oxadiazoles and Schistosomiasis-mansoni

Drug discovery is mostly guided by innovative and knowledge by the application of experimental and computational approaches. Quantitative structure-activity relationships (QSAR) have a critical task in the discovery and optimization of lead compounds, thereby contributing to the development of new chemical entities. 3D-QSAR methods use the information of the tridimensional molecular structure of ligands and can be applied to elucidate the relationships between 3D molecular interactions and their measured biological property, therefore, providing a rational approach for the development of new potential compounds. The purpose of this review is to provide a perspective of the utility of 3DQSAR approaches in drug design, focusing on progress, challenges and future orientations. The essential steps involved to generate reliable and predictive CoMFA models are discussed. Moreover, we present an example of application of a CoMFA study to derive 3D-QSAR models for a series of oxadiazoles inhibitors of Schistosoma mansoni Thioredoxin Glutathione Reductase (SmTGR).

Topics: Animals; Antiparasitic Agents; Drug Design; Humans; Models, Molecular; Oxadiazoles; Quantitative Structure-Activity Relationship; Schistosoma mansoni; Schistosomiasis mansoni

Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends almost exclusively on praziquantel. Millions of people are treated annually with praziquantel, and drug-resistant parasites thus are likely to evolve. Phosphinic amides and oxadiazole 2-oxides, identified from a quantitative high-throughput screen, were shown to inhibit a parasite enzyme, thioredoxin glutathione reductase (TGR), with activities in the low micromolar to low nanomolar range. Incubation of parasites with these compounds led to rapid inhibition of TGR activity and parasite death. The activity of the oxadiazole 2-oxides was associated with a donation of nitric oxide. Treatment of schistosome-infected mice with 4-phenyl-1,2,5-oxadiazole-3-carbonitrile-2-oxide led to marked reductions in worm burdens from treatments against multiple parasite stages and egg-associated pathologies. The compound was active against the three major schistosome species infecting humans. These protective effects exceed benchmark activity criteria set by the World Health Organization for lead compound development for schistosomiasis.

Topics: Amides; Animals; Drug Design; Enzyme Inhibitors; Humans; Mice; Multienzyme Complexes; NADH, NADPH Oxidoreductases; Nitric Oxide Donors; Oxadiazoles; Schistosoma mansoni; Schistosomiasis mansoni; Schistosomicides; Structure-Activity Relationship