Projective QSAR

When utilizing the analytical model of QSAR/Spectral-SAR for environmental interactions, one should eonsider the framework of the principles both at the general and applied levels. As such, regarding the general principles or green ehemistry and engineering, they are provided in Table 3.2 to ensure that they ean be readily compared (Putz, 2010a). 

However, while restraining the analysis to the specific interactions between chemical structures and biological species, the Organization for 

TABLE 3.2 The Twelve Principles of Green Chemistry and Engineering  

Principle of Green Chemistry Principle of Green Engineering 

Prevention of waste that must cleaned afterwards Prevention rather than treatment 

---

Optimization of biological properties in a series of miticidal and mite ovicidal 2-aryl-l,3-cycloalkanediones, Ia,b, and enol esters, II, was achieved through analog synthesis and testing supported by the development of quantitative structure/ activity trends during the course of the project. QSAR equations developed during an initial phase provided the basis for both... 

Total projected QSAR activity The probability that this molecule is a Contact Allergen is 95.0% ... 

Verhaar HJM, Mulder W, Hermens JLM (1995) QSARs for ecotoxicity. Report prepared within the framework of the project QSAR for Prediction of Pate and Effects of Chemicals in the Environment, an international project of the Environmental Technologies RTD Programme (DGXII/D-1) of the European Commission under Contract number EV5V-CT92 0211... 

Projective QSAR (for Ionic Liquids on D hnia Magna). 325... 

E Johansson and M Cocchi 1993. PLS - Partial Least-squares Projections to Latent Structures. In binyi H (Editor) 3D QSAR in Drug Design. Leiden, ESCOM, pp. 523-550. 

Chemoinformatics (or cheminformatics) deals with the storage, retrieval, and analysis of chemical and biological data. Specifically, it involves the development and application of software systems for the management of combinatorial chemical projects, rational design of chemical libraries, and analysis of the obtained chemical and biological data. The major research topics of chemoinformatics involve QSAR and diversity analysis. The researchers should address several important issues. First, chemical structures should be characterized by calculable molecular descriptors that provide quantitative representation of chemical structures. Second, special measures should be developed on the basis of these descriptors in order to quantify structural similarities between pairs of molecules. Finally, adequate computational methods should be established for the efficient sampling of the huge combinatorial structural space of chemical libraries. 

Another recent tool has been developed within the ORCHESTRA project. The tool keeps into account both the chemometric information and the toxicity predictions done by the model, and in particular what kind of errors have been done by the model. It applies to the CAESAR QSAR models. Furthermore, this tool is based not only on the a priori data and information, as the other approaches, but also on the a posteriori result of the model. The user knows if the model can or cannot be used for a certain compound. In some cases a warning is given, recommending expert opinion. In all cases the reasons for the reliability is given, and it can be evaluated in a transparent way. 

Finally, a QSAR evaluation of different chemicals from waste-related products and recycling is shown in order to underline how in silico models can be used as a valid tool to fill in the gaps and to obtain information on toxicological profile and physicochemical information on compounds. In particular, a focus on compounds suggested by EU project Riskcycle is presented. 

Comparative QSAR Evaluation of Toxicological Properties of Chemicals Suggested by EU Riskcycle Project... 

Within the project we also evaluated alternative methods as tools to obtain information on the toxicological and physicochemical profile of the pollutants. In this paragraph, an example of the application of QSARs models is reported a comparison is done between predicted values from different models or between QSARs evaluation and experimental values from internationally recognized databases. 

QSAR models addressing five endpoints relevant for REACH legislation have been developed by the European funded CAESAR research project [56]. These models are focused on BCF in fish, mutagenesis, carcinogenesis, developmental toxicity, and skin sensitization. The developed models have been implemented into a Java-based applet available through the Internet. 

Partial least squares (PLS) projections to latent structures [40] is a multivariate data analysis tool that has gained much attention during past decade, especially after introduction of the 3D-QSAR method CoMFA [41]. PLS is a projection technique that uses latent variables (linear combinations of the original variables) to construct multidimensional projections while focusing on explaining as much as possible of the information in the dependent variable (in this case intestinal absorption) and not among the descriptors used to describe the compounds under investigation (the independent variables). PLS differs from MLR in a number of ways (apart from point 1 in Section 16.5.1) ... 

Wold, S., Johansson, E., Cocchi, M., PLS - Partial least-squares projections to latent structures, in 3D QSAR in Drug Design. Kubinyi, H. (ed.). ESCOM, Leiden, 1993, pp. 523-... 

Hansch. C. and Leo. A. Pomona College Medicinal Chemistry Project Claremont, CA Pomona College, Jnly 1987). Hansch. C.. Leo. A., and Hoekman, D. Exploring QSAR hydrophobic, electronic and steric effects (Washington, DC American Chemical Society. 1995). 

Jaworska, J., Nikolova-Jeliazkova, N. and Aldenberg, T. (2005) QSAR applicabilty domain estimation by projection of the training set descriptor space a review. Altern. Lab. Arum,., 33 (5), 445-459. 

---