Fragmental descriptors

Molnar, L, Keserii, G. M., Papp A., Gulyas, Z., Darvas, F. A neural network based prediction of octanol-water partition coefficients using atomicS fragmental descriptors. Bioorg. Med. Chtm. Lett. 2004, 14, 851-853. 

The D-score is computed using the maximum dissimilarity algorithm of Lajiness (20). This method utilizes a Tanimoto-like similarity measure defined on a 360-bit fragment descriptor used in conjunction with the Cousin/ChemLink system (21). The important feature of this method is that it starts with the selection of a seed compound with subsequent compounds selected based on the maximum diversity relative to all compounds already selected. Thus, the most obvious seed to use in the current scenario is the compound that has the best profile based on the already computed scores. Thus, one needs to compute a preliminary consensus score based on the Q-score and the B-score using weights as defined previously. To summarize this, one needs to... 

Baskin, I. Varnek, A. Building a chemical space based on fragment descriptors. Comb. Chem. High Throughput Screening 2008, 11 (8), 661-668. 

Niculescu, S.P., Kaiser, K.L.E., and Schultz, T.W., Modeling the toxicity of chemicals to Tetmhymena pyri-formis using molecular fragment descriptors and probabilistic networks, Arch. Environ. Contamination Toxicol., 39, 289-298, 2000. 

Fragment Descriptors in SARj QSAR/QSPR Studies,... 

The unique properties of fragment descriptors are related to the fact that (i) any molecular graph invariant i.e., any molecular descriptor or property)... 

Methodologies based on fragment descriptors in QSAR/QSPR studies are not strictly confined to particular types of properties or compounds. In the 1970s Adamson and coworkers" " were the first to apply fragment descriptors in multiple linear regression analysis to find correlations with some biological activities,physicochemical properties, and reactivity. ... 

Starting in the early 1990s, various approaches and related software tools based on fragment descriptors have been developed and are listed in several conceptual and mini-review papers. Because of the wide scope and large variety of different approaches and applications in this field, many important... 

Thus, by substituting spectral moments in the QSPR Equation (1.4) for their expansions (Equations 1.5-1.10) one can obtain the following QSPR equation with fragment descriptors ... 

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