A simple and straightforward method for determination of oxime group configuration in ethanone oximes by differential NOE experiments

Modulating leishmanial pteridine metabolism machinery via some new coumarin-1,2,3-triazoles: Design, synthesis and computational studies

In accordance with WHO statistics, leishmaniasis is one of the top neglected tropical diseases, affecting around 700 000 to one million people per year. To that end, a new series of coumarin-1,2,3-triazole hybrid compounds was designed and synthesized. All new compounds exerted higher activity than miltefosine against L. major promastigotes and amastigotes. Seven compounds showed single digit micromolar IC₅₀ values whereas three compounds (13c, 14b and 14c) displayed submicromolar potencies. A mechanistic study to elucidate the antifolate-dependent activity of these compounds revealed that folic and folinic acids abrogated their antileishmanial effects. These compounds exhibited high safety margins in normal VERO cells, expressed as high selectivity indices. Docking simulation studies on the folate pathway enzymes pteridine reductase and DHFR-TS imparted strong theoretical support to the observed biological activities. Besides, docking experiments on human DHFR revealed minimal binding interactions thereby highlighting the selectivity of these compounds. Predicted in silico physicochemical and pharmacokinetic parameters were adequate. In view of this, the structural characteristics of these compounds demonstrated their suitability as antileishmanial lead compounds.

E/Z configurational determination of oximes and related derivatives through quantum mechanics NMR calculations: scope and limitations of the leading probabilistic methods

Oximes and related derivatives featuring a CN double bond are important in many areas of chemistry. Different methods for the determination of the E/Z configuration have been developed, each with its own scope and limitations. While some cannot be used when only one isomer is available, others require special NMR experiments. Here, three popular computational methodologies (DP4, DP4+, and ML-J-DP4) have been thoroughly studied using a challenging test set. Although DP4+ provides the best confidence, its computational cost might be high. On the other hand, ML-J-DP4 shows excellent performance in most cases in a fraction of CPU time. A detailed analysis of the structural factors affecting the NMR prediction and sense of the assignment is also provided.