Substituent effect on the chemical and biological properties of diisatin dihydrazone Schiff bases: DFT and docking studies.

According to the considered role of lipophilicity-hydrophobicity on organic Schiff base hydrazones, different substituents of phenyl, ethyl, and methyl groups were inserted in the synthetic strategy of diisatin dihydrazones (L1-4). The biochemical enhancement was evaluated depending on their inhibitive potential of the growth power of three human tumor cells, fungi, and bacteria. The biochemical assays assigned the effected role of different substituents of phenyl, ethyl, and methyl groups on the effectiveness of their diisatin dihydrazone reagents. The interacting modes with calf thymus DNA (i.e. Ct-DNA) were studied via viscometric and spectrophotometric titration. The organo-reagent L1 with the oxalic derivative assigned a performed inhibitive action for the examined microbes and the human tumor cell lines growing up over the terephthalic (L4) > malonic (L2) > succinic (L3) ones. From Kb = binding constant, and ∆Gb≠ = Gibb's free energy values, the binding of interaction within Ct-DNA was evaluated for all compounds (L1-4), in which L1, L3, and L4 assigned the highest reactivity referring to the covalent/non-covalent modes of interaction, as given for (L1-4), 14.32, 13.28, 10.87, and 12.41 × 107 mol-1 dm3, and -45.17, -43.24, -43.75, and -44.05 kJ mol-1, respectively. DFT and docking studies were achieved to support the current work.

Bimetallic bis-Aroyldihydrazone-Isatin Complexes of High O=V(IV) and Low Cu(II) Valent Ions as Effective Biological Reagents for Antimicrobial and Anticancer Assays.

Due to the versatile bioreactivity of aroyldihydrazone complexes as cost-effective alternatives with different transition metals, two novel bimetallic homo-complexes (VOLph and CuLph) were prepared via the coordination of a terephthalic dihydrazone diisatin ligand (H2Lph) with VO2+ and Cu2+ ions, respectively. The structure elucidation was confirmed by alternative spectral methods. Biologically, the H2Lph ligand and its MLph complexes (M2+ = VO2+ or Cu2+) were investigated as antimicrobial and anticancer agents. Their biochemical activities towards ctDNA (calf thymus DNA) were estimated using measurable titration viscometrically and spectrophotometrically, as well as the gel electrophoresis technique. The growth inhibition of both VOLph and CuLph complexes against microbial and cancer cells was measured, and the inhibition action, MIC, and IC50 were compared to the inhibition action of the free H2Lph ligand. Both VOLph and CuLph showed remarkable interactive binding with ctDNA compared to the free ligand H2Lph, based on Kb = 16.31, 16.04 and 12.41 × 107 mol-1 dm3 and ΔGb≠ = 47.11, -46.89, and -44.05 kJ mol-1 for VOLph, CuLph, and H2Lph, respectively, due to the central metal ion (VIVO and CuII ions). VOLph (with a higher oxidation state of the V4+ ion and oxo-ligand) exhibited enhanced interaction with the ctDNA molecule compared to CuLph, demonstrating the role and type of the central metal ion within the performed electronegative and electrophilic characters.

Nucleoside Scaffolds and Carborane Clusters for Boron Neutron Capture Therapy: Developments and Future Perspective.

Nucleosides containing carboranes are one of the most important boron delivery agents for boron neutron capture therapy, BNCT, which are good substrates of hTK1. The development of several nucleosides containing carboranes at early stages led to the discovery of the first generation of 3CTAs by incorporating a hydrocarbon spacer between the thymidine scaffold and carborane cluster and attaching dihydroxylpropyl group on the second carbon (C2) atom of the carborane cluster (e.g., N5 and N5-2OH). Phosphorylation rate, tumor cellular uptake, and retention have been evaluated in parallel to change the length of the tether arm of spacers in these compounds. Many attempts were reported and discussed to overcome the disadvantage of the first generation of 3CTAs by a) incorporating modified spacers between thymidine and carborane clusters, such as ethyleneoxide, polyhydroxyl, triazole, and tetrazole units, b) attaching hydrophilic groups at C2 of the carborane cluster, c) transforming lipophilic closo-carboranes to hydrophilic nidocarborane. The previous modifications represented the second generation of 3CTAs to improve the hydrogen bond formation with the hTK1 active site. Moreover, amino acid prodrugs were developed to enhance biological and physicochemical properties. The structure-activity relationship (SAR) of carboranyl thymidine analogues led to the roadmap for the development of the 3rd generation of the 3CTAs for BNCT.

Bioreactivity of divalent bimetallic vanadyl and zinc complexes bis-oxalyldihydrazone ligand against microbial and human cancer series. ctDNA interaction mode.

Two novel divalent bimetallic complexes were constructed from the complexation of O=V4+ and Zn2+ ions (VOL and ZnL), respectively, with diisatin oxalyldihydrazone ligand (H2L). Various spectroscopic tools were used to confirm their chemical structures (FT-IR, NMR, EI-Mass, and electronic spectra), besides, elemental analyses and conductivity features. To estimate the role of divalent metal ions in their coordination compound for developing their bio-reactivity, the free ligand H2Lox, and its complexes (VOL and ZnL) were employed spectroscopic investigations against the growth of some microbial series (fungi and bacteria) and also against three human cancer/normal cells. Furthermore, their interaction behavior against calf thymus DNA (ctDNA) was studied through viscometric and spectrophotometric studies to discover the role of O=V4+ and Zn2+ ions to determine the mode of binding with ctDNA. The inhibiting effect of H2L, VOL, and ZnL versus the titled microbial (bacterial and fungal) was built upon their inhibited zone areas in mm and the MIC concentrations in µM. Their action against the three human cancer cells' growth was evaluated by IC50 values in µM and the selectivity index in percentage. Both VOL and ZnL complexes exhibited an amazing series with three human cancer cell growth (according to the zone values in mm of inhibition, MIC in µM, and IC50 values in µM) compared to those of their uncoordinated H2L ligand. VOL demonstrated a distinguished interacting behavior with ctDNA more than that interaction of ZnL depending on the variation of the central metal ion chemical features. Within the covalent and non-covalent interaction modes, the interaction binding between H2L, VOL, and ZnL with ctDNA was discussed based on the electronic spectroscopic observation.

Anticorrosion Evaluation of Novel Water-Soluble Schiff Base Molecules for C1018 Steel in CO2-Saturated Brine by Computational and Experimental Methodologies.

In this work, three different derivatives of Schiff base, as mono- and di-Schiff bases, were successfully synthesized by the facile condensation of 2-aminopyridine, o-phenylenediamine, or 4-chloro-o-phenylenediamine with sodium salicylaldehyde-5-sulfonate (H1, H2, and H3, respectively). A combination of theoretical and practical studies was accomplished on the corrosion mitigation effect of the prepared Schiff base derivatives on C1018 steel in CO2-saturated 3.5% NaCl solution. The corrosion inhibition effect of the synthesized Schiff base molecules was studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) methods. The outcomes exhibited that Schiff base derivatives have an outstanding corrosion inhibition effect on carbon steel at particularly low concentrations in sweet conditions. The outcomes showed that Schiff base derivatives exhibited a satisfactory inhibition efficiency of 96.5% (H1), 97.7% (H2), and 98.1% (H3) with a dosage of 0.5 mM at 323 K. SEM/EDX analysis confirms the adsorbed inhibitor film's formation on the metal surface. The polarization plots indicate that the studied compounds behaved as inhibitors of the mixed type according to the isotherm model of Langmuir. The computational inspections (MD simulations and DFT calculations) display a good correlation with the investigational findings. The outcomes could be applied to assess the efficiency of the inhibiting agents in the gas and oil industry.

Synthesis, spectral characterization, DFT calculations, pharmacological studies, CT-DNA binding and molecular docking of potential N, O-multidentate chelating ligand and its VO(II), Zn(II) and ZrO(II) chelates.

The pharmacological efficacy of the variety tetradentate ligands encouraged us to design attractive compounds through effective synthetic procedure. The prepared Schiff base ligand 6,6'-((1E,1'E)-((4-chloro-1,2-phenylene)bis(azaneylylidene))bis(methaneylylidene))bis(2-ethoxy phenol (H2L), which derived from 4-chloro-o-phenylenediamine and 3-ethoxy-salicylaldehyde and its VO(II), Zn(II) and ZrO(II) metal chelates, have been synthesized and characterized with aim of that it may struggle the invasion of drug resistance. The chemical structural of studied compounds were discussed by TGA, elemental analysis, UV-Vis., 1H NMR, 13C NMR, FTIR, mass spectral, PXRD, molar conductance, magnetic susceptibility measurements and density functional theory. The results assigned square pyramid geometries for [VOL] and [ZrOL].2H2O chelates and an octahedral geometry for [ZnL(H2O)2].2H2O chelate. Powder XRD data showed that the complexes are monoclinic with polycrystalline nature. The results of CT-DNA interaction with the titled chelates showed that the binding between CT-DNA and the metal complexes occurs through intercalation mode. Their CT-DNA binding efficiency estimated in terms of their binding constants (Kb), which gave the order: VOL (6.9 × 105) > ZrOL (6.3 × 105) > ZnL(H2O)2 (5.5 × 105). The antimicrobial activities of the synthesized compounds were tested against selected fungal and bacterial strains using well diffusion technique. The obtained chelates showed higher antifungal and antibacterial activities than their corresponding ligand. Furthermore, the M-complexes showed higher potent cytotoxic effect toward HEK-293, human colorectal HepG-2, HCT-116 and MCF-7 adenocarcinoma cell lines compared to the free H2L ligand. Investigation of antioxidant property represented that all the prepared complexes have better radical scavenging potencies against DPPH radicals than the free H2L ligand. To study the molecular docking of proposed compounds versus Tyrosine kinases receptor (TKR), we used AutoDock1.5.6rc3® suite. The current compounds (H2L, VOL, ZrOL and ZnL(H2O)2) and STI were found to bind with C-kit of TKR with HBs at ILE789.A, ILE808.A, ASP810.A, GLU640.A and TYR846 amino acid residue and the binding energies were - 8.9, -8.93, -8.83, -1.48 and -10.39 kcal/mol respectively.

Biological and catalytic potential of sustainable low and high valent metal-Schiff base sulfonate salicylidene pincer complexes.

ONO-Pincer Schiff base salicylidene (HSaln ligand) complexes with VO2+, UO2 2+, MoO2 2+ and Mn2+ ions (MSaln complexes = VOSaln, UO2Saln, MoO2Saln and MnSaln, respectively) were synthesized and fully characterized by different physico-chemical tools. The VOSaln complex was further treated with 1,10-phenanthroline which afforded a new VO-complex (VOSaln-Ph). All complexes and their ligands, as eco-friendly reagents, were explored for their biological potential as antibacterial and antifungal agents. Reactivity of MSaln complexes against the tested pathogen strains exhibited a remarkable inhibitory effect compared to the coordinated ligand (HSaln) and applicable standard drugs. Moreover, the MSaln complex-DNA interaction was investigated by ultraviolet-visible spectroscopy, viscosity and gel electrophoresis techniques affording binding strengths in the order: UO2Saln > MnSaln > MoO2Saln > VOSaln-Ph > VOSaln. Additionally, the biological potential of the investigated compounds was further explored by molecular docking to illustrate the nature of the drug-DNA interactions. All MSaln complexes show respectable anti-proliferative potential as anticancer agents against selected human carcinoma cell lines. Aside from the biological activities these complexes (MSaln complexes) were also investigated for catalytic efficiency in the Suzuki-Miyaura cross-coupling system of phenylboronic acid with 2-bromopyridine in water, sustainably. The results indicated that the MnSaln catalyst performed well with high yield. The catalytic potential of MnSaln was compared in water, water-ionic liquid mixtures and ionic liquids.

Biological potential of oxo-vanadium salicylediene amino-acid complexes as cytotoxic, antimicrobial, antioxidant and DNA interaction.

New series of oxo-vanadium N-salicyledieneamino acid Schiff base complexes are synthesized and characterized. They are synthesized from the reaction of sodium salicylaldehyde-5-sulfonate, some amino acids, alanine (VOHL1), leucine (VOHL2) or glycine (VOHL3) in an aqueous media, and leucine (VOHLpy1) or tryptophan (VOHLpy2) in pyridine with vanadyl acetylacetonate. The complexes are characterized by EA, TGA, IR, UV-Visible and mass spectra, conductivity and magnetic measurements. The biological activity of the VO-complexes shows that VOHL1, VOHL2 and VOHL3 exhibit anti-proliferative effect and may be used as anticancer drugs. VO-complexes manifest high toxicity, except VOHL2 is less toxic, and could be applied for the human being. VOHL1, VOHL2 and VOHL3 display remarkable SOD like potential and act as high inhibiting reagents. VOHLpy1 and VOHLpy2 show low inhibiting potentials. VO-complexes have good anti-oxidant effect, in which VOHL3 affords the best antioxidant activity. The interaction between VO-complexes and DNA is studied spectrophotometrically and by gel electrophoresis. Binding constants and spectrophotometric parameters indicate a strong interaction between VO-complexes and DNA. VO-complexes have respectable anti-bacterial and antifungal activities, where VOHL3 shows the maximum potential. DFT calculations of VOHL1 and VOHL3 were discussed in the light of their biological activity, which are convenient with the obtained results.