Patents by Inventor Hans J. Cahnmann

Hans J. Cahnmann 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).

  • Method for concentrating a solute by countercurrent chromatography
    Patent number: 5354473
    Abstract: A method for concentrating a solute from a mixture by countercurrent chromatography, by introducing a stationary phase into a countercurrent chromatographic centrifuge, introducing a sample of a mixture containing a solute into the centrifuge, introducing a sufficient quantity of an elution peak sharpening agent into the centrifuge, introducing a mobile phase into the centrifuge, and performing countercurrent chromatographic centrifugation. The eluting fractions containing the concentrated solute are identified and collected.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: October 11, 1994
    Assignee: The United States of America as represented by the Departent of Health and Human Services
    Inventors: Yoichiro Ito, Hans J. Cahnmann
  • Synthesis and characterization of N-bromoacetyl-3,3'5-triiodo-L-thyronine using high speed countercurrent chromatography
    Patent number: 5169984
    Abstract: A method for synthesizing N-bromoacetyl-3,3',5-triiodo-L-thyronine which involves subjecting 3,3', 5-triiodo-L-thyronine to a one-step bromacetylation reaction wherein 3,3', 5-triiodo-L-thyronine and bromoacetyl bromide are refluxed together in a solution of ethyl acetate. After formation the N-bromoacetyl-3,3'-triiodo-L-thyronine is purified by fractionation utilizing high speed countercurrent chromatography. Labeled N-bromoacetyl-3,3'-5-triiodo-L-thryonine may be made by a one-step bromacetylation reaction by reducing either [.sup.125 I]T.sub.3 or [.sup.14 C]T.sub.3 with bromoacetyl bromide.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: December 8, 1992
    Assignee: The United States of America as represented by the Department of Health and Human Services
    Inventors: Hans J. Cahnmann, Yoichiro Ito