Structure, properties and application to water-soluble coatings of complex antimicrobial agent Ag-carboxymethyl chitosan-thiabendazole

The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.

Development of controlled release formulations of thiabendazole

This study aimed to develop controlled release formulation of Thiabendazole for reduced contaminations to soil water and agricultural produces. The idea behind this work was based on changing the ionization status of Thiabendazole molecule throughout pH changes to become a cation then adsorbing it to bentonite clay surfaces. Equilibrium concentrations of Thiabendazole in the adsorption solutions were determined by HPLC. Results showed that Thiabendazole was better adsorbed in clay at the lowest pH value (pH 3). Furthermore, raising the temperature of the adsorption reaction increased the adsorbed amount of Thiabendazole. Release experiments showed that Thiabendazole is extremely slower at pH 3 than at pH 5.5 or pH 9. These promising results suggest that application of Thiabendazole clay based formulation may reduce the applied rate and that the released fraction consequently may reduce the environmental contamination. It is also advantageous to use these formulations in the acidic soil for plant disease control.

Crystal Structure of a Mn(Ⅱ) Coordination Polymer:[Mn(TP)(TBZH)_(2n)(TBZH=Thiabendazole,TP=Terephthalic Acid)

The structure of a manganese（Ⅱ） polymer,[Mn（TP）（TBZH）]2n 1（TBZH=thiabendazole,TP=terephthalic acid）,has been determined by X-ray crystallography and characterized by elemental analysis,IR spectrum and thermogravimetric analysis.It crystallizes in the orthorhombic system,space group Pbcn with a=12.7813（12）,b=10.7544（10）,c=20.1270（19）A,V=2766.6（4）A^3,Z=8,C14H9Mn0.50N3O2S,Mr=310.77,Dc=1.492g/cm^3,F（000）=1268,μ=0.674 mm^-1 and S=1.064.The 1-D chain architecture of 1 is constructed from terephthalic acid and manganese atoms.Hydrogen bonds and aryl ring π-π stacking interactions in 1 contribute to form a 3-D supramo-lecular structure.

Crystal Structure of a Cu(Ⅱ) Coordination Polymer: [Cu(IP)(TBZH)]_(2n) (TBZH = Thiabendazole, IP = Isophthalic Acid)

The structure of a copper（Ⅱ） polymer, [Cu（IP）（TBZH）]2n 1 （TBZH = thiabendazole, IP = isophthalic acid）, has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 11.76, b = 10.41, c = 14.08A^°, β = 104.80°, V= 1666.0（3）A^°^3, Z = 4, Mr= 428.90, Dc= 1.710 g/cm^3, F（000） = 868,μ = 1.468 mm^-1 and S = 1.001. The 2-D layered gridding architecture of 1 is constructed from isophthalic acid and binuclear copper atoms. Hydrogen bonds and aryl ring π-π stacking interactions in 1 contribute to a supramolecular structure.

Rapid determination of thiabendazole in orange extract using excitation-emission matrix fluorescence and second-order calibration based on alternating trilinear decomposition/alternating normalization-weighted error algorithms

A novel approach is proposed for direct quantitative analysis of thiabendazole in the orange extract by using excitation-emission matrix fluorescence coupled with second-order calibration methods based on the alternating trilinear decomposition(ATLD) and the alternating normalization-weighted error(ANWE) algorithms,respectively. The average recoveries of thiabendazole in the orange extract by using ATLD and ANWE with an estimated component number of two were 99.7 ± 3.3% and 103.5 ± 4.1%,respectively. Furthermore,the accuracy of the two algorithms was also evaluated through elliptical joint confidence region(EJCR) tests as well as figures of merit,such as sensitivity(SEN),selectivity(SEL) and limit of detection(LOD). The experimental results demonstrate that both algorithms have been satisfactorily applied to the determination of thiabendazole in orange extract,and the perform-ance of ANWE is slightly better than that of ATLD.

Thiabendazole inhibits ubiquinone reduction activity of mitochondrial respiratory complex Ⅱ via a water molecule mediated binding feature

The mitochondrial respiratory complex Ⅱ or succinate:ubiquinone oxidoreductase(SQR)is a key membrane complex in both the tricarboxylic acid cycle and aerobic respiration.Five disinfectant compounds were investigated with their potent inhibition effects on the ubiquinone reduction activity of the porcine mitochondrial SQR by enzymatic assay and crystallography.Crystal structure of the SQR bound with thiabendazole(TBZ)reveals a different inhibitor-binding feature at the ubiquinone binding site where a water molecule plays an important role.The obvious inhibitory effect of TBZ based on the biochemical data(IC50~100μmol/L)and the significant structure-based binding affinity calculation(~94μmol/L)draw the suspicion of using TBZ as a good disinfectant compound for nematode infections treatment and fruit storage.

Degradation and Detoxification of Banana Postharvest Treatment Water Using Advanced Oxidation Techniques

The elimination and detoxification of water contaminated with the principal commercial fungi-cides—thia- bendazole (Textar 60 T) and imazalil sulphate (Fruitgard IS 7.5)—used in the postharvest treatment of bananas was successfully achieved through the use of advanced oxidation processes (AOPs). The techniques tested were heterogeneous photocatalysis with TiO2 and TiO2-activated carbon (TiO2-CA) and Fenton and photo-Fenton processes. The evolution of fungicide concentration during degradation was studied together with mineralization and toxicity levels. When treated with any of the methods under study, the water meets the conditions stipulated by the legislation currently in force for its reuse in irrigation. However, this study proposes that the Fenton process is the best option for treatment of this type of water due to the efficiency of its reactions and its low economic cost.