Substructure approach

An enhancement of the simple substructure approach is the Fragment Reduced to an Environment that is Limited (FREL) method introduced by Dubois et al. [7] With the FREL method several centers of the molecule are described, including their chemical environment. By taking the elements H, C, N, O, and halogens into account and combining all bond types (single, double, triple, aromatic), the authors found descriptors for 43 different FREL centers that can be used to characterize a molecule. 

Helguera AM, Perez MAC, Gonzalez MP, Ruiz RM, Dfaz HG. A topological substructural approach applied to the computational prediction of rodent carcinogenicity. Bioorg Med them 2005 13 2477-88. 

HaU AJ, AchiUi L, Manesiotis P, Quaglia M, De Lorenzi E, SeUergren B. A substructure approach toward polymeric receptors targeting dihydrofolate reductase inhibitors. 2. Molecularly imprinted polymers against Z-L-glutamic acid showing affinity for larger molecules. J Org Chem 2003 68 9132-9135. 

Planche AS, Scotti MT, Lopez AG et al (2009) Design of novel antituberculosis compounds using graph-theoretical and substructural approaches. Mol Divers 13 445-458... 

The proliferation of methodologies and programs to calculate partition coefficients continues unabated. These programs are based on substructure approaches or whole-molecule approaches (142,143). Substructure... 

Cabrera MA, Gonzalez I, Fernandez C, Navarro C, Bermejo M. A topological substructural approach for the prediction of P-glycoprotein substrates. J Pharm Sci 2006 95 589-606. 

Cabrera et al. pursued a topological substructural approach for the prediction of P-gp substrates. A linear discriminant model classified 163 compounds with an accuracy of 81% based on standard bond distance, polarizability, and the Casteiger-Marsilli atomic charge [35]. Furthermore, the predictive potential ofthis TOPS-MODE approach was demonstrated for a set of 6-fluoroquinolones not included in the training set. 

Fulton, R.E. Su, P.S. 1992. Parallel substructure approach for massively parallel computers. Computers in Engineering, 2 75-82. 

In using a substructure approach, we determined that only 58% of the 138 citing papers would have been retrieved. Thus we observe that no single approach, reaction, substructure, cited reference, or keyword, would allow for complete retrieval of related papers and therefore a comprehensive search strategy must include multiple approaches. 

Molina, E.> Gonzalez-Dlaz, H., Gonzalez, M. R> Rodriguez, E., 8c Uriarte, E. (2004). Designing antibacterial compovmds through a topological substructural approach. Journal of Chemical Information and Computer Science, 44, 515. 

A third approach uses two different methods to simulate IR spectra. The first uses harmonic frequencies and intensities of a semiempirical calculation, and the second a list of 40 substructures expected to be typical of IR spectra. Both types of data serve as input for back-propagation neural networks, which are trained with the quantum chemical or the structural information. The quantum chemical and the substructure approaches both exhibited similiar performance concerning... 

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