A novel validated assay to support the discovery of new anti-malarial gametocytocidal agents

Additional file 1. Graphical representation of the expression of 12 selected genes throughout the 30 days of gametocytogenesis. Y-axis shows the gene expression represented as (Ctgene−Ct18S rRNA)Ttime × −(Ctgene−Ct18S rRNA)T0, considering the time 0 as the basal expression. Although only the gametocytogenesis during 30 days is presented, similar results were obtained from day 0 to day 15 in both assays

Development of a novel secondary phenotypic screen to identify hits within the mycobacterial protein synthesis pipeline

Background Whole‐cell phenotypic screening is the driving force behind modern anti‐tubercular drug discovery efforts. Focus has shifted from screening for bactericidal scaffolds to screens incorporating target deconvolution. Target‐based screening aims to direct drug discovery toward known effective targets and avoid investing resources into unproductive lines of enquiry. The protein synthesis pipeline, including RNA polymerase and the ribosome, is a clinically proven target in Mycobacterium tuberculosis. Screening for new hits of this effective target pathway is an invaluable tool in the drug discovery arsenal. Methods Using M. tuberculosis H37Rv augmented with anhydrotetracycline‐inducible expression of mCherry, a phenotypic screen was developed for the identification of protein synthesis inhibitors in a medium throughput screening format. Results The assay was validated using known inhibitors of protein synthesis to show a dose‐dependent reduction in mCherry fluorescence. This was expanded to a proprietary screen of hypothetical protein synthesis hits and modified to include quantitative viability measurement of cells using resazurin. Conclusion Following the success of the proprietary screen, a larger scale screen of the GlaxoSmithKline anti‐tubercular library containing 2799 compounds was conducted. Combined single shot and dose‐response screening yielded 18 hits, 0.64% of all screened compounds

Чорноморсько-середземноморський коридор упродовж останніх 30 тис. років

Висунуто багато гіпотез щодо реконструкцій давнього навколишнього середовища та палеоклімату Чорноморсько-Середземноморського регіону й визначення факторів, що спричинили динаміку рівня моря. Цій проблематиці було присвячено Другу пленарну конференцію та польові екскурсії, згідно з Проектом IGCP-521 «Чорноморсько-Середземноморський коридор упродовж останніх 30 тис. років: зміни рівня моря та адаптація людини», що відбулися 20—28 серпня 2006 р. у м. Одеса на базі Одеського національного університету ім. І.І. Мечникова (ОНУ). Роботи здійснювалися під егідою ЮНЕСКО, IUGS, IGCP, INQUA

Novel inhibitors of Mycobacterium tuberculosis GuaB2 identified by a target based high-throughput phenotypic screen

High-throughput phenotypic screens have re-emerged as screening tools in antibiotic discovery. The advent of such technologies has rapidly accelerated the identification of ‘hit’ compounds. A pre-requisite to medicinal chemistry optimisation programmes required to improve the drug-like properties of a ‘hit’ molecule is identification of its mode of action. Herein, we have combined phenotypic screening with a biased target-specific screen. The inosine monophosphate dehydrogenase (IMPDH) protein GuaB2 has been identified as a drugable target in Mycobacterium tuberculosis, however previously identified compounds lack the desired characteristics necessary for further development into lead-like molecules. This study has identified 7 new chemical series from a high-throughput resistance-based phenotypic screen using Mycobacterium bovis BCG over-expressing GuaB2. Hit compounds were identified in a single shot high-throughput screen, validated by dose response and subjected to further biochemical analysis. The compounds were also assessed using molecular docking experiments, providing a platform for their further optimisation using medicinal chemistry. This work demonstrates the versatility and potential of GuaB2 as an anti-tubercular drug target

Mycobacterial dihydrofolate reductase inhibitors identified using chemogenomic methods and in vitro validation.

The lack of success in target-based screening approaches to the discovery of antibacterial agents has led to reemergence of phenotypic screening as a successful approach of identifying bioactive, antibacterial compounds. A challenge though with this route is then to identify the molecular target(s) and mechanism of action of the hits. This target identification, or deorphanization step, is often essential in further optimization and validation studies. Direct experimental identification of the molecular target of a screening hit is often complex, precisely because the properties and specificity of the hit are not yet optimized against that target, and so many false positives are often obtained. An alternative is to use computational, predictive, approaches to hypothesize a mechanism of action, which can then be validated in a more directed and efficient manner. Specifically here we present experimental validation of an in silico prediction from a large-scale screen performed against Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis. The two potent anti-tubercular compounds studied in this case, belonging to the tetrahydro-1,3,5-triazin-2-amine (THT) family, were predicted and confirmed to be an inhibitor of dihydrofolate reductase (DHFR), a known essential Mtb gene, and already clinically validated as a drug target. Given the large number of similar screening data sets shared amongst the community, this in vitro validation of these target predictions gives weight to computational approaches to establish the mechanism of action (MoA) of novel screening hit

CD4陽性T細胞に発現するA20(tnfaip3) はTh2型アレルギー性気道炎症を抑制する

研究科: 千葉大学大学院医学薬学府（先端医学薬学専攻）学位記番号: 千大院医薬博甲第医1412号博士（医学）千葉大学 = Chiba Universit

Prioritizing multiple therapeutic targets in parallel using automated DNA-encoded library screening

AbstractThe identification and prioritization of chemically tractable therapeutic targets is a significant challenge in the discovery of new medicines. We have developed a novel method that rapidly screens multiple proteins in parallel using DNA-encoded library technology (ELT). Initial efforts were focused on the efficient discovery of antibacterial leads against 119 targets from Acinetobacter baumannii and Staphylococcus aureus. The success of this effort led to the hypothesis that the relative number of ELT binders alone could be used to assess the ligandability of large sets of proteins. This concept was further explored by screening 42 targets from Mycobacterium tuberculosis. Active chemical series for six targets from our initial effort as well as three chemotypes for DHFR from M. tuberculosis are reported. The findings demonstrate that parallel ELT selections can be used to assess ligandability and highlight opportunities for successful lead and tool discovery.</jats:p

Effets de solvant et catalyse micellaire dans le cas d’une substitution nucléophile aromatique type : la réaction de l’aniline sur le trinitro-2,4,6 anisole

La réaction de l’aniline sur le trinitro-2,4,6 anisóle obéit aux règles générales de la substitution nucléophile aromatique. Compte tenu de la faible basicité de la fonction amine aromatique et de la résistance à l’éjection du groupement méthoxy, ce système permet d’observer deux types de comportements cinétiques selon la valeur du pH : en milieu basique, la vitesse de la réaction est indépendante du pH alors qu’elle lui est liée en milieu neutre ou faiblement acide et décroît alors exponentiellement. Nous avons étudié cette réaction en milieu aqueux, dans des solvants mixtes eau-CHaOH et dans des solutions micellaires réalisées avec des détergents anioniques ou cationiques.La forme générale des graphes cinétiques se conserve d’un type de milieu à un autre, ce qui montre que le mécanisme réactionnel est également conservé. Il est alors possible de mettre en évidence les effets des divers additifs sur chacune des étapes de la transformation. La première étape, qui correspond à la formation d’un complexe d’addition zwittérionique par association des deux réactifs est peu affectée par le méthanol et facilitée en présence de micelles, quel que soit leur type de charge (effet de surconcentration locale). La deuxième partie du mécanisme implique la perte d’un proton par le zwittérion précédent : celle-ci est plus difficile en présence de méthanol ou de micelles négatives alors qu’elle est favorisée par la présence de micelles positives. Lorsque la vitesse globale de transformation est limitée par cette deuxième partie du mécanisme, l’addition d’un électrolyte dans le milieu réactionnel change la vitesse du processus si celui-ci s’effectue en présence de micelles, en l’accélérant lorsque les micelles sont négatives et en le ralentissant dans le cas contraire.Le modèle développé précédemment pour décrire le comportement des systèmes micellaires permet de rendre compte de l’ensemble de ces effets, qualitativement et quantitativement

Des changements de comportements de mobilité quotidienne concomitants à desdéménagements ? Quand les données invitent a réorienter les politiques publiques

International audienc

Trioxaquines and Heme-Artemisinin Adducts Inhibit the In Vitro Formation of Hemozoin Better than Chloroquine▿

Trioxaquines, potential antimalarial agents, and heme-artemisinin adducts, resulting from the alkylation of heme by artemisinin, were evaluated as inhibitors of β-hematin formation in 10 M acetate medium at pH 5