Carrageenans from nuclear phases of subantartic Mazzaella laminarioides (Gigartinales, Rhodophyta) and graft copolymerization of alkali-modified carrageenan with acrylamide

Abstract

Aqueous extraction of cystocarpic, tetrasporic, and vegetative individuals of Mazzaella laminariodes collected in the Magellan Ecoregion, Southern Chile, afforded sulfated galactans. Analysis by Fourier transform infrared spectroscopy (FT-IR) and by 1 H and 13 C NMR spectroscopy indicated that purified extracts from cystocarpic (CP) and vegetative individuals (VP) were mixtures of κ/ι-type carrageenans and their precursors μ-and ν-carrageenans, whereas the aqueous extract from tetrasporic individuals was a λ-type carrageenan. Alkaline treatment of CP and VP polysaccharides produced modified polysaccharides with lower content of sulfate groups and with a concomitant increase of 3,6-anhydrogalactose content; analysis by 2D 1 H and 13 C NMR indicated the presence of hybrid κ-ι-carrageenans. Copolymerization of alkalitreated CP carrageenan with acrylamide was achieved by using ceric ammonium nitrate as the initiator; studies by NMR spectroscopy indicated grafting of polyacrylamide at position C-6 of β-galactopyranosyl residues. Reaction of modified CP with acrylamide assisted by microwave irradiation in the presence of ammonium persulfate afforded a copolymer grafted at position C-2 of β-galactopyranosyl residues.

Superabsorbent polymers: A review on the characteristics and applications of synthetic, polysaccharide-based, semi-synthetic and ‘smart’ derivatives

“…The latter improves the gelling properties as reflected by their strength [184][185][186]. By using alkaline hydrolysis or microwave irradiation, carrageenan gels have already been 'cross-linked' with poly(acrylamide) [187][188][189], acrylic acid [190] and methyl methacrylate [191]. In addition, a copolymerization with acrylic acid and 2-acrylamido-2-methylpropane-sulfonic acid has already been performed as well [192].…”

Application of Glyoxal Acrylamide Modified Κ-Carrageenan as A Superabsorbent Polymer in Drug Delivery System

“…Increasing the crosslinking density of SAP will result in a decrease in the space between the polymer chains. A rigid structure is formed which cannot hold large amounts of air (Zhang, et al, 2011;Montaser, et al, 2019;Yu, et al 2011;Kulkarni, et al 2012;Arias, et al 2016). Zhang et al, 2011 reported that more crosslinked networks in polymeric chains occurred, affect a higher crosslinking density and more insoluble copolymers in the water.…”

“…All samples were analyzed with the same size (5 cm x10 cm). SAP films were equilibrated at 27•C and 53% relative humidity in desiccators with silica absorbent for 2 days prior to testing (Arias et al, 2016).…”

Antiviral activity of red algae phycocolloids against herpes simplex virus type 2 in vitro

“…2012 [46] and Arias et al . 2016 [45] , respectively. The red macroalgae A. chilense and M. laminarioides were collected at Caleta Lenga (Latitude −36.764330°; Longitude −73.173123°) and Caleta Cocholgüe (Latitude −36.590200°; Longitude −72.980159°) respectively, in Biobío Region, Chile.…”

“…Exopolysaccharides from P. cruentum and P. purpureum were obtained according to a modified extractive procedure described by Arias et al. 2016 [45] . The microalgal cultures were centrifuged at 4000 RPM for 6 min in order to separate the precipitated biomass from the supernatant.…”