Package chemaxon.alignment

Class AtropIsomerDetector

java.lang.Object
chemaxon.alignment.AtropIsomerDetector
All Implemented Interfaces:
Licensable
@PublicApi public class AtropIsomerDetector extends Object implements Licensable
Molecular mechanics based atropisomer detection.

If the full rotation around a rotatable bond is blocked a steric proximity usually two isomers occurs. The algorithm rotates all rotatable bonds stepwise and optimizes the conformation id the domain of the remaining dihedrals. The energy values are obtained from MMFF dihedral potential and MMFF long range. If the conformational energy barrier is higher than a user defined limit that bond defined as atrop bond by the current implementation.

Usage:

 Molecule m = MolImporter
         .importMol("CC(C)[C@@](C)(N(C(=O)C=C)C1=C(I)C=CC=C1)C(O)=O");
 AtropIsomerDetector atp = new AtropIsomerDetector();
 atp.calculate(m);
 int[] found = atp.getAtropBonds();

Limitations:

  • The presence of a single rotational barrier is recognized as an atrop bond. This can result false positives for simpler hindered rotatable bonds.
  • Symmetries of the rotated parts are not examined. This can result in false positives for symmetric structures showing rotation barriers without differentiable conformers.
See Also:

  • Field Details

    • DEFAULT_SAMPLING_ACCURACY

      public static final int DEFAULT_SAMPLING_ACCURACY
      Default for parameter setSamplingAccuracy(int).

  • Constructor Details

  • Method Details

    • isLicensed

      public boolean isLicensed()
      Description copied from interface: Licensable
      Checks if the required license is available for using this class or product.
      Specified by:
      isLicensed in interface Licensable
      Returns:
      true if this software component is correctly licensed

    • setLicenseEnvironment

      public void setLicenseEnvironment(String env)
      Description copied from interface: Licensable
      Sets the current license environment identifier. For internal use only!
      Specified by:
      setLicenseEnvironment in interface Licensable
      Parameters:
      env - license environment. It is string identifier of a certain integration environment.

    • setMethylsRotatable

      public void setMethylsRotatable(boolean methylsRotatable)
      This is a speedup heuristics. Rotating the three hydrogens of a methyl group rarely results in atrop bonds.
      Parameters:
      methylsRotatable - if true rotate methyl groups too. Default is false.

    • setNumberOfAtomsAcceptToRotate

      public void setNumberOfAtomsAcceptToRotate(int numberOfAtomsAcceptToRotate)
      If only a given number of atoms (or less) can be found at one of the side of the dihedral skip this.
      Parameters:
      numberOfAtomsAcceptToRotate - default is 1.

    • setBarrierLimit

      public void setBarrierLimit(double barrierLimit)
      Set the energy barrier limit.
      Parameters:
      barrierLimit - New energy barrier limit in kcal/mol. default is 200

    • setSamplingAccuracy

      public void setSamplingAccuracy(int accuracy)
      Set sampling accuracy.
      Parameters:
      accuracy - Sample count for a full rotation to use

    • setTimeoutInSeconds

      public void setTimeoutInSeconds(int timeoutInSeconds)
      Set time out.
      Parameters:
      timeoutInSeconds - Timeout to use or 0 for no timeout.

    • setSamplingAccuracy

      public void setSamplingAccuracy(AtropIsomerDetector.Accuracy accuracy)
      Set sampling accuracy.
      Parameters:
      accuracy - Preset value representing sample count for a full rotation to use

    • setFlexibleRingRotatableBondCount

      public void setFlexibleRingRotatableBondCount(int i)

    • setFlexibleRingSize

      public void setFlexibleRingSize(int size)

    • calculate

      public void calculate(Molecule input) throws AlignmentException
      Run the atropisomer calculation.
      Parameters:
      input - the input molecule
      Throws:
      AlignmentException - Propagated

    • getAtropBonds

      public int[] getAtropBonds()
      After the calculate method finished.
      Returns:
      the indices of the detected atrop bonds.

    • getDihedralScanResults

      @Beta public List<DihedralScanResult> getDihedralScanResults()
      Get results of executed dihedral scans.

      Please note that this method is marked with Beta annotation, so it can be subject of incompatible changes or removal in any of the later releases.

      Returns:
      Executed dihedral scan results

    • getRealRotatableBondCount

      public int getRealRotatableBondCount()
      Rotatable bond count (atrop bonds excluded)
      Returns:
      Rotatable bond count

    • getPossibleRotatableBondCount

      public int getPossibleRotatableBondCount()
      Rotatable bond count before the atrop isomer calculation.
      Returns:
      All rotatable bond count

    • getResultMolecule

      public Molecule getResultMolecule()
      The result molecule will be 3D and aromatized version of the input molecules. Hydrogens are also added.
      Returns:
      the result molecule.