Predicting solubility of small molecules is a very difficult undertaking due to the lack of reliable and consistent experimental solubility data. It is well known that for a molecule in a crystal lattice to be dissolved, it must, first, dissociate from the lattice and then, second, be solvated. The melting point of a compound is proportional to the lattice energy, and the octanol-water partition coefficient (log ) is a measure of the compound's solvation efficiency.
View Article and Find Full Text PDFA method is presented for an ultrafast shape-based search workflow for the screening of large compound collections, i.e., those of vendors.
View Article and Find Full Text PDFProfile-quantitative structure-activity relationship (pQSAR) is a massively multitask, two-step machine learning method with unprecedented scope, accuracy, and applicability domain. In step one, a "profile" of conventional single-assay random forest regression models are trained on a very large number of biochemical and cellular pIC assays using Morgan 2 substructural fingerprints as compound descriptors. In step two, a panel of partial least squares (PLS) models are built using the profile of pIC predictions from those random forest regression models as compound descriptors (hence the name).
View Article and Find Full Text PDFWhile conventional random forest regression (RFR) virtual screening models appear to have excellent accuracy on random held-out test sets, they prove lacking in actual practice. Analysis of 18 historical virtual screens showed that random test sets are far more similar to their training sets than are the compounds project teams actually order. A new, cluster-based "realistic" training/test set split, which mirrors the chemical novelty of real-life virtual screens, recapitulates the poor predictive power of RFR models in real projects.
View Article and Find Full Text PDFJ Chem Inf Model
February 2014
A phenotypic screen (PS) is used to identify compounds causing a desired phenotype in a complex biological system where mechanisms and targets are largely unknown. Deconvoluting the mechanism of action of actives and identification of relevant targets and pathways remains a formidable challenge. Current methods fail to use the rich information available regarding compounds and their targets in a systematic way for this deconvolution.
View Article and Find Full Text PDFWeb services are a new technology that enables to integrate applications running on different platforms by using primarily XML to enable communication among different computers over the Internet. Large number of applications was designed as stand alone systems before the concept of Web services was introduced and it is a challenge to integrate them into larger computational networks. A generally applicable method of wrapping stand alone applications into Web services was developed and is described.
View Article and Find Full Text PDFEmergence of chloroquine-resistant Plasmodium falciparum strains necessitates discovery of novel antimalarial drugs, especially if the agents can be synthesized from commercially available, inexpensive precursors via short synthetic routes. While exploring structure-activity relationships, we found a gallium(III) complex, [(1,12-bis(2-hydroxy-5-methoxybenzyl)-1,5,8,12-tetraazadodecane)-gallium(III)](+) [Ga-5-Madd](+), 1, that possessed antimalarial efficacy. Like previously reported complexes, the crystal structure of 1 revealed gallium(III) in a symmetrical octahedral environment surrounded by four secondary amine nitrogen atoms in equatorial plane and two axial oxygen atoms.
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