DNA binding,antibacterial and antifungal activities of copper(II) complexes with some S-alkenyl derivatives of thiosalicylic acid

The biological activities of two binuclear copper(II) complexes containing S-alkenyl derivatives of thiosalicylic acid are reported [alkenyl = propenyl (L1), isobutenyl (L2)]. The structure of the complex with the S-isobutenyl derivative (C2) was confirmed by single-crystal X-ray structure analysis, which revealed that the structure consists of centrosymmetric, dinuclear complex molecules [Cu₂(S-i-butenyl-thiosal)₄(DMSO)₂] containing two Cu(II) centers bridged by four S-isobutyl-thiosalicylate ligands in a paddle-wheel type structure. The Cu(II) atom is situated in a distorted square-pyramidal environment formed by carboxylate oxygen atoms in the basal plane and a DMSO ligand in the axial position. The reactivities of the complexes toward guanosine-5′-monophosphate (5′-GMP) were investigated. Complex C2 ([Cu₂(S-i-butenyl-thiosal)₄(H₂O)₂]) reacted more rapidly with 5′-GMP than complex C1. The interactions of complexes C1 and C2 with calf thymus DNA (CT-DNA) were examined by absorption (UV–Vis) and emission spectral studies (ethidium bromide displacement studies), revealing good DNA interaction abilities. The antimicrobial activities of the free ligands and their complexes were tested by microdilution method, and both minimal inhibitory and microbicidal concentrations were determined. All the tested substances demonstrated selective and moderate antibacterial activity on gram-positive bacteria, but low antibacterial activity on gram-negative bacteria. Also, the tested substances demonstrated low antifungal activity.     

DNA binding and antitumor activities of platinum(IV) and zinc(II) complexes with some S-alkyl derivatives of thiosalicylic acid

A series of complexes of platinum(IV) (C1–C5) and zinc(II) (C6–C10) with S-alkyl derivatives of thiosalicylic acid were prepared and characterized. The interactions of the complexes with calf thymus DNA were analyzed by absorption (UV–Vis) and emission spectral studies (ethidium bromide displacement studies). The cytotoxic activities of complexes C1–C10 were determined against mouse B cell lymphocytic leukemia cells (BCL1), human B-prolymphocytic leukemia (JVM-13), mouse mammary carcinoma cells (4T1), and human mammary carcinoma cells (MDA-MB-468) and compared to the activities of the free ligand precursors and cisplatin. The cytotoxicities of the platinum(IV) and zinc(II) complexes toward mouse tumor cell lines were higher compared with their effects on human tumor cell lines. The zinc(II) complex C9 showed the highest antitumor activity toward the tested human cell lines, while the platinum(IV) complex C4 exhibited the highest antitumor activity toward mouse BCL1 and 4T1 cells. Both C4 and C9 have ligands derived from S-propyl thiosalicylic acid.     

Blow-Up Scenarios for the 3D Navier–Stokes Equations Exhibiting Sub-Criticality with Respect to the Scaling of One-Dimensional Local Sparseness

It is shown that, if the vorticity magnitude associated with a (presumed singular) three-dimensional incompressible Navier–Stokes flow blows-up in a manner exhibiting certain time dependent local structure, then time independent bounds on the L ¹ norm of ${|\omega| \log \sqrt{1+ |\omega|^2}}$ follow. The implication is that the volume of the region of high vorticity decays at a rate of greater order than a rate connected to the critical scaling of one-dimensional local sparseness and, consequently, the solution becomes sub-critical.     

Electron swarm transport in THF and water mixtures

In this paper, nonlinear Schrödinger equation (NLSE) with self-steepening term for dispersive permittivity and permeability which governs the ultrashort pulse propagation through negative-index materials (NIMs) is studied. The Lax pair is constructed for this model by employing AKNS procedure. The soliton solutions are generated with symbolic computation through Darboux transformation and the frequency regimes for their existence have been worked out. Through the graphical analysis of the soliton solutions, the propagation features of optical pulses and their interaction behaviours in NIMs are investigated.     

X‐ray Excited Optical Fluorescence and Diffraction Imaging of Reactivity and Crystallinity in a Zeolite Crystal: Crystallography and Molecular Spectroscopy in One

Structure–activity relationships in heterogeneous catalysis are challenging to be measured on a single‐particle level. For the first time, one X‐ray beam is used to determine the crystallographic structure and reactivity of a single zeolite crystal. The method generates μm‐resolved X‐ray diffraction (μ‐XRD) and X‐ray excited optical fluorescence (μ‐XEOF) maps of the crystallinity and Brønsted reactivity of a zeolite crystal previously reacted with a styrene probe molecule. The local gradients in chemical reactivity (derived from μ‐XEOF) were correlated with local crystallinity and framework Al content, determined by μ‐XRD. Two distinctly different types of fluorescent species formed selectively, depending on the local zeolite crystallinity. The results illustrate the potential of this approach to resolve the crystallographic structure of a porous material and its reactivity in one experiment via X‐ray induced fluorescence of organic molecules formed at the reactive centers.     

Pressurized-Liquid Extraction as an Efficient Method for Valorization of Thymus serpyllum Herbal Dust towards Sustainable Production of Antioxidants

The aim of this study was to valorize Thymus serpyllum herbal dust, a particular fraction distinguished as an industrial waste from filter-tea production. Pressurized liquid extraction (PLE) was used with the aim of overcoming certain obstacles of conventional extraction techniques in terms of shortening extraction time, reducing solvent consumption and energy costs, using “green” solvents and obtaining high yield and quality products. In order to optimize PLE of T. serpyllum herbal dust, the preliminary screening of the independent variables in order to define the most influential parameters and their domain was done first. After the screening, the optimization study using the face-centered central composite experimental design (CCD) with response surface methodology (RSM) was implemented. Additionally, taking into account the high awareness of the positive influence of antioxidants on the human health and associating it with high content of polyphenolic compounds in various members of Lamiaceae family, PLE has proven to be a great approach for antioxidants recovery from T. serpyllum herbal dust.     

Recurrence Formulas for Kostka and Inverse Kostka Numbers via Quantum Cohomology of Grassmannians

A Gröbner basis for the small quantum cohomology of Grassmannian G _k,n is constructed and used to obtain new recurrence relations for Kostka numbers and inverse Kostka numbers. Using these relations it is shown how to determine inverse Kostka numbers which are related to the mod-p Wu formula.     

Order complex of ideals in a commutative ring with identity

Order complex is an important object associated to a partially ordered set. Following a suggestion from V. A. Vassiliev (1994), we investigate an order complex associated to the partially ordered set of nontrivial ideals in a commutative ring with identity. We determine the homotopy type of the geometric realization for the order complex associated to a general commutative ring with identity. We show that this complex is contractible except for semilocal rings with trivial Jacobson radical when it is homotopy equivalent to a sphere.