Also, the spectrophotometric
analyses were performed in triplicate for each wine. The free radical scavenging activity of the wine samples was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenger method measured at 518 nm (Brand-Williams, Cuvelier, & Berset, 1995) and ABTS 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) according to Re et al. (1999), measured at 754 nm. Lipid peroxidation Selleckchem ABT-263 inhibition was assayed using the TBARS method, as described by Chen and Tappel (1996). Results were expressed as Trolox equivalents (mm TEAC). The analyses were carried out in triplicate. Analysis of variance (ANOVA), the Tukey HSD Test and PCA were carried out using Statistica 7 (2006) (StatSotft Inc., Tulsa, OK) and
p < 0.05 values were considered statistically significant. The GSI-IX clinical trial linear regression, the square of the correlation coefficient of the regression line, and the limits of detection and quantitation obtained from the calibration data for catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, PA B1 and PA B2 standards are shown in Table 1. The % RSD obtained experimentally with 12 analyses of the wine sample were as follows: for free flavan-3-ols: catechin, 3.80%; epicatechin, 3.78%; gallocatechin, 4.04%; epigallocatechin, 2.87%; PA B1, 3.86%; and PA B2, 3.56%; for proanthocyanidins, terminal units: catechin, 4.71%; epicatechin, 4.07%; gallocatechin, 4.03%; epigallocatechin, 3.06%; and epicatechin gallate, 4.57%; and extension units: catechin, 6.75%; epicatechin, 3.17%; epigallocatechin, 1.87%; and epicatechin gallate 6.26%. All results were considered acceptable for research purposes. The flavan-3-ol monomers catechin (C), epicatechin (EC), gallocatechin (GC) and epigallocatechin (EGC) and PA dimers B1
and B2 were identified and quantified in wine samples of Cabernet Franc, Merlot, Sangiovese and Syrah, from 2006 and 2007 vintages, from São Joaquim – SC, Brazil (Fig. 1, Table 2). The main flavan-3-ol monomers found were catechin and epicatechin. These results are in agreement with those in the literature, since these P-type ATPase are the main monomers in the skin and seeds of grapes (Chira et al., 2009, Mattivi et al., 2009 and Prieur et al., 1994) and, consequently, in wine. Catechin was the main monomer in the wine samples evaluated, with the highest concentrations observed in all samples, representing, on the average, 60% of the total monomers, as also observed in other studies (Monagas, Gómez-Cordovés, Bartolomé, Laureano, & Ricardo da Silva, 2003). The highest concentrations of catechin were observed in Merlot 2007 and Syrah 2006 samples. Epicatechin represented approximately 25% of the monomers quantified in the samples, with concentrations ranging from 4 to 16 mg L−1, Merlot and Syrah being the varieties showing the highest concentrations.