Self-Organizing Maps of Molecular Descriptors for Sesquiterpene Lactones and Their Application to the Chemotaxonomy of the Asteraceae Family

Molecules

Marcus T. Scotti⁴  Vicente Emerenciano¹  Marcelo J. P. Ferreira⁵  Luciana Scotti³  Ricardo Stefani²  Marcelo S. da Silva³ 

[1] Institute of Chemistry, University of São Paulo, Postal Box 26777, São Paulo, 05513-970, Brazil;Universidade Federal de Mato Grosso, Instituto de Ciências Exatas da Terra – ICET, Rodovia MT-100 Km 3,5, 78698-000, Pontal do Araguaia, MT, Brazil;Universidade Federal da Paraíba, Centro de Biotecnologia, Campus I 50670-910, João Pessoa, PB, Brazil;Universidade Federal da Paraíba, Departamento de Engenharia e Meio Ambiente, Campus IV, 58297-000, Rio Tinto, PB, Brazil;Universidade Presbiteriana Mackenzie, Cep 01302-907, São Paulo, Brazil

关键词: astearaceae;    chemotaxonomy;    sesquiterpene lactones;   

DOI  :  10.3390/molecules17044684

来源: mdpi

【 摘 要 】

The Asteraceae, one of the largest families among angiosperms, is chemically characterised by the production of sesquiterpene lactones (SLs). A total of 1,111 SLs, which were extracted from 658 species, 161 genera, 63 subtribes and 15 tribes of Asteraceae, were represented and registered in two dimensions in the SISTEMATX, an in-house software system, and were associated with their botanical sources. The respective 11 block of descriptors: Constitutional, Functional groups, BCUT, Atom-centred, 2D autocorrelations, Topological, Geometrical, RDF, 3D-MoRSE, GETAWAY and WHIM were used as input data to separate the botanical occurrences through self-organising maps. Maps that were generated with each descriptor divided the Asteraceae tribes, with total index values between 66.7% and 83.6%. The analysis of the results shows evident similarities among the Heliantheae, Helenieae and Eupatorieae tribes as well as between the Anthemideae and Inuleae tribes. Those observations are in agreement with systematic classifications that were proposed by Bremer, which use mainly morphological and molecular data, therefore chemical markers partially corroborate with these classifications. The results demonstrate that the atom-centred and RDF descriptors can be used as a tool for taxonomic classification in low hierarchical levels, such as tribes. Descriptors obtained through fragments or by the two-dimensional representation of the SL structures were sufficient to obtain significant results, and better results were not achieved by using descriptors derived from three-dimensional representations of SLs. Such models based on physico-chemical properties can project new design SLs, similar structures from literature or even unreported structures in two-dimensional chemical space. Therefore, the generated SOMs can predict the most probable tribe where a biologically active molecule can be found according Bremer classification.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.