Synthesis and X-ray Crystal Structure of N’-Cyano-N,N’-dimethyl-4-nitrobenzohydrazide

Synthesis, Crystal Structure and Cyclic Voltammetric Behavior of N-aroyl-N′-(4′-cyanophenyl)thioureas

Herein, two title compounds, N-benzoyl-N′-(4′-cyanophenyl)thiourea (1) and N-(4-nitrobenzoyl)-N′-(4′-cyanophenyl)thiourea (2) were synthesized in a high yield, via different applications of aroyl isocyanate and 4-aminobenzonitrile. The structure of the prepared compounds was characterized by elemental analysis and FT-IR, 1H, and 13C-NMR spectroscopic methods. The crystal structure of the title compound 1 was determined by an X-ray single-crystal technique and an intramolecular C=O…H-N hydrogen bond and intermolecular C=S…H-N and C=S…H-C hydrogen interactions, which were observed for the crystal structure. The molecular electrostatic potential (MEP) and the Mulliken atomic charges of title compounds 1 and 2 were theoretically calculated and interpreted. Cyclic voltammetric (CV) experiments for the compounds were performed with the glassy carbon electrode. The reduction in potential values of the different functional groups such as nitro and cyano in title compounds were investigated using CV curves.

Azanitrile Inhibitors of the SmCB1 Protease Target Are Lethal to Schistosoma mansoni: Structural and Mechanistic Insights into Chemotype Reactivity

Azapeptide nitriles are postulated to reversibly covalently react with the active-site cysteine residue of cysteine proteases and form isothiosemicarbazide adducts. We investigated the interaction of azadipeptide nitriles with the cathepsin B1 drug target (SmCB1) from Schistosoma mansoni, a pathogen that causes the global neglected disease schistosomiasis. Azadipeptide nitriles were superior inhibitors of SmCB1 over their parent carba analogs. We determined the crystal structure of SmCB1 in complex with an azadipeptide nitrile and analyzed the reaction mechanism using quantum chemical calculations. The data demonstrate that azadipeptide nitriles, in contrast to their carba counterparts, undergo a change from E- to Z-configuration upon binding, which gives rise to a highly favorable energy profile of noncovalent and covalent complex formation. Finally, azadipeptide nitriles were considerably more lethal than their carba analogs against the schistosome pathogen in culture, supporting the further development of this chemotype as a treatment for schistosomiasis.

Design, Synthesis, and Evaluation of X-ray Crystal Structure, Biological Activities, DFT Calculations, and Molecular Docking of Phenyl Imidazolidin-2-One Derivatives

Eight phenyl imidazolinone derivatives were synthesized from N2-(2,4-dimethylphenyl)-N1-methyformamidine (DPMF) via scaffold-hopping method using the ring-closure approach. The prepared compounds were verified using 1H and 13C NMR and HRMS spectroscopies. The structure of compound 3c was confirmed by single-crystal X-ray diffraction analysis. The mean plane of the phenyl and imidazolinone moieties was almost coplanar with an angle of 8.85(4)°. In the crystal, molecules were interlinked with intermolecular hydrogen bonds (N–H···O and C–H···O), generating a network structure. Additionally, compound 3f displayed the highest insecticidal activity (86.7%) against Plutella xylostella at 600 mg/L, which was significantly higher than the insecticidal activity (23.0%) of DPMF. Also, compound 3d displayed good fungicidal activities against Phytophthora capsici, Phytophthora sojae, and Phytophthora infestans. Density functional theory (DFT) calculations were performed to explain the insecticidal and fungicidal activities of phenyl imidazolidin-2-one derivatives, especially potent compounds 3f and 3d. Moreover, the binding modes of compounds 3a–h and DPMF against octopamine receptor of Plutella xylostella were studied by homology modeling and molecular docking. Therefore, a preliminary structure–activity relationship (SAR) was derived and discussed. These results encourage the exploration of novel insecticides and fungicides based on DPMF.