DARC TOPOLOGICAL DESCRIPTORS FOR PATTERN-RECOGNITION IN MOLECULAR DATABASE-MANAGEMENT SYSTEMS AND DESIGN

The DARC environment module called FRELs (Fragment Reduced to an Environment that is Limited) are concentric ordered graphs. We show that FRELs can be vectorized or built with four Graph Basic Branches (GBB). Colored branches can be derived by the introduction onto these GBBs of chromatic edges or vertices. Statistics of GBB occurrences within a set of carbon-centered topological FRELs are excellent tools for the investigation of environmental features in large structural databases. Occurrences of chromatic information, such as the statistics of "double-bond GBBs" within an isomeric set of olefinic FREL-Bs, are also easily carried out with the GBB concepts. A very small set of topological and chromatic GBBs provides excellent category descriptors and allows for more detailed analysis of molecular neighbor problems. They also facilitate cross-checking of GBB information within augmented atom substructures.