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A new N-alkylation Schiff base [N2,N6-bis(2-hydroxy-3-methoxybenzyl)pyridine-2,6-dicarboxamide] was synthesized from o-vanillin and pyridine-2,6-dicarboxamide by a solid-phase microwave green synthesis without catalyst and solvent. A new bismuth(III) complex was prepared by reaction of the ligand with BiCl3. The ligand and its bismuth(III) complex were characterized by elemental analysis, spectral techniques (1HNMR, MS, FT-IR and UV), chemical analysis, thermogravimetric analysis and molar conductance. The compositions of the ligand and its bismuth(III) complex were (C23H23N3O6) and Bi(C23H21N3O6)Cl. Moreover, the antibacterial activity of the ligand and its bismuth(III) complex against S. pombe was evaluated by bio-microcalorimetry at 32 °C. The quantitative relationship between some thermokinetic parameters (k, tG and I) with the concentration (c) of the ligand and its bismuth(III) complex was investigated. The half inhibition concentrations (IC50) of the ligand and its bismuth(III) complex were obtained as 4.63 × 10–3 mol dm−3 and 2.10 × 10–3 mol dm−3, respectively. The results showed that the antibacterial activity of bismuth(III) complex was stronger than that of the ligand. Further, the action target of bismuth(III) complex on bovine serum albumin (BSA) was studied by the molecular docking simulation method, and we found that bismuth(III) complex bounded at in the hydrophobic cavity of the substructure domain IIB of BSA. [ABSTRACT FROM AUTHOR]

A Valen Schiff-base ligand [1,5-bis(2-hydroxy-3-methoxybenzylidene)thiocarbonohydrazide] and its bismuth(III) complex were synthesized. The compositions and structures of two compounds were characterized by elemental analysis, spectrometry (1HNMR, MS, FT-IR, and UV-visible), chemical analysis, molar conductivity, and TG–DTA analysis. The results showed that the molecular formula of Schiff base and its bismuth(III) complex was C17H18O4N4S (abbreviated as H2L, L = C17H16O4N4S) and [Bi(C17H16O4N4S)Cl·H2O] (abbreviated as [Bi(L)Cl·H2O]), respectively. Furthermore, the thermokinetic properties of the action of Schiff base and its bismuth(III) complex on the growth metabolism of S. pombe were studied by bio-microcalorimetry at 305.15 K. The growth rate constant (k), maximum heat power, generation time, inhibition ratio (I) and half inhibition concentration (IC50), and their quantitative relationship with the concentration were calculated, respectively. Experimental results indicated that both Schiff base and its bismuth(III) complex could inhibit the growth of S. pombe, but the inhibitory effect of Schiff base was stronger than that of the complex. The half inhibition concentrations of Schiff base and its bismuth(III) complex were found to be 4.17 × 10−3 mol L−1 and 6.13 × 10−3 mol L−1, respectively. [ABSTRACT FROM AUTHOR]

In this study, a new Schiff base ligand [2-{[4-amino-5-(3,4,5-trimethoxy-benzyl)-pyrimidin-2-ylimino]-methyl}-6-methoxy-phenol, C22H24N4O5] and its bismuth(III) complex [BiC22H22N4O5Cl] were synthesized using o-vanillin and trimethoprim in anhydrous solvents. Chemical analysis, elemental analysis, spectrum analysis and TG-DSC analysis were employed to characterize the compositions and structures of the two new compounds. In particular, the metabolic thermogenic curves of Schizosaccharomyces pombe (S. pombe) and Helicobacter pylori (H. pylori) cells treated by the two new compounds at different concentrations were monitored by an isothermal microcalorimeter at 32.00 and 37.00 °C, respectively. On the basis of the metabolic thermogenic curves, some important biothermokinetic parameters such as the microbial growth rate constant (k), inhibition ratio (I) and half inhibition concentration (IC50) were estimated. The experimental results indicated that both the Schiff base ligand and its bismuth(III) complex could inhibit the growth metabolism of S. pombe and H. pylori, but the inhibitory abilities of the two compounds were as follows: the Schiff base ligand > the complex for S. pombe and the Schiff base ligand < the complex for H. pylori, respectively. More importantly, the results also found that the Schiff base bismuth(III) complex exhibited bidirectional biological effect and hormesis effect on H. pylori cell line, i.e., the complex can stimulate the growth metabolism of H. pylori at low concentration, while inhibiting its growth at high concentration. [ABSTRACT FROM AUTHOR]

The title complex [(CHN)Bi(ONO)] was synthesized by reaction of 1,10-phenanthroline (phen) and Bi(NO)·5HO. The structure of the complex was characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. An advanced solution-reaction isoperibol microcalorimeter was applied to determine the standard molar enthalpies of formation at 298.15 K of the complex and Bi(NO)·5HO, giving -(798.92 ± 5.99) and -(1986.87 ± 0.20) kJ mol, respectively. The biological effect of the complex was evaluated by microcalorimetry on the growth of Schizosaccharomyces pombe ( S. pombe). According to thermogenic curves, the corresponding thermokinetics and thermodynamic parameters were derived. The complex had good bioactivity on the growth metabolism of S. pombe, with the value of IC being 2.8 × 10 mol L. [ABSTRACT FROM AUTHOR]

In this work, a new Schiff base [ N, N′- bis(2-hydroxy-3-methoxyphenylmethylidene)-2,6-pyridinediamine, CHNO] and its bismuth(III) complex [Bi(CHNO)]Cl·2HO were synthesized with o-vanillin and 2,6-pyridinediamine in ethanol and THF solvent, respectively. The compositions and structures of the two synthetic compounds were characterized by elemental analysis, chemical analysis, spectrum analysis (including MS, FT-IR, NMR, and UV-Vis), and thermogravimetric analysis. The thermogenic curves for the growth metabolism of Helicobacter pylori ( H. pylori) and Schizosaccharomyces pombe ( S. pombe) treated by different concentrations of the two synthetic compounds were determined by isothermal heat conduction microcalorimetry at 37.00 and 32.00 °C, respectively. Based on the thermogenic curves, some important thermokinetic parameters including the microbial growth rate constant ( k), inhibition ratio ( I), and half inhibition concentration (IC) were calculated. The obtained results revealed that the Schiff base stimulated the growth of H. pylori, while the complex inhibited its growth. By contrast, both the Schiff base and the complex inhibited the growth of S. pombe, but the inhibitory effect of the complex was stronger than that of the Schiff base. [ABSTRACT FROM AUTHOR]

A copper(II) Schiff-base complex [CuL·2MeOH·HO] was prepared by reaction of the ligand [HL = N, N′- o-phenylene-bis(3-methoxysalicylideneimine)] and Cu(OAc)·HO in methanol at 328.15 K. X-ray diffraction analysis revealed that the title complex was crystallized in the triclinic crystal system with space group P-1, in which copper(II) ion was located in the NO ligand binding sites. According to two designed thermochemical cycles, the dissolution enthalpies of relevant substances of two reactions in the calorimetric solvents were determined by a solution-reaction isoperibol calorimeter, respectively. Combined with some other auxiliary thermodynamic data, the standard molar enthalpies of formation of the ligand and the complex were calculated to be: $$ \Delta_{\text{f}} H_{\text{m}}^{\theta } $$ [HL(s), 298.15 K] = −(384.2 ± 9.10) kJ mol and $$ \Delta_{\text{f}} H_{\text{m}}^{\theta } $$ [CuL·2MeOH·HO (s), 298.15 K] = −(1072.6 ± 9.2) kJ mol. [ABSTRACT FROM AUTHOR]

o-Vanillin and trimethoprim are two main raw materials for the synthesis of Valen Schiff bases which have been proved to possess established biological activities and may be used as the antibacterial agent candidates. The standard molar enthalpy of combustion and the standard molar enthalpy of formation of a substance are some of the most fundamental thermodynamic properties, and closely related to other physical, biological, physiological, and chemical properties. However, up to now, no reports about those thermodynamic properties of the title compounds were found in literatures. In this paper, the constant-volume energies of combustion of o-vanillin and trimethoprim at T = 298.15 K and p = 3.01 MPa were measured by a precision oxygen-bomb combustion calorimeter to be Δ U [ o-vanillin(s), 298.15 K] = −(24,971.89 ± 22.02) J g and Δ U [trimethoprim(s), 298.15 K] = −(26,366.77 ± 21.96) J g, respectively. According to the definition of combustion enthalpy, the standard ( p = 0.1 MPa) molar enthalpies of combustion of o-vanillin and trimethoprim were determined to be $$ \Delta_{\text{c}} H_{\text{m}}^{\varTheta } $$ [ o-vanillin(s), 298.15 K] = −(3,800.55 ± 3.35) kJ mol and $$ \Delta_{\text{c}} H_{\text{m}}^{\varTheta } $$ [trimethoprim(s), 298.15 K] = −(7,657.05 ± 6.38) kJ mol, respectively. Finally, the standard ( p = 0.1 MPa) molar enthalpies of formation of o-vanillin and trimethoprim were calculated to be $$ \Delta_{\text{f}} H_{\text{m}}^{\varTheta } $$ [ o-vanillin(s), 298.15 K] = −(490.85 ± 3.51) kJ mol and $$ \Delta_{\text{f}} H_{\text{m}}^{\varTheta } $$ [trimethoprim(s), 298.15 K] = −(424.56 ± 6.64) kJ mol from a combination of the experimental values of enthalpies of combustion and some other auxiliary thermodynamic data through a designed thermochemical cycle based on a supposed chemical reaction. [ABSTRACT FROM AUTHOR]

The product, [Pr(CHO)(CHNO)], which was formed by praseodymium nitrate hexahydrate, salicylic acid (CHO), and 8-hydroxyquinoline (CHNO), was synthesized and characterized by elemental analysis, UV spectra, IR spectra, molar conductance, and thermogravimetric analysis. In an optimalizing calorimetric solvent, the dissolution enthalpies of [Pr(NO)·6HO(s)], [2 CHO(s) + CHNO(s)], [Pr(CHO)(CHNO)(s)], and [solution D (aq)] were measured to be, by means of a solution-reaction isoperibol microcalorimeter, $$ \begin{gathered}\Updelta_{\text{s}} H_{\text{m}}^{\theta}\left[ {{ \Pr }\left( {{\text{NO}}_{ 3} } \right)_{ 3} \cdot 6{\text{H}}_{ 2} {\text{O}}\left( {\text{s}} \right), 2 9 8. 1 5{\text{ K}}} \right] \, = - ( 20. 6 6 { } \pm \, 0. 29)\,{\text{kJ}}\,{\text{mol}}^{ - 1} , \hfill \\\Updelta_{\text{s}} H_{\text{m}}^{\theta } \left[ { 2 {\text{C}}_{7} {\text{H}}_{ 6} {\text{O}}_{ 3} \left( {\text{s}} \right) +{\text{ C}}_{ 9} {\text{H}}_{ 7} {\text{NO}}\left( {\text{s}}\right),{ 298}. 1 5 {\text{ K}}} \right] \, = \, ( 4 2. 2 7 { }\pm \, 0. 3 1)\,{\text{kJ}}\,{\text{mol}}^{ - 1} , \hfill \\\Updelta_{\text{s}} H_{\text{m}}^{\theta } \left[ {{\text{solutionD }}\left( {\text{aq}} \right), 2 9 8. 1 5 {\text{ K}}} \right] \,= - \left( { 8 9. 1 5 { } \pm \, 0. 4 3}\right)\,{\text{kJ}}\,{\text{mol}}^{ - 1} , \hfill \\\end{gathered} $$ and $$ \Updelta_{\text{s}} H_{\text{m}}^{\theta } \left\{ {\left[ {{\Pr }\left( {{\text{C}}_{ 7} {\text{H}}_{ 5} {\text{O}}_{ 3} }\right)_{ 2} \left( {{\text{C}}_{ 9} {\text{H}}_{ 6} {\text{NO}}}\right)} \right]\left( {\text{s}} \right),{ 298}. 1 5 {\text{ K}}}\right\} \, = - \left( { 4 1.0 4 { } \pm \, 0. 3 3}\right)\,{\text{kJ}}\,{\text{mol}}^{ - 1} $$ , respectively. Through an improved thermochemical cycle, the enthalpy change of the designed coordination reaction was calculated to be $$\Updelta_{\text{r}} H_{\text{m}}^{\theta} = \, ( 2 1 3. 1 8\pm0. 6 9)\,{\text{kJ}}\,{\text{mol}}^{ - 1} $$ , the standard molar enthalpy of the formation was determined as $$ \Updelta_{\text{f}} H_{\text{m}}^{\theta} \left\{ {\left[ {{\Pr }\left( {{\text{C}}_{ 7} {\text{H}}_{ 5} {\text{O}}_{ 3} }\right)_{ 2} \left( {{\text{C}}_{ 9} {\text{H}}_{ 6} {\text{NO}}}\right)} \right]\left( {\text{s}} \right), 2 9 8. 1 5 {\text{K}}}\right\} \, = \, - \, ( 1 8 7 5. 4\pm 3.1)\,{\text{kJ}}\,{\text{mol}}^{ - 1} $$ . [ABSTRACT FROM AUTHOR]