Antioxidant molecules

Sulphur compounds, e.g., thiopropionate esters and metal dithiolates (Table la, AO 16 and 17), decompose hydroperoxides catalytically, i.e., one antioxidant molecule destroys several hydroperoxides through the intermediacy of sulphur acids [19,20]. Scheme 6 shows a simplified scheme for the antioxidant mechanism of simple alkyl sulphides. 

A larger fcq/fc, ratio for the molecule A, better is its ability as catalytic quencher, since physical quenching of 1O2 (eqn. 9) does not consume the antioxidant molecule (Montenegro et al, 2002 Moran Vieyra et al., 2009). 

Besides all the sensory and texturizing properties, GA has interesting antioxidant properties such as an efficient capacity for deactivation of excited electronic states and moderated radical scavenging capacity. There is increasing experimental evidence that associate the antioxidant function with its protein fraction, mainly by amino acid residues such as histidine, tyrosine and lysine, which are generally considered as antioxidants molecules (Marcuse, 1960,1962 Park et al., 2005). 

Characterization and singlet oxygen quenching ability of spray-dried microcapsules of edible biopolymers containing antioxidant molecules. Journal of Agricultural and Food Chemistry, Vol. 58, No.l3, (June 2010), pp. 8004-8011, ISSN 0021-8561. 

Another point is the concentration of the antioxidant which, in order to have physiological relevance, should be in the physiological range, i.e., not above 1 to 5 aM. Finally, when evaluating antioxidant capacities of foods and food extracts, one should take into account the presence of all the possible antioxidant molecules (phenols, vitamin E, etc.) to explain the results because interactions can occur between antioxidant molecules. 

Results obtained in in vivo and ex vivo experiments are of various types. Some studies have found positive effects of the consumption of carotenoids or foods containing carotenoids on the markers of in vivo oxidative stress, even in smokers. Other studies demonstrated no effects of carotenoid ingestion on oxidative stress biomarkers of lipid peroxidation. " It should be noted that for studies using food, the activity observed may also be partly due to other antioxidant molecules in the food (phenols, antioxidant vitamins) or to the combination of actions of all the antioxidants in the food. 

A more recent study, which measured three established markers of free-radical activity in addition to serum ascorbic acid in two groups of elderly diabetic patients (with and without retinopathy), found no significant differences in any of the markers between patients and age-matched controls despite significant depletion of ascorbic acid in patients with diabetes, especially those with retinopathy (Sinclair et al., 1992). These rather paradoxical findings suggest the existence of a complex interrelationship between the levels of individual antioxidant molecules in cells and tissues. 

Lombardi-Boccia G, Lucarini M, Lanzi S, Aguzzi A and Cappelloni M (2004), Nutrients and antioxidant molecules in yellow plums (Prunus domestica L.) from conventional and organic productions a comparative study , J Agric Food Chem, 52, 90-94. 

The question then arises whether the formation of ROS can indeed be causally related to cell death or whether it simply constitutes an epiphenomenon. The strongest evidence for a causal relationship comes from studies that demonstrate the ability of iron chelators and antioxidants to protect against aminoglycoside-induced ototoxicity. Effective protectants include chelators such as deferoxamine and dihydroxybenzoic acid and a variety of other antioxidant molecules includ-... 

Lombardi-Boccia, G. Lucarini, M. Lanzi, S. Aguzzi, A. Cappelloni, M. Nutrients and Antioxidant Molecules in Yellow Plums (Prunus domestica L.) from Conventional and Organic Productions A Comparative Study. J. Agric. Food Chem. 2004, 52, 90-94. 

The use of reactive antioxidants containing two polymerisable polymer-reactive functions in the same antioxidant molecule is outlined here. Careful choice of the processing parameters, the type, and the amount of free radical initiator can lead to very high levels of antioxidant grafting [53, 57]. For example, melt grafting of concentrates (e.g. 5-20 wt%) of the di-acrylate hin-... 

Probably the most important antioxidant molecule is glutathione, a tripeptide formed from glutamic acid, cysteine, and glycine amino acids ... 

The production of aromatic compounds by a membrane bioreactor is widely studied and some examples are also patented. Aromatic compounds are important substances in pharmaceutical, food, and cosmetic industries due to their natural properties and because they are strong antioxidant molecules with a strong free-radical scavenging activity. 

Indole Derivatives Connected to a Known Antioxidant Molecule. 156... 

Antioxidants, such as 2,6-di-te/ /-butyl-4-mcthylphenol (also known as butylated hydroxytoluene or BHT) and 2-/ert-butyl-4-methoxyphenol (also known as butylated hydroxyanisole or BHA), are added to many organic materials to prevent autoxidation. They function by interfering with the autoxidation chain reaction. When a radical encounters an antioxidant molecule, such as BHA, it abstracts a hydrogen to produce a resonance-stabilized radical ... 

The reaction of the inhaled particles with endogenous molecules present in the pulmonary surfactant e.g. surfactant, antioxidant molecules and proteins may determine the fate of the particles in the early steps of the pathological process. Although the silica samples considered in the present work are very pure, with the SiC>2 content great then 98%, they strongly differ in surface properties. The observed different interaction of BSA with the dusts considered is a consequence of such variability. Since the response of macrophages to silica particles may be different depending on the amount of protein adsorbed, the in vivo and/or in vitro toxicity of the silica dusts may be affected by the different affinities for pulmonary surfactant proteins. 

Antioxidant compounds are an important defense for immediate detoxication of highly reactive intermediates. They act as competing nucleophiles and can bind to the intermediate, forming a less reactive species. Glutathione is one antioxidant molecule that can directly interact with free radicals. Other chemical antioxidants include vitamins A (retinol), C (ascorbic acid), and E. Ascorbic acid, for example, may react directly with reactive intermediates by hydrogen abstraction, resulting in the formation of dehydroascorbic acid. 

LDL oxidation is prevented by antioxidant molecules (11). On average, one LDL particle contains about 6 molecules of a-tocopherol [11], with lowest and highest a-tocopherol contents of 3 and 10 molecules [11]. The reason for this high variation is not clear, but it is reasonable to assume that it reflects to some extent the different dietary conditions. 

It was shown that radicals formed upon exposures of DNA and proteins may, like lipid radicals, enter into exchange reactions with antioxidants as a result, the free valence passes from biopolymer radical to the antioxidant molecule and forms inactive radical from the antioxidant [InH] [6-8. 

We suggested that addition of a saturated fatty-acid tail (buoy) that incorporates in the antioxidant molecule membrane may make the membrane more rigid and thus contribute to the therapeutic effect of ichfan. As is seen from Table 1, after introduction of the compoimd to mice, the microviscosity of the membrane near-surface sites studied by the method of EPR spin probes either changes insignificantly or increases the latter is a desirable effeet. It should be emphasized particularly for membranes isolated from a coarse fraction of synaptosomes because AD is associated mostly with damages of nerve fibers. 

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