Extraction, structural characterization, and antioxidant and immunomodulatory activities of a polysaccharide from Notarchus leachii freeri eggs

作者：Pan, Qiting; Sun, Yulin; Li, Xuyan; Zeng, Buyan; Chen, Daohai^*

来源：Bioorganic Chemistry, 2021, 116: 105275.

DOI：10.1016/j.bioorg.2021.105275

• Notarchus leachii freeri eggs
• Polysaccharide
• Response surface methodology
• Structure characterization
• Antioxidant activity
• Immunomodulatory activity

The crude polysaccharides (NLCEP) were extracted from Notarchus leachii freeri eggs strings by the salt extraction method. The extraction conditions were optimized using the single-factor experiment method and response surface method (RSM). The results showed that the maximum extraction yield of NLCEP was obtained under the following conditions: NaCl solution concentration of 2.96 %, raw material to liquid ratio of 1: 40 g/mL, extraction time of 2 h and extraction temperature of 69 degrees C. A new novel pure polysaccharide fraction named as NLCEPs-1 was fractionated from NLCEP by using DEAE-Cellulose 52 and Sephadex G-100. Its structure and immunomodulatory and antioxidant activities were analyzed. The results exhibited that the molecular weight of NLCEPs-1 was 31.4 kDa and it was composed of rhamnose, glucose, galactose, xylose and arabinose in the molar percentage of 11.128: 63.770: 5.439: 6.585: 13.077. The backbone of NLCEPs-1 was mainly consisted of ->)4 alpha-D-Glcp (1 ->, -> 6)-alpha-D-Glcp (1 ->, -> 1)-beta-D-Galp and beta-D-Galp-(1 -> NLCEPs-1 exhibited the strong antioxidant activity in scavenging ability of various free radicals and immunomodulatory activity by the enhancement of the pinocytic capacity, nitric oxide (NO) and cytokines.