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 [ref]. 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 publication for details on the library and how it should be used. The TorsionAnalyzer software can be downloaded from here.
The full histograms derived from CSD data cannot be published due to legal restrictions. Apart from this, the full torsion pattern library including preferred angles and tolerances derived are made available as supporting information of the corresponding publication [ref]. We plan to make further updates of the library and derived data available here.
TorsionAnalyzer Pattern Set: Version 1.0
In 2015, colleagues at Roche and the ZBH optimized the torsion library. A detailled description about the changes made can be found here.
TorsionAnalyzer Pattern Set: Version 2.0
In July 2016, we updated to Version 2.1 which contains improvements related to a few patterns creating a high number of alerts.
Note that the current version 2.1 does not contain torsion data derived from the PDB. We plan to make this available in the near future. The torsion library including full histogram data is available for license holders of the Cambridge Structural Database (CSD) and is available for download from here.
The supporting information can be found here: pubs.acs.org/doi/suppl/10.1021/jm3016816
The second, updated version of the TorsionAnalyzer Pattern set is described and contained as supporting information in the following Application Note: http://pubs.acs.org/doi/abs/10.1021/acs.jcim.5b00522
The supporting information can be found here: http://pubs.acs.org/doi/suppl/10.1021/acs.jcim.5b00522
Ehrlich, H.-C., Rarey, M. (2012). Systematic benchmark of substructure search in molecular graphs - From Ullmann to VF2. Journal of Cheminformatics, 4(13).
Schärfer, C.; Schulz-Gasch, T.; Hert, J.; Heinzerling, L. ; Schulz, B.; Inhester, T.; Stahl, M.; Rarey, M. (2013). CONFECT: Conformations from an Expert Collection of Torsion Patterns. ChemMedChem, 8:1690-1700.
Guba, W.; Meyder, A.; Rarey, M.; Hert, J. (2015). Torsion Library Reloaded: A New Version of Expert-Derived SMARTS rules for Assessing Conformations of Small Molecules. Journal of Chemical Information and Modeling:in press.