Analysis of Compound Synergy in High-Throughput Cellular Screens by Population-Based Lifetime Modeling

Despite the successful introduction of potent anti-cancer therapeutics, most of these drugs lead to only modest tumor-shrinkage or transient responses, followed by re-growth of tumors. Combining different compounds has resulted in enhanced tumor control and prolonged survival. However, methods querying the efficacy of such combinations have been hampered by limited scalability, analytical resolution, statistical feasibility, or a combination thereof. We have developed a theoretical framework modeling cellular viability as a stochastic lifetime process to determine synergistic compound combinations from high-throughput cellular screens. We apply our method to data derived from chemical perturbations of 65 cancer cell lines with two inhibitors. Our analysis revealed synergy for the combination of both compounds in subsets of cell lines. By contrast, in cell lines in which inhibition of one of both targets was sufficient to induce cell death, no synergy was detected, compatible with the topology of the oncogenically activated signaling network. In summary, we provide a tool for the measurement of synergy strength for combination perturbation experiments that might help define pathway topologies and direct clinical trials

Synthesis and evaluation of pseudosaccharin amine derivatives as potential elastase inhibitions

keine AngabenElastase is a serine protease which by definition is able to solubilize elastin by hydrolytic cleavage.Human Leukocyte Elastase, HLE (EC 3.4.21.37), is involved in deseases such as adult respiatory distress syndrome, pulmonary emphysema, smoking related chronic bronchitits, ischemic-reperfusion injury and rheumatoid arthritis. Hence, the elastase inhibitors have clinical utility in these diseases. Heterocyclic compounds are one of the most important classes of the elastase inhibitiors. In the present work different pseudosaccharin amine derivatives were synthesized and tested against the elastase. The synthesis of pseudosaccharin amine dervatives was carried out from the amines and(1,1-dioxobenzo[d]isothiazol-3-ylsulfanyl)acetonitrile in different solvents. Futhermore, the pseudosaccharin amines were obtained by refluxing the thiosaccarinates in absolute acetic acid. The reaction of 3-ethoxybenzo[d]isothiazole 1,1-dioxide with different amines in dioxane under reflux resulted into the desired pseudosaccharin amine derivatives in higher yields. Pseudosaccharin chloride was also used in the synthesis of these derivatives.A detail study of the synthesis of pseudosaccharin amine dervatives from the above differnt routes is described. Peptides were also synthesized by using the mixed anhydride method. The ester, acid, amide and peptide derivatives were tested against the Porcine Pancreatic Elastase (PPE) and Human Leukocyte Elastase (HLE). The esters were found to be the reversible inhibitors of HLE. The process of the PPE inhibion by cyanomethyl(2S)-2-(1,1-dioxobenzo[d]isothiazol-3-ylamino)-3-methylbutanoate was studied. Michaelis-Menten curve and Lineweaver-Burk double reciprocal plot were constructed in order to study the kinetic of this reaction. The compounds showing high inhibition of HLE were further stuied for determination of their inhibitory constant(Ki). The esters were found to be the higly active compounds against HLE. The cyanomethyl(2S)-2-(1,1-dioxobenzo[d]isothiazol-3-ylamino)-3-methylbutanoate and cyanomethyl(2S,3S)-2-(1,1-dioxobenzo[d]isothiazol-3-ylamino)-3-methylpentanoate showed the competitive reversible inhibition of HLE.The cyanomethyl(2S,3S)-2-(1,1-dioxobenzo[d]isothiazol-3-ylamino)-3-methylpentanoate is highly potent inhibitor of HLE. The possible mechanism of inhibition of elastase by these compounds is discussed. Molecular modelling of some of the ester derivatives is also discussed

Methyl 3-[(1,1-dioxo-1λ6,2-benzothiazol-3-yl)amino]-5-nitrothiophene-2-carboxylate

The title nitrothiophene compound, C13H9N3O6S2, crystallizes with two independent molecules in the asymmetric unit; the molecular structure of each is stabilized by an intramolecular N—H...O hydrogen bond. The two molecules adopt flattened but slightly different conformations, viz. the dihedral angle between the thiophene ring and the essentailly planar 1,2-benzisothiazole fragment (r.m.s. deviations = 0.0227 and 0.0108 Å, respectively) is 15.62 (11)° in one molecule and 5.46 (11)° in the other. In the crystal, molecules are arranged into layers parallel to (-111) with weak Car—H...O interactions formed within the layer. N—H...O hydrogen bonds also occur. There are π–π stacking interactions between the molecules in neighbouring layers, the distance between the centroids of the 1,2-benzisothiazole benzene rings being 3.8660 (16) Å. Moreover, dipolar S=O...C=O interactions with an O...C distance of 2.893 (3) Å are observed between the symmetry-independent molecules in different layers. The title compound showed weak inhibition of HLE (human leukocyte elastase)

Chemically Diverse Compound Library

24-27Open Source Drug Discovery (OSDD) foresees building of a chemically diverse compound library which could greatly aid the project’s drug discovery process. </span

Strategies towards the synthesis of anti-tuberculosis drugs

International audienc

A Chemical Genetic Approach for Covalent Inhibition of Analogue-Sensitive Aurora Kinase

The perturbation of protein kinases with small organic molecules is a powerful approach to dissect kinase function in complex biological systems. Covalent kinase inhibitors that target thiols in the ATP binding pocket of the kinase domain proved to be ideal reagents for the investigation of highly dynamic cellular processes. However, due to the covalent inhibitors' possible off-target reactivities, it is required that the overall shape of the inhibitor as well as the intrinsic reactivity of the electrophile are precisely tuned to favor the reaction with only the desired cysteine. Here we report on the design and biological characterization of covalent anilinoquinazolines as potent inhibitors of genetically engineered Aurora kinase in fission yeast

Identification of New Molecular Entities (NMEs) as Potential Leads against Tuberculosis from Open Source Compound Repository.

The purpose of this study was to provide a number of diverse and promising early-lead compounds that will feed into the drug discovery pipeline for developing new antitubercular agents. The results from the phenotypic screening of the open-source compound library against Mycobacterium smegmatis and Mycobacterium bovis (BCG) with hit validation against M. tuberculosis (H37Rv) have identified novel potent hit compounds. To determine their druglikeness, a systematic analysis of physicochemical properties of the hit compounds has been performed using cheminformatics tools. The hit molecules were analysed by clustering based on their chemical finger prints and structural similarity determining their chemical diversity. The hit compound library is also filtered for druglikeness based on the physicochemical descriptors following Lipinski filters. The robust filtration of hits followed by secondary screening against BCG, H37Rv and cytotoxicity evaluation has identified 12 compounds with potential against H37Rv (MIC range 0.4 to 12.5 μM). Furthermore in cytotoxicity assays, 12 compounds displayed low cytotoxicity against liver and lung cells providing high therapeutic index > 50. To avoid any variations in activity due to the route of chemical synthesis, the hit compounds were re synthesized independently and confirmed for their potential against H37Rv. Taken together, the hits reported here provides copious potential starting points for generation of new leads eventually adds to drug discovery pipeline against tuberculosis