Interaction between anthocyanins (3-glucosides of cyanidin, peonidin and malvidin), procyanidin B2 (B2), and acetaldehyde and the formation of new colored compounds was studied in model wine solutions. The anthocyanin−procyanidin B2 condensation reaction showed first-order kinetics with or without the presence of acetaldehyde, and the reaction rates were calculated. In all the model solutions containing anthocyanins, procyanidin B2, and acetaldehyde, rapid color augmentation with shifts toward violet were observed. Two principal new compounds (thought to be trimers, linked at different positions) were detectable by HPLC, and their spectral properties were studied by diode-array spectroscopy. Malvidin 3-glucoside reacts more slowly than cyanidin 3-glucoside and peonidin-3 glucoside. Similar color changes were observed in model solutions containing anthocyanins alone with acetaldehyde. Finally, we observed that the degradation constant rates for each anthocyanin increased in the following order:  anthocyanins alone < anthocyanins + B2 < anthocyanins + acetaldehyde < anthocyanins + B2 + acetaldehyde. Similar increasing order of the reaction rates of procyanidin B2 was observed. In both cases, the presence of acetaldehyde was of major importance in accelerating the chemical transformation of phenolic compounds, inducing the formation of new products. Keywords: Anthocyanins; procyanidin B2; acetaldehyde; condensation reaction

No abstract

The present study investigated the efficacy and safety effects of Sinetrol-XPur (polyphenolic citrus dry extract) in weight management; metabolic parameters; and inflammatory, glycemic and oxidative status. In a 12-week, randomized, double-blind, placebo-controlled trial, Sinetrol-XPur was given to overweight subjects twice daily with meals in the tested group (N = 47) versus a placebo group (N = 48). Waist and hip circumference and abdominal fat were decreased in the Sinetrol-XPur group as compared with the placebo group (p < 0.0001) (-5.71% vs. -1.56% for waist, -4.71% vs. -1.35% for hip and -9.73% vs. -3.18% for fat). Inflammatory markers were reduced (C-reactive protein: -22.87% vs. +61%; fibrinogen: -19.93% vs. -1.61%, p < 0.01). Oxidative stress was lowered as seen by the reduction of malondialdehyde (-14.03% vs. 2.76%) and the increase in superoxide dismutase and glutathione (17.38% vs. 2.19% and 4.63% vs. -2.36%, respectively, p < 0.01). No adverse effects were observed. Kidney, liver, and lipid panels remained unchanged. These results indicated that Sinetrol-XPur supplementation is a viable option for reducing abdominal fat, waist and hip circumference, and body weight and for improving inflammatory, glycemic, and oxidative status in healthy overweight individuals.

Interactions of grape seed flavanols, dimeric, galloylated dimeric and trimeric procyanidins with malvidin-3-glucoside and acetaldehyde were studied in wine-like model solutions. Malvidin-3-glucoside and oligomeric procyanidins reacted very slowly, with eventual formation of yellow xanthylium salts. The concentrations of malvidin-3-glucoside and oligomeric procyanidins decreased faster in the presence of acetaldehyde and the colour augmentation with shift towards violet was attributed to the formation of new coloured compounds, detectable by HPLC and linked at different positions by CH,CH bridges. The rate of loss of procyanidins in the presence of malvidin-3-glucoside and acetaldehyde varied according to the complexity of the components. Monomeric (+)catechin and (-)-epicatechin reacted more slowly than dimer procyanidins B,, B, and B, while trimer C, (epicatechin 48 --* 8 epicatechin 48 + 8 epicatechin) presented the highest degradative reaction rate.

Epidemiological studies suggest that metabolic ageing process of overweight and obese populations is associated with an increased risk of developing non-communicable diseases (NCDs). Inflammation, hyper-glycaemia, dyslipidemia and oxidative stress have been associated with early stages of NCDs development whereas cohort surveys have demonstrated health benefits of dietary polyphenols from various dietary sources to reverse such progress. Obese volunteers were included in a double-blind, randomized, parallel pilot trial where they received daily for a 12-week period 900 mg of a polyphenol-rich treatment extracted from fruit and vegetables frequently consumed within the Mediterranean diet. Anthropometric and blood parameters were assessed before and at the end of the intervention period. After 12 weeks, while the silhouette slimmed down, metabolic parameters were significantly improved and general satisfaction considerably ameliorated. These data suggest that over a 12-week period, the synergistic action of bioactives within the treatment improves metabolic ageing process and quality of life in obese volunteers.