“…Selenium could prevent free radicals from damaging cells and tissues in vivo . Zhao and others () studied the selenylation‐modified polysaccharides from P. anserine L., and found that their antioxidant activities were significantly enhanced. Selenylation of polysaccharides from L. barbarum significantly enhanced glutathione peroxidase (GSH‐Px) and superoxide dismutase (SOD) activities, and decreased malondialdehyde (MDA) content, showing significantly stronger antioxidant activities and bioactivities than the original polysaccharide (Qiu and others ).…”
Section: Influence Of Molecular Modification On Bioactivities Of Polymentioning
Polysaccharides are ideal natural resources for supplements and pharmaceuticals that have received more and more attention over the years. Natural polysaccharides have been shown to have fewer side effects, but because of their inherently physicochemical properties, their bioactivities were difficult to compare with those of synthetic drugs. Thus, researchers have modified the structures and properties of natural polysaccharides based on structure-activity relationships and have obtained better functionally improved polysaccharides. This review focuses on the major modification methods of polysaccharides, and discusses the effect of molecular modification on their physicochemical properties and bioactivities. Molecular modification methods mainly include chemical, physical, and biological changes. Chemical modification is the most widely used method; it can significantly increase the water solubility and bioactivities of polysaccharides by grafting onto other groups. Physical and biological modifications only change the molecular weight of a polysaccharide, and thereby change its physicochemical properties and bioactivities. Most of the molecular modifications bring about an increase in the antioxidant activity of polysaccharides, and among these, sulfated and acetylated modifications are very common. Furthermore, phosphorylation modification is the most common application to increase antitumor activity, and modified polysaccharides have been shown to have anti-HIV activity as the result of sulfated modification.
“…Selenium could prevent free radicals from damaging cells and tissues in vivo . Zhao and others () studied the selenylation‐modified polysaccharides from P. anserine L., and found that their antioxidant activities were significantly enhanced. Selenylation of polysaccharides from L. barbarum significantly enhanced glutathione peroxidase (GSH‐Px) and superoxide dismutase (SOD) activities, and decreased malondialdehyde (MDA) content, showing significantly stronger antioxidant activities and bioactivities than the original polysaccharide (Qiu and others ).…”
Section: Influence Of Molecular Modification On Bioactivities Of Polymentioning
Polysaccharides are ideal natural resources for supplements and pharmaceuticals that have received more and more attention over the years. Natural polysaccharides have been shown to have fewer side effects, but because of their inherently physicochemical properties, their bioactivities were difficult to compare with those of synthetic drugs. Thus, researchers have modified the structures and properties of natural polysaccharides based on structure-activity relationships and have obtained better functionally improved polysaccharides. This review focuses on the major modification methods of polysaccharides, and discusses the effect of molecular modification on their physicochemical properties and bioactivities. Molecular modification methods mainly include chemical, physical, and biological changes. Chemical modification is the most widely used method; it can significantly increase the water solubility and bioactivities of polysaccharides by grafting onto other groups. Physical and biological modifications only change the molecular weight of a polysaccharide, and thereby change its physicochemical properties and bioactivities. Most of the molecular modifications bring about an increase in the antioxidant activity of polysaccharides, and among these, sulfated and acetylated modifications are very common. Furthermore, phosphorylation modification is the most common application to increase antitumor activity, and modified polysaccharides have been shown to have anti-HIV activity as the result of sulfated modification.
“…However, their limited water-solubility and relatively low biological activities hinder their application. Chemical modification of polysaccharide chains, such as phosphorylation (Song, Ni, Hu, & Li, 2015), sulphation (Jin, Wang, Huang, Lu, & Wang, 2014), selenylation (Zhao et al, 2013), or the introduction of hydroxamates (Aiedeh & Taha, 2001), leads to changes in the physicochemical and biological properties of polysaccharides.…”
In order to improve the antioxidant and antimicrobial abilities, hydroxamated degraded polysaccharides from Enteromorpha prolifera (HCDPE) were prepared from the corresponding carboxymethylated degraded polysaccharides (CDPE). HCDPE was characterized by FT-IR. The weight-average molecular weight of HCDPE was determined as 55.4kDa. The in vitro antioxidant activity of HCDPE was evaluated by determining the radical (1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals) scavenging abilities and total antioxidant activity. It was found that DPPH radical scavenging ability and total antioxidant activity of HCDPE were significantly improved compared to those of CDPE. The inhibitory effects of polysaccharides against the five bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella spp.) were also evaluated by bacterial inhibition zone and minimum inhibitory concentration (MIC) assays. The results indicated that CDPE and HCDPE possess marked antimicrobial ability, while such an effect was not observed for the crude polysaccharides (PE) and the degraded polysaccharides (DPE).
“…Absorption bands for the polysaccharides in the range of 950–1200 cm −1 were found in cases in which C–O–C and C–O–H link band positions were found. Absent in the spectrogram of CEPS, a weak characteristic absorption band in that of Se-CEPS was found at 882.9 cm −1 , indicating an asymmetrical Se = O stretching vibration of selenium ester [19], and another characteristic absorption band was found at 610.6 cm −1 , indicating an asymmetrical Se − O − C stretching vibration [20], which demonstrated that Se-CEPS was successfully modified by selenylation.Fig. 2IR spectra of the CEPS ( a ) and Se-CEPS ( b ) in the range of 400–4000 nm…”
BackgroundCordyceps sobolifera (C. sobolifera) isolated from cicadae was used as the starting fungus to produce selenium-enriched C. sobolifera extracellular polysaccharide (Se-CEPS). An orthogonal experimental design based on a single-factor experiment was used to optimize the C. sobolifera fermentation conditions, including the potato juice, peptone, and KH2PO4 concentrations. Ultraviolet (UV) and infrared (IR) analyses of CEPS and Se-CEPS were conducted, as well as an in vivo anti-tumor analysis.ResultsUnder optimal conditions (i.e., 40 potato juice, 0.4 KH2PO4, and 0.5 % peptone), the fermentation yield of Se-CEPS was 5.64 g/L. UV and IR spectra showed that Se-CEPS contained a characteristic absorption peak of a selenite Se = O double bond, demonstrating the successful preparation of Se-CEPS. Activity tests showed that Se-CEPS improved the immune organ index, serum cytokine content, and CD8+ and CD4+ T lymphocyte ratio in colon cancer CT26 tumor-bearing mice, thereby inhibiting tumor growth. When combined with 5-FU, Se-CEPS reduced the toxicity and enhanced the function of 5-FU.ConclusionThe result of these experiments indicated that orthogonal experimental design is a promising method for the optimization of Se-CEPS production, and the Se-CEPS from C. sobolifera can improve the anti-tumor capacity of mice.Electronic supplementary materialThe online version of this article (doi:10.1186/s13036-016-0029-0) contains supplementary material, which is available to authorized users.
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