Selenourea and thiourea derivatives of chiral and achiral enetetramines: Synthesis, characterization and enzyme inhibitory properties.

A series of chiral and achiral cyclic seleno- and thiourea compounds bearing benzyl groups on N-atoms were prepared from enetetramines and appropriate Group VI elements in good yields. All the synthesized compounds were characterized by elemental analysis, FT-IR, 1H NMR and 13C NMR spectroscopy, and the molecular and crystal structures of (R,R)-4b and (R,R)-5b were confirmed by the single-crystal X-ray diffraction method. These assayed for their activities against metabolic enzymes acetylcholinesterase, butyrylcholinesterase, and α-glycosidase. These selenourea and thiourea derivatives of chiral and achiral enetetramines effectively inhibit AChE and BChE with IC50 values in the range of 3.32-11.36 and 1.47-9.73 µM, respectively. Also, these compounds inhibited α-glycosidase enzyme with IC50 values varying between 1.37 and 8.53 µM. The results indicated that all the synthesized compounds exhibited excellent inhibitory activities against mentioned enzymes as compared with standard inhibitors. Representatively, the most potent compound against α-glycosidase enzyme, (S,S)-5b, was 12-times more potent than standard inhibitor acarbose; 7b and 8a as most potent compounds against cholinesterase enzymes, were around 5 and 13-times more potent than standard inhibitor tacrine against achethylcholinesterase (AChE) and butyrylcholinesterase (BChE), respectively.

Prediction of Biological Activities, Structural Investigation and Theoretical Studies of meta-cyanobenzyl Substituted Benzimidazolium Salts.

The structuralproperties of meta-cyanobenzyl substituted N-heterocyclic carbene (NHC) precursors were investigated theoretically. The molecular and crystal structure of one of the compounds was determined by using the single-crystal X-ray diffraction method. Global reactivity descriptors were analyzed to understand the biological activity behaviors of the compounds with Density Functional Theory (DFT) B3LYP method with 6-31G* basis set. Vibrational frequencies, chemical shifts and absorption wavelengths were computed and compared to experimental data. A predictive study for the biological activities was done using PASS (prediction of activity spectra for biologically active structures) online software. Biological activity predictions showed the analgesic, substance P antagonist, non-opoid and antiinflammatory activities of the compounds.

Novel 2-aminopyridine liganded Pd(II) N-heterocyclic carbene complexes: Synthesis, characterization, crystal structure and bioactivity properties.

In this work, the synthesis, crystal structure, characterization, and enzyme inhibition effects of the novel a series of 2-aminopyridine liganded Pd(II) N-heterocyclic carbene (NHC) complexes were examined. These complexes of the Pd-based were synthesized from PEPPSI complexes and 2-aminopyridine. The novel complexes were characterized by using 13C NMR, 1H NMR, elemental analysis, and FTIR spectroscopy techniques. Also, crystal structures of the two compounds were recorded by using single-crystal X-ray diffraction assay. Also, these complexes were tested toward some metabolic enzymes like α-glycosidase, aldose reductase, butyrylcholinesterase, acetylcholinesterase enzymes, and carbonic anhydrase I, and II isoforms. The novel 2-aminopyridine liganded (NHC)PdI2(2-aminopyridine) complexes (1a-i) showed Ki values of in range of 5.78 ±â€¯0.33-22.51 ±â€¯8.59 nM against hCA I, 13.77 ±â€¯2.21-30.81 ±â€¯4.87 nM against hCA II, 0.44 ±â€¯0.08-1.87 ±â€¯0.11 nM against AChE and 3.25 ±â€¯0.34-12.89 ±â€¯4.77 nM against BChE. Additionally, we studied the inhibition effect of these derivatives on aldose reductase and α-glycosidase enzymes. For these compounds, compound 1d showed maximum inhibition effect against AR with a Ki value of 360.37 ±â€¯55.82 nM. Finally, all compounds were tested for the inhibition of α-glycosidase enzyme, which recorded efficient inhibition profiles with Ki values in the range of 4.44 ±â€¯0.65-12.67 ±â€¯2.50 nM against α-glycosidase.