The main metabolites of caffeic and ferulic acids (ferulic acid-4′-O-sulfate, caffeic acid-4′-O-sulfate, and caffeic acid-3′-O-sulfate), the most representative phenolic acids in fruits and ...vegetables, and the acyl glucuronide of ferulic acid were synthesized, purified, and tested for their antioxidant activity in comparison with those of their parent compounds and other related phenolics. Both the ferric reducing antioxidant power (FRAP) assay and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging method were used. Ferulic acid-4′-O-sulfate and ferulic acid-4′-O-glucuronide exhibited very low antioxidant activity, while the monosulfate derivatives of caffeic acid were 4-fold less efficient as the antioxidant than caffeic acid. The acyl glucuronide of ferulic acid showed strong antioxidant action. The antioxidant activity of caffeic acid-3′-O-glucuronide and caffeic acid-4′-O-glucuronide was also studied. Our results demonstrate that some of the products of phenolic acid metabolism still retain strong antioxidant properties. Moreover, we first demonstrate the ex vivo synthesis of the acyl glucuronide of ferulic acid by mouse liver microsomes, in addition to the phenyl glucuronide.
Non-alcoholic fatty liver disease (NAFLD) is defined as the accumulation of fat in liver cells, which causes serious health consequences. Animal and human studies suggest that the gut microbiota ...plays a role in the pathogenesis of NAFLD. Here, we investigated whether spinach consumption could ameliorate high-fat-diet-induced disturbances in certain intestinal bacterial groups and products derived from their metabolism, such as short-chain fatty acids (SCFAs) and microbial phenolic catabolites. Attention is also paid to blood lipids and glucose. In the study, a rat model of high-fat-diet-induced NAFLD was used. There were six experimental groups: NC (normal diet), NB (normal diet + 2.5% spinach), NA (normal diet + 5% spinach), HC (high-fat diet), HB (high-fat diet + 2.5% spinach) and HA (high-fat diet + 5% spinach). The rats consumed these diets for five weeks, and after that, they were sacrificed and plasma, urine, intestinal content, faeces and liver samples were taken. Biochemical parameters were analyzed in plasma, phenolic catabolites were quantified in the faeces, urine, plasma and liver by UPLC-ESI-MS/MS, and the analysis of the microbiota and SCFAs in the intestinal content was performed by qPCR and GLC. Consumption of a high-fat diet caused NAFLD and dislipaemia and altered the gut microbiota and the pattern of SCFAs and phenolic gut microbial catabolites. Supplementation with spinach partially ameliorated some alterations induced by the high-fat diet, in particular by increasing the Lactobacillus counts, reducing the fasting glucose and total and LDL-cholesterol and preventing excess liver cholesterol accumulation, thereby improving the values of the steatosis biomarkers.
Gut microbiota may play a role in the pathogenesis of NAFLD. We investigated whether tomato juice consumption for 5 weeks could ameliorate high-fat diet-induced alterations in certain intestinal ...bacterial groups and products arising from their metabolism (short-chain fatty acids and microbial phenolic catabolites). For this, we used a rat model with NAFLD induced by a high-fat diet, involving four experimental groups: NA (standard diet and water), NL (standard diet and tomato juice), HA (high-fat diet and water) and HL (high-fat diet and tomato juice). The onset of NAFLD impacted the gut microbiota profile, reducing the abundance of Bifidobacterium and Lactobacillus and increasing that of Enterobacteriaceae. Also, reduced concentrations of propionate, butyrate and phenolic catabolites and an increased acetate to propionate (Ac : Pr) ratio were observed. Tomato juice intake partially ameliorated high-fat diet-induced disturbances, particularly by increasing Lactobacillus abundance and diminishing the Ac : Pr ratio, suggesting a potential improvement of the metabolic pattern of NAFLD.
Background and Aims: Red wine is a very rich source of flavanols, consisting of catechins and oligomeric and polymeric proanthocyanidins (PAs). The aim of this study was to investigate the ...composition of the fraction of flavanols, which is extractable from the grape into the wine.
Methods and Results: Using HPLC‐DAD‐MS analysis carried out before and after thioacidolysis of wine‐like extracts obtained from skins and seeds, the flavanol composition of 20 samples derived from Cabernet Sauvignon, Carmenere, Marzemino, Merlot, Pinot Noir, Syrah and Teroldego was determined.
Conclusions: It was confirmed that grape extracts are mainly rich in monomers and small oligomers (mean degree of polymerization <8). Grape seed extracts contained three monomers (catechin, epicatechin and epicatechin gallate) and procyanidin oligomers. Grape skin extracts contained four monomers (catechin, epicatechin, gallocatechin and epigallocatechin), procyanidins and prodelphinidins oligomers. Upper and extension units of PAs were constituted mainly of epicatechin units, with the co‐presence of catechin and epicatechin gallate in the seed PAs, and of gallocatechin in the case of skin PAs. The terminal units of the grape PAs were a mixture of five compounds, the same found also as monomers. Catechin gallate, gallocatechin gallate and epigallocatechin gallate, which are found in other flavanol‐rich, plant‐derived foods and beverages, were not present in grape extracts.
Significance of the Study: The grape variety determines both the amount and the structure of wine flavanols, leading to differences in the composition, which are likely to play an important role in the nutritional and sensorial properties of the wines.
Background and Aims: In the Vitaceae, stilbenoid viniferins constitute a relatively restricted group of molecules based on a trans‐resveratrol structure and represent the main known phytoalexins. ...The aim of this work was the development of a new method for the chromatographic separation and accurate quantification of viniferins found in grapevine leaves following infection with Plasmopara viticola.
Methods and Results: An interspecific F1 population was used, deriving from the cross between Merzling and Teroldego, respectively, partially resistant and susceptible to P. viticola. Analysis was carried on a liquid chromatography‐mass spectrometry (LC‐MS) system, using a reverse phase column. A method was validated for detailed metabolite profiling, with accurate identification and quantification of trans‐resveratrol, trans‐piceid, trans‐pterostilbene, a condensation product between (+)‐catechin and caffeic acid, and the whole class of stilbenoid viniferins in P. viticola‐infected grapevine leaves, using their respective standards. Synthesis was ongoing, and 6 days after infection, it was possible to see the highest concentration of stilbenoids for all genotypes. On the other hand, the intensity of stilbene induction did not show a clear and homogeneous correlation with the position of the leaves in the young shoot.
Conclusions: The method described in this paper provides the basis for performing in a single run a targeted analysis of resveratrol, piceid, pterostilbene and the whole class of stilbenoids in P. viticola‐infected grapevine genotypes.
Significance of the Study: To our knowledge, this is the first paper that has reported on detailed metabolite profiling with accurate identification and quantification of the main viniferins in grape leaves following infection with P. viticola, using the respective standards.
Ellagitannins are a major class of phenolics largely responsible for the astringent and antioxidant properties of raspberries and blackberries. The Rubus ellagitannins constitute a complex mixture of ...monomeric and oligomeric tannins. Rubus oligomeric ellagitannins contain, beside the well-known ellagic acid and gallic acid moieties, the sanguisorboyl linking ester group. When exposed to acids or bases, ester bonds are hydrolyzed and the hexahydroxydiphenic acid spontaneously cyclizes into ellagic acid. This study describes a new, rapid procedure for the acid hydrolysis of Rubus ellagitannins in methanol, which results in maximal yield and enables the quantification of all the major reaction products. Additionally, the method provides the rationale for estimating the mean degree of polymerization of Rubus ellagitannins. Keywords: Rubus; ellagitannins; ellagic acid; sanguisorbic acid; gallic acid; hexahydroxydiphenic acid
Self-healing is a process by which concrete is able to recover its properties after the appearance of cracks, which can improve mechanical properties and durability and reduce the permeability of ...concrete. Self-healing materials can be incorporated into concrete to contribute to crack closure. This study aims to evaluate the influence of crystalline admixtures and silica fume on the self-healing of concrete cracks. The rapid chloride penetration test was performed on cracked and uncracked samples, from which it was possible to estimate the service life of concretes. The concretes were characterized by tests of compressive strength and water absorption by capillarity. The use of crystalline admixtures did not have a negative influence on concrete properties, but did not favor the chloride penetration resistance. The concrete with silica fume showed the lowest charge passed and highest values of estimated service life. Keywords: chloride penetration resistance; crystalline admixture (CA); self-healing; service life prediction; silica fume.
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