Dual effects of anti-inflammatory 2-arylpropionic acid derivatives on a major isoform of human liver 3alpha-hydroxysteroid dehydrogenase

Combinations of protein-chemical complex structures reveal new targets for established drugs

Biological networks are powerful tools for predicting undocumented relationships between molecules. The underlying principle is that existing interactions between molecules can be used to predict new interactions. Here we use this principle to suggest new protein-chemical interactions via the network derived from three-dimensional structures. For pairs of proteins sharing a common ligand, we use protein and chemical superimpositions combined with fast structural compatibility screens to predict whether additional compounds bound by one protein would bind the other. The method reproduces 84% of complexes in a benchmark, and we make many predictions that would not be possible using conventional modeling techniques. Within 19,578 novel predicted interactions are 7,793 involving 718 drugs, including filaminast, coumarin, alitretonin and erlotinib. The growth rate of confident predictions is twice that of experimental complexes, meaning that a complete structural drug-protein repertoire will be available at least ten years earlier than by X-ray and NMR techniques alone.

Predicting drug-target interactions is a hot topic, and many efforts have been undertaken to do this, many using large interaction networks. We take a novel approach using protein-chemical interactions derived from 3D structures. The basic premise is that two proteins sharing a common bound chemical will likely share others. We use protein and chemical superimpositions and physical tests of chemical-protein compatibility to identify the most likely candidates among the nearly one million potential interactions. We show for a benchmark that known protein-chemical structures are reconstructed with good accuracy and sometimes via very different proteins and chemicals. We make thousands of confident predictions, including structures for known protein-drug interactions lacking a structure (e.g. topoisomerase-2/radicicol) and many new interactions. The number of confident predictions grows faster than the number of known structures, suggesting that this approach will play a key role in completing the protein-chemical interaction repertoire.

Synthesis and structural pattern recognition of 5-(2'-alkoxycarbonyl-substituted phenoxy)furfural derivatives

The ethyl 5-(2'-alkoxycarbonyl-substituted phenoxy)furan-2-carboxylates (1C-13C) showed good anti-platelet aggregation,(1)) anti-allergic(2)) and anti-inflammatory activities.(2)) A series of 5-(2'-alkoxycarbonyl-substituted phenoxy)furfurals (1F-13F) were prepared for comparing the above activities. The objectives of this research are the synthesis and structural pattern recognition of compounds 1F-13F. The Silica Gel 60 column chromatography method was employed to separate and purify pure compounds 1F-13F by three solvent systems. For the structure elucidation of compounds 1F-13F, four spectroscopic methods were used: electron impact mass (EI-MS), UV-VIS, IR and NMR spectrometers. With the help of spectrometers, investigations can be performed on spectroscopic data. A simple methodology for recognizing structural patterns was carried out with the aid of statistical analysis designed to establish the classification model of the structural skeleton in this research. It was found that compounds 1C-13C and 1F-13F have similar chemical profiles and are clustered into one group. The pattern plots revealed valuable information and showed good correlation between compounds 1C-13C and 1F-13F. These findings correlate directly with the resulting spectroscopic data. These results with those obtained by EI-MS and NMR patterns give insight into a reliable pattern recognition for determining both 1C-13C and 1F-13F skeletons.

Multiplicity of mammalian reductases for xenobiotic carbonyl compounds

A variety of carbonyl compounds are present in foods, environmental pollutants, and drugs. These xenobiotic carbonyl compounds are metabolized into the corresponding alcohols by many mammalian NAD(P)H-dependent reductases, which belong to the short-chain dehydrogenase/reductase (SDR) and aldo-keto reductase superfamilies. Recent genomic analysis, cDNA isolation and characterization of the recombinant enzymes suggested that, in humans, the six members of each of the two superfamilies, i.e., total of 12 enzymes, are involved in the reductive metabolism of xenobiotic carbonyl compounds. They comprise three types of carbonyl reductase, dehydrogenase/reductase (SDR family) member 4, 11beta-hydroxysteroid dehydrogenase type 1, L-xylulose reductase, two types of aflatoxin B1 aldehyde reductase, 20alpha-hydroxysteroid dehydrogenase, and three types of 3alpha-hydroxysteroid dehydrogenase. Accumulating data on the human enzymes provide new insights into their roles in cellular and molecular reactions including xenobiotic metabolism. On the other hand, mice and rats lack the gene for a protein corresponding to human 3alpha-hydroxysteroid dehydrogenase type 3, but instead possess additional five or six genes encoding proteins that are structurally related to human hydroxysteroid dehydrogenases. Characterization of the additional enzymes suggested their involvement in species-specific biological events and species differences in the metabolism of xenobiotic carbonyl compounds.

Development of a novel screen for protease inhibitors

We have developed a novel plasmid-based, quantitative, in vitro screen to test the protease-inhibiting activities of existing and newly discovered agents.