The kinetics of formation of resveratrol-ß-cyclodextrin-NH2 and resveratrol analog-ß-cyclodextrin-NH2 supramolecular complexes.

The determination of the kinetics of inclusion processes is significant for the application of inclusion complexes as carriers for bioactive molecules. We determined the kinetic parameters of inclusion between modified ß-cyclodextrin (ß-CD-NH2) and the polyphenols resveratrol (RES) and its structural analog (RESAn1), using the real-time analysis of surface plasmon resonance. The association and dissociation rate constants (ka and kd) showed that RESAn1 inclusion and its dissociation from ß-CD-NH2 were faster than a similar process for RES ( [Formula: see text]  = 3.10∙104 ± 0.14 M-1s-1, [Formula: see text] =1.87∙103 ± 0.11 M-1s-1; [Formula: see text] =0.39 ± 0.02 s-1, [Formula: see text] =0.30 ± 0.02 s-1, at 25 °C). The activated complex formation was also affected by the structural differences between the polyphenols, as showed by the activation energies of the association step ( [Formula: see text] 14.81 ± 0.64 kJ∙mol-1, [Formula: see text] -15.01 ± 0.75 to 82.35 ± 4.47 kJ∙mol-1). These effects of polyphenol structural differences are due to the desolvation process of interacting molecules. These results elucidate the role of small group to the dynamics of the molecular inclusion of ß-CD.

Multi-response optimal hot pressurized liquid recovery of extractable polyphenols from leaves of maqui (Aristotelia chilensis [Mol.] Stuntz).

Multi-response optimization of hot pressurized liquid extraction (HPLE) was applied for the first time to obtain maqui (Aristotelia chilensis [Mol.] Stuntz) leaf extracts. The total polyphenol content (TPC), the antioxidant capacity (AC) as well as the total polyphenol purity of the maqui leaf extracts were accurately predicted (RSD < 8%) at the evaluated extraction scales. The optimum HPLE conditions that prioritized TPC and AC equally (OPT1) recovered ~3 times more TPC (205.14 mg GAE/g leaves) than maqui leaf extracts obtained by maceration, while the extract that prioritized purity over TPC and AC presented the highest purity (36.29%) and an EC50 ~3 times lower than currently reported values. It was found by multi-response optimization that maqui leaves and HPLE are among the best natural sources and extraction techniques, respectively, to recover protocatechuic acid, quercetin, and catechin.

Human serum albumin-resveratrol complex formation: Effect of the phenolic chemical structure on the kinetic and thermodynamic parameters of the interactions.

The thermodynamics and kinetics of binding between human serum albumin (HSA) and resveratrol (RES) or its analog (RESAn1) were investigated by surface plasmon resonance (SPR). The binding constant and the kinetic constants of association and dissociation indicated that RESAn1 has higher affinity toward HSA than does RES. The formation of these complexes was entropically driven ( [Formula: see text] , [Formula: see text]  KJ mol-1). However, for both polyphenols, the activation energy (Eact) of association (a) of free molecules was higher than that for dissociation (d) of the stable complex ( [Formula: see text]  KJ mol-1), and the rate of association was faster than that of dissociation since the activation Gibbs free energy (ΔG‡) was lower for the former (ΔGaHSA-RES‡â‰…54.73,ΔGdHSA-RES‡â‰…73.83,ΔGaHSA-RESAn1‡â‰…54.14,ΔGdHSA-RESAn1‡â‰…73.97 KJ mol-1). This study showed that small differences in the structure of polyphenols such as RES and RESAn1 influenced the thermodynamics and kinetics of the complex formation with HSA.

Oligostilbenoids in Vitis vinifera L. Pinot Noir grape cane extract: Isolation, characterization, in vitro antioxidant capacity and anti-proliferative effect on cancer cells.

The following oligostilbenoids were isolated from extracts of Vitis vinifera L. Pinot Noir grape canes produced at a pilot-plant scale: (E)-ε-viniferin, (E)-resveratrol, (E)-piceatannol, ampelopsin A, vitisin B, pallidol, (E)-δ-viniferin, (E)-ω-viniferin, (E)-trans-cis-miyabenol C, isorhapontigenin, scirpusin A, and a new isomer named isoscirpusin A. The antioxidant capacity of the isolated stilbenoids was studied by three different assays, and their 50% inhibition concentration (IC50) against cancer cells was determined by MTT reduction assay. Besides (E)-resveratrol, stilbenoids have outstanding antioxidant capacity in the ORAC-FL assay. The strongest antiproliferative effect was observed for (E)-piceatannol and ampelopsin A against the bladder cancer cell line J82. (E)-Piceatannol has inhibitory effect on human lung cancer SK-MES-1 cells. Moreover, the whole extract has antiproliferative effect on all tested cell lines. In conclusion, beside (E)-resveratrol, grape cane extract contains oligostilbenoids with potential health benefits. This underexploited viticultural residue has the potential to produce valuable phytochemicals or ingredients in functional foods.

Ultrasonic-assisted extraction combined with sample preparation and analysis using LC-ESI-MS/MS allowed the identification of 24 new phenolic compounds in pecan nut shell [Carya illinoinensis (Wangenh) C. Koch] extracts.

Ultrasonic-assisted extraction combined with statistical tools (factorial design, response surface methodology and kinetics) were used to evaluate the effects of the experimental conditions of temperature, solid-to-solvent ratio, ethanol concentration and time for the extraction of the total phenolic content from pecan nut shells. The optimal conditions for the aqueous and hydroalcoholic extract (with 20% v/v of ethanol) were 60 and 80 °C; solid to solvent ratio of 30 mL·g-1 (for both) and extraction time of 35 and 25 min, respectively. Using these optimize extraction conditions, 426 and 582 mg GAE·g-1 of phenolic compounds, from the aqueous and hydroalcoholic phases respectively, were obtained. In addition, the analysis of the phenolic compounds using the LC-ESI-MS/MS system allowed the identification of 29 phenolic compounds, 24 of which had not been reported in literature for this raw material yet.

Small Brazilian wild fruits: Nutrients, bioactive compounds, health-promotion properties and commercial interest.

Brazilian berries present great nutritional, functional and economic characteristics comparable to temperate berries. They constitute an important innovation domain for the food, pharmaceutical and cosmetic industries, due to their positive health effects and market potential. The main objective of this review was to describe the physicochemical, nutritional and biological aspects of six Brazilian small native wild fruits from the Arecaceae (açaí, buriti and pupunha), Mirtaceae (camu-camu and jaboticaba) and Malpighiaceae (murici) families, highlighting their antioxidant, anti-lipidaemic, anti-inflammatory, antiproliferative, and antigenotoxic potential among others. It also discussed some relevant topics for new studies that could be of benefit to industry and improve the local economy where these fruits are found. Thus, the dissemination of the works already carried out with these fruits strategically relevant can stimulate new lines of research to consolidate this new field for the food industries.

Distinct metabolic effects of resveratrol on lipogenesis markers in mice adipose tissue treated with high-polyunsaturated fat and high-protein diets.

OBJECTIVE: A healthy diet is essential for the prevention of metabolic syndrome. The present study evaluated the effect of resveratrol associated with high-polyunsaturated fat and high-protein diets on expression of adipogenic and lipogenic genes. RESEARCH METHODS & PROCEDURES: FVB/N mice were divided into 6 groups (n=7 each) and fed with experimental diets for 60days: standard (ST), high-fat diet (HFD), and high-protein diet (HPD), with and without resveratrol (RSV) (4g/kg diet). The body weight, food intake, energy intake (kcal), and blood parameters (HDL-C, total cholesterol, glucose, and triglyceride levels) were assessed. Real-time PCR was performed to analyze the expression of adipogenesis and lipogenesis markers: PPARγ, SREBP-1c, ACC and FAS in samples from perigonadal adipose tissue. RESULTS: In the HPD+RSV group, resveratrol decreased body weight, body adiposity, adipose tissue weight, adipocyte area, total cholesterol, ACC and FAS expression, and increased HDL-cholesterol in comparison to HPD. In the HPD group there was a decrease in adipocyte area, as well as PPARγ, SREBP-1c and ACC expression in comparison to ST. While in HFD+RSV, resveratrol decreased levels of total cholesterol in comparison to HFD. In the HFD group there was decrease in body weight, and PPARγ, SREBP-1c and ACC expression in comparison to ST. CONCLUSIONS: The obtained results show that resveratrol decreases lipogenesis markers and metabolic parameters in the setting of a high-protein diet. Moreover, resveratrol decreased total cholesterol in both diets. These results point to the increased potential of resveratrol use in prevention of metabolic syndrome, acting on different dietary compositions.

Bioactive potential of Vitis labrusca L. grape juices from the Southern Region of Brazil: phenolic and elemental composition and effect on lipid peroxidation in healthy subjects.

Grapes are rich in polyphenols with biologically active properties. Although the bioactive potential of grape constituents are frequently reported, the effects of Brazilian Vitis labrusca L. grape juices ingestion have not been demonstrated in humans. This study identified the phenolic and elemental composition of red and white grape juices and the effect of organic and conventional red grape juice consumption on lipid peroxidation in healthy individuals. Concentrations of anthocyanins, flavanols and phenolic acids and the in vitro antioxidant activity were significantly higher in the organic juice. The macro-elements K, Ca, Na and Mg were the most abundant minerals in all juices. The acute consumption of red grape juices promoted significant decrease of lipid peroxides in serum and TBARS levels in plasma. It is concluded that red V. labrusca L. grape juices produced in Southern Brazil showed lipid peroxidation inhibition abilities in healthy subjects, regardless of the cultivation system.