Patents by Inventor Vasulinga T. Ravikumar

Vasulinga T. Ravikumar 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).

  • Process for the synthesis of oligomeric compounds
    Publication number: 20030149260
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Application
    Filed: November 8, 2002
    Publication date: August 7, 2003
    Applicant: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole
  • Purification of oligonucleotides
    Patent number: 6586586
    Abstract: Methods and compounds useful for the purification of oligonucleotides and their analogs are provided wherein the oligonucleotides are contaminated with at least one oligonucleotide having at least one abasic site by the formation of imines at the aldehyde moiety of the abasic site and subsequent separation based on extractions, precipitations or chromatography.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: July 1, 2003
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Achim H. Krotz, Vasulinga T. Ravikumar
  • Process for the synthesis of oligomeric compounds
    Publication number: 20030088088
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. The oligomers have substantially reduced exocyclic adducts deriving from acrylonitrile or related contaminants.
    Type: Application
    Filed: August 30, 2002
    Publication date: May 8, 2003
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Methods for preparing oligonucleotides having chiral phosphorothioate linkages
    Publication number: 20030069410
    Abstract: Methods are provided for preparing internucleotide phosphorothioate linkages that are enhanced in the Sp or Rp enantiomer comprising coupling a synthon with a 2′-substituted nucleoside in the presence of coupling agent that is selected to enhance either the Rp or Sp
    Type: Application
    Filed: June 14, 2001
    Publication date: April 10, 2003
    Applicant: ISIS Pharmaceuticals, Inc.
    Inventor: Vasulinga T. Ravikumar
  • Process for the synthesis of oligomeric compounds
    Patent number: 6521775
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: February 18, 2003
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole
  • Process for the synthesis of oligomeric compounds
    Patent number: 6465628
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. The oligomers have substantially reduced exocyclic adducts deriving from acrylonitrile or related contaminants.
    Type: Grant
    Filed: April 9, 1999
    Date of Patent: October 15, 2002
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Reagent useful for synthesizing sulfurized oligonucleotide analogs
    Patent number: 6399831
    Abstract: The present invention is directed to a method of synthesizing sulfurized oligonucleotide analogs by reacting an oligonucleotide analog containing a phosphorous(III) linkage with a dithiocarbonic acid diester polysulfide having the formula to produce a sulfurized oligonucleotide analog. The diester polysulfide reagent is useful in solution and solid phase oligonucleotide analog synthesis.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: June 4, 2002
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole, Daniel C. Capaldi
  • Process for the synthesis of oligomeric compounds
    Patent number: 6399756
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Grant
    Filed: July 8, 1999
    Date of Patent: June 4, 2002
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole
  • Process for the synthesis of oligomeric compounds
    Publication number: 20020055623
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Application
    Filed: December 11, 2001
    Publication date: May 9, 2002
    Applicant: ISIS Pharmaceuticals. Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole
  • Method of preparing phosphoramidites
    Patent number: 6335439
    Abstract: Improved methods for preparation of phosphoramidite compounds are disclosed. The phosphoramidites are useful, for example, for the preparation of oligonucleotides by solid state oligonucleotide synthetic regimes.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: January 1, 2002
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Alessandra Eleuteri, Daniel C. Capaldi, Vasulinga T. Ravikumar
  • Process for the synthesis of oligomeric compounds
    Patent number: 6326478
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, phosphorodithioate, or other covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: December 4, 2001
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole
  • Synthesis of sulfurized 2'-substituted oligonucleotides
    Patent number: 6242591
    Abstract: Methods for the formation of sulfurized oligonucleotides are provided. The methods allow for the formation of phosphorothioate linkages in the oligonucleotides or derivatives, without the need for complex solvent mixtures and repeated washing or solvent changes. Oligonucleotides having from about 8, and up to about 50, nucleotides can be sulfuiized according to the methods of the invention with higher yields than have been previously reported.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: June 5, 2001
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Douglas L. Cole, Vasulinga T. Ravikumar, Zacharia S. Cheruvallath
  • Process for the synthesis of oligomeric compounds
    Patent number: 6160152
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, and phosphorodithioate covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Grant
    Filed: October 7, 1999
    Date of Patent: December 12, 2000
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Daniel C. Capaldi, Vasulinga T. Ravikumar
  • Synthesis of sulfurized oligonucleotides
    Patent number: 6114519
    Abstract: Methods for the formation of sulfurized oligonucleotides are provided. The methods allow for the formation of phosphorothioate linkages in the oligonucleotides or derivatives, without the need for complex solvent mixtures and repeated washing or solvent changes. Oligonucleotides having from about 8, and up to about 50, nucleotides can be sulfurized according to the methods of the invention with higher yields than have been previously reported.
    Type: Grant
    Filed: October 15, 1997
    Date of Patent: September 5, 2000
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Douglas L. Cole, Vasulinga T. Ravikumar, Zacharia S. Cheruvallath
  • Method for the synthesis of nucleotide or oligonucleotide phosphoramidites
    Patent number: 6103891
    Abstract: The present invention presents novel methods for recovery of phosphoramidites from the waste products of oligonucleotide synthesis. The methods include reacting a trihalophenoxydihalophosphorane with a H-phosphonate in the presence of an amine.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: August 15, 2000
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Richard H. Griffey, Douglas L. Cole, Vasulinga T. Ravikumar
  • Process for the synthesis of oligomeric compounds
    Patent number: 6051699
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, and phosphorodithioate covalent linkages. Also provided are synthetic intermediates useful in the processes.
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: April 18, 2000
    Assignee: Isis Pharmaceuticals, Inc.
    Inventor: Vasulinga T. Ravikumar
  • Reagent useful for synthesizing sulfurized oligonucleotide analogs
    Patent number: 6040438
    Abstract: The present invention is directed to a method of synthesizing sulfurized oligonucleotide analogs by reacting an oligonucleotide analog containing a phosphorous(III) linkage with a dithiocarbonic acid diester polysulfide having the formula ##STR1## to produce a sulfurized oligonucleotide analog. The diester polysulfide reagent is useful in solution and solid phase oligonucleotide analog synthesis.
    Type: Grant
    Filed: June 25, 1998
    Date of Patent: March 21, 2000
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole, Daniel C. Capaldi
  • Process for the synthesis of oligomeric compounds
    Patent number: 6020475
    Abstract: Synthetic processes are provided wherein oligomeric compounds are prepared having phosphodiester, phosphorothioate, and phosphorodithioate covalent linkages. Also provided are synthetic intermediates useful in such processes.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: February 1, 2000
    Assignee: Isis Pharmeuticals, Inc.
    Inventors: Daniel C. Capaldi, Vasulinga T. Ravikumar
  • Protecting group for synthesizing oligonucleotide analogs
    Patent number: 5959099
    Abstract: A 2-N-amidoethyl protected nucleoside analog phosphoramidite of formula (1): ##STR1## is useful in the synthesis of a wide variety of oligonucleotide analogs. Coupling yields with phosphoramidite (1) in solution or solid phase oligonucleotide analog synthesis are high and the 2-N-amidoethyl protecting group can be removed easily under standard conditions.
    Type: Grant
    Filed: June 24, 1998
    Date of Patent: September 28, 1999
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Daniel C. Capaldi, Vasulinga T. Ravikumar, Douglas L. Cole
  • Reagent useful for synthesizing sulfurized oligonucleotide analogs
    Patent number: 5902881
    Abstract: The present invention is directed to a method of synthesizing sulfurized oligonucleotide analogs by reacting an oligonucleotide analog containing a phosphorous(III) linkage with a dithiocarbonic acid diester polysulfide having the formula ##STR1## to produce a sulfurized oligonucleotide analog. The diester polysulfide reagent is useful in solution and solid phase oligonucleotide analog synthesis.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: May 11, 1999
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole, Daniel C. Capaldi