Preparation, structural characterization, and bioactivity of PHPD-IV-4 derived from Porphyra haitanensis

• Published in: Food chemistry Vol. 329; p. 127042
• Main Authors: Gong, Guiping, Dang, Tiantian, Fang, Jie, Deng, Yangni, Liu, Qian, Dai, Wei, Sun, Jing, Wang, Langhong, Liu, Yuxia, Sun, Tingting, Song, Shuang, Fan, Luodi, Huang, Linjuan, Wang, Zhongfu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2020
• Subjects: Antioxidant activity; Degradation; Immunomodulatory activity; Porphyra haitanensis polysaccharides; Structural characterization; DPPH; Structural characterization; Antioxidant activity; PHPD; FT-IR; MTT; MAPK; LPS; Degradation; DMEM; Immunomodulatory activity; PHP; Porphyra haitanensis polysaccharides
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.127042

•Four different molecular weight fractions were obtained from PHP through degradation.•PHPD-IV with the lowest molecular weight showed strongest biological activity.•PHPD-IV-4 derived from PHPD-IV elicited strongest immunostimulatory activity.•PHPD-IV-4 could induce immunity activation of macrophages.•PHPD-IV-4 are repeated units of G-A and G-L6S. Polysaccharides are a major active component of Porphyra haitanensis, which is an important food source in many countries. Four different molecular-weight fractions, namely PHPD-I (329 kDa), PHPD-II (203 kDa), PHPD-III (128 kDa), and PHPD-IV (10 kDa), were obtained from P. haitanensis polysaccharides by degradation using the H2O2/ascorbic acid system. PHPD-IV elicited the highest level of antioxidant and immunostimulatory activity among the four fractions. PHPD-IV was purified by DEAE-cellulose column and five fractions were obtained, designated PHPD-IV-1–PHPD-IV-5. PHPD-IV-4 displayed the greatest biological activity by up-regulating the phosphorylation of MAPK signalling molecules. PHPD-IV-4 was further purified, and its structure was characterized by monosaccharide composition and 1/2D-NMR analysis. The result revealed that PHPD-IV-4 was repeated units of → 3) β-d-galactose (1 → 4) 3, 6-anhydro-α-l-galactose (1→, and → 3) β-d-galactose (1 → 4) α-l-galactose-6-S (1→. This study provides a theoretical basis for the utilisation and structure-activity assessment of P. haitanensis polysaccharides.