Search results for "PHENOLS"
showing 10 items of 766 documents
Chromatographic Separation of Cresol Isomers by a β‐Cyclodextrin: Application for the Determination of Volatile Phenols in Alcoholic Beverages
2006
Abstract The chromatographic separation of o‐cresol, m‐cresol, and p‐cresol by using β‐cyclodextrin as a chiral reagent has been studied. Conditions for the chromatographic separation of these isomers by using the cyclodextrin in the mobile phase or bonded in the stationary phase were optimized, and both procedures provided good results for the resolution of the chromatographic peaks. The use of fluorimetric detection (λexc 275 nm λem 300 nm) allows detection and quantification limits of the µg/L for eight studied phenols by using both procedures. The determination of volatile phenols in alcoholic beverages must be carried out using the cyclodextrin in the mobile phase because of the co‐elu…
Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms
2021
Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-act…
Functional implications of bound phenolic compounds and phenolics–food interaction: A review
2022
Sizeable scientific evidence indicates the health benefits related to phenolic compounds and dietary fiber. Various phenolic compounds-rich foods or ingredients are also rich in dietary fiber, and these two health components may interrelate via noncovalent (reversible) and covalent (mostly irreversible) interactions. Notwithstanding, these interactions are responsible for the carrier effect ascribed to fiber toward the digestive systemand canmodulate the bioaccessibility of phenolics, thus shaping health-promoting effects in vivo. On this basis, the present review focuses on the nature, occurrence, and implications of the interactions between phenolics and food components. Covalent and nonc…
Apple-products phytochemicals and processing: a review.
2009
Epidemiological studies have linked the consumption of apples with reduced risk of some cancers, cardiovascular disease, asthma, and diabetes. Extensive research exists on apples and the health benefits of their beverages and phytochemicals. The purpose of this paper is to review the most recent literature in this area focusing on phytochemicals, phytochemical bioavailability and antioxidant behavior.
Effect of Supplementation with Wheat Bran Aqueous Extracts Obtained by Ultrasound-Assisted Technologies on the Sensory Properties and the Antioxidant…
2015
Phenolic compounds have antioxidant properties and activate endogenous detoxification defense systems able to scavenge the reactive species of oxygen. The external layers of wheat caryopsis, largely constituting by-products of the milling industry such as bran and various middlings, contain relevant amounts of phenolic compounds. The aim of the research has been to evaluate the effect of supplementation with wheat bran aqueous extracts, obtained by ultrasound-assisted technologies, on the sensory properties and antioxidant activity of dry pasta. The HPLC-DAD characterization of the extract evidenced the presence of ferulic and p-coumaric acids. The supplemented pasta showed significantly h…
Different Sorption Behaviors for Wine Polyphenols in Contact with Oak Wood
2007
The evolution of polyphenols of enological interest- monomeric anthocyanins, (+)-catechin, (-)-epicatechin, gallic acid, and trans-resveratrol-in the presence of oak wood was investigated in aging-model conditions. Disappearance kinetics showed that, except for gallic acid, all of the wine polyphenols tend to disappear from the model wine in presence of oak wood, to reach an equilibrium after 20 days of contact. At equilibrium, the higher disappearance rates were obtained for monomeric anthocyanins and trans-resveratrol with values of 20 and 50%, respectively. For monomeric anthocyanins, the rate of disappearance seemed to be independent of their nature. In order to evaluate the contributio…
Protocol for rational design of covalently interacting inhibitors.
2014
The inhibition potencies of covalent inhibitors mainly result from the formation of a covalent bond to the enzyme during the inhibition mechanism. This class of inhibitors has essentially been ignored in previous target-directed drug discovery projects because of concerns about possible side effects. However, their advantages, such as higher binding energies and longer drug-target residence times moved them into the focus of recent investigations. While the rational design of non-covalent inhibitors became standard the corresponding design of covalent inhibitors is still in its early stages. Potent covalent inhibitors can be retrieved from large compound libraries by covalent docking approa…
Multifactorial nature of hepatocellular carcinoma drug resistance: Could plant polyphenols be helpful?
2007
Primary hepatocellular carcinoma (HCC) is a quite frequent tumor which results in high mortality and most often exhibits a poor response to present drug therapies. Clearly, a thorough understanding of the biological bases of this malignancy might suggest new strategies for its treatment. Here we examine the evidences that both "pharmacological" mechanisms (e.g. drug transporter or detoxification enzyme over-expression) and alterations in other critical factors, including the IAPs (Inhibitory of Apoptosis Proteins), involved in enhancement of cell survival and proliferation may determine the therapeutic resistance of HCC; we also underline the possible role in the process of the activation o…
Natural polyphenols in cancer therapy.
2011
Natural polyphenols are secondary metabolites of plants involved in defense against different types of stress. Extracts containing these compounds have been used for thousands of years in traditional eastern medicine. Polyphenols act on multiple targets in pathways and mechanisms related to carcinogenesis, tumor cell proliferation and death, inflammation, metastatic spread, angiogenesis, or drug and radiation resistance. Nevertheless, reported effects claimed for polyphenols are controversial, since correlations between in vitro effects and in vivo evidence are poorly established. The main discrepancy between health claims versus clinical observations is the frequent use of nonphysiological…
Multi-residue determination of 47 organic compounds in water, soil, sediment and fish—Turia River as case study
2017
A sensitive and reliable method based on solid-liquid extraction (SLE) using McIlvaine-Na2EDTA buffer (pH = 4.5)-methanol and solid-phase extraction (SPE) clean up prior to ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS) was applied to determine 47 organic contaminants in fish, soil and sediments. The SPE procedure to clean-up the extracts was also used as extraction method to determine these compounds in water. Recoveries ranged from 38 to 104% for all matrices with RSDs 50% for 36 compounds in front of 9, matrix effect < 20% for 31 compounds against 21, and LOQs <25 ng g−1 for 38 compounds against 22) indicates that the proposed method is mor…