Application of X‐ray diffraction and energy dispersive spectroscopy in the isolation of sulfated polysaccharide from Porphyra haitanensis and its antioxidant capacity under in vitro digestion

Abstract

BACKGROUND:The separation and purification of Porphyra haitanensis polysaccharide (PHP), and the determination of changes in molecular weight (Mw) and antioxidant capacity after in vitro digestion, were undertaken. RESULTS: Analysis of two polysaccharide fractions (PHP0.5-1-UF and PHP1.0-1-UF) by various techniques showed that they were very pure sulfated polysaccharides without pigment or protein. PHP0.5-1-UF was filamentous or 'tape-like' sheets, whereas PHP1.0-1-UF had some filaments and large numbers of rounded aggregates. The Mw of PHP, PHP0.5-1-UF and PHP1.0-1-UF was 2.06 × 10 6 (±2.02%), 6.68 × 10 6 (±3.17%), and 1.14 × 10 6 (±3.44%) (g mol -1 ), respectively. After in vitro digestion, the Mw of PHP, PHP0.5-1-UF, and PHP1.0-1-UF decreased. Their antioxidant capacities were markedly higher than before digestion, especially PHP0.5-1-UF and its digestion products, which might be related to the reductions in Mw.CONCLUSION: These findings provide a greater understanding of the separation and purification of sulfated polysaccharides and the influence of digestion on biological activity. They also contribute to the practical application of sulfated polysaccharides in functional foods.

Porphyra haitanensis Polysaccharides Attenuates Blood Lipid via Gut‐Liver Axis in Diet‐Induced High‐Fat Mesocricetus auratus through Multiple Integrated Omics

“…P. haitanensis polysaccharide was extracted according to the previous method. [ 15 ] M. auratus [license No. SCXK (Shanghai) 2017‐0008] were purchased from the Songjian Experimental Animal Farm (Songjiang District, Shanghai, China).…”

“…[14] Polysaccharide is the main component of P. haitanensis. In our previous study, we isolated two fractions from P. haitanensis polysaccharide (PHP) [15] and characterized them as sulfated galactan [16] and sulfated glucogalactan. [17] Owing to its structure, high sulfate content and other factors, PHP has a variety of biological activities, such as anti-oxidation, [18] immune regulation, [19,20] anti-tumor, [21,22] intestinal flora regulation, [23,24] and hypolipidemic [25] effects.…”

Food Xanthan Polysaccharide Sulfation Process with Sulfamic Acid

“…It is known [23,43,[55][56][57][58][59] that sulfation of polysaccharides leads to greater amorphization of their structure. Thus, the data shown in Figure 6 are in good agreement with the literature.…”

“…In the process of sulfation, an increase in the amorphization of the initial xanthan structure was observed, which was manifested by a decrease in the intensity in X-ray diffraction patterns from 17° to 50° 2θ. It is known [23,43,[55][56][57][58][59] that sulfation of polysaccharides leads to greater amorphization of their structure. Thus, the data shown in Figure 6 are in good agreement with the literature.…”

In vitro-simulated intestinal flora fermentation of Porphyra haitanensis polysaccharides obtained by different assisted extractions and their fermented products against HT-29 human colon cancer cells

“…12 P. haitanensis polysaccharides (PHPs) are mainly composed of alternating β-(1 → 3)-D-galactose and α-(1 → 4)-3,6-endoether-L-galactose units and a sulfated linear skeleton. 13 Numerous studies have demonstrated that PHPs have immunomodulatory, anticancer, 14 and anti-bacterial, [14][15][16] anti-tumor, 17 and antioxidant 15,18 activities. PHPs can protect against human colon cancer cells through cell cycle arrest and apoptosis without causing adverse effects in vitro.…”