ECCENTRIC CONNECTIVITY INDEX - A NOVEL HIGHLY DISCRIMINATING TOPOLOGICAL DESCRIPTOR FOR STRUCTURE-PROPERTY AND STRUCTURE-ACTIVITY STUDIES

A novel, distance-cum-adjacency topological descriptor, termed as ecce ntric connectivity index, has been conceptualized, and its discriminat ing power has been investigated with regard to physical/biological pro perties of molecules. Correlation coefficients ranging from 95% to 99% were obtained using eccentric connectivity index in various datasets with regard to physical properties of diverse nature. These correlatio ns were far superior to those correspondingly derived from the Wiener index. For structure-activity studies, a dataset, comprised of 94 subs tituted piperidinyl methyl ester and methylene methyl ester analogs as analgesic agents, was selected. Values of the eccentric connectivity index, the Wiener index, and Randic's molecular connectivity index wer e calculated, and active ranges were identified. Good correlations bet ween topological descriptors and analgesic activity of these analogs w ere obtained. Eccentric connectivity index exhibited highest predictab ility of the order of 86%. High discriminating power as revealed by ex cellent correlations obtained from structure-property and structure-ac tivity studies offers an eccentric connectivity index of vast potentia l in QSPR/QSAR.