On the history of the connectivity index: from the connectivity index to the exact solution of the protein alignment problem.
We briefly review the history of the connectivity index from 1975 to date. We hope to throw some light on why this unique, by its design, graph theoretical molecular descriptor continues to be of interest in QSAR, having wide use in applications in structure-property and structure-activity studies. We will elaborate on its generalizations and the insights it offered on applications in Multiple Regression Analysis (MRA). Going beyond the connectivity index we will outline several related developments in the development of molecular descriptors used in MRA, including molecular ID numbers (1986), the variable connectivity index (1991), orthogonal regression (1991), irrelevance of co-linearity of descriptors (1997), anti-connectivity (2006), and high discriminatory descriptors characterizing molecular similarity (2015). We will comment on beauty in QSAR and recent progress in searching for similarity of DNA, proteins and the proteome. This review reports on several results which are little known to the structure-property-activity community, the significance of which may surprise those unfamiliar with the application of discrete mathematics to chemistry. It tells the reader many unknown stories about the connectivity index, which may help the reader to better understand the meaning of this index. Readers are not required to be familiar with graph theory.
a National Institute of Chemistry , Ljubljana , Slovenia.
M
M
Randić
D019295:Computational Biology / Q000266:history*; D004247:DNA / Q000737:chemistry; D049673:History, 20th Century; D049674:History, 21st Century; D016014:Linear Models; D015394:Molecular Structure; D015999:Multivariate Analysis; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D021281:Quantitative Structure-Activity Relationship; D012044:Regression Analysis; D016415:Sequence Alignment
D011506:Proteins; D004247:DNA
QSAR, QSPR; connectivity index; history; orthogonal molecular descriptors; protein alignment; topological indices