[id] => 15
[recorddate] => 2007:01:12:20:37:11
[lastupdate] => 2007:01:12:20:37:11
[type] => article
[place] => www, Internet
[subject] => chemistry - organic; mathematics - modeling
[relatedworks] =>
• 4 (some):
  • Numerical Simulation of Concurent Diffusion and Reaction, ?id=20
[file] => ?f=15
[mime] => application/pdf
[size] => 348314
[pubname] => Leonardo Electronic Journal of Practices and Technologies
[pubinfo] => AcademicDirect
[pubkey] => ISSN 1583-1078
[workinfo] => 1(1), p. 1-18
[year] => 2002
[title] => Topological Substituent Descriptors
[authors] => Mircea V. DIUDEA, Lorentz JÄNTSCHI, Ljupco PEJOV
[abstract] =>
Motivation. Substituted 1,3,5-triazines are known as useful herbicidal substances. In view of reducing the cost of biological screening, computational methods are carried out for evaluating the biological activity of organic compounds. Often a class of bioactives differs only in the substituent attached to a basic skeleton. In such cases substituent descriptors will give the same prospecting results as in case of using the whole molecule description, but with significantly reduced computational time. Such descriptors are useful in describing steric effects involved in chemical reactions.
Method. Molecular topology is the method used for substituent description and multi linear regression analysis as a statistical tool.
Results. Novel topological descriptors, XLDS and Ws, based on the layer matrix of distance sums and walks in molecular graphs, respectively, are proposed for describing the topology of substituents linked on a chemical skeleton. They are tested for modeling the esterification reaction in the class of benzoic acids and herbicidal activity of 2-difluoromethylthio-4,6-bis(monoalkylamino)-1,3,5-triazines.
Conclusions. Ws substituent descriptor, based on walks in graph, satisfactorily describes the steric effect of alkyl substituents behaving in esterification reaction, with good correlations to the Taft and Charton steric parameters, respectively. Modeling the herbicidal activity of the seo of 1,3,5-triazines exceeded the models reported in literature, so far.
[keywords] => Steric effect; Substituent descriptors; Molecular topology; Herbicidal activity
[acknowledgment] => The work was supported in part by the Romanian GRANT CNCSIS 2002.