Screening the medicines for Malaria Venture "Malaria Box" against the Plasmodium falciparum aminopeptidases, M1, M17 and M18

Malaria is a parasitic disease that remains a global health burden. The ability of the parasite to rapidly develop resistance to therapeutics drives an urgent need for the delivery of new drugs. The Medicines for Malaria Venture have compounds known for their antimalarial ac- tivity, but not necessarily the molecular targets. In this study, we assess the ability of the “MMV 400” compounds to inhibit the activity of three metalloaminopeptidases from Plasmo- dium falciparum, PfA-M1, PfA-M17 and PfM18 AAP. We have developed a multiplex assay system to allow rapid primary screening of compounds against all three metalloaminopepti- dases, followed by detailed analysis of promising compounds. Our results show that there were no PfM18AAP inhibitors, whereas two moderate inhibitors of the neutral aminopepti- dases PfA-M1 and PfA-M17 were identified. Further investigation through structure-activity relationship studies and molecular docking suggest that these compounds are competitive inhibitors with novel binding mechanisms, acting through either non-classical zinc coordina- tion or independently of zinc binding altogether. Although it is unlikely that inhibition of PfA- M1 and/or PfA-M17 is the primary mechanism responsible for the antiplasmodial activity re- ported for these compounds, their detailed characterization, as presented in this work, pave the way for their further optimization as a novel class of dual PfA-M1/PfA-M17 inhibitors uti- lising non-classical zinc binding groups

Potent dual inhibitors of Plasmodium falciparum M1 and M17 aminopeptidases through optimization of S1 pocket interactions

Malaria remains a global health problem, and though international efforts for treatment and eradication have made some headway, the emergence of drug-resistant parasites threatens this progress. Antimalarial therapeutics acting via novel mechanisms are urgently required. P. falciparum M1 and M17 are neutral aminopeptidases which are essential for parasite growth and development. Previous work in our group has identified inhibitors capable of dual inhibition of PfA-M1 and PfA-M17, and revealed further regions within the protease S1 pockets that could be exploited in the development of ligands with improved inhibitory activity. Herein, we report the structure-based design and synthesis of novel hydroxamic acid analogues that are capable of potent inhibition of both PfA-M1 and PfA-M17. Furthermore, the developed compounds potently inhibit Pf growth in culture, including the multi-drug resistant strain Dd2. The ongoing development of dual PfA-M1/PfA-M17 inhibitors continues to be an attractive strategy for the design of novel antimalarial therapeutics

Kinetic Target-Guided Synthesis as a Tool for Drug Discovery: Successes, Challenges, and Applications to Metalloproteases

Target-guided synthesis has emerged as an elegant and efficient lead- and drug-discovery strategy. [...

A simple reaction to produce small structurally complex and diverse molecules

In order to mimic the complexity of natural products, we designed and obtained with simple synthetic methods, building blocks with 'quaternary chiral centers'. These tricyclic lactams resulted from the reaction of a functional [gamma]-keto-acid and various commercially available bi-nucleophiles.We describe the stereoselective synthesis of tricyclic lactams containing a chiral quaternary center and suitable for the synthesis of chemical libraries in order to mimic the complexity of natural compounds

Insulin-Degrading Enzyme, an Under-Estimated Potential Target to Treat Cancer?

International audienceInsulin-degrading enzyme (IDE) is a multifunctional protease due to the variety of its substrates, its various cellular locations, its conservation between species and its many non-proteolytic functions. Numerous studies have successfully demonstrated its implication in two main therapeutic areas: metabolic and neuronal diseases. In recent years, several reports have underlined the overexpression of this enzyme in different cancers. Still, the exact role of IDE in the physiopathology of cancer remains to be elucidated. Known as the main enzyme responsible for the degradation of insulin, an essential growth factor for healthy cells and cancer cells, IDE has also been shown to behave like a chaperone and interact with the proteasome. The pharmacological modulation of IDE (siRNA, chemical compounds, etc.) has demonstrated interesting results in cancer models. All these results point towards IDE as a potential target in cancer. In this review, we will discuss evidence of links between IDE and cancer development or resistance, IDE’s functions, catalytic or non-catalytic, in the context of cell proliferation, cancer development and the impact of the pharmacomodulation of IDE via cancer therapeutics

Multi-Component Reaction for the Preparation of 1,5-Disubstituted 1,2,3-Triazoles by In-Situ Generation of Azides and Nickel-Catalyzed Azide-Alkyne Cycloaddition

International audienceAn efficient one-pot procedure combining bromide conversion into azide followed by NiAAC for the preparation of 1,5-disubstituted 1,2,3-triazoles has been developed. This procedure prevents the use of isolated azides, which are insufficiently commercially available and could be potentially unstable and difficult to handle. Moreover, this one-pot method tolerates a broad range of functional moieties including ester, carbamate or alcohol. Diverse 1,5-disubstituted 1,2,3-triazoles can be obtained from functionalized aryl and alkyl alkynes and bromides with modest to excellent yields and regioselectivities. This procedure will enable the synthesis of libraries of functionalizable 1,5disubstituted 1,2,3-triazoles particularly helpful for diverse applications such as medicinal chemistry and chemical biology purposes

Novel non-carboxylic acid retinoids: 1,2,4-oxadiazol-5-one derivatives.

International audienceWe have successfully obtained 1,2,4-oxadiazol-5-one bioisoteres of Am580 or Tazarotene-like retinoids. In particular compound 4 displays an EC(50) of 26nM on RAR-beta