Production of Bioactive Compounds from the Sulfated Polysaccharides Extracts of Ulva lactuca: Post-Extraction Enzymatic Hydrolysis Followed by Ion-Exchange Chromatographic Fractionation

Abstract

This paper describes a novel combined post-extraction process for obtaining bioactive compounds from the aqueous high molecular weight sulfated polysaccharides (SPs) extracts of the green algae, Ulva lactuca. After extracting the SPs, they were enzymatically hydrolyzed then the hydrolysate (V45) was fractionated into eight different molecular weight fractions (F1–F8) using ion exchange chromatography. Crude SPs together with V45 and (F1–F8) were examined for their carbohydrate, protein, and sulfate contents. In addition, their degree of polymerization (DP) was estimated and they were characterized by Fourier Transform Infrared Spectroscopy (FTIR). Fractions S1, F4, F5, and F8 showed promising antioxidant and antitumor activities in vitro. In particular, the remarkable antitumor activity of F5 on three types of cancer cell lines could be attributed to its comparable contents of protein, carbohydrate, and sulfate, in addition to its comparable contents of rhamnose and glucuronic acid, and the same for glucose and arabinose. F5 also possessed the highest Hill coefficient among the four promising fractions indicating a higher degree of cooperativity in ligand binding. Other influencing factors including DP, composition, and type of characteristic functional groups were also discussed. The implications of this work could potentially benefit the industries of food supplements and pharmaceuticals.

Optimisation and Modelling of Pb(II) and Cu(II) Biosorption onto Red Algae (Gracilaria changii) by Using Response Surface Methodology

“…The peaks observed at 1243.88 cm −1 was attributed to the C-O stretching [45]. The sulfoxide band was assigned to the peak observed at 1030.15 cm −1 [52,53]. The numerous characteristic peaks observed on the surface indicate the…”

Chemically Diverse and Biologically Active Secondary Metabolites from Marine Phylum chlorophyta

“…Ulva pertusa , isolated from heteropolysaccharides, was proven to show high inhibitory activities vs. hydroxyl and superoxide radicals. The low molecular weight, 28.2 kDa ulvan, also revealed strong reduction capacity and strong metal chelating properties, rendering it a powerful antioxidant agent [ 79 , 80 ]. An in vivo study highlighted the antioxidant capacity of Ulva pertusa sulfated Ulvan derivative in the liver of hyper-lipidemic rats.…”

Ulvan, a Polysaccharide from Macroalga Ulva sp.: A Review of Chemistry, Biological Activities and Potential for Food and Biomedical Applications

“…Yields will increase with increasing extraction pH at a constant temperature [22]. The polysaccharides in ulvan have a strong ligand bond, a factor that may provide a therapeutic effect [31].…”

“…The isolation process will vary depending on a laboratory/factory capabilities and availability or raw material and resources. Extraction yields a crude extract that is purified using a vacuum to remove residual solvents [31]. Another study isolated the ulvan component using 2 N HCl solvent reflux in methanol for 2 h, followed by separating the solvent using vacuum chromatography, then purified the extract using preparative thin layer chromatography (TLC) [13].…”

“…Ulvan reduces ROS production by AAPH and attenuates lipid peroxidation, evaluated by thiobarbituric acid reactive substances (TBARS), according to erythrocyte-based assays [80]. Ulvan's antioxidant mechanism involves sulfate and low-molecular-weight polysaccharides [31,83,113]. The latter inhibit cholinesterases and have neuroprotective potential [4].…”