Table 2. Chemical shifts used for identification and quantification of amino acids, other amino compounds and other compounds in 1H-NMR spectra of beet root and leaf polar extracts (in D2O, pHapparent 6.0), expressed as relative values to the TSP resonance at 0 ppm.
s: singlet, d: doublet, dd: doublet of doublets, t: triplet, m: multiplet.
| Compound | Group | Multiplicity | δ1H (ppm) D2O pH6 |
Root (R) Leaf (L) |
Identification statusa | Integrated range (ppm) used for quantification |
|---|---|---|---|---|---|---|
| Amino acids and other amino compounds | ||||||
| Alanine | C3H3 | d | 1.48 | L R |
1 | 1.484 +/- 0.015 1.484 +/- 0.015 |
| Arginine | C7H2 | m | 1.63 | L | 1 | 1.635 +/- 0.027 |
| Asparagine | ½ (C3H2) | m | 2.88 | L R |
1 | 2.979 +/- 0.006 2.882 +/- 0.016 |
| Aspartic acid | ½ (C3H2) | ½ dd | 2.82 | L R |
1 | 2.819 +/- 0.027 2.800 +/- 0.012 |
| GABA | C2H2 | t | 2.30 | R | 1 | 2.303 +/- 0.003 |
| Glutamic acid | C3H2 | m | 2.36 | L R |
1 | 2.360 +/- 0.007 2.359 +/- 0.007 |
| Glutamine | C4H2 | m | 2.46 | L R |
1 | 2.459 +/- 0.025 2.458 +/- 0.025 |
| Isoleucine | C6H3 | s | 1.02 | L R |
1 | 1.022 +/- 0.006 1.020 +/- 0.006 |
| Phenylalanine | C5H + C6H | m | 7.41 | L R |
1 | 7.405 +/- 0.050 7.409 +/- 0.050 |
| Proline | C4H2 | m | 2.33 | L R |
2 | 2.334 +/- 0.004 2.333 +/- 0.005 |
| Pyroglutamic acid | C2H | dd | 4.17 | L R |
1 | 4.178 +/- 0.018 4.172 +/- 0.014 |
| Serine | C2H2 | m | 3.97 | L R |
1 | 3.967 +/- 0.003 3.981 +/- 0.008 |
| Tryptophan | C7H | d | 7.55 | L R |
1 | 7.541 +/- 0.016 7.546 +/- 0.015 |
| Tyrosine | C3H2 | d | 6.91 | L R |
1 | 6.905 +/- 0.020 |
| C2H2 | d | 7.19 | L R |
1 | 7.189 +/- 0.008 | |
| Valine | C4H3 | d | 1.04 | L R |
1 | 1.045 +/- 0.013 1.046 +/- 0.014 |
| C5H3 | d | 1.00 | LR | 1 | ||
| Choline | N-C3H3+N-C4H3+N-C5H3 | s | 3.20 | R | 1 | 3.205 +/- 0.006 |
| Glycine betaine | N-C3H3+N-C4H3+N-C5H3 | s | 3.27 | L R |
1 | 3.269 +/- 0.010 3.267 +/- 0.015 |
| C2H2 | s | 3.83 | LR | 1 | ||
| Trigonelline | C2H | s | 9.17 | L | 2 | 9.127 +/- 0.008 |
| N-CH3 | s | 4.44 | L | 2 | ||
| Other compounds | ||||||
| Xanthine_like | C2H | s | 8.46 | R | 3 | 8.459 +/- 0.004 |
| UnknownS8.29 | s | 8.29 | L | 4 | 8.297 +/- 0.018 | |
| UnknownS5.35 | s | 5.35 | R | 4 | 5.395 +/- 0.004 | |
| UnknownS5.25 | s | 5.25 | L | 4 | 5.254 +/- 0.006 | |
| UnknownS2.75 | s | 2.75 | R | 4 | 2.755 +/- 0.006 | |
| UnknownD1.84 | d | 1.84 | L | 4 | 1.842 +/- 0.009 | |
a Identification level: 1, Identified compounds (checked with standard); 2, Putatively annotated compounds; 3, Putatively characterized compound classes; 4, Unknown.