Natural Polyphenols: Chemical Classification, Definition of Classes, Subcategories, and Structures

Abstract

Background: Polyphenols are natural compounds synthesized exclusively by plants with chemical features related to phenolic substances and eliciting strong antioxidants properties. Objective: The aim of this paper is to give a reliable overview of the chemical classification of natural polyphenols. Methods: Literature survey was done through google scholar, pubmed and scopus search engine. Results and Discussion: These molecules or classes of natural substances are characterized by two phenyl rings at least and one or more hydroxyl substituents. This description comprehends a large number of heterogeneous compounds with reference to their complexity. Therefore, polyphenols can be simply classified into flavonoids and non-flavonoids, or be subdivided in many sub-classes depending on the number of phenol units within their molecular structure, substituent groups, and/or the linkage type between phenol units. Polyphenols are widely distributed in plant tissues where they mainly exist in form of glycosides or aglycones. The structural diversity of flavonoid molecules arises from variations in hydroxylation pattern and oxidation state resulting in a wide range of compounds: flavanols, anthocyanidins, anthocyanins, isoflavones, flavones, flavonols, flavanones, and flavanonols.

Description of the antioxidant capacity of Calafate berries (Berberis microphylla) collected in southern Chile

“…Calafate (Berberis microphylla), native to South American Patagonia, is the most widely distributed member of the Berberidaceae family of shrubs in Chile (Bustamante et al, 2018). It has great antioxidant capacity, comparable to that contained in other native berries (Brito et al, 2014), which correlates with the high content of total polyphenols in the fruit and its concentration of anthocyanins (Speisky et al, 2012), mainly delphinidin 3-glycoside, cyanidin 3-glycoside and malvidin 3-glycoside (Chamorro et al, 2019), corresponding to a group of water-soluble pigments, which give the berries their blue, red, violet or purple color (Singla et al, 2019). The consumption of these compounds has been proposed as a method of protection against diseases (Yu et al, 2016), and may act as exogenous agents capable of protecting the cell from oxidative damage (Hostetler et al, 2017), However, their synthesis may be influenced by abiotic stress, corresponding to environmental factors such as temperature, humidity and/or ultraviolet radiation, to which the bush is subjected during its growth (Liu et al, 2017;Khoo et al, 2017).…”

Prevention of 7-Ketocholesterol-Induced Overproduction of Reactive Oxygen Species, Mitochondrial Dysfunction and Cell Death with Major Nutrients (Polyphenols, ω3 and ω9 Unsaturated Fatty Acids) of the Mediterranean Diet on N2a Neuronal Cells

“…So, we choose three polyphenols, which are widely represented in the Mediterrannean diet: RSV, QCT and API [12]. Among polyphenols, two classes are distinguished: Flavonoids and non-flavonoids [23]. Resveratrol (RSV; including trans-RSV which is biologically active) is a non-flavonoid; it is a member of the stilbenoid class of polyphenols; QCT (flavonol) and API (flavone) belong to the flavonoids class.…”

Natural Polyphenols in Metabolic Syndrome: Protective Mechanisms and Clinical Applications

“…By this, antioxidant and anti-inflammatory compounds might have beneficial effects on the onset and progression of MetS [ 18 ]. Natural polyphenols are a class of biomolecules widely found in plants, with more than 8000 species, most of which exist in cocoa beans, nuts, soybeans, olives, sesame seeds, tea, red wine, vegetables, and fruits [ 19 ]. Their structure is mainly characterized by containing one or more phenolic groups, and can be simply divided into flavonoids and non-flavonoids [ 20 ].…”