non-enzymatically acting antioxidant molecules, of which reduced glutathione (GSH), ubiquinol, DDR1 Purity & Documentation dehydrolipoic acid, melatonin, ferritin, Antioxidants 2022, 11, 133. doi.org/10.3390/antiox11010133 mdpi/journal/antioxidants caeruloplasmin, and metallothioneins are endogenously synthesized [8], although -tocopherol, ascorbic acid, carotenoids and phenolics are acquired by way of dietary sources [9].with regard to jurisdictional claims inAntioxidants 2022, 11,two ofIn addition to this cooperative array of enzyme-based antioxidant defense mechanisms, cells include a number of non-enzymatically acting antioxidant molecules, of which decreased glutathione (GSH), ubiquinol, dehydrolipoic acid, melatonin, ferritin, caeruloplasmin, and metallothioneins are endogenously synthesized [8], although -tocopherol, ascorbic acid, carotenoids and phenolics are acquired through dietary sources [9]. Among the latter molecules, academia and market have paid an awesome deal of attention to phenolics, especially flavonoids, because of their comparatively larger antioxidant capacity and ubiquitous presence in edible plants [10,11]. two. Flavonoids as Antioxidants Flavonoids have attracted the focus of biomedical researchers on account of their prospective to induce an array of DP custom synthesis health-promoting biological actions [125]. Main assistance for the prospective health rewards of those compounds initially emerged from epidemiologic research carried out inside the 1990s. At that point, inverse correlations among the intake of flavonoid-rich foods and the relative danger of developing certain chronic noncommunicable ailments (NCDs) had been established [161]. During the last two decades, on the other hand, the conclusions arising from these population-based research have gained support by way of a variety of animal research, in vitro cell mechanistic investigations and human intervention research [19,227]. Comprehensive reviews on the overall health effects of dietary flavonoids have appeared in recent years [15,281]. Close to eight thousand flavonoids happen to be described to date inside the plant kingdom [11]. The systematic study of these of dietary origin has led for the improvement of many reports and/or databases that inform on their contents in foods and dietary amount of consumption, and their biotransformation and bioavailability [325]. From a chemical point of view, the term flavonoid comprises all these molecules whose structural backbone (a flavan nucleus, C6 3 6, Figure 1) consists of two benzene rings (A and B) which are linked via three carbon atoms that type a pyran heterocyclic ring (C). This structure makes it possible for various patterns and substitutions that give rise to numerous subclasses of flavonoids, among which flavonols, flavones, flavanones, flavanols and anthocyanidins could be distinguished. Such categorization is determined by no matter whether the flavan nucleus contains a hydroxyl moiety in C3 (i.e., flavonols, flavanols and anthocyanidins), a keto group in C4 (i.e., flavonol, of 29 flavones Antioxidants 2022, 11, x FOR PEER Assessment 3 and flavanones), a double bond in C2 3 (i.e., flavonols and flavones), a double bond in O1 two and a different in C3 4 (anthocyanidins).Figure 1. Flavan nucleus, 2-phenyl-3,4-dihydro-2H-1-benzopyran skeleton, common to all flavoFigure 1. Flavan nucleus, 2-phenyl-3,4-dihydro-2H-1-benzopyran skeleton, common to all flavonoids noids (C6 3 six). (C6 3 six).Along with flavonoids, you will discover isoflavonoids, primarily represented by the isoflavones, whose structure includes a double bond at C2 three in addition to a keto group at C4. Iso
