Untitled

Pospı́šil, Lubomı́r; Trsková, R.; Colombini, Maria Perla; Fuoco, Roger

doi:10.1023/a:1007924517198

Cited by 17 publications

(4 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, the water rinsing method that uses a solubility enhancer is considered the best way to remove these pollutants in an environment-friendly way [34,35]. As atrazine is also practically insoluble, there are some studies that have focused on increasing the solubility of atrazine using normal CDs and CDs anchored on silica, forming a hybrid material [36,37,38]. Therefore, application of CDs for water treatment have been reported in several review articles due to the relatively hydrophobic environment of their interior cavity [39].…”

Section: Introductionmentioning

confidence: 99%

Solubility Enhancement of Atrazine by Complexation with Cyclosophoraose Isolated from Rhizobium leguminosarum biovar trifolii TA-1

et al. 2019

View full text Add to dashboard Cite

Rhizobium leguminosarum biovar trifolii TA-1, a kind of soil bacteria, produces cyclosophoraoses (Cys). Cyclosophoraoses contain various ring sizes with degrees of polymerization ranging from 17 to 23. Atrazine is a hardly-soluble herbicide that contaminates soil and drinking water, and remains in soil for a long time. To remove this insoluble contaminant from aqueous solutions, we have enhanced the solubility of atrazine by complexation with Cys. The complex formation of Cys and atrazine was confirmed using 1H nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), rotating frame nuclear overhauser spectroscopy (ROESY), and molecular modeling studies. The aqueous solubility of atrazine was enhanced 3.69-fold according to the added concentrations (20 mM) of Cys, compared to the 1.78-fold enhancements by β-cyclodextrin (β-CD). Cyclosophoraoses as an excellent solubility enhancer with long glucose chains that can effectively capture insoluble materials showed a potential application of microbial polysaccharides in the removal of hazardous hardly-soluble materials from aqueous solutions in the fields of biological and environmental industry.

show abstract

Section: Introductionmentioning

confidence: 99%

Solubility Enhancement of Atrazine by Complexation with Cyclosophoraose Isolated from Rhizobium leguminosarum biovar trifolii TA-1

et al. 2019

View full text Add to dashboard Cite

show abstract

“…βCD acts here as an efficient proton donor, and the presence of βCD influences profoundly the stereochemistry of the products. We have been involved in systematic studies of the mechanistic changes of the reduction processes of electroactive organic compounds in the presence of cyclodextrin cavities as well. − In the case of atrazine pesticide the reduction of an uncomplexed form proceeds only after a protonation step (at low pH), whereas the hydrogen bonding in the inclusion complex with CD is sufficient to render the electron transfer possible even in neutral aqueous solutions. Marked changes in the reduction mechanism were observed for the group of dicarboximide-type pesticides, where it was shown that the electrochemical reduction proceeds through a release of the chloride ions (dechlorination) in the presence of CD, whereas reduction of free pesticides yields products due to the ring opening (chlorinated anilines).…”

Section: Introductionmentioning

confidence: 99%

Models of Pesticides inside Cavities of Molecular Dimensions. A Role of the Guest Inclusion in the Dechlorination Process

et al. 2005

View full text Add to dashboard Cite

The reduction mechanism of the pesticide vinclozoline (3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-1,3-oxazolidine-2,4-dione) was studied in nonaqueous solvents in the confined environment of a cyclodextrin (CD) cavity. The effect of the cavity dimensions on the mechanism of the redox process was evaluated using glucose as a reference and using three cyclodextrin molecules of different cavity sizes, namely, alphaCD, betaCD, and gammaCD. In the absence of CD the main reduction product of vinclozoline in the first reduction step is dichloroaniline. An addition of glucose leads to a quantitative change of mechanism with 10 products in total. Addition of CD, however, leads exclusively to dechlorination of the phenyl ring. The degree of dechlorination depends strongly on the choice of cyclodextrin molecule. The importance of the complex formation equilibria in the change of the mechanism is supported by a series of semiempirical AM1 quantum-mechanical calculations. Very good correlation (correlation coefficient 0.995) was obtained between the complex stabilization energy of the inclusion complex and the degree of pesticide dechlorination. Additionally, we were able to show that the complexes are stabilized by the formation of intermolecular hydrogen bonds between the host and guest species. CD molecules do not simply act as proton donors in a nonaqueous environment, but also protect parts of the molecule included within the cavity and steer the degradation process toward fewer products.

show abstract

“…These authors had previously demonstrated that the redox properties of the fungicide difenzoquat were also affected by stronger complexation of its reduction product in the presence of b-CyD [7]. In the case of atrazine, which forms complexes with all three natural CyDs, its inclusion into the host cavity enables its reduction even in the non-protonized form [40].…”

mentioning

confidence: 99%

Cyclodextrins and Their Complexes

Dodziuk¹

2006

412

View full text Add to dashboard Cite

The ability of cyclodextrins, CyDs, to form inclusion complexes with a wide variety of hydrophobic guest molecules has been used in agriculture. Their ability to alter the physical, chemical, and biological properties of guest molecules has been used for the preparation of new formulations of pesticides. CyDs form complexes with a wide variety of agricultural chemicals including herbicides, insecticides, fungicides, repellents, pheromones, and growth regulators [1,2].Each CyD has its own ability to form inclusion complexes with specific pesticides, depending on a proper fit of the pesticide molecule into the hydrophobic CyD cavity. The principal advantage is that the binding of pesticide molecules within the host molecule is not fixed or permanent but rather is a dynamic equilibrium. Dissociation of the inclusion complex is a relatively rapid process usually driven by a large increase in the number of water molecules in the surrounding environment [3]. aAQ16.3.1aSimilarly to CyD applications in the pharmaceutical (Chapters 14 and 15) and other industries, the most common benefits of CyD applications in agriculture include, among others, alterations of the solubility of the pesticide, stabilization against the effects of light or biochemical degradation, and a reduction of volatility. In some applications, more than one benefit is obtained by complexation with CyDs. However, the application of these hosts in pesticide formulations is very modest, and represents less than 1% of the CyD literature [4]. Moreover, most of these publications are not directly practice oriented. Instead they deal with the preparation of pesticides@CyD complexes using different oligosaccharides and processing methods and their characterization using a wide variety of techniques.Among these papers, some are more or less theoretical papers dealing with the correlation between the properties of the new complexes obtained and the properties of the CyDs, pesticides, or external parameters used. Viernstein et al.

show abstract

Untitled

Cited by 17 publications

References 8 publications

Solubility Enhancement of Atrazine by Complexation with Cyclosophoraose Isolated from Rhizobium leguminosarum biovar trifolii TA-1

Solubility Enhancement of Atrazine by Complexation with Cyclosophoraose Isolated from Rhizobium leguminosarum biovar trifolii TA-1

Models of Pesticides inside Cavities of Molecular Dimensions. A Role of the Guest Inclusion in the Dechlorination Process

Cyclodextrins and Their Complexes

Contact Info

Product

Resources

About