Patents by Inventor Shawn DeFrees

Shawn DeFrees 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).

  • Low cost manufacture of oligosaccharides
    Publication number: 20020001831
    Abstract: This invention provides recombinant cells, reaction mixtures, and methods that are useful for the enzymatic synthesis of product saccharides. The recombinant cells contain a heterologous gene that encodes a glycosyltransferase which catalyzes at least one step of the enzymatic synthesis, as well as a system for generating a nucleotide sugar that can serve as a substrate for the glycosyltransferase.
    Type: Application
    Filed: January 8, 2001
    Publication date: January 3, 2002
    Inventors: Shawn Defrees, Karl Johnson
  • Enzymatic synthesis of oligosaccharides
    Patent number: 6030815
    Abstract: The present invention provides improved methods for the preparation of sialyl galactosides. The methods use sialyl transferase cycle in which the reaction conditions are optimized to provide increased yields.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: February 29, 2000
    Assignee: Neose Technologies, Inc.
    Inventors: Shawn DeFrees, Robert J. Bayer, Murray Ratcliffe
  • Enzymatic synthesis of glycosidic linkages
    Patent number: 5922577
    Abstract: The present invention provides improved methods for the formation of glycosidic linkages. These methods are useful for the preparation of compounds of formula:NeuAc.alpha.(2.fwdarw.3)Gal.beta.(1.fwdarw.4)(Fuc.alpha. 1.fwdarw.3)GlcN(R').beta.(1.fwdarw.3)Gal.beta.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: July 13, 1999
    Assignee: Cytel Corporation
    Inventors: Shawn Defrees, Robert J. Bayer, Murray Ratcliffe
  • Enzymatic synthesis of oligosaccharides
    Patent number: 5876980
    Abstract: The present invention provides improved methods for the preparation of sialyl galactosides. The methods use sialyl transferase cycle in which the reaction conditions are optimized to provide increased yields.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: March 2, 1999
    Assignee: Cytel Corporation
    Inventors: Shawn DeFrees, Robert J. Bayer, Murray Ratcliffe
  • Enzymatic synthesis of glycosidic linkages
    Patent number: 5728554
    Abstract: The present invention provides improved methods for the formation of glycosidic linkages. These methods are useful for the preparation of compounds of formula:NeuAc.alpha.(2.fwdarw.3)Gal.beta.(1.fwdarw.4)(Fuc.alpha. 1.fwdarw.3)GlcN(R').beta.(1.fwdarw.3)Gal.beta.
    Type: Grant
    Filed: April 11, 1995
    Date of Patent: March 17, 1998
    Assignee: Cytel Corporation
    Inventors: Robert J. Bayer, Shawn DeFrees, Murray Ratcliffe
  • Derivatives of phosphinic acid useful as endothelin converting enzyme inhibitors
    Patent number: 5476847
    Abstract: Phosphinic acid derivatives of the structural formula ##STR1## or a pharmaceutically acceptable salt thereof, wherein R is H, alkyl or alkanoyloxymethylene;R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are H, alkyl, alkenyl, alkenylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, hydroxyalkyl, carboxyalkyl, thioalkyl, alkoxythioalkyl, aminoalkyl, alkylaminoalkyl, cycloalkyl-substituted alkyl or heterocycloalkyl; or R.sub.1 and R.sub.2 form a cycloalkyl ring of 3-8 members and R.sub.3 and R.sub.4 are as defined; or R.sub.3 and R.sub.4 form a cycloalkyl ring of 3-7 members and R.sub.1 and R.sub.2 are as defined; or R.sub.1 and R.sub.2 together, and R.sub.3 and R.sub.4 together, each form a cycloalkyl ring;R.sub.5 is --OR.sub.9 or --NHR.sub.9, wherein R.sub.9 is hydrogen or alkyl;n is 0 or 1;A.sub.1 is p-aminobenzoyl or p-aminobenzenesulfonyl, or A.sub.1 and R.sub.5 together form a radical of an .alpha.-aminoacyl derivative; andR.sub.6 is phenylmethoxycarbonyl, arylcarbonyl, heteroarylcarbonyl or --A.sub.2 --R.sub.
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: December 19, 1995
    Assignee: Schering Corporation
    Inventors: Brian A. McKittrick, Michael F. Czarniecki, Samuel Chackalamannil, Shin Chung, Shawn DeFrees, Andrew W. Stamford