scholarly journals SYNERGISTIC EFFECT OF BINARY QUERCETIN–MONOSACCHARIDE MIXTURES IN THE RE-ACTION WITH FREE RADICALS

2019 ◽  
Vol 62 (2) ◽  
pp. 38-42
Author(s):  
Natal'ya I. Belaya ◽  
Aleksandr V. Belyi ◽  
Galina A. Tikhonova ◽  
Yaroslav S. Udalov ◽  
Galina O. Andriyenko
Keyword(s):  
Synergistic Effect ◽  
Antiradical Activity ◽  
Molecular Complexes ◽  
Cottonseed Oil ◽  
Model Reaction ◽  
Peroxy Radicals ◽  
Carbonyl Groups ◽  
Hydroxy Groups ◽  
State Concentration ◽  
Hydrazyl Radical

The presence of a synergistic effect of binary mixtures of quercetin–monosaccharide in the model reaction with the 2,2'-diphenyl-1-picrylhydrazyl radical in deoxygenated ethanol was established. It was shown that the studied carbohydrates related to the tetrose, pentose and hexose groups exhibit a synergistic effect to some extent enhancing the anti-radical effect of quercetin. The synergistic effect of the mixture is determined by the number of hydroxyl substituents and by the presence of aldehyde or ketone groups in carbohydrate molecules. The synergistic compositions of quercetin with glucose and galactose in the ratio of 60:40% showed the highest antiradical activity. The maximum synergistic effect of the mixture is 75%.  It is achieved due to the fact that, firstly, when dissolved in water, quercetin transforms into a tautomeric diketo form where hydrogen bonds form between its carbonyl groups and hydroxy groups of the monosaccharide, promoting the formation of molecular complexes, improving solubility of flavonoid in water and the manifestation of a synergistic effect in a mixture with carbohydrate. Secondly, reducing carbohydrates are able to restore oxidized forms of quercetin, which is confirmed by the great synergistic effect of aldose in comparison with ketoses, regardless of the number of hydroxy groups in the molecule. The synergistic effect of the quercetin–monosaccharide compositions, established in a model reaction with a hydrazyl radical, was compared to that in the autoxidation process of cottonseed oil. In the reaction with the peroxy radicals of cottonseed oil, the synergistic effect of the quercetin monosaccharide compositions increases up to 300% only for sugars capable of reducing quercetin radicals and reacting with air oxygen, reducing the steady-state concentration of peroxy radicals in the system.

scholarly journals Synthesis of γ-Butyrolactones Containing Hydroxy Groups and Carbonyl Groups in Their Side Chains Using Lithium Naphthalenide

1977 ◽  
Vol 26 (11) ◽  
pp. 720-726
Author(s):  
Tsutomu FUJITA ◽  
Kyoichi SUGA ◽  
Shoji WATANABE ◽  
Hisashi NAKAYAMA ◽  
Masamoto HOKYO
Keyword(s):  
Side Chains ◽  
Carbonyl Groups ◽  
Hydroxy Groups

scholarly journals Crystal structure of methyl 4-(4-hydroxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate monohydrate

2016 ◽  
Vol 72 (9) ◽  
pp. 1335-1338 ◽  
Author(s):  
Keshab M. Bairagi ◽  
Katharigatta N. Venugopala ◽  
Pradip Kumar Mondal ◽  
Bharti Odhav ◽  
Susanta K. Nayak
Keyword(s):  
Hydrogen Bonds ◽  
Organic Molecules ◽  
Weak Interactions ◽  
Three Dimensional ◽  
Ester Group ◽  
Dihedral Angles ◽  
Water Molecules ◽  
Carbonyl Groups ◽  
Dimensional Network ◽  
Hydroxy Groups

The title hydrate, C13H14N2O4·H2O, crystallizes with two formula units in the asymmetric unit (Z′ = 2). The dihedral angles between the planes of the tetrahydropyrimidine ring and the 4-hydroxyphenyl ring and ester group are 86.78 (4) and 6.81 (6)°, respectively, for one molecule and 89.35 (4) and 3.02 (4)° for the other. In the crystal, the organic molecules form a dimer, linked by a pair of N—H...O hydrogen bonds. The hydroxy groups of the organic molecules donate O—H...O hydrogen bonds to water molecules. Further, the hydroxy group accepts N—H...O hydrogen bonds from amides whereas the water molecules donate O—H...O hydrogen bonds to the both the amide and ester carbonyl groups. Other weak interactions, including C—H...O, C—H...π and π–π, further consolidate the packing, generating a three-dimensional network.

Determination of the content of hydroxy groups in cottonseed oil

1979 ◽  
Vol 15 (3) ◽  
pp. 259-261
Author(s):  
S. G. Yunusova ◽  
F. M. Kantsepol'skaya ◽  
�. L. Kristallovich ◽  
A. I. Glushenkova ◽  
A. U. Umarov
Keyword(s):  
Cottonseed Oil ◽  
Hydroxy Groups

Radical products of hydroxylamines, nitrones and spin adducts in the process of gradual oxidation with coordinated peroxy-radicals

1981 ◽  
Vol 46 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Vlado Cholvad ◽  
Andrej Staško ◽  
Alexander Tkáč ◽  
Anatolii L. Buchanenko ◽  
L'ubomír Malík
Keyword(s):  
Peroxy Radical ◽  
Epr Spectra ◽  
Spin Adduct ◽  
Peroxy Radicals ◽  
Carbonyl Groups ◽  
Radical Intermediates

Hydroxyperoxides and cobalt-coordinated peroxy-radicals oxidize hydroxyolamines as e.g. Et2NOH, (PhCH2)2NOH, PhCH2PhNOH to the respective nitrones, and the spin adducts - nitrone and peroxy-radical - are formed. In contrast to hydroxyperoxides the coordinated peroxy radicals can oxidize the formed spin adduct, the methylene or methine groups next to nitrogen being converted into carbonyl groups. The radical intermediates corresponding to individual steps of the gradual oxidation have been identified by means of EPR spectra.

Study on the Properties of Poly(lactic acid)/Starch/Chitosan Blended Materials

2011 ◽  
Vol 391-392 ◽  
pp. 530-534
Author(s):  
Peng Liu ◽  
Cai Qin Gu ◽  
Qing Zhu Zeng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Carbonyl Groups ◽  
Amino Groups ◽  
Molecular Force ◽  
Hydroxy Groups

Former researchers have studied the properties of PLA/starch blended materials, but the influence of chitosan for them has not been studied yet. In this paper, it prepared the blended materials of PLA/starch/chitosan, and studied the compatible, mechanical and thermal properties of them. The results demonstrated that, since chitosan molecules had hydroxy and amino groups, which could form molecular force with the hydroxy groups in starch molecules and the carbonyl groups in PLA molecules respectively, the addition of it would improve the compatibility of PLA and starch. The SEM surface and section photos of blended materials could prove this compatibility, and the mechanical properties of blended materials also certified it. Specifically, with the addition of chitosan, the elongation, tensile modulus and tensile strength were all increase. For thermal properties, the addition of chitosan had no influence on it.

Intramolecular addition of hydroxy groups to the carbonyl groups of trihaloacetate esters

1973 ◽  
Vol 38 (1) ◽  
pp. 110-112 ◽  
Author(s):  
Jack Hine ◽  
Daniele Ricard ◽  
Robert Perz
Keyword(s):  
Carbonyl Groups ◽  
Hydroxy Groups

scholarly journals Antiradical Activity of Porphyrins with a Diisobornylphenol Fragment at the Macrocycle Periphery

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1718 ◽  
Author(s):  
Dmitrii Belykh ◽  
Lidiya Mazaletskaya ◽  
Nataliya Sheludchenko ◽  
Tatyana Rocheva ◽  
Irina Khudyaeva ◽  
...  
Keyword(s):  
Free Radicals ◽  
Antiradical Activity ◽  
Model Reaction ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Electronic Effects ◽  
Ethylbenzene Oxidation ◽  
Porphyrin Macrocycle

This article focuses on the antiradical activity of a number of 2,6-diisobornylphenol-porphyrin conjugates with various spacers between the porphyrin and phenolic fragments in the model reaction of ethylbenzene oxidation initiated by azoisobutyric acid dinitrile. The study has shown that the electronic effects of the groups directly related to the 2,6-diisobornylphenol fragment exert the predominant influence both on the reactivity of the phenolic hydroxyl group in interaction with free radicals and on the antiradical activity of the molecule as a whole. The antiradical activity of the molecule is generally less affected by the nature of the substituents in the porphyrin macrocycle, mainly due to a change in the stoichiometric inhibition coefficient in the presence of relatively easily oxidizable groups. It was found that the length of the spacer between the porphyrin and phenolic fragments does not affect the antiradical activity of the conjugate.

scholarly journals THE ACTIVITY OF INTERMOLECULAR HYDROGEN COMPLEXES OF QUERCETIN WITH GLUCOSE IN REAC-TIONS WITH COTTON OIL PEROXY RADICALS

2020 ◽  
pp. 57-65
Author(s):  
Natal'ya Ivanovna Belaya ◽  
Aleksandr Vladimirovich Belyy ◽  
Galina Anatol'yevna Tikhonova ◽  
Yaroslav Sergeyevich Udalov
Keyword(s):  
Synergistic Effect ◽  
Ionization Potential ◽  
Quantitative Measure ◽  
Dft Method ◽  
Peroxyl Radicals ◽  
Peroxy Radicals ◽  
Reducing Ability ◽  
Effective Antioxidant ◽  
Reac Tions ◽  
Cotton Oil

The presence of a strong synergistic effect of the binary quercetin–glucose composition in the reaction with peroxyl radicals generated during the auto- and initiated oxidation of cottonseed oil was established. The highest antiradical activity showed the synergistic compositions at a ratio of 60 : 40%. The established synergism refers to the type when products, formed during reaction, interacts with peroxy radicals more effectively than the original individual substances. Such products may be intermolecular hydrogen-bonded complexes of quercetin and glucose, the existence of such complexes confirmed by NMR spectroscopy. DFT method showed that the most stable is the donor H-complex, where quercetin acts as a hydrogen donor. A quantitative measure of the electron-donating properties of H complexes – the ionization potential – was calculated in the gas phase. The ionization potential of the donor complex is lower so its reducing ability in reaction with radicals is higher than that of the monomeric antioxidant.This can explain the presence of the maximum synergistic effect in the quercetin-glucose mixture at the ratio of 60 : 40%, when, probably, the proportion of donor H-complexes in the reaction mixture is maximum. Obtained results make it possible to carry out a targeted search for effective antioxidant synergistic flavonoid–carbohydrate compositions in plant extracts.

Sign in / Sign up

Export Citation Format

Share Document