Find Patent Markush Structures

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Use a Patent Markush search to find structures (including generic structures) matching your query within patent references.

For example:


The inventor need not have tested or prepared all members of the family, but can make a chemically plausible claim of equivalence via a Markush structure.

A Markush search differs from a substructure search in that it matches the structure query against generic structures found in patents. The result is a list of patent references.


Markush searches use the following structure presets:

  • Element Count LIMITED:
    • all atoms (Ring and Chain)
    • A, Q, M, X, Ak, Cb, Cy and Hy variables
  • Match Level Atom:
    • all Ring atoms
    • A, Q, M, X variables in Rings
    • Cb, Cy and Hy variables
  • Match Level Class:
    • all Chain atoms
    • A, Q, M, X variables in Chains
    • Ak variables
  • All chain nodes and bonds are Chain-only.
  • All rings are Isolated.

Note: Shortcuts (such as Me, Et, etc.) are considered atoms, so the above atom presets will also apply to these.

To conduct a Patent Markush search, click the Substances search type. Draw the query using a structure editor, and then check the box for Search Patent Markush.

Click the magnifying glass to submit the query.


Results are displayed on the Patent Markush page.