Table 1.
1H NMR chemical shifts (δ) and coupling constants (Hz) of wine phenolics identified by references and using 1D and 2D NMR spectra
| Compounds | Chemical shifts (δ) |
|---|---|
| Alanine | 1.48 (d, J = 7.4) |
| Threonine | 1.32 (d, J = 6.5), 3.51 (d, J = 5.0), 4.27 (m) |
| Valine | 1.01 (d, J = 7.0), 1.06 (d, J = 7.0), 2.28 (m) |
| Proline | 2.35 (m), 3.37 (m) |
| Methionine | 2.15 (m), 2.65 (t, J = 8.0) |
| Tyrosine | 6.85 (d, J = 8.5), 7.19 (d, J = 8.5) |
| Phenylalanine | 3.15 (dd, J = 8.2, 14.5), 3.91 (t, J = 9.6) |
| Glutamine | 2.14 (m), 2.41 (td, J = 16.2, 7.5) |
| Glutamate | 2.13 (m), 2.42 (m), 3.71 (dd, J = 7.0, 1.9) |
| Arginine | 1.75 (m), 3.75 (t, J = 5.5) |
| Aspartate | 2.80 (m), 3.80 (m) |
| β-glucose | 4.58 (d, J = 7.8) |
| α-glucose | 5.17 (d, J = 3.7) |
| Sucrose | 5.39 (d, J = 3.9) |
| GABA | 1.90 (m), 2.31(t, J = 7.5), 3.01 (t, J = 7.5) |
| Choline | 3.20 (s) |
| Glycerol | 3.56 (m), 3.64 (m) |
| 2,3-butanediol | 1.14 (d, J = 6.5) |
| Acetic acid | 1.94 (s) |
| Succinic acid | 2.53 (s) |
| Fumaric acid | 6.52 (s) |
| Formic acid | 8.45 (s) |
| Citric acid | 2.56 (d, J = 17.6), 2.74 (d, J = 17.6) |
| Malic acid | 2.68 (dd, J = 16.6, 6.6), 2.78 (dd, J = 16.6, 4.7), 4.34 (dd, J = 6.6, 4.7) |
| Lactic acid | 1.40 (d, J = 7.0) |
| Tartaric acid | 4.35 (s) |
| cis-Resveratrol | 6.21 (t, J = 2.1), 6.31 (d, J = 2.1), 6.68 (d, J = 13.3), 6.71 (d, J = 8.5), 6.76 (d, J = 13.3), 7.18 (d, J = 8.5) |
| Gallic acid | 7.03 (s) |
| Syringic acid | 3.89 (s), 7.31 (s) |
| Vanillic acid | 3.90 (s), 6.77 (d, J = 8.2), 7.22 (m) |
| p-Benzoic acid | 6.83 (d, J = 8.7), 7.94 (d, J = 8.6) |
| p-Coumaric acid | 6.38 (d, J = 16.0), 6.84 (d, J = 8.8), 7.50 (d, J = 8.8), 7.59 (d, J = 16.0) |
| Caffeic acid | 6.24 (d, J = 16.0), 6.87 (d, J = 8.4), 7.02 (dd, J = 8.4, 2.0), 7.12 (d, J = 2.0), 7.52 (d, J = 16.0) |
| (+)-Catechin | 2.52 (dd, J = 16.1, 8.2), 2.83 (dd, J = 16.0, 5.4), 4.04 (m), 4.55 (d, J = 7.5), 5.89 (d, J = 2.2), 6.75 (d, J = 8.0), 6.80 (dd, J = 8.5, 2.0), 6.88 (d, J = 8.5), 6.9 (d, J = 2.0) |
| (−)-Epicatechin | 2.72 (dd, J = 16.8, 2.6), 2.89 (dd, J = 16.9, 4.6), 4.26 (m), 6.03 (d, J = 2.0), 6.06 (d, J = 2.0), 6.88 (brs), 6.96 (d, J = 2.2) |
| Quercetin | 6.27 (d, J = 2.0), 6.49 (d, J = 2.0), 6.99 (d, J = 8.6), 7.66 (dd, J = 8.5, 2.0), 7.71 (d, J = 2.0) |
| Kaempferol | 6.28 (d, J = 2.0), 6.52 (d, J = 2.0), 6.74 (d, J = 8.6), 8.04 (d, J = 8.6), |
| trans-Caftaric acid | 5.77 (s), 6.29 (d, J = 16.0), 6.88 (d, J = 8.4), 7.02 (dd, J = 8.4, 2.0), 7.12 (d, J = 2.0), 7.52 (d, J = 16.0) |
| trans-p-Coutaric acid | 5.84 (s), 6.36 (d, J = 16.0), 6.87 (d, J = 8.8), 7.51 (d, J = 8.8), 7.59 (d, J = 16.0) |
| cis-Caftaric acid | 5.34 (s), 5.92 (d, J = 13.0), 6.71 (d, J = 8.4), 6.81 (d, J = 13.0), 7.03 (dd, J = 8.4, 2.0), 7.44 (d, J = 2.0) |
| cis-p-Coutaric acid | 5.41 (s), 5.94 (d, J = 13.0), 6.73 (d, J = 9.2), 6.86 (d, J = 13.0), 6.93 (d, J = 9.2), 7.61 (d, J = 9.2) |