Design, synthesis, and biological evaluation of dinuclear bismuth(III) complexes with Isoniazid-derived Schiff bases.

Four dinuclear bismuth(III) Schiff-base complexes bearing Schiff-base ligands have been synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis, and spectral techniques (FT-IR, NMR and MS). The analytical data reveal the bismuth(III) complexes possess 1:1 metal-ligand ratios. In vitro biological studies have revealed that bismuth(III) complexes displayed much higher antibacterial and antitumor activities than their parent ligands, which involves two gram-negative (S. aureus, B. subtili) and two gram-positive (E. coli, P. aeruginosa) bacteria, and human gastric cancer SNU-16 cells. The power-time curves of S. pombe exposed to tested compounds were detected by bio-microcalorimetry. Some thermokinetic parameters (k, Pmax,tG and Qtotal) were derived based on the metabolic power-time curves, and their quantitative relationships with the concentrations (c) were further discussed.

Microcalorimetric study of the effect of Ce(III) on metabolic activity of mitochondria isolated from indice rice 9311.

Rare earth elements (REEs) have beneficial influence on plant growth and are widely used in agriculture practice, but little is known about behavior of the REEs on mitochondria in plant cells. Thermogenic metabolic curves were determined by the ampoule method at 303 K using a TAM air isothermal microcalorimeter in mitochondria isolated from indice rice 9311 (Oryza sativa L.), and the effect of Ce(III) on mitochondrial metabolism was investigated. By analyzing the obtained heat flux curves, the crucial parameters such as activity recovery rate constant (k) and maximum heat power (P(m)) were investigated. Application of Ce3+ in concentrations ranging from 0 to 120 microg/ml significantly increased k and P(m) values, with the maximum reaching 261 and 180% of the control, respectively. Concentrations from 140 to 150 microg/ml had the opposite effect. These results were consistent with previous reports on the effects of REEs on plant growth. It was concluded that the Ce(III)-induced change of mitochondrial metabolic activity is a possible mechanism by which Ce(III) influenced indice rice 9311 growth.

Bioenergetic investigation of action of lithium to Tetrahymena thermophila bF5 by microcalorimetry.

Microcalorimetry was employed to investigate the action of Li(I) to aquatic ecosystem from the point view of bioenergetics. Tetrahymena thermophila BF5 was chosen as the model organism. The power-time curves of T. thermophila BF5 growth metabolism in the absence and presence of Li(I) were obtained. The corresponding thermokinetic parameters were derived. The generation time was calculated as 592.3 min, which was consistent with the biomass values. Low concentration of Li(I) (1-20 mmol l-1) stimulated the growth of T. thermophila BF5, whereas the inhibition effect was observed in high concentration (30-100 mmol l-1). The value of IC50 was 52.8 mmol l-1. In the concentration range of 30-100 mmol l-1, the growth rate constants (k) and the maximum heat out power (P max) decrease with the concentration of Li(I), whereas the heat output (Q) increases slightly compared to the control. Other than the classic mechanism of inositol-phosphate cycle, the involvement of mitochondria mechanism was discussed and suggested.

Synthesis, crystal structure and spectroscopic studies of bismuth(III) complex with 2-substituted benzimidazole ligands.

Reaction of BiCl3 with 2-(2-hydroxy-3-methoxyphenyl)benzimidazole (HL) in tetrahydrofuran (THF) under reflux gave mononuclear complex of formula [Bi(HL)2Cl3·H2O]. The binding interaction of the complex with bovine serum albumin (BSA) was investigated using the fluorescence quenching method. The experimental results showed that the complex could bind to BSA in the proportion of about 1:1. The binding reaction was spontaneous and hydrophobic force played major role in the reaction. The binding of the complex to BSA could change the microenvironment and conformation of BSA.

Synthesis of nordihydroguaiaretic acid derivatives and their bioactivities on S. pombe and K562 cell lines.

Nordihydroguaiaretic acid (NDGA) and its synthetic analogues are potentially useful in treating diseases related to cancers, diabetes, viral and bacterial infections, and inflammation. In this paper, we report the optimal synthetic methods and the bioactivity study of terameprocol 2, NDGA derivative 3, and its cyclized analogue 4. The IC50 of these three compounds 2, 3 and 4 on the growth metabolism of Schizosacchromyces pombe and K562 cell lines were determined by microcalorimetry. The preliminary results showed that the compounds 2, 3 and 4 possessed good inhibition activities on S. pombe and K562 cell lines, and exhibited bidirectional biological effect and Hormesis effect. In particular, terameprocol 2 was found to possess the most potent inhibitory effect on K562 cell lines.

Synthesis and bioactive studies of complex 8-hydroxyquinolinato-bis-(salicylato) yttrium (III).

This paper reports the synthesis of a new bioactive complex, 8-hydroxyquinolinato-bis-(salicylato) yttrium (III) (HSAY), whose composition and structure were characterized by elemental analysis, IR spectra, thermogravimetric analysis, and X-ray diffraction. The power-time curves of the compounds HSAY, C(7)H(6)O(3), C(9)H(7)NO, and YCl(3)·6H(2)O on the growth metabolism of Schizosaccharomyces pombe (S. pombe) were determined at 32.00°C, respectively. The corresponding thermokinetics parameters, which include the microbial growth rate constant (κ), inhibition ratio (I), and half inhibition concentration (IC(50)), were also derived. The results showed that the generation time was 168.2 min, and all the compounds HSAY, C(7)H(6)O(3), C(9)H(7)NO, and YCl(3)·6H(2)O possessed good bioactivities on the growth metabolism of S. pombe, with the values of IC(50) being 0.055, 3.57, 0.057, and 1.35 mmol L(-1), respectively. The inhibition ability of these compounds above on the growth of the S. pombe has been observed to decrease in the order HSAY>C(9)H(7)NO>YCl(3)·6H(2)O>C(7)H(6)O(3).