Torsion Library

Crystal structure databases offer ample opportunities to derive small molecule conformation preferences. We developed a comprehensive and extendable expert system enabling quick assessment of the probability of a given conformation to occur [1]. It is based on a hierarchical system of torsion patterns that cover a large part of druglike chemical space. Each torsion pattern has associated frequency histograms generated from CSD and PDB data and, derived from the histograms, traffic-light rules for frequently observed, rare, and highly unlikely torsion ranges. Please see the publications for details on the library and how it should be used.

The full histograms derived from CSD data could not be published for the 2013 and 2016 Torsion Library due to legal restrictions. This has changed with the 2022 version of the Torsion Library, which includes both CSD as well as PDB histograms. The full torsion pattern library including preferred angles and tolerances derived are made available as supporting information of the corresponding publications [1][2][3]. We plan to also make further updates of the library and derived data available here.

- Version 1.0 [Torsion Library 2013]

- Version 2.0 [Torsion Library 2016]

- Version 3.0 [Torsion Library 2022]

References

1. Schärfer, C.; Schulz-Gasch, T.; Ehrlich, H.-C.; Guba, W.; Rarey, M., Stahl, M. (2013). Torsion Angle Preferences in Drug-like Chemical Space: A Comprehensive Guide. Journal of Medicinal Chemistry, 56(6), 2016-28. DOI

2. Guba, W., Meyder, A., Rarey, M., Hert, J. (2016) Torsion Library Reloaded: A New Version of Expert-Derived SMARTS Rules for Assessing Conformations of Small Molecules. Journal of Chemical Information and Modeling, 56(1), 1-5. DOI

3. Penner, P., Guba, G., Schmidt, R., Meyder, A., Stahl, M., Rarey, M. (2022) The Torsion Library: Semiautomated Improvement of Torsion Rules with SMARTScompare. Journal of Chemical Information and Modeling, XX(X), X-X. DOI