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Andre Lomaka

Publications and source records attributed to Andre Lomaka.

8 recordsLinked to original sources
PubMed2002

Six-membered cyclic ureas as HIV-1 protease inhibitors: a QSAR study based on CODESSA PRO approach. Quantitative structure-activity relationships.

Quantitative structure-activity relationships (QSAR) for HIV-1 protease inhibitory activity of substituted tetrahydropyrimidinones have been produced using CODESSA PRO methodology and software. The best four-parameter equation (R(2)(cv)=0.847) allowed us to reveal two main structural factors which are strongly correlated with the title activity: molecular hydrophobicity and ability to form hydrogen bonds with the target enzyme.

HIV Protease Inhibitors↗
PubMedDate not supplied

Correlation of the melting points of potential ionic liquids (imidazolium bromides and benzimidazolium bromides) using the CODESSA program.

The melting points of several imidazolium-based ionic liquids or ionic liquid analogues were correlated using the CODESSA program in order to develop predictive tools for determination of suitable ionic liquid salts. The data set consisted of melting point data (degrees C) for 104 substituted imidazolium bromides divided on the basis of the N-substituents into three subsets: A-57 compounds, B-29 compounds, and C-18 compounds. The 45 benzimidazolium bromides form set D. Five-parameter correlations were obtained for (i) set A with R2 = 0.7442, (ii) set B with R2 = 0.7517, and (iii) set D with R2 = 0.6899, while set C was correlated with a three parameter equation with R(2) = 0.9432. These descriptors for predicting the melting points of the imidazolium and benzimidazolium bromides were based on the size and electrostatic interactions in the cations.

Journal Article↗
PubMedDate not supplied

QSPR correlation of the melting point for pyridinium bromides, potential ionic liquids.

In an attempt to develop predictive tools for the determination of new ionic liquid solvents, QSPR models for the melting points of 126 structurally diverse pyridinium bromides in the temperature range 30-200 degrees C were developed with the CODESSA program. Six- and two-descriptor equations with squared correlation coefficients (R(2)) of 0.788 and 0.713, respectively, are reported for the melting temperatures. The models illustrate the importance of information content indices, total entropy, and the average nucleophilic reactivity index for an N atom.

Journal Article↗
PubMedDate not supplied

Prediction of ultraviolet spectral absorbance using quantitative structure-property relationships.

High performance liquid chromatography (HPLC) with ultraviolet (UV) spectrophotometric detection is a common method for analyzing reaction products in organic chemistry. This procedure would benefit from a computational model for predicting the relative response of organic molecules. Models are now reported for the prediction of the integrated UV absorbance for a diverse set of organic compounds using a quantitative structure-property relationship (QSPR) approach. A seven-descriptor linear correlation with a squared correlation coefficient (R2) of 0.815 is reported for a data set of 521 compounds. Using the sum of ZINDO oscillator strengths in the integration range as an additional descriptor allowed reduction in the number of descriptors producing a robust model for 460 compounds with five descriptors and a squared correlation coefficient 0.857. The descriptors used in the models are discussed with respect to the physical nature of the UV absorption process.

Journal Article↗
PubMedDate not supplied

A general treatment of solubility. 1. The QSPR correlation of solvation free energies of single solutes in series of solvents.

We present an extended QSPR modeling of solubilities of about 500 substances in series of up to 69 diverse solvents. The models are obtained with our new software package, CODESSA PRO, which is furnished with an advanced variable selection procedure and a large pool of theoretically derived molecular descriptors. The squared correlation coefficients and squared standard deviations (variances) range from 0.837 and 0.1 for 2-pyrrolidone to 0.998 and 0.02 for dipropyl ether, respectively. The predictive power of the models was verified by using the "leave-one-out" cross-validation procedure. The QSPR models presented are suitable for the rapid evaluation of solvation free energies of organic compounds.

Journal Article↗
PubMedDate not supplied

A general treatment of solubility. 2. QSPR prediction of free energies of solvation of specified solutes in ranges of solvents.

As part of our general QSPR treatment of solubility (started in the preceding paper), we now present quantitative relationships between solvent structures and the solvation free energies of individual solutes. Solvation free energies of 80 diverse organic solutes are each modeled in a range from 15 to 82 solvents using our CODESSA PRO software. Significant correlations (in terms of squared correlation coefficient) are found for all the 80 solutes: the best fit is obtained for n-propylamine (R(2) = 0.996); the lowest R(2) corresponds to toluene (0.604).

Journal Article↗
PubMedDate not supplied

Open computing grid for molecular science and engineering.

Grid is an emerging infrastructure for distributed computing that provides secure and scalable mechanisms for discovering and accessing remote software and data resources. Applications built on this infrastructure have great potential for addressing and solving large scale chemical, pharmaceutical, and material science problems. The article describes the concept behind grid computing and will present the OpenMolGRID system that is an open computing grid for molecular science and engineering. This system provides grid enabled components, such as a data warehouse for chemical data, software for building QSPR/QSAR models, and molecular engineering tools for generating compounds with predefined chemical properties or biological activities. The article also provides an overview about the availability of chemical applications in the grid.

Journal Article↗