Antioxidant activity and cytoprotective effect of κ-carrageenan oligosaccharides and their different derivatives

Carrageenans: Biological properties, chemical modifications and structural analysis – A review

“…7). All derivatives exhibited an antioxidant activity higher than that of j-carrageenan, suggesting that chemical modification can enhance antioxidant activity of carrageenans (Yuan et al, 2006). Previously, Jones, Colfen, and Antonietti (2000) had shown that j-carrageenan acts in vitro as an efficient stabilizer of iron oxides even up to very high pH values.…”

Preparation, composition analysis and antioxidant activities of konjac oligo-glucomannan

“…The reaction mixture was shaken well and incubated for 30 min at 33 • C in the dark and the absorbance of the resulting solution was read at 517 nm against a blank, the radical scavenging activity was measured as a decrease in the absorbance of DPPH. The reducing power of extracts was determined by the method of Yuan et al (2006) with some modifications. 2.0 mL test samples were mixed with 2.0 mL of phosphate buffer (0.2 mM, pH 6.6) and 2.0 mL of 1% potassium ferricyanide (w/v).…”

“…A multitude of natural antioxidants have already been isolated from different kinds of plant materials such as seeds, cereal crops, vegetables, fruits, leaves, roots, spices, and herbs (Yuan et al, 2006). Sun, Yao, Zhou, and Mao (2008) reported that the N-carboxymethyl chitosan oligosaccharides (N-CMCOSs) have antioxidant activity, and different degrees of substitution of N-CMCOSs have different ability in the scavenging of 1,1-diphenyl-2-picrylhrazyl radical (•DPPH) radical, superoxide anion and determination of reducing power.…”

Enhanced immunostimulatory and antitumor activity of different derivatives of κ-carrageenan oligosaccharides from Kappaphycus striatum

“…In our previous work, κ-carrageenan oligosaccharides from Kappaphycus striatum were found to have antitumor activity both in vitro and in vivo and immunomodulation effects on S180-bearing mice Yuan et al 2006a). We also prepared sulfated, acetylated, and phosphorylated derivatives of κ-carrageenan oligosaccharides and found that the different derivatives exhibited higher antioxidant activity than carrageenan oligosaccharides in certain antioxidant systems in vitro, which indicated that the chemical modification of carrageenan oligosaccharides can enhance their antioxidant activity Yuan et al 2006b). In the present study, the antitumor and immunomodulative effects of different κ-carrageenan oligosaccharides derivatives on S180-bearing mice were investigated in order to evaluate whether the chemical modification will have any influence on the activities.…”