## 3 Results and Discussion
### NMR Analysis  
As showed in Figure 5A,B, the signals crowded in the regions of \(\delta_{\rm H}\) 3.0-5.5 ppm and \(\delta_{\rm C}\) 60-110 ppm was the typical distribution of polysaccharides [27]. The chemical shifts of the protons of N-acetyl group (\(\delta\) 1.0-3.6 ppm) showed the presence of protein [28], this result was agreed with the analytic data of protein content and UV spectrum. In addition, the characteristic chemical shifts of furanose at \(\delta\) 107-109 ppm and \(\delta\) 82-84 ppm were absent, which confirmed that PSPE was composed of pyranose [29].  
The C-1 signals at \(\delta\) 5.17, 4.92, 4.90, 4.51, and 4.44 ppm in \({}^{1}\)H NMR spectrum showed four \(\beta\)-type glycosidic linkages and one \(\alpha\)-type glycosidic linkage [30; 31]. The anomeric carbon signals at \(\delta\) 102.35, 98.55, 97.70, 96.37, and 91.68 in \({}^{13}\)C NMR spectrum revealed that PSPE contained five types of monosaccharide residues, which was agreed with the \({}^{1}\)H NMR spectrum. As seen in HSQC spectrum (Figure 5C), the chemical shifts of \(\delta\) 4.44/102.18, 4.89/98.38, 4.86/97.91, 4.51/95.99, and 5.16/91.63 were assigned to the anomeric region of H1/C1. According to the reported literatures [32; 33], the chemical shifts of \(\delta\) 5.16/91.63, 3.47/70.98, 3.81/76.46, 3.96/81.42, 3.89/77.27, and 3.71/61.24 were assigned to H1/C1-H6/C6 of \(\rightarrow\)4)-\(\alpha\)-D-Glc\(p\)-(1\(\rightarrow\) The presence of \(\rightarrow\)3,6)-\(\beta\)-D-Glap-(1\(\rightarrow\) was confirmed by characteristic signals at \(\delta\) 4.51/95.99 (H1/C1), 3.64/72.93(H2/C2), 3.95/82.97 (H3/C3), 4.03/74.43 (H4/C4), 3.40/75.31 (H5/C5), and 3.93/68.56 (H6/C6) [34; 35]. The signals of \(\delta\) 4.89/98.38, 4.07/70.05, 3.33/69.12, 3.91/81.34, 3.17/73.65, and 3.61/62.63 showed the existence of \(\rightarrow\)4)-\(\beta\)-d-Man\(p\)-(1\(\rightarrow\) residue [36]. In addition, the signal of \(\delta\) 4.44/102.18 ppm was attributed to H1/C1 of \(\beta\)-d-galactose [15].  
Figure 4: Characterization of PSPE. (**A**: UV scanning spectrum; **B**: HPLC elution profile; **C**: FT-IR spectrum).  
Figure 5: \(Cont.\)Up to now, three purified polysaccharides (PSP-I, PSP-1 and PSPE) were isolated from pumpkin seeds. NMR spectra analysis confirmed that PSP-I was mainly contained \(\rightarrow\)4)-\(\beta\)-d-Glc\(p\)-(1\(\rightarrow\), \(\rightarrow\)2)-\(\alpha\)-d-Gl\(ap\)-(1\(\rightarrow\), \(\rightarrow\)6)-\(\alpha\)-d-Man\(p\)-(1\(\rightarrow\) and \(\alpha\)-d-galactose [15]. The main backbone structure of PSP-1 comprised \(\rightarrow\)6)-\(\beta\)-D-Gal\(p\)-(1\(\rightarrow\), \(\rightarrow\)6)-\(\alpha\)-d-Gl\(p\)-(1\(\rightarrow\), and \(\rightarrow\)3,6)-\(\beta\)-d-Man\(p\)-(1\(\rightarrow\). Branch linkage was composed of \(\alpha\)-d-Glc\(p\)-(1\(\rightarrow\) and \(\rightarrow\)4)-\(\alpha\)-d-D-Galp-(1\(\rightarrow\)[14]. The present result confirmed that PSPE consisted of \(\rightarrow\)4)-\(\alpha\)-d-Glc\(p\)-(1\(\rightarrow\), \(\rightarrow\)3,6)-\(\beta\)-D-Glap-(1\(\rightarrow\), \(\rightarrow\)4)-\(\beta\)-d-Man\(p\)-(1\(\rightarrow\), and \(\beta\)-d-galactose. All of the data confirmed that these three polysaccharides did not have the same structures, even though they had the same monosaccharide composition (Man, Glc and Gal). In addition, the above results further demonstrated that different polysaccharides could be obtained from the same materials with using different extraction methods.