Characterization of ulvan extracts to assess the effect of different steps in the extraction procedure

In Vitro Cytotoxicity Assessment of Ulvan, a Polysaccharide Extracted from Green Algae

“…Characterization of the extracted polysaccharide revealed different physicochemical properties which are summarized in Table (adapted from Costa et al ., ).…”

Overview on Biological Activities and Molecular Characteristics of Sulfated Polysaccharides from Marine Green Algae in Recent Years

“…First, accurately determining the sugar composition of ulvans is difficult because the aldobiouronic linkage is refractory to acid hydrolysis and IdA is partially destroyed during acid hydrolysis. To minimize these effects, innovative methods combining mild acid hydrolysis with enzymatic degradation have been developed, and these techniques allow more accurate insights into the sugar composition of ulvans and authentication of the presence of IdA within the SP backbone [113,120,121]. Differences in species also contribute to the compositional variability of ulvans.…”

Production of sulfated oligosaccharides from the seaweed Ulva sp. using a new ulvan-degrading enzymatic bacterial crude extract

“…These interesting features make ulvan an excellent candidate as a renewable and cheap compound for industrial purposes. Unfortunately its structure is difficult to define [7,40,41]. An enzymatic or chemical reduction of its molecular weight could lead to a more definable structure and improve the range of its activities, the efficiency and reduce the polydispersity of its molecular weight.…”

“…The genus Persicivirga has recently been merged in the genus Nonlabens [51] and the newly named Nonlabens ulvanivorans has been described to produce a β-glucuronyl hydrolase implicated in the degradation of ulvan [52]. Other authors have described the degradation of ulvan by enzymatic means but with alginate-degrading commercial enzymes or without further characterization of the bacteria used to obtain the enzyme [7,19,53]. The main challenge of enzymatic degradation is to maintain the basic structure of repetitive subunits with the sulfate functional groups while controlling the kinetics of degradation to obtain oligomers with a constant yield and molecular size.…”

“…The main structural subunit ulvanobiuronic acid type A (A3 S ) is composed of L-rhamnose sulfated on the third carbon and linked on its non-reducing end with a β-Dglucuronic acid with an α 1-3 linkage, the B type ulvanobiuronic acid contains iduronic acid instead of glucuronic acid (B3 S ) [4][5][6]. Its molecular weight depends on the algal species and the extraction protocol; however it is generally high and can round up to 700-800 kDa [7]. This glycosaminoglycan-like structure has anticoagulant [8], antioxidant [9][10][11], immunomodulator [12,13], antihypercholesterolemic [14], antihyperlipidemic [15,16], antiviral [17], antitumoral [18,19] and plant defense elicitor activities [20][21][22][23].…”