Ni(II)-Salophen-Comprehensive Analysis on Electrochemical and Spectral Characterization and Biological Studies.

New aspects of the Ni(II)-salophen complex and salophen ligand precursor were found during deep electrochemical and optical characterization, as well as biological studies for new pharmacological applications. Physicochemical and spectroscopic methods (1H- and 13C-NMR, FT-IR and UV-Vis, electrospray ionization mass spectroscopy, thermogravimetric analysis, and molar conductance measurements) were also used to prove that the salophen ligand acts as a tetradentate and coordinates to the central metal through nitrogen and oxygen atoms. The electrochemical behavior of the free Schiff salophen ligand (H2L) and its Ni(II) complex (Ni(II)L) was deeply studied in tetrabutylammonium perchlorate solutions in acetonitrile via CV, DPV, and RDE. Blue films on the surfaces of the electrodes as a result of the electropolymerization processes were put in evidence and characterized via CV and DPV. (H2L) and Ni(II)L complexes were tested for their antimicrobial, antifungal, and antioxidant activity, showing good antimicrobial and antifungal activity against several bacteria and fungi.

Introducing chirality in halogenated 3-arylsydnones and their corresponding 1-arylpyrazoles obtained by 1,3-dipolar cycloaddition.

New 1-arylpyrazoles substituted with halogen atoms (Br, I) were synthesized from the corresponding sydnones by 1,3-dipolar cycloaddition. By introduction of a prochiral group such as isopropyl, in the ortho position of the benzene ring, in the starting phenylglycine 1 the rotamers caused by the hindered rotation between the phenyl and the heterocyclic ring were detected by NMR spectroscopy for 1-arylpyrazoles and for the first time for 3-arylsydnones. The N-nitrosophenylglycines present E-Z stereoisomerism due to the partial C-N double bond character. All the new compounds were structurally characterized by NMR spectroscopy and confirmed by X-ray crystallography. The crystal structures of N-nitrosophenylglycine 2c and of the sydnone 3c present similar Br⋯Br type II halogen contacts.

Bis(µ-N,N-di-allyl-dithio-carbamato)bis[(N,N-di-allyl-dithio-carbamato)cadmium].

The title compound, [Cd2(C7H10NS2)4], is a neutral dinuclear cadmium(II) complex bearing four bis N,N-di-allyl-di-thio-carbamate ligands coordinating to two CdII cations. In each of the monomeric subunits, there are four S atoms of two di-thio-carbamate ligands [Cd-S = 2.5558 (3), 2.8016 (3), 2.6050 (3) and 2.5709 (3) Å] that coordinate to one CdII atom in a bidentate mode. The dimers are located over an inversion centre bridged by two additional bridging Cd-S bonds [2.6021 (3) Å], leading to a substantial distortion of the geometry of the monomeric subunit from the expected square-planar geometry. The five-coordinate environment around each of the CdII ions in the dimer is best described as substanti-ally tetra-gonally distorted square pyramidal. The di-thio-carbamate groups are themselves planar and are also coplanar with the CdII ions. The negative charge on these groups is delocalized by resonance across the S atoms bound to the CdII cation. This delocalization of the π electrons in the di-thio-carbamate groups also extends to the C-N bonds as they reveal significant double bond character [C-N = 1.3213 (16) and 1.3333 (15) Å].

HPLC-Based Activity Profiling for hERG Channel Inhibitors in the South African Medicinal Plant Galenia africana.

The human ether-a-go-go-related gene channel is a voltage-activated K(+) channel involved in cardiac action potential. Its inhibition can lead to QT prolongation, and eventually to potentially fatal arrhythmia. Therefore, it is considered a primary antitarget in safety pharmacology. To assess the risk of human ether-a-go-go-related gene channel inhibition by medicinal plants, 700 extracts from different parts of 142 medicinal plants collected in Southern Africa were screened on Xenopus laevis oocytes. A CH2Cl2 extract from the stems and leaves of Galenia africana (Aizoaceae) reduced the peak tail human ether-a-go-go-related gene current by 50.4 ± 5.5 % (n = 3) at a concentration of 100 µg/mL. By means of high-performance liquid chromatography-based activity profiling, nine flavonoids were identified in the active time windows. However, the human ether-a-go-go-related gene channel inhibition of isolated compounds was less pronounced than that of extract and active microfractions (human ether-a-go-go-related gene inhibition between 10.1 ± 5 and 14.1 ± 1.6 at 100 µM). The two major constituents, 7,8-methylenedioxyflavone (1) and 7,8-dimethoxyflavone (13), were quantified (4.3 % and 9.4 %, respectively, in the extract). Further human ether-a-go-go-related gene inhibition tests for compounds 1 and 13 at 300 µM showed a concentration-dependent inhibitory activity (33.2 ± 12.4 and 30.0 ± 7.4, respectively). In a detailed phytochemical profiling of the active extract, a total of 20 phenolic compounds, including six new natural products, were isolated and identified.