Autoxidation of biological molecules. 1. Antioxidant activity of vitamin E and related chain-breaking phenolic antioxidants in vitro

1981 ◽  
Vol 103 (21) ◽  
pp. 6472-6477 ◽  
Author(s):  
G. W. Burton ◽  
K. U. Ingold
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
Biological Molecules ◽  
Phenolic Antioxidants ◽  
Chain Breaking

scholarly journals Synthesis, DFT Calculations, and In Vitro Antioxidant Study on Novel Carba-Analogs of Vitamin E

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 589 ◽  
Author(s):  
Aneta Baj ◽  
Jakub Cedrowski ◽  
Ewa Olchowik-Grabarek ◽  
Artur Ratkiewicz ◽  
Stanislaw Witkowski
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Vitamin E ◽  
Density Functional ◽  
Lone Pair ◽  
Hydrogen Atom Transfer ◽  
Hydroxyl Group ◽  
Styrene Oxidation ◽  
Chain Breaking

Vitamin E is the most active natural lipophilic antioxidant with a broad spectrum of biological activity. α-Tocopherol (α-T), the main representative of the vitamin E family, is a strong inhibitor of lipid peroxidation as a chain-breaking antioxidant. Antioxidant and antiradical properties of vitamin E result from the presence of a phenolic hydroxyl group at the C-6 position. Due to stereoelectronic effects in the dihydropyranyl ring, the dissociation enthalpy for phenolic O–H bond (BDEOH) is reduced. The high chain-breaking reactivity of α-T is mainly attributed to orbital overlapping of the 2p-type lone pair on the oxygen atom (O1) in para position to the phenolic group, and the aromatic π-electron system. The influence of the O1 atom on the antioxidant activity of vitamin E was estimated quantitatively. The all-rac-1-carba-α-tocopherol was synthesized for the first time. Along with model compounds, 1-carba-analog of Trolox and its methyl ester were screened for their in vitro antioxidant activity by inhibition of styrene oxidation, and for the radical-reducing properties by means of 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging assay. To study the antioxidant activity, density functional theory (DFT) was also applied. Reaction enthalpies related to HAT (hydrogen atom transfer), SET–PT (sequential electron transfer—proton transfer), and SPLET (sequential proton loss—electron transfer) mechanisms were calculated.

scholarly journals The Nutritional Value of Non-Traditional Gluten-Free Flakes and Their Antioxidant Activity

Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 565
Author(s):  
Kristýna Šťastná ◽  
Martina Mrázková ◽  
Daniela Sumczynski ◽  
Betül Cındık ◽  
Erkan Yalçın
Keyword(s):  
Antioxidant Activity ◽  
High Performance ◽  
Sugar Content ◽  
Chenopodium Quinoa ◽  
Biologically Active ◽  
Eragrostis Tef ◽  
Total Phenolic ◽  
Phenolic Antioxidants ◽  
In Vitro Digestibility

Nowadays, there is a growing interest for foods with a lower sugar content and rich in fiber and biologically active substances. The main purpose of this study was to prepare flakes from non-traditional pigmented cereals (Oryza sativa, Chenopodium quinoa, and Eragrostis tef) and to analyze their fibre, sugar, and in vitro digestibility values. Regarding phenolic antioxidants (soluble, soluble conjugated, and insoluble bound fractions), their content and antioxidant activity were measured using spectrophotometry and high performance liquid chromatography (HPLC) methods. Hydrothermally treated grains resulted in flakes with higher total dietary fibre contents (11.1–24.4%), quinoa and teff flakes were rich in maltose (up to 42.0 mg/g). Non-traditional flakes had lower in vitro digestibility, but conversely, they exhibited the highest phenolic contents corresponding with the highest antioxidant activity values (up to 2.33 mg Gallic acid equivalent/g of total phenolic content and 1.59 mg Trolox equivalent/g for 2,2-diphenyl-1-picrylhydrazyl (DPPH) in case of brown teff). Among free phenolics, the main contributors to an antioxidant activity were p-coumaric, o-coumaric, and gallic acids (r > 0.8186); among the soluble conjugated fractions, they were epigallocatechin, epicatechin, caffeic, and vanillic acids (r > 0.5935); while caffeic, protocatechuic, and ferulic acids (r > 0.5751) were the main contributors among the insoluble bound phenolics.

scholarly journals Pomegranate as a natural source of phenolic antioxidants

2020 ◽  
Vol 9 ◽  
Author(s):  
Fellipe Lopes De Oliveira ◽  
Thaise Yanka Portes Arruda ◽  
Renan Da Silva Lima ◽  
Sabrina Neves Casarotti ◽  
Maressa Caldeira Morzelle
Keyword(s):  
Antioxidant Activity ◽  
Chronic Diseases ◽  
Biological Effects ◽  
Meat Products ◽  
Phenolic Antioxidants ◽  
Antioxidant Compounds ◽  
Health Promoting

Pomegranate, a recognized source of phenolic compounds, has been associated with health-promoting benefits, mostly due to its antioxidant activity. Ellagic and gallic acids, anthocyanins, and ellagitannins are the main phenolics in pomegranate, showing antioxidant activity. For this reason, pomegranate has been used in foods, such as meat products, as an attempt to retard lipid oxidation and increase shelf-life. In recent years, in vitro, in vivo, and human studies reported the antioxidant activity of pomegranate, especially its peels, with reduced incidence of chronic diseases (e.g., cardiovascular ailments, cancer, neurodegenerative disease, type 2 diabetes, chronic kidney disease). This review aims to present the main antioxidant compounds on pomegranate and their biological effects, the antioxidant activity of pomegranate-based foods, the application of pomegranate as a natural antioxidant food additive, the role of pomegranate in the prevention and management of chronic diseases, as well as the trends and prospects regarding the application of pomegranate in innovative food and health.

In Vitro Antioxidant Activity of 2,5,7,8-tetramethyl-2-(2′-carboxyethyl)-6-hydroxychroman (α-CEHC), a Vitamin E Metabolite

2002 ◽  
Vol 36 (8) ◽  
pp. 915-921 ◽  
Author(s):  
Alejandro Betancor-Fernandez ◽  
Helmut Sies ◽  
Wilhelm Stahl ◽  
M. Cristina Polidori
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
In Vitro Antioxidant Activity

Tocopherol Fate in Plasma and Liver of Streptozotocin-Treated Rats that Orally Received Antioxidants and Spirulina Extracts

2007 ◽  
Vol 77 (4) ◽  
pp. 263-271 ◽  
Author(s):  
García-Martínez ◽  
Rupérez ◽  
Ugarte ◽  
Barbas
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
Storage Conditions ◽  
Tocopherol Content ◽  
Diabetic Rats ◽  
Tocopherol Concentration ◽  
Analytical Methodology ◽  
Before And After

Streptozotocin-induced diabetic rats constitute a model of oxidative stress, and vitamin E continues to be a topic of speculation in this area. On the other hand, marine extracts, particularly microalgae extracts obtained with environmentally clean technologies and which demonstrate antioxidant activity in vitro, are a potential source of in vivo antioxidant defense. We have studied the α-tocopherol content in the plasma and liver of diabetic rats after 7 and 14 days under the condition, and before and after the treatment with vitamin E and C, as well as with different Spirulina extracts, as compared with the corresponding controls. The improvement of analytical methodology related to the determination of α-tocopherol in the plasma and liver of rats was also considered. To do this, a method previously developed for plasma, employing a single extraction step, was adapted and validated for liver after minor modifications. Moreover, stability of α-tocopherol in plasma of diabetic and control animals was compared in different storage conditions. Results showed that diabetic plasma strongly influences stability of α-tocopherol, even at –20° C, but samples are stable for at least one year at –80° C. Finally, regarding supplementation, results indicate that supplementation with α-tocopherol increases stored α-tocopherol in liver, but not in plasma, but this availability is strongly dependent on the stage of diabetes of the animal. Extracts of Spirulina platensis, despite showing antioxidant activity in vitro, increased α-tocopherol concentration in neither plasma nor liver.

Antioxidant Activity of Vitamin E and Trolox: Understanding of the Factors that Govern Lipid Peroxidation Studies In Vitro

2009 ◽  
Vol 4 (4) ◽  
pp. 312-320 ◽  
Author(s):  
Marlene Lúcio ◽  
Cláudia Nunes ◽  
Diana Gaspar ◽  
Helena Ferreira ◽  
José L. F. C. Lima ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Vitamin E

scholarly journals FORMULATION AND EVALUATION OF ANTIAGING PHYTOSOMAL GEL

2018 ◽  
Vol 11 (3) ◽  
pp. 409 ◽  
Author(s):  
Julie Mariam Joshua ◽  
Athira Anilkumar ◽  
Verjina Cu ◽  
Deepa T Vasudevan ◽  
Saritha A Surendran
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
Grape Seed ◽  
Seed Extract ◽  
Premature Aging ◽  
Coconut Water ◽  
Herbal Extracts ◽  
Ic50 Value ◽  
Tender Coconut

 Objective: The aim of the present study was to prepare and evaluate antiaging phytosomal gel.Method: For this purpose, tender coconut water, Aloe vera extract, grape seed extract, vitamin E, and jojoba oil were taken. The cytokinins present in coconut water show astounding effects in preventing premature aging. A. vera contains Vitamin E and C and phenol compounds which contribute to aging. Grape seed extract contains polyphenols mainly in the form of flavonoids which are highly potent antioxidants. It also possessed an antiaging vitamin known as oligomeric proanthocyanidins which prevented premature aging. Vitamin E was chosen because of its antioxidant properties. Jojoba oil was chosen because it had good moisturizing properties and it was similar to human skin oil, sebum. Conventional dosage forms such as creams and gels were prepared using these ingredients, but they showed less antiaging effect. Therefore, phytosome was prepared by binding herbal extracts to phosphatidylcholine (acts as a carrier and nourishes the skin). They had a phospholipid molecular structure which included a water-soluble head and two fat-soluble tails, and due to this dual solubility, it was better absorbed and so it was used for the treatment of skin disorders, antiaging, and skin carcinomas.Result: Nine different formulations of the antiaging cream, gel, and phytosomal gel were prepared. Physicochemical parameters such as pH, viscosity, homogeneity, spreadability, and extrudability were determined. In vitro antioxidant studies were performed for the prepared antiaging cream, gel, and phytosomal gel. Among the three different formulations, phytosomal gel was chosen to be the best formulation to treat wrinkles and blemishes on the skin. When compared to the conventional dosage forms such as creams and gels, the phytosomal gel could release the herbal ingredients and showed better penetration into the skin. From the nine different formulations, F2 containing both tender coconut water and A. vera extract was chosen as the optimized formula. Optimization was done on the basis of in vitro antioxidant studies and physicochemical parameters. F2 acts as a potent free radical scavenger and inhibits oxidation by free radicals. 2,2-diphenylpicrylhydrazyl free radical scavenging assay was chosen as the best method in screening the antioxidant activity of the herbal extracts. The IC50 value of the prepared antiaging cream, gel, and phytosomal gel was found to be 70.5 μg/ml, 65.0 μg/ml, and 47.0 μg/ml, respectively. The lower the IC50 value, the highest the antioxidant activity. Thus, the antiaging phytosomal gel proved to show the highest antioxidant activity. The stability of the optimized formulation was carried out at two different temperatures, 30°C ± 2°C and 4°C ± 2°C, and the formulation was found to be stable at the end of 45 days.Conclusion: From the present study, it can be concluded that the prepared antiaging phytosomal gel was safe, convenient, and efficient carrier to deliver the herbal extracts. It also showed better penetration into the skin. Hence, the desired antiaging property was obtained. It is because of this reason, it is used in skin care cosmetics, mainly for antiaging treatment.

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