Synthesis, X-Ray Crystal Structure of Oxidovanadium(V) Complex Derived from 4-Bromo-N’-(2-hydroxybenzylidene) benzohydrazide with Catalytic Epoxidation Property.

A new oxidovanadium(V) complex, [VOL(OCH3)(CH3OH)], where H2L = 4-bromo-N'-(2-hydroxybenzylidene)benzohydrazide, has been synthesized and fully characterized on the basis of CHN elemental analysis, FT-IR, UV-Vis, 1H and 13C NMR spectroscopy. Structures of the free hydrazone and the complex were further characterized by single crystal X-ray diffraction, which indicates that the V atom in the complex adopts octahedral coordination, and the hydrazone ligand behaves as a tridentate ligand. The catalytic epoxidation property of the complex was investigated.

Preparation of zinc tungstate nanomaterial and its sonocatalytic degradation of meloxicam as a novel sonocatalyst in aqueous solution.

Zinc tungstate (ZnWO4) was previously used as a photocatalyst. In this paper, for the first time as an sonocatalyst, the performance of ZnWO4 for sonocatalytic degradation of meloxicam (MEL) under ultrasonic irradiation were studied. Firstly, ZnWO4 nanomaterials were synthesized at different acidity (pH = 5, 6, 7, 8, 9) via the hydrothermal method. Utilizing SEM, XRD and EDS techniques to characterize composition and morphology of each product, the same crystal forms, but different morphologies (nano-sheet, nano-microspheres or nano-rod) of ZnWO4 could be obtained. Secondly, the sonocatalytic activities of ZnWO4 on degradation of MEL were studied. It was found that the degradation ratio varied with the synthetic pH values, with ZnWO4 under synthetic pH = 6 exhibiting the best sonocatalytic performance (75.7%). Whilebeing synthesized at this pH value, ZnWO4nano-microspheres had the largest BET surface area (27.068 m2/g), the smallest particle size (40-60 nm) so as to provide more active sites on its surface, which were able to produce more reactive oxygen species (ROS) and holes under ultrasonic irradiation. These ROS and holes had a positive effect on the degradation of MEL into CO2, H2O and inorganic. Thirdly, various influential factors including ultrasonic power intensity, ultrasonic time, catalyst addition dosage, initial concentration of MEL solution and reusability of catalyst were also explored. Under the condition of 10 mg/L MEL concentration, 20 mg catalyst dosage, 120 min irradiation time, 0.278 W/cm2 ultrasonic power intensity, the degradation ratio on MEL reached 75.7%. Finally, the presence of hydroxyl radical (OH) and singlet molecular oxygen (1O2) in the reaction was confirmed by adding ROS scavenger. The experimental results suggested that ZnWO4 nanoparticle could be used not only as an effective photocatalyst, but also, under the condition of ultrasonic irradiation, a promising sonocatalyst for degradation of organic pollutants in aqueous media.

Metabolism and pharmacokinetics of major polyphenol components in rat plasma after oral administration of total flavonoid tablet from Anemarrhenae Rhizoma.

Total flavonoid tablet from Anemarrhenae Rhizoma (Zhimu tablet), which was made of total polyphenol components extracted from the dried rhizome of Anemarrhena asphodeloides Bge. (Zhimu in Chinese), is a novel traditional Chinese medicine prescribed for the treatment of diabetes. Mangiferin (MF) and neomangiferin (NMF) are the two main components detected and determined in Zhimu tablet, accounting for 8.9% of the total weight of each tablet. In the present study, high performance liquid chromatography (HPLC) coupled with time-of-flight (TOF) tandem mass spectrometry (MS) was applied to characterize the metabolites of MF and NMF in rat plasmas collected at different time points after oral administration of Zhimu tablet at a dose of 3.63g/kg (corresponding to 270mg/kg MF). Accurate mass measurement was used to determine the elemental composition of metabolites and thus to confirm the proposed structures of identified metabolites. Time points of appearance of some metabolites, such as isomers, were also taken into account during the structure confirmation. A total of 21 potential metabolites were found in rat plasma at different time points, and the metabolic pathways in vivo were involved in hydrolysis, methylation, glucuronide conjugation, glycoside conjugation, sulphation, dehydration and isomerisation. Furthermore, a selective and accurate LC-MS assay method was developed and validated for the quantification of MF in plasma. Semi-quantification of main conjugated metabolites was also performed in order to describe the dynamic metabolism profiles of polyphenol components in Zhimu tablet. MF concentration in plasma reached 1.36±0.47µgmL(-1) about 5.0h after oral administration of Zhimu tablet, which showed a 3.24- and 4.91-fold increase in plasma maximum concentration and area under the concentration-time curve (AUC) from 0 to 24h of MF compared with those for rats administered with free MF, respectively. The results indicated that the pharmacokinetic processes and bioavailability of MF in rats would be affected by other components in Zhimu tablet.