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Expired Canadian patentCanada

Chromogenic dibenzoxazepinone enzyme substrates

CA 2013525 C · Owner: Corey, Paul F. · Inventors: Corey, Paul F.

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Chromogenic enzyme substrate compounds comprising a dibenz b,e1,4oxazepinone or dibenzob,e1,4thiazepinone nucleus having an enzyme-cleavable group such as a radical of a sugar carboxylic acid, amino acid, peptide, phosphoric acid, or sulfuric acid. The substrate compounds are, in general, highly soluble in aqueous media and only slightly colored, and produce, upon enzyme cleavage, a chromogen exhibiting a large change in absorbance and a pKa below 7. Such substrates find use as indicators for the determination of enzyme analytes and enzymes used as markers in a variety of assays, including immunoassays.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed March 30, 1990 and granted March 4, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 30, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 30, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 30, 1990
GrantedMarch 4, 1997
Term endedMarch 30, 2010
Patent numberCA 2013525 C
Classification (IPC)C07D267/18 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedMarch 30, 1990Patent grantedMarch 4, 1997Term endedMarch 30, 2010

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.