Patents by Inventor Luben K. Yankov

Luben K. Yankov 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: 6765015
    Abstract: This invention is directed to novel halogenated paclitaxel derivatives, processes for their preparation and use as effective anti-tumor agents.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: July 20, 2004
    Assignee: Xechem International, Inc.
    Inventors: Ramesh C. Pandey, Luben K. Yankov
  • Publication number: 20020107409
    Abstract: This invention is directed to novel halogenated paclitaxel derivatives, processes for their preparation and use as effective anti-tumor agents.
    Type: Application
    Filed: August 23, 2001
    Publication date: August 8, 2002
    Applicant: Xechem, Inc.
    Inventors: Ramesh C. Pandey, Luben K. Yankov
  • Patent number: 6177456
    Abstract: The present invention provides a 3″-monohalocephalomannine of the formula: wherein R is halogen.
    Type: Grant
    Filed: July 10, 1998
    Date of Patent: January 23, 2001
    Assignee: Xechem International, Inc.
    Inventors: Luben K. Yankov, Ramesh C. Pandey
  • Patent number: 5854278
    Abstract: Provided are novel paclitaxel analogues which are selectively chlorinated stereospecific derivatives of cephalomannine and 7-epi-cephalomannine having paclitaxel-like antitumor efficacy, methods for their preparation and methods for treating tumors with these compounds.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: December 29, 1998
    Assignee: Xechem International, Inc.
    Inventors: Ramesh C. Pandey, Luben K. Yankov, Raghu Nair, Alex Poulev
  • Patent number: 5840930
    Abstract: Provided are antineoplastic derivatives by a process of selective halogenation of side chains of unsaturated taxanes; more particularly, the process involves the use of halogens, particularly bromine, which is easily added to the side chain double bond of cephalomannine, leaving paclitaxel unchanged, and wherein diastereomeric mixtures of 2", 3"-dibromocephalomannine display high activity against: Leukemia cell line HL-60 (TB); Non-Small Cell Lung Cancer line NCI-H522; Colon Cancer cell lines COLO 205 and HT 29; CNS Cancer cell lines SF-539 and SNB-75; Ovarian Cancer Cell line OVCAR-3; Renal Cancer cell line RXF-393; and Breast Cancer cell lines MCF7, MDA-MB-231/ATCC, HS 578T, MDA-MB-435 and MDA-N.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: November 24, 1998
    Assignee: Xechem International, Inc.
    Inventors: Luben K. Yankov, Ramesh C. Pandey
  • Patent number: 5840748
    Abstract: Provided are antineoplastic derivatives by a process of selective halogenation of side chains of unsaturated taxanes; more particularly, the process involves the use of halogens, particularly bromine, which is easily added to the side chain double bond of cephalomannine, leaving paclitaxel unchanged, and wherein diastereomeric mixtures of 2", 3"-dibromocephalomannine display high activity against: Leukemia cell line HL-60 (TB); Non-Small Cell Lung Cancer line NCI-H522; Colon Cancer cell lines COLO 205 and HT 29; CNS Cancer cell lines SF-539 and SNB-75; Ovarian Cancer Cell line OVCAR-3; Renal Cancer cell line RXF-393; and Breast Cancer cell lines MCF7, MDA-MB-231/ATCC, HS 578T, MDA-MB-435 and MDA-N.
    Type: Grant
    Filed: December 13, 1995
    Date of Patent: November 24, 1998
    Assignee: Xechem International, Inc.
    Inventors: Luben K. Yankov, Ramesh C. Pandey
  • Patent number: 5807888
    Abstract: Provided are novel paclitaxel analogues, namely selectively brominated stereospecific derivatives of cephalomannine and 7-epi-cephalomannine having in vivo and in vitro paclitaxel-like antitumor efficacy, methods of preparation therefor and methods for treating tumors with these compounds.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: September 15, 1998
    Assignee: Xechem International, Inc.
    Inventors: Ramesh C. Pandey, Luben K. Yankov, Raghu Nair, Alex Pouley
  • Patent number: 5654448
    Abstract: A novel process for extraction, isolation and separation of taxanes, particularly paclitaxel, from natural sources such as bark, needles and twigs from Taxus species, tissue cultures, and fungi is described, wherein the taxanes are separated from the crude extracts by partitioning between polar and nonpolar solvents, precipitation in nonpolar solutions, reacting the mixture by halogenation of unsaturated taxane derivatives, followed by chromatographically separating and crystallizing taxanes from a mixture of polar and nonpolar solvents; more particularly, the process of halogenation of unsaturated side chain taxane derivatives, particularly cephalomannine in presence of paclitaxel, is described, wherein bromine is preferably added to the double bond of unsaturated taxanes leaving paclitaxel unchanged, with paclitaxel being easily separated from the mixture including the less polar halogenated taxane derivatives.
    Type: Grant
    Filed: December 13, 1995
    Date of Patent: August 5, 1997
    Assignee: Xechem International, Inc.
    Inventors: Ramesh C. Pandey, Luben K. Yankov