Effect of Ultrasonic Irradiation on the Physicochemical and Structural Properties of Laminaria japonica Polysaccharides and Their Performance in Biological Activities

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 1; p. 8
• Main Authors: Wu, Jinhui, Wang, Huiying, Liu, Yanfei, Xu, Baojun, Du, Bin, Yang, Yuedong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20.12.2022; MDPI
• Subjects: Acids; anti-inflammatory; antioxidant activity; Antioxidants - pharmacology; Biological activity; Bonding strength; Free radicals; Glucose; Hydrogen; Inflammation; Irradiation; Laminaria - chemistry; Laminaria japonica; Laminaria japonica polysaccharide; Macrophages; Molecular structure; Molecular weight; physicochemical characteristics; Polysaccharides; Polysaccharides - chemistry; R&D; RAW264.7 macrophages; Research & development; Saccharides; Scavenging; Spectrum analysis; Ultrasonic imaging; Ultrasonics; ultrasound; α-Amylase; Laminaria japonica polysaccharide; anti-inflammatory; RAW264.7 macrophages; antioxidant activity; ultrasound; physicochemical characteristics
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28010008

Due to the large molecular weight and complex structure of polysaccharides (LJP), which limit their absorption and utilization by the body, methods to effectively degrade polysaccharides had received more and more attention. In the present research, hot water extraction coupled with three-phase partitioning (TPP) was developed to extract and isolate LJP. Ultrasonic polysaccharides (ULJP) were obtained by ultrasonic degradation. In addition, their physicochemical characteristics and in vitro biological activities were investigated. Results indicated that ULJP had lower weight-average molecular weight (153 kDa) and looser surface morphology than the LJP. The primary structures of LJP and ULJP were basically unchanged, both contained α-hexo-pyranoses and were mainly connected by 1,4-glycosidic bonds. Compared with LJP, ULJP had stronger antioxidant activity, α-amylase inhibitory effect and anti-inflammatory effect on RAW264.7 macrophages. The scavenging rate of DPPH free radicals by ULJP is 35.85%. Therefore, ultrasonic degradation could effectively degrade LJP and significantly improve the biological activity of LJP, which provided a theoretical basis for the in-depth utilization and research and development of in the fields of medicine and food.