Fucoidan Extracted From Sporophyll of Undaria pinnatifida Grown in Weihai, China - Chemical Composition and Comparison of Antioxidant Activity of Different Molecular Weight Fractions

Jing Yu; Qianqian Li; Jun Wu; Xiaotong Yang; Shiping Yang; Wei Zhu; Yang Liu; Wei Tang; Shaoping Nie; Amira Hassouna; William Lindsey White; Yu Zhao; Jun Lu

doi:10.3389/fnut.2021.636930

Fucoidan Extracted From Sporophyll of Undaria pinnatifida Grown in Weihai, China - Chemical Composition and Comparison of Antioxidant Activity of Different Molecular Weight Fractions

Front Nutr. 2021 May 28:8:636930. doi: 10.3389/fnut.2021.636930. eCollection 2021.

Authors

Jing Yu^{1

2}, Qianqian Li¹, Jun Wu¹, Xiaotong Yang¹, Shiping Yang², Wei Zhu³, Yang Liu³, Wei Tang⁴, Shaoping Nie⁴, Amira Hassouna^{5

6}, William Lindsey White⁷, Yu Zhao¹, Jun Lu^{5

7

8

9

10

11}

Affiliations

¹ College of Life Sciences, Shanghai Normal University, Shanghai, China.
² College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, China.
³ Shanghai Institute of Quality Inspection and Technical Research, Shanghai, China.
⁴ State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
⁵ Faculty of Health and Environmental Sciences, School of Public Health and Interdisciplinary Studies, Auckland University of Technology, Auckland, New Zealand.
⁶ Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Cairo University, Cairo, Egypt.
⁷ School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand.
⁸ Institute of Biomedical Technology, Auckland University of Technology, Auckland, New Zealand.
⁹ Maurice Wilkins Centre for Molecular Discovery, Auckland, New Zealand.
¹⁰ College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China.
¹¹ College of Food Engineering and Nutrition Sciences, Shaanxi Normal University, Shaanxi, China.

Abstract

Fucoidan is a multifunctional marine carbohydrate polymer that differs in its chemical composition and bioactivity both between seaweed species and within species from different locations across the globe. In this study, fucoidan was extracted from the sporophyll of Undaria pinnatifida grown in Weihai, Shandong Province, China. Fucoidan fractions with molecular weight cutoffs (MWCO) of >300 kDa and <10 kDa were obtained via dialysis. The fucoidan standard from Sigma (Fstd, ≥95, CAS: 9072-19-9), fucoidan crude extract (WH), >300 kDa fraction (300k) and <10 kDa fraction (10k) were compared in terms of chemical composition and antioxidant capacity. Based on Fourier transform infrared spectroscopy (FT-IR) analysis, Fstd, WH, and 300k all showed strong bands around 830 cm^-1, corresponding to the sulfate substituent in the molecule. The results showed that compared with WH and 300 k, the degree of sulfation at 10k was the lowest. From Nuclear magnetic resonance spectroscopy (NMR) result, the four fucoidan samples all contain α-_L-fucose. The primary antioxidant ability of the 10k is significantly higher than that of the 300k, WH, and Fstd, but the secondary antioxidant capabilities of the 10k and 300k were similar, and both were higher than that of the butylated hydroxyanisole (BHA). The ferric reducing antioxidant ability was higher in the 300k and WH fractions. This demonstrates that fucoidan extracted from U. pinnatifida grown in Weihai, China should be a useful nutraceutical resource.

Keywords: antioxidant; chemical composition; fraction; fucoidan; molecular weight; nutraceutical.