TorsionAnalyzer enables the analysis and inspection of torsion angles in small molecules. The tool is based on a collection of SMARTS patterns and rules derived from collections of high-quality crystal structures. The rotatable bonds of a molecule are assigned to three categories (frequent, moderately frequent, infrequent) and colored accordingly. Users can evaluate large quantities of molecules with a given torsion library. The result table contains each torsion bond along with its corresponding torsion rule, angle, observed frequency, and quality category. The software displays a molecule in a conformation of interest and highlights bonds that exhibit geometrically unusual torsion angles. The software was developed in collaboration with F. Hoffmann-La Roche Ltd. in Basel and the ZBH - Center for Bioinformatics. 
With TorsionAnalyzer, you can visually inspect the torsion angles of a given molecule and compare the angles to those observed in the Cambridge Structural Database (CSD) or Protein Data Bank (PDB) or recalculate angle frequencies based on your own data set.
TorsionPatternMiner is an all-in-one command-line tool to populate torsion angle statistics for SMARTS torsion patterns for selected libraries of molecular conformations. SMARTScompare enables in-depth SMARTS pattern analysis. Users can apply the resulting torsion rules in many conformer generators such as Conformator, RDKit, or OMEGA.

Publikationen

1. Penner, P.; Guba, W.; 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, 62(7):1644-1653.
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.
3. 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):2016-2028.