Isolation, Characterization and Bioactive Properties of Alkali-Extracted Polysaccharides from Enteromorpha prolifera

Abstract

Four new purified polysaccharides (PAP) were isolated and purified from the Enteromorpha prolifera by alkali extraction, and further characterization was investigated. Their average molecular weights of PAP-1, PAP-2, PAP-3, and PAP-4 were estimated as 3.44 × 104, 6.42 × 104, 1.20 × 105, and 4.82 × 104 Da, respectively. The results from monosaccharide analysis indicated that PAP-1, PAP-2, PAP-3 were acidic polysaccharides and PAP-4 was a neutral polysaccharide. PAP-1 and PAP-2 mainly consist of galacturonic acid, while PAP-3 and PAP-4 mainly contained rhamnose. Congo red test showed that no triple helical structure was detected in the four polysaccharides. The antioxidant activities were investigated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), Superoxide, and 2, 2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical assay. In vitro antitumor activities were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. PAP-1 exhibited relatively stronger antioxidant activities among the four polysaccharides in a dose-dependent manner. At a concentration of 1.00 mg/mL, the antioxidant activities of PAP-1 on the DPPH radical scavenging rate, superoxide anion radical scavenging rate, and ABTS radical rate at 1.00 mg/mL were 56.40%, 54.27%, and 42.07%, respectively. They also showed no significant inhibitory activity against MGC-803, HepG2, T24, and Bel-7402 cells. These investigations of polysaccharides provide a scientific basis for the use of E. prolifera as an ingredient in functional foods and medicines.

Extraction Techniques, Biological Activities and Health Benefits of Marine Algae Enteromorpha prolifera Polysaccharide

“…In addition, the concentration of elution solvent affects the monosaccharide composition and content. Recently, Zhao et al (26) extracted crude polysaccharide from E. prolifera using the alkali method and fractionated it by stepwise elution with 0 (AP-1), 0.3 (AP-2), 0.5 (AP-3), 0.7 (AP-4) M NaCl solution through an anion-exchange column. The monosaccharide analysis indicated that PAP-1 and PAP-2 mainly consist of galacturonic acid, while PAP-3 and PAP-4 mainly contained rhamnose.…”

“…E. prolifera polysaccharides have been increasingly investigated for their role in the functional food and pharmaceutical industry (26). For example, Enteromorpha species was used as an ingredient in the preparation of pakoda, a common traditional snack food in India (27).…”

Effects of dietary Glycyrrhiza polysaccharide on growth performance, blood parameters and immunity in weaned piglets

“…Similar results were reported in other studies (Ao & Kim, 2020; Guo et al, 2021; Ming et al, 2009). The enhancement of antioxidant activity may be related to plant polysaccharide characteristics, such as molecular weight, monosaccharide composition, and spatial structure (M. Zhang, Wang et al, 2014; Zhao et al, 2020). In addition, the components of polysaccharides also have an impact on antioxidant capacity (L. Wang et al, 2008).…”

Phytochemical Assessment of Certain Seaweeds of Enteromorpha Species in Coastal Regions of Ramanathapuram, Tamil Nadu, India

“…From a nutritional standpoint, the main properties of sea lettuce are its richness in polysaccharides, protein and Amino acids, Fatty acids, Minerals and Vitamins. Therefore, their nutritional value makes them valuable food supplements 36,37 .…”