Phenolic components bioactivity

Solvents used for elution in various cases are different, and the order of use also makes differences. For fractionation of polymeric proanthocyanidins, the solvent combination used is acetone with water which is applied for both Sephadex G-50 and LH-20 [22, 154]. The elution of solvents depends on the solubility of specific phenolic components in specific solvents. Anthocyanins are not soluble in ethyl acetate however, many other polyphenolic compounds are soluble in ethyl acetate. Hence, in the protocol mentioned in the book Handbook of Food Analytical Chemistry-Pigments, Colorants, Flavors, Texture, and Bioactive Food Components for the separation of anthocyanins from the rest of the components in a polyphenolic extract, ethyl acetate is used for elution of the polyphenolic components other than anthocyanins, while the anthocyanins are eluted with acidic methanol [12]. pH is another important property affecting the separation of polyphenols through SPE. Phenolic acids have been reported to be completely ionized at pH 7.0 and un-ionized at pH 2.0 hence, this property is used as the basis for fractionation of neutral polyphenohcs at pH 7.0 and acidic polyphenohcs at pH 2.0, which helps in prevention of interference in-between polyphenohc compounds during HPLC [12]. In certain cases, combination of various SPE methods is used for the fractionation of the extracts, and then the purified extracts are further processed to be analyzed [140, 141, 150]. 

Phenolics are one of the major groups of non-essential dietary components that have been associated with the inhibition of atherosclerosis and cancer. The bioactivity of phenolics may be related to their antioxidant behavior, which is attributed to their ability to chelate metals, inhibit lipoxygenase, and scavenge free radicals. However, phenolics can also function as prooxidants by chelating metals in a manner that maintains or increases their catalytic activity (Fig. 6). Also, poly-phenolics reduce metals, thereby increasing their ability to form free radicals from peroxide. 

Observations of lower rates of certain chronic diseases in several Asian countries compared to the United States served as the impetus for studies that were conducted to identify the factors that were accountable (Tham et al., 1998). Consumption of soy is one factor that correlated with these lower rates. From this information, much research focused on soy protein and accompanying bioactive compounds with regard to elucidating mechanisms associated with risk markers for chronic disease, particularly CVD. The combination of macro- (protein, fiber, fat) and micro-components (isoflavones, saponins, tocopherols) as part of many traditional soy foods may underlie the epidemiological observations associated with soy intake. A body of cell culture and animal data shows potential health effects of a multitude of bioactive components in soy (i.e., saponins, phenolic acids, peptides). However, studies determining the independent effects of saponins, phenolic acids, and protease inhibitors in humans are yet to be conducted. 

For decades, research on the health-promoting effects of Mediterranean diet has revealed that olive oil consumption is a key factor in the cardiovascular protection found in Mediterranean countries [139]. It is well established that the healthful properties of olive oil depend mostly on its high oleic acid content. However, many arguments demonstrate that in olive oil there are minor bioactive components, other than oleic acid, responsible for its cardiovascular protective properties among them, the phenolic fraction of olive oil, and in particular OL and HT, has demonstrated antioxidant, anti-platelet aggregation, vasodilatatory, and anti-inflammatory effects, all involved in this health beneficial action [7,108-110]. 

Phenolic compounds are important bioactive constituents derived from plants and are active ingredients in traditional medicine, pharmaceuticals, and nutraceuticals. Extraction process for phenolic acids requires standardization as within plant tissue they can stay either in the soluble fraction or as conjugates with carbohydrates or linked to cell wall components. HPLC is by far the most popular method of separation. Mass spectrometers, especially LC-MS and MALDI-TOF, provide a viable rapid and accurate method of identification and characterization of the simple phenolic acids. 

Rechner AR, Watts WMP, Gibson GR, Rice-Evans CA. Colonic metabolism of dietary phenolics implications for the nature of the bioactive component. Free Rad Biol Med 2001 31 89S. 

Phenols are considered important bioactive compounds isolated from plants because of their potential role in human health management. Phenolic structure consists of an aromatic ring with attached hydroxyl groups. Based on structural differences, phenols can be classified into groups and components. The broad classifications include phenolic acids, stilbenes, lignans, and fiavonoids [4]. 

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