Antioxidative activity acylation

Tamura, H. and Yagami, A., Antioxidative activity of mono-acylated anthocyanins isolated from Muscat Bailey A grape, J. Agric. Food Chem., 42, 1612, 1994. 

The patatin family consists of various glycoproteins in plants making up more than 40% of the total soluble protein in potato tubers. Patatins serve as storage proteins and it has been demonstrated that they exhibit both lipid acyl hydrolase and acetyl transferase activities, which might be involved in tissue wounding responses. Further, recent studies report on antioxidant activities of the major potato allergen Sola t 1 (Seppala et al. 2000). 

Medina I, Alcantara D, Gonzalez MJ, Torres P, Lucas R, Roque J, Plou FJ, Morales JC (2010) Antioxidant activity of resveratrol in several fish lipid matrices effect of acylation and glucosylation. J Agric Food Chem 58 9778-9786 Lunn J (2006) Superfoods. Nutr Bull 31 171-172... 

The modification of these natural polyhydroxylated compounds via acylation of the hydroxyl functions with aliphatic molecules not only increases their structural diversity, producing analogs that may be useful models for the study of structure-activity relationships, but also changes their physicochemical properties, increasing their solubility in lipophilic media. Moreover, the selective acylation of these natural compounds with various acyl donors could enhance their biological activities, such as their antioxidant and antimicrobial activity, as well as their pharmacological properties [5, 6]. 

The first chemoenzymatic synthesis of organoselenium containing amines was recently reported by Andrade and Silva (Figure 14.7) [10]. Compounds containing a selenium atom have important antioxidant and anti inflammatory activities. Lipase mediated acylation of amine 13 gave the corresponding chiral amides 14 and amines 13 with excellent enantioselectivity (up to 99% ee). 

SDG directly lowers serum cholesterol. Because lignans modulate the enzymes 7-hydroxylase and acyl CoA cholesterol transferase, they may be able to decrease serum cholesterol, as both of these enzymes are involved in cholesterol metabolism. Lignans may also lower oxidative stress. Enterodiol, enterolactone, and SDG act as antioxidants by inhibiting the peroxidation of PUFA in vitro at levels that may be achievable in vivo. Inhibiting peroxidation of PUFA may decrease oxidation of low-density lipoprotein, a key player in atherogenesis. Finally, SDG has been reported to act as an antagonist of platelet-activating factor (PAF) [58]. 

The activity of antioxidants reverses under certain conditions they become prooxidants. One way in which a-tocopherol can become perox-idatively active is shown in Formula 3.81. Another way is through the formation of the chro-manoxyl radical in concentrations high enough to overcome the inertness mentioned in 3.7.3.1 and abstract H-atoms from unsaturated acyl lipids to a definite extent, starting lipid peroxidation. This activity reversion, which is also undesirable from a nutritional and physiological point of... 

The present chapter deals with the study of edible films based on deacylated and/or acylated forms of gellan gum to support L-(+)-ascorbic acid (AA) in view of natural antioxidant protection of foods, by leveraging its activity as a vitamin in the human metabolism. Kinetics of AA-destruction and subsequent non enzymatic browning development were studied in the films stored at constant temperature (25 C) and relative humidity (33.3, 57.7 or 75.2%) and their relationship with the microstructure, at the macromolecular and molecular levels, was also analyzed with the purpose of ensuring a better AA retention as well as lower browning rate as a consequence of controlled water mobility in the polymeric networks. 

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