Cyclic imides and an open-chain amide carboxylic acid from the facile reaction ofcis-cyclohexane-1,2-carboxylic anhydride with the isomeric monofluoroanilines

Novel Organoselenium Redox Modulators with Potential Anticancer, Antimicrobial, and Antioxidant Activities

Novel organic selenides were developed in good yields (up to 91%), and their chemical entities were confirmed by IR, MS, and ¹H- and ¹³C-NMR spectroscopy. Their anticancer and antimicrobial properties were estimated against different human cancer (MCF-7 and HepG2) and healthy (WI-38) cell lines, as well as several microbial strains (Escherichia coli, Staphylococcus aureus, and Candida albicans). Furthermore, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) bioassays were used for the estimation of the antioxidant activities. Generally, cytotoxicity results were more pronounced against the MCF-7 cells than HepG2 cells. Compound 2-((4-((1-hydroxynaphthalen-2-yl)diazenyl)phenyl)selanyl)-N-phenylacetamide (9) was the most cytotoxic, even more than doxorubicin, with IC₅₀ of 3.27 ± 0.2 against 4.17 ± 0.2 µM and twelve-times more selective, respectively. Interestingly, compound 9 exhibited similar antimicrobial potential to reference antibacterial and antifungal drugs and comparable antioxidant activity to vitamin C. These results point to selective cytotoxicity against MCF-7 cells and interesting antimicrobial and antioxidant properties of some newly synthesized organic selenides, which in turn needs further in vitro studies.

Hirshfeld surface analysis and crystal structure of N-(2-meth-oxy-phen-yl)acetamide

The title compound, C9H11NO2, was obtained as unexpected product from the reaction of (4-{2-benz-yloxy-5-[(E)-(3-chloro-4-methyl-phen-yl)diazen-yl]benzyl-idene}-2-phenyl-oxazol-5(4H)-one) with 2-meth-oxy-aniline in the presence of acetic acid as solvent. The amide group is not coplanar with the benzene ring, as shown by the C-N-C-O and C-N-C-C torsion angles of -2.5 (3) and 176.54 (19)°, respectively. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (53.9%), C⋯H/H⋯C (21.4%), O⋯H/H⋯O (21.4%) and N⋯H/H⋯N (1.7%) inter-actions.

Aspherical scattering factors for SHELXL - model, implementation and application

A new aspherical scattering factor formalism has been implemented in the crystallographic least-squares refinement program SHELXL. The formalism relies on Gaussian functions and can optionally complement the independent atom model to take into account the deformation of electron-density distribution due to chemical bonding and lone pairs. Asphericity contributions were derived from the electron density obtained from quantum-chemical density functional theory computations of suitable model compounds that contain particular chemical environments, as defined by the invariom formalism. Thanks to a new algorithm, invariom assignment for refinement in SHELXL is automated. A suitable parameterization for each chemical environment within the new model was achieved by metaheuristics. Figures of merit, precision and accuracy of crystallographic least-squares refinements improve significantly upon using the new model.

Estimating temperature-dependent anisotropic hydrogen displacements with the invariom database and a new segmented rigid-body analysis program

Invariom partitioning and notation are used to estimate anisotropic hydrogen displacements for incorporation in crystallographic refinement models. Optimized structures of the generalized invariom database and their frequency computations provide the information required: frequencies are converted to internal atomic displacements and combined with the results of a TLS (translation-libration-screw) fit of experimental non-hydrogen anisotropic displacement parameters to estimate those of H atoms. Comparison with TLS+ONIOM and neutron diffraction results for four example structures where high-resolution X-ray and neutron data are available show that electron density transferability rules established in the invariom approach are also suitable for streamlining the transfer of atomic vibrations. A new segmented-body TLS analysis program called APD-Toolkit has been coded to overcome technical limitations of the established program THMA. The influence of incorporating hydrogen anisotropic displacement parameters on conventional refinement is assessed.

Organoselenocyanates and symmetrical diselenides redox modulators: Design, synthesis and biological evaluation

Oxidative stress (OS) and disturbed intracellular redox balance have been predominantly observed in different types of cancer, including hepatocellular carcinoma (HCC). Agents which can stop OS multi-stressor events and modulate the intracellular redox state are becoming a major focus in HCC prevention. Among them, compounds with glutathione peroxidase (GPx)-like activity are of particularly concern. We herein report the synthesis of novel series of organoselenocyanates and symmetrical diselenide antioxidants, inspired by the natural redox enzyme, GPx and the synthetic organoselenium ebselen antioxidants. Their cytotoxic activity was evaluated against Hep G2 cells and their antimicrobial activities were evaluated against Candida albicans (C. albicans) fungus as well as against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), gram-negative and gram-positive bacteria, respectively. These compounds were also tested for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH), GPx-like activity and bleomycin dependent DNA damage assays and a basic structure-activity relationship was subsequently established. The physicochemical parameters and drug-likeness were computed employing the Molinspiration online property calculation toolkit and MolSoft software. Interestingly, some compounds proved to be more cytotoxic than ebselen and the known anticancer drug 5-Fu and in the same time they showed similar, sometime even more, antifungal activity than the reference antifungal drugs. Among these compounds, compound 16 was considered to be the most interesting with free radical-scavenging activity comparable to ascorbic acid and a GPx-like activity similar to ebselen. As most of these compounds comply with Lipinski's Rule of Five, they promise good bioavailability, which needs to be studied as part of future investigations.

Hydrogen bonding in cyclic imides and amide carboxylic acid derivatives from the facile reaction ofcis-cyclohexane-1,2-carboxylic anhydride witho- andp-anisidine andm- andp-aminobenzoic acids

The structures of the open-chain amide carboxylic acidrac-cis-2-[(2-methoxyphenyl)carbamoyl]cyclohexane-1-carboxylic acid, C15H19NO4, (I), and the cyclic imidesrac-cis-2-(4-methoxyphenyl)-3a,4,5,6,7,7a-hexahydroisoindole-1,3-dione, C15H17NO3, (II), chiralcis-3-(1,3-dioxo-3a,4,5,6,7,7a-hexahydroisoindol-2-yl)benzoic acid, C15H15NO4, (III), andrac-cis-4-(1,3-dioxo-3a,4,5,6,7,7a-hexahydroisoindol-2-yl)benzoic acid monohydrate, C15H15NO4·H2O, (IV), are reported. In the amide acid (I), the phenylcarbamoyl group is essentially planar [maximum deviation from the least-squares plane = 0.060 (1) Å for the amide O atom] and the molecules form discrete centrosymmetric dimers through intermolecular cyclic carboxy–carboxy O—H...O hydrogen-bonding interactions [graph-set notationR22(8)]. The cyclic imides (II)–(IV) are conformationally similar, with comparable benzene ring rotations about the imide N—Carbond [dihedral angles between the benzene and isoindole rings = 51.55 (7)° in (II), 59.22 (12)° in (III) and 51.99 (14)° in (IV)]. Unlike (II), in which only weak intermolecular C—H...Oimidehydrogen bonding is present, the crystal packing of imides (III) and (IV) shows strong intermolecular carboxylic acid O—H...O hydrogen-bonding associations. With (III), these involve imide O-atom acceptors, giving one-dimensional zigzag chains [graph-setC(9)], while with the monohydrate (IV), the hydrogen bond involves the partially disordered water molecule which also bridges molecules through both imide and carboxy O-atom acceptors in a cyclicR44(12) association, giving a two-dimensional sheet structure. The structures reported here expand the structural database for compounds of this series formed from the facile reaction ofcis-cyclohexane-1,2-dicarboxylic anhydride with substituted anilines, in which there is a much larger incidence of cyclic imides compared to amide carboxylic acids.