Table 3.
Monosaccharide compositional analysis of three PPS samples by 1H NMR and HSQC NMR
| Quantitative 1H NMR analysis | ||||
|---|---|---|---|---|
| Monosaccharide residue | PPS 1 | PPS 2 | PPS 3 | |
| Xyl+XylNR | 72.6 | 72.7 | 73.2 | |
| XylRE | 10.5 | 10.6 | 11.0 | |
| Xyl3Ac-2MGA | 2.2 | 2.2 | 2.1 | |
| ΔXyl | 1.1 | 1.2 | 1.1 | |
| ΔXylred(CHO) | 1.1 | 1.1 | 1.0 | |
| Xylα(Py) + Xylβ(Py) | 0.9 | 0.9 | 1.0 | |
| Xyl*6 (5.08 ppm) | 6.7 | 6.2 | 5.8 | |
| MGA-(Xyl3Ac) | 2.1 | 2.1 | 2.1 | |
| MGA-(Xyl) | 1.7 | 1.7 | 1.6 | |
| MGA*-(Xyl) | 1.2 | 1.3 | 1.1 | |
| Degree of acetylation | 3.6 | 3.5 | 3.6 | |
| AcXyl3Ac-2MGA/Ac.tot | 66 | 66 | 63 | |
| Quantitative HSQC NMR analysis | ||||
| Monosaccharide residue | CV% | PPS 1 | PPS 2 | PPS 3 |
| Xyl+XylNR | 0.5 | 73.62 | 74.10 | 73.11 |
| Xylα | 3.8 | 3.98 | 4.00 | 3.53 |
| Xylβ | 1.2 | 6.35 | 6.36 | 6.20 |
| Xyl3Ac-2MGA | 1.0 | 1.75 | 1.78 | 1.58 |
| ΔXylred | 11.4 | 0.97 | 0.95 | 1.08 |
| Xylα(Py) | 15.9 | 0.52 | 0.40 | 0.56 |
| Xylβ(Py) | 3.6 | 0.23 < LOQ | 0.28 < LOQ | 0.35 < LOQ |
| MGA-(Xyl3Ac) + MGA-(Xyl) | 1.9 | 3.75 | 3.68 | 3.85 |
| MGA*-(Xyl) | 6.2 | 0.93 | 0.99 | 0.99 |
| Xyl*2 (6.0/116.2) | 11.2 | 0.20 < LOQ | 0.13 < LOQ | 0.25 < LOQ |
| Xyl*3 (5.21/100.4) | 8.8 | 0.80 | 0.65 | 0.96 |
| Xyl*4 (5.19/95.2) | 4.7 | 1.15 | 0.99 | 1.04 |
| Xyl*5 (5.16/99.9) | 8.8 | 0.86 | 0.71 | 1.25 |
| Xyl*6 (5.10/98.8) | 1.8 | 4.88 | 4.95 | 5.24 |
| Xyl*7 (5.10/106.3) | 3.7 | 0.98 | 0.97 | 1.09 |
| MGA tot (from C1) | 1.6 | 4.69 | 4.67 | 4.84 |
| MGA tot (from C4) | 2.0 | 4.69 | 4.95 | 4.80 |
| 3ΔXyl (CHO) | 12.6 | 0.84 | 0.46 | 1.00 |
*
- related to substituents not fully elucidated
Degree of acetylation - ratio of acetyl groups ((2.35–2.10 ppm)/3) *100/ sum of xylose signals
Ac Xyl3Ac-2MGA/Ac.tot - ratio of AcXyl3Ac-2MGA(2.31ppm) *100/Ac.tot (2.35-2.13 ppm)Calculation – monosaccharide residue (C1)*100/C1-SUM, Xyl* – C1 signals related to substituents not fully elucidated (1H-13C ppm), MGA tot (from C1)– sum of MGA residues, MGA tot (from C4)– 4MGA(3.46–83.8 ppm)*100/ C1-SUM, 3ΔXyl(CHO) – 3ΔXyl(CHO) (6.78-141.3ppm)*100/ C1-SUM. Apex number (e.g. 3Xyl) shows the number of the carbon observed in signal.