The technology available to handle and analyse Markush-based libraries has been pioneered by BCI, a wholly owned subsidiary of Digital Chemistry. Our approach enables the very rapid analysis of extremely large combinatorial libraries at speeds only achieved using proprietary BCI technology.

Markush structures occur frequently in chemical patent claims, enabling the protection of a class of compounds rather than a few specific structures. Markush structures also have a number of applications outside the patent field; most substructure search systems use some Markush features and the results of QSAR analyses are frequently presented in the form of a Markush structure.

Combinatorial libraries may also be conveniently represented as Markush structures. Although analysis of such libraries can be achieved via enumeration of all of the individual structures represented, more efficient techniques have been developed that allow (sub)structure searching and property calculation of specific molecules within the libraries without the need for enumeration. Moreover, new possibilities are provided through an ability to analyse the Markush format itself - library comparisons, such as overlap analysis for example, may be readily achieved.

• Extremely rapid enumeration of specifics for the members of a library, typically > 500,000 structures per second.
• Calculation of physicochemical properties (including the Lipinski "rule of 5" properties), topological indices and structure fingerprints for library members, without the need for prior enumeration of the structures.
• Identification of the overlap between combinatorial libraries, without the need for full enumeration.
• Ability to define custom properties based upon fragment weightings.
• Full structure and substructure searching within combinatorial libraries (also without enumeration).
• Library data is interchangeable with other parts of the Digital Chemistry Toolkit, for example to allow clustering of library members with the Clustering components.