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).

  • Publication number: 20080293929
    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: Application
    Filed: April 21, 2008
    Publication date: November 27, 2008
    Applicant: Isis Pharmaceuticals, Inc.
    Inventors: Douglas L. Cole, Vasulinga T. Ravikumar, Zacharia S. Cheruvallath
  • Patent number: 7378516
    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: May 17, 2004
    Date of Patent: May 27, 2008
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Douglas L. Cole, Vasulinga T. Ravikumar, Zacharia S. Cheruvallath
  • Patent number: 7273933
    Abstract: Improved methods for synthesis of oligonucleotides and other phosphorus-linked oligomers are disclosed. The methods include the use of aromatic solvents, alkyl aromatic solvents, halogenated aromatic solvents, halogenated alkyl aromatic solvents, or aromatic ether solvents to achieve deprotection of protected hydroxyl groups.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: September 25, 2007
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Achim H. Krotz, Vasulinga T. Ravikumar
  • Patent number: 7227016
    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: December 28, 2004
    Date of Patent: June 5, 2007
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Patent number: 7227015
    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: January 10, 2001
    Date of Patent: June 5, 2007
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Douglas L. Cole, Vasulinga T. Ravikumar, Zacharia S. Cheruvallath
  • Patent number: 7199236
    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: September 14, 2004
    Date of Patent: April 3, 2007
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Patent number: 7041816
    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: January 20, 2004
    Date of Patent: May 9, 2006
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Patent number: 6858715
    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: August 30, 2002
    Date of Patent: February 22, 2005
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Patent number: 6858722
    Abstract: Synthetic processes are provided wherein oligomers are prepared using phosphoramidite compositions. Oligomers having phosphodiester, phosphorothioate, phosphorodithioate covalent linkages are prepared that can include other covalent linkages. Also provided are compositions useful in such processes.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: February 22, 2005
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Daniel C. Capaldi, Douglas L. Cole
  • Patent number: 6846922
    Abstract: The present invention relates to improved methods for the preparation of nucleoside phosphoramidites and oligonucleotides. In one aspect, the methods of the invention are used to prepare phosphitylating reagents using pyridinium salts as activators. In a further aspect, the methods of the invention are used to prepare internucleoside linkages using activators which include at least one pyridinium salt and at least one substituted imidazole. In a further aspect, methods are provided preparation of internucleoside linkages between nucleosides having 2?-substituents using imidazolium or benzimidazolium salts as an activator. In a further aspect, methods are provided preparation of internucleoside linkages between nucleosides having bioreversible protecting group that confers enhanced chemical and biophysical properties, without exocyclic amine protection, using imidazolium or benzimidazolium salts as an activator.
    Type: Grant
    Filed: November 8, 2000
    Date of Patent: January 25, 2005
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Muthia Manoharan, Vasulinga T. Ravikumar
  • Publication number: 20040219577
    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: January 20, 2004
    Publication date: November 4, 2004
    Inventors: Vasulinga T. Ravikumar, Muthiah Manoharan, Daniel C. Capaldi, Achim Krotz, Douglas L. Cole, Andrei Guzaev
  • Publication number: 20040185491
    Abstract: Improved methods for synthesis of oligonucleotides and other phosphorus-linked oligomers are disclosed. The methods include the use of aromatic solvents, alkyl aromatic solvents, halogenated aromatic solvents, halogenated alkyl aromatic solvents, or aromatic ether solvents to achieve deprotection of protected hydroxyl groups.
    Type: Application
    Filed: March 23, 2004
    Publication date: September 23, 2004
    Applicant: ISIS Pharmaceuticals, Inc.
    Inventors: Achim H. Krotz, Vasulinga T. Ravikumar
  • Patent number: 6677471
    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: November 8, 2002
    Date of Patent: January 13, 2004
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Zacharia S. Cheruvallath, Vasulinga T. Ravikumar, Douglas L. Cole
  • Publication number: 20030229220
    Abstract: Synthetic processes are provided wherein oligomers are prepared using phosphoramidite compositions. Oligomers having phosphodiester, phosphorothioate, phosphorodithioate covalent linkages are prepared that can include other covalent linkages. Also provided are compositions useful in such processes.
    Type: Application
    Filed: May 23, 2003
    Publication date: December 11, 2003
    Inventors: Vasulinga T. Ravikumar, Daniel C. Capaldi, Douglas L. Cole
  • Patent number: 6649750
    Abstract: Synthetic processes are provided wherein high purity oligomers are prepared using support bound phosphoramidite protocols starting with a nucleoside or larger synthon linked to a support media through a nucleosidic heterocyclic base moiety. Intermediates undergoing depurination at the support linkage site are removed during the wash cycle. Also provided are compositions useful in such processes.
    Type: Grant
    Filed: January 5, 2000
    Date of Patent: November 18, 2003
    Assignee: Isis Pharmaceuticals, Inc.
    Inventors: Daniel C. Capaldi, Vasulinga T. Ravikumar, Douglas L. Cole
  • Publication number: 20030212267
    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: Application
    Filed: December 12, 2002
    Publication date: November 13, 2003
    Inventors: Douglas L Cole, Vasulinga T Ravikumar, Zacharia S Cheruvallath
  • Patent number: 6642373
    Abstract: The present invention relates to improved methods for the preparation of nucleoside phosphoramidites and oligonucleotides. In one aspect, the methods of the invention are used to prepare phosphitylating reagents using pyridinium salts as activators. In a further aspect, the methods of the invention are used to prepare internucleoside linkages using activators which include at least one pyridinium salt and at least one substituted imidazole. In a further aspect, methods are provided preparation of internucleoside linkages between nucleosides having 2′-substituents using imidazolium or benzimidazolium salts as an activator. In a further aspect, methods are provided preparation of internucleoside linkages between nucleosides having bioreversible protecting group that confers enhanced chemical and biophysical properties, without exocyclic amine protection, using imidazolium or benzimidazolium salts as an activator.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: November 4, 2003
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Muthia Manoharan, Vasulinga T. Ravikumar
  • Publication number: 20030191304
    Abstract: The present invention relates to improved methods for the preparation of nucleoside phosphoramidites and oligonucleotides. In one aspect, the methods of the invention are used to prepare phosphitylating reagents using pyridinium salts as activators. In a further aspect, the methods of the invention are used to prepare internucleoside linkages using activators which include at least one pyridinium salt and at least one substituted imidazole. In a further aspect, methods are provided preparation of internucleoside linkages between nucleosides having 2′-substituents using imidazolium or benzimidazolium salts as an activator. In a further aspect, methods are provided preparation of internucleoside linkages between nucleosides having bioreversible protecting group that confers enhanced chemical and biophysical properties, without exocyclic amine protection, using imidazolium or benzimidazolium salts as an activator.
    Type: Application
    Filed: December 12, 2002
    Publication date: October 9, 2003
    Inventors: Muthiah Manoharan, Vasulinga T. Ravikumar
  • Patent number: 6610842
    Abstract: Synthetic processes are provided wherein oligomers are prepared using phosphoramidite compositions. Oligomers having phosphodiester, phosphorothioate, phosphorodithioate covalent linkages are prepared that can include other covalent linkages. Also provided are compositions useful in such processes.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: August 26, 2003
    Assignee: ISIS Pharmaceuticals, Inc.
    Inventors: Vasulinga T. Ravikumar, Daniel C. Capaldi, Douglas L. Cole
  • Publication number: 20030153742
    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: Application
    Filed: January 2, 2003
    Publication date: August 14, 2003
    Inventors: Achim H. Krotz, Vasulinga T. Ravikumar