title: Extension of a Highly Discriminating Topological Index.
abstract: A highly discriminating topological index, EAID, is generated in our laboratory. A systematic search for degeneracy was performed on a total of over 14 million structures, and no duplicate occurred. These structures are as follows: over 3.8 million alkane trees with 1-22 carbon atoms; over 0.38 million structures containing heteroatoms; over 4 million benzenoids with 1-13 benzene rings; and over 5.9 million compounds from three reality databases. However, in a search of over 20 million alkane trees with 23 and 24 carbon atoms, five and 13 duplicates occurred, respectively, and for over 20 million compounds from the ZINC database, 10 duplicates occurred. To increase the discriminating power of the index, EAID has been extended, and the resulting index is termed 2-EAID. All of the over 55 million structures mentioned above were uniquely identified by 2-EAID except for two duplicates that occurred for the ZINC database. EAID and 2-EAID are the most highly discriminating indices examined to date. Thus, the two indices possess not only theoretical significance but also potential applications. For example, they could possibly be used as a supplementary reference for CAS Registry Numbers for structure documentation.
authors.affiliation: †Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: †Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Wu
authors.affiliation: †Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Zheng
authors.affiliation: †Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Tanfeng
authors.initials: T
authors.lastname: Zhao
authors.affiliation: †Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: ‡Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Xu
mesh_terms: D000473:Alkanes / Q000737:chemistry; D001554:Benzene / Q000737:chemistry; D003196:Computer Graphics; D062313:Databases, Pharmaceutical; D055808:Drug Discovery; D048088:Informatics / Q000379:methods*; D021281:Quantitative Structure-Activity Relationship
chemical_list: D000473:Alkanes; D001554:Benzene