| Abstract
| - Several series of novel chirality descriptors of chemical organic molecules have been introduced. Thedescriptors have been developed on the basis of conventional topological descriptors of molecular graphs.They include modified molecular connectivity indices, Zagreb group indices, extended connectivity, overallconnectivity, and topological charge indices. These modified descriptors make use of an additional termcalled chirality correction, which is added to the vertex degrees of asymmetric atoms in a molecular graph.Chirality descriptors can be real or complex numbers. Advantages and drawbacks of different series ofchirality descriptors are discussed. These descriptors circumvent the inability of conventional topologicalindices to distinguish chiral or enantiomeric isomers, which so far has been the major drawback of 2Ddescriptors as compared to true 3D descriptors (e.g., shape, molecular fields) of molecular structure. Thesenovel chirality descriptors have been implemented in a quantitative structure−activity releationship (QSAR)study of a set of ecdysteroids with a high content of chiral and enantiomeric compounds using the k nearestneighbor QSAR method (kNN) recently developed in this laboratory. We show that the results of this studycompare favorably with those obtained with the comparative molecular field analysis (CoMFA) applied tothe same dataset. The novel chirality descriptors of molecular structure should find their applications inQSAR studies and related investigations of molecular sdatasets.
|
