Superaugmented eccentric connectivity indices: new-generation highly discriminating topological descriptors for QSAR/QSPR modeling

Abstract

New-generation highly discriminating topological descriptors, termed superaugmented eccentric connectivity indices (SAξc), have been conceptualized in the present study. The values of SAξc for all the possible structures of three, four, and five vertices were computed using an in-house computer program. The sensitivity to branching, discriminating power, and degeneracy of SAξc were investigated for all the possible structures of three, four, and five vertices and subsequently compared with those of the eccentric and augmented eccentric connectivity indices. The proposed superaugmented eccentric connectivity indices exhibited high sensitivity towards branching, exceptionally high discriminating power, and extremely low degeneracy. The superaugmented eccentric connectivity index-3 (SAξc3) exhibited an exceptionally high discriminating power of > 4000 for all possible structures containing only five vertices. The statistical significance of the proposed indices was investigated using intercorrelation analysis with Wiener’s index; Balaban’s J index (the average distance sum connectivity); the molecular connectivity index; the eccentric connectivity index; and the augmented eccentric connectivity index values. The high sensitivity to branching and exceptionally high discriminating power amalgamated with extremely low degeneracy give these indices vast potential for isomer discrimination, similarity/dissimilarity, drug design, quantitative structure–activity/structure–property relationships, lead optimization, and combinatorial library design.