R.sup.4 in which R.sup.
    Type: Grant
    Filed: July 5, 1984
    Date of Patent: August 5, 1986
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Seigo Sawada, Kenichiro Nokata, Eiichi Sugino, Masahiko Mutai
  • Patent number: 4545880
    Abstract: New Camptothecin derivatives possessing high anti-tumor activity with slight toxicity, represented by the general formula: ##STR1## wherein R.sup.1 stands for a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group or an acyloxy group, R.sup.2 for a hydrogen atom, an alkyl group, an aralkyl group, a hydroxymethyl group, a carboxymethyl group or an acyloxymethyl group, and R.sup.3 for the grouping --XR' (where R' is a hydrogen atom, an alkyl group or an acyl group and X is an oxygen atom or a sulfur atom), a nitro group, an amino group, an alkylamino group, an acylamino group or a halogen atom, with the proviso that when both of R.sup.1 and R.sup.2 are hydrogen atoms, R.sup.3 should not be hydroxyl group, methoxy group or acetoxy group. These new camptothecin derivatives are prepared by treating a 5-R.sup.1 -7-R.sup.2 camptothecin derivative with a peroxidant and then reacting the resultant 5-R.sup.1 -7-R.sup.
    Type: Grant
    Filed: July 18, 1984
    Date of Patent: October 8, 1985
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Seigo Sawada, Kenichiro Nokata, Masahiko Mutai
  • Patent number: 4513138
    Abstract: New 5- and/or 7-substituted camptothecin-1-oxide derivatives possessing anti-tumor activity with slight toxicity, represented by the general formula: ##STR1## wherein R is a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group or an acyloxy group and R' is a hydrogen atom, an alkyl group, an aralkyl group, a hydroxymethyl group, an acyloxymethyl group or a carboxymethyl group, with the proviso that both of R and R' should not be hydrogen atoms. These 5- and/or 7-substituted camptothecin-1-oxide derivatives are prepared by treating the corresponding 5- and/or 7-substituted camptothecins with a peroxidant as an N-oxidizing reagent.
    Type: Grant
    Filed: September 2, 1982
    Date of Patent: April 23, 1985
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Seigo Sawada, Kenichiro Nokata, Masahiko Mutai
  • Patent number: 4473692
    Abstract: New Camptothecin derivatives possessing high anti-tumor activity with slight toxicity, represented by the general formula: ##STR1## wherein R.sup.1 is a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group or an acyloxy group, R.sup.2 for a hydrogen atom, an alkyl group, an aralkyl group, a hydroxymethyl group, a carboxymethyl group or an acyloxymethyl group, and R.sup.3 is the grouping --XR' (where R' is a hydrogen atom, an alkyl group or an acyl group and X is an oxygen atom or a sulfur atom), a nitro group, an amino group, an alkylamino group, an acylamino group or a halogen atom, with the proviso that when both of R.sup.1 and R.sup.2 are hydrogen atoms, R.sup.3 should not be a hydroxyl group, methoxy group or acetoxy group. These new camptothecin derivatives are prepared by treating a 5-R.sup.1 -7-R.sup.2 -camptothecin derivative with a peroxidant and then reacting the resultant 5-R.sup.1 -7-R.sup.
    Type: Grant
    Filed: September 1, 1982
    Date of Patent: September 25, 1984
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Seigo Sawada, Kenichiro Nokata, Masahiko Mutai
  • Patent number: 4399276
    Abstract: New 7-substituted camptothecin derivatives possessing anti-tumor activity with slight toxicity, represented by the general formula: ##STR1## wherein R stands for --CHO, --CH.sub.2 OR', --CH(OR').sub.2 or --CH.dbd.N--X where R' is a lower alkyl group with 1-6 carbon atoms or a phenylalkyl group with 1-3 carbon atoms in the alkylene moiety thereof, and X is a hydroxyl group or --NR.sup.1 R.sup.2 where R.sup.1 and R.sup.2 are the same or different and each represents a hydrogen atom or a lower alkyl group with 1-6 carbon atoms, or when R.sup.1 is hydrogen, R.sup.2 may be a lower alkyl group with 1-6 carbon atoms, a substituted or unsubstituted aryl group, a carbamoyl group, an acyl group, an aminoalkyl group or an amidino group, or when R.sup.1 is the lower alkyl group, R.sup.2 may be an aminoalkyl group, or R.sup.1 and R.sup.2 may be combined together with the nitrogen atom, to which R.sup.1 and R.sup.2 are bound, to form a heterocyclic group, and quaternary salts thereof.
    Type: Grant
    Filed: December 31, 1981
    Date of Patent: August 16, 1983
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Masahiko Mutai, Seigo Sawada, Kenichiro Nokata
  • Patent number: 4399282
    Abstract: New camptothecin derivatives possessing either or both of high anti-tumor activity and slight toxicity, represented by the general formula: ##STR1## wherein X is H, CH.sub.2 OH, COOH, an alkyl group, an aralkyl group or the grouping CH.sub.2 OR.sup.1 or COOR.sup.2 wherein R.sup.1 is an alkyl group or an acyl group and R.sup.2 is a lower alkyl group, Y is H, OH or the grouping OR.sup.3 wherein R.sup.3 is a lower alkyl group or an acyl group, and Z is H or an acyl group, with the proviso that when X is CH.sub.2 OH, an alkyl group or an aralkyl group, both Y and Z are H, that when X is the grouping CH.sub.2 OR.sup.1 or COOR.sup.2, Y is H, that when Y is OH, both X and Z are H, and that when Y is the grouping OR.sup.3, X is H, and water-soluble alkali metal salts thereof.
    Type: Grant
    Filed: July 8, 1980
    Date of Patent: August 16, 1983
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Masahiko Mutai, Seigo Sawada, Kenichiro Nokata, Hisao Hagiwara
  • Patent number: RE32518
    Abstract: New camptothecin derivatives possessing either or both of high anti-tumor activity and slight toxicity, represented by the general formula: ##STR1## wherein X is H, CH.sub.2 OH, COOH, an alkyl group, an aralkyl group or the grouping CH.sub.2 OR.sup.1 or COOR.sup.2 wherein R.sup.1 is an alkyl group or an acyl group and R.sup.2 is a lower alkyl group, Y is H, OH or the grouping OR.sup.3 wherein R.sup.3 is a lower alkyl group or an acyl group, and Z is H or an acyl group, with the proviso that when X is CH.sub.2 OH, an alkyl group or an aralkyl group, both Y and Z are H, that when X is the grouping CH.sub.2 OR.sup.1 or COOR.sup.2, Y is H, that when Y is OH, both X and Z are H, .[.and.]. that when Y is the grouping OR.sup.3, X is H, .Iadd.and that X, Y and Z are not each simultaneously hydrogen, .Iaddend.and water-soluble alkali metal salts thereof.
    Type: Grant
    Filed: November 29, 1984
    Date of Patent: October 13, 1987
    Assignee: Kabushiki Kaisha Yakult Honsha
    Inventors: Tadashi Miyasaka, Masahiko Mutai, Seigo Sawada, Kenichiro Nokata, Hisao Hagiwara