Frontier orbitals and transition states in the oxidation and degradation ofl-ascorbic acid: a DFT study

2015 ◽  
Vol 13 (13) ◽  
pp. 4002-4015 ◽  
Author(s):  
Shinichi Yamabe ◽  
Noriko Tsuchida ◽  
Shoko Yamazaki ◽  
Shigeyoshi Sakaki

DFT calculations were carried out to investigate reaction paths ofl-ascorbic acid, hydroxyl radicals and water clusters up to threonic, oxalic, xylonic and lyxonic acids.

2021 ◽  
Author(s):  
Hui-min Lin ◽  
Xue-er Qi ◽  
Shan-shan Shui ◽  
Soottawat Benjakul ◽  
Santiago P. Aubourg ◽  
...  

The oxidative effects of hydroxyl radicals derived from a FeCl3/ascorbic acid/H2O2 system on the stability of muscle proteins in peeled shrimp (Litopenaeus vannamei) were investigated.


Author(s):  
Hanlin Gan ◽  
Liang Peng ◽  
Feng Long Gu

The mechanism of the Cu(i)-catalyzed domino reaction furnishing 1-aryl-1,2,3-triazole assisted by CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is explored with density functional theory (DFT) calculations.


RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 7779-7789 ◽  
Author(s):  
Asmat Ullah Khan ◽  
Rasheed Ahmad Khera ◽  
Naveed Anjum ◽  
Rao Aqil Shehzad ◽  
Saleem Iqbal ◽  
...  

DFT calculations are carried out to investigate nonlinear optical (NLO) properties of superhalogen (BCl4) and superalkali (NLi4) doped graphitic carbon nitride (GCN).


2019 ◽  
Vol 21 (6) ◽  
pp. 3227-3241 ◽  
Author(s):  
Krishnamoorthy Arumugam ◽  
Neil A. Burton

Of particular interest within the +6 uranium complexes is the linear uranyl(vi) cation and it forms numerous coordination complexes in solution and exhibits incongruent redox behavior depending on coordinating ligands. This DFT study predicts VI/V reduction potentials of a range of uranyl(vi) complexes in non-aqueous solutions within ∼0.10−0.20 eV of experiment.


2003 ◽  
Vol 69 (4) ◽  
pp. 2245-2252 ◽  
Author(s):  
J. B. Cross ◽  
R. P. Currier ◽  
D. J. Torraco ◽  
L. A. Vanderberg ◽  
G. L. Wagner ◽  
...  

ABSTRACT An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction involves the conversion of aqueous dissolved oxygen to hydrogen peroxide by an ionic catalyst (Cu2+) and then subsequent conversion to hydroxyl radicals. Results are given for the modified Fenton reagent deactivating spores of Bacillus globigii. A biocidal mechanism is proposed that is consistent with our experimental results and independently derived information found in the literature. This mechanism requires diffusion of relatively benign species into the interior of the spore, where dissolved O2 is then converted through a series of reactions which ultimately produce hydroxyl radicals that perform the killing action.


2018 ◽  
Vol 14 ◽  
pp. 2897-2906 ◽  
Author(s):  
Stanislav V Lozovskiy ◽  
Alexander Yu Ivanov ◽  
Olesya V Khoroshilova ◽  
Aleksander V Vasilyev

In strong Brønsted acids (CF3SO3H, FSO3H, D2SO4), (arysulfonyl)allenes (ArSO2–CR1=C=CR2R3) and (arylsulfinyl)allenes (ArSO–CR1=C=CR2R3) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl, leads to their deprotonation with a stereoselective formation of (arysulfonyl)butadienes (for instance, ArSO2–CR1=C–C(Me)=CH2, for R2 = R3 = Me, yields of 87–98%). Reactions of (arysulfonyl)allenes in the system TfOH (0.1 equiv)–HFIP (hexafluoropropan-2-ol) followed by hydrolysis give rise to allyl alcohols (ArSO2–CR1=CH–C(OH)R2R3, yields of 78–99%). Reflux of solutions of (arysulfonyl)allenes in the presence of TfOH (1 equiv) in 1,2-dichlorobenzene leads to the cyclization into thiochromene 1,1-dioxides in high yields. Under the action of TfOH or AlX3 (X = Cl, Br) followed by hydrolysis of reaction mixtures, (arylsulfinyl)allenes give allyl alcohols (ArSO2–CR1=CH–C(OH)R2R3). Plausible reaction mechanisms have been proposed for all studied reactions.


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