Purification, characterization and anti-aging capacity of mycelia zinc polysaccharide by Lentinus edodes SD-08.

BACKGROUND: In the modern society, aging had been a major problem. People may rely on many medicines to delay it. However, lots of medicines were chemosynthetic, and they would do a bad side-effect on human body. Microbial sources could be used as a potential means of producing natural antioxidants. Lentinus edodes, commercial obtained in daily life, had recently become more attractive in physiological research. Zinc was now considered as a major element in assuring the correct functioning of an organism and essential for maintaining coordination of the major homeostatic networks. To investigate the bioconversion of zinc and the physiological effects of their complex (MZPS), the present studies were processed. METHODS: Mycelia polysaccharides (MPS) and mycelia zinc polysaccharides (MZPS) of Lentinus edodes SD-08 were extracted by hot water leaching and purified by DEAE-52 cellulose anion-exchange column chromatography separately. The zinc content was determined by flame atomic absorption spectrometry. The evaluation of monosaccharide compositions and proportions used gas chromatogram. The analysis of molecular weight used HPGPC chromatogram. The typical structure of polysaccharide was evaluated by IR spectrum. The antioxidant activities in vitro measured through reducing power, the scavenging effects on hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The anti-aging activities in vivo measured through the total antioxidant capacity (T-AOC), GSH peroxide (GSH-Px), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA). RESULTS: MPS and MZPS of Lentinus edodes SD-08 were extracted and purified by DEAE-52 cellulose anion-exchange column chromatography separately, and four fractions (MPS-1, MPS-2, MZPS-1 and MZPS-2) were obtained. In addition, MPS composing of rhamnose, arabinose and mannose (molar proportion = 1.75:1.00:3.02) and MZPS containing rhamnose, arabinose, mannose and glucose (molar proportion = 7.19:2.26:1.00:8.39) were investigated by gas chromatography. Infrared spectrum analysis indicated that there were C-H, C=O and -CH2 bonds in MPS and MZPS. MPS also had the typical absorption of -NH3 (+), -NH2 and -COOH. Compared with MPS, MZPS showed in vitro positive rising of reducing power and certain scavenging effects on hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. MZPS were found to upregulate in vivo the anti-aging activities of total antioxidant capacity (T-AOC), GSH peroxide (GSH-Px), superoxide dismutase (SOD), and decrease the contents of malondialdehyde (MDA). CONCLUSIONS: MZPS effectively showed potential anti-aging activities in vivo and antioxidant activities in vitro, and the molecular constituents, chemical bonds and functional groups of MZPS were superior to MPS, suggesting that the MZPS of L. edodes SD-08 could be used as a potential natural antioxidant.

Degradation of Thiamethoxam in aqueous solution by ozonation: Influencing factors, intermediates, degradation mechanism and toxicity assessment.

This paper focuses on the degradation of Thiamethoxam (THIA) in aqueous solution by ozonation. Four influencing factors: pH, THIA initial concentration, ozone concentration and temperature were investigated in order to optimize the conditions, and pH showed the greatest impact; the removal efficiency reached up to 71.19% under the condition of pH 5-11, THIA initial concentration 50-300 mg L(-1), the ozone concentration 10-22.5 mg L(-1) at 293-308 K after 90 min. Four main intermediates were separated and identified and the possible degradation mechanism was proposed. The luminous intensity of photobacteria and the chemical oxygen demand (COD) were measured to assess the changes of toxicity and mineralization in ozonation process, and results showed that the inhibition rate decreased by 60% and 76% of COD was removed after 180 min with the THIA initial concentration was 200 mg L(-1). Our study powerfully demonstrates that the degradation of THIA in aqueous solution by ozonation is a promising technology.

Enzymatic and acidic degradation effect on intracellular polysaccharide of Flammulina velutipes SF-08.

The intracellular polysaccharide (IPS) from Flammulina velutipes SF-08 mycelia was isolated and degraded by enzyme and acid. IPS and its derivative were purified by DEAE-52 cellulose chromatography, and five fractions were obtained. The structural features and antioxidant activities in vitro of the isolated fractions were evaluated. On the basis of chemical composition and antioxidant ability analyses, rhamnose as the main monosaccharide might contribute to the strongest antioxidant capacity. The in vivo results showed that IPS significantly enhanced the activities of anti-aging enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, and reduced the content of lipid peroxidantion (LPO). These results suggested that IPS should be a potent natural polymer and can be developed to be novel functional food.

Antihyperlipidemic and hepatoprotective activities of residue polysaccharide from Cordyceps militaris SU-12.

Cordyceps militaris has been artificially cultivated in China, and the great amounts of produced medium residue were discarded after the harvest. The aims of this work were to analyze the structure of the residue polysaccharide (RPS) of C. militaris SU-12, and to investigate the pharmacological effects of RPS on lipid metabolism and oxidative stress. RPS was composed of glucose, arabinose and mannose with a ratio of 62:1.6:1 by gas chromatography analysis, and the Mw (weight-average molecular weight), Mn (number-average molecular weight) and Mz (z-average molecular weight) of RPS were 2.86×10(3), 6.85×10(2), and 1.97×10(4)Da, respectively. The mice experiments demonstrated that RPS could reduce the levels of blood and liver lipid, and improve the glutamate pyruvate transaminase and antioxidant activity. The histopathological observations of mice livers indicated that RPS could attenuate liver cell injury. Results suggest that the RPS might be used as a potential antihyperlipidemic, hepatoprotective and antioxidant product.

[Kinetics and influencing factors of dimethyl phthalate degradation in aqueous solution by ozonation].

The rate constants for the reaction of higher concentrations of DMP with ozone and hydroxyl radical (*OH) were determined by competition kinetics method, in which nitrobenzene (NB) was selected as the reference organic compound. The effects of *OH inhibitor tert-butyl alcohol, pH and a variety of ions on the degradation of DMP were discussed. Experimental results showed that the degradation of DMP by ozonation followed pseudo-first-order kinetics. The rate constants of DMP with ozone and *OH were (0.064 +/- 0.014) L x (mol x s)(-1) and 3.59 x 10(9) L x (mol x s)(-1), respectively. The system pH decreased due to the carboxylic acids intermediates generated by ozonation at initial pH of 6.08 and 9.07, but the system pH was stabilized in strong alkali or acidic solution. A large number of intermediates resulted in the removal rate of COD lagging behind the degradation efficiency of DMP, and part of the intermediates were difficult to be mineralized. The reaction of DMP with *OH was not inhibited by lower concentrations of tert-butyl alcohol. But the reaction was inhibited when the concentration of tert-butyl alcohol was 90.21 times as high as that of DMP, and the degradation efficiency of DMP decreased from 98.7% to 8.8%. The degradation efficiency of DMP was higher with phosphate buffer solution for pH adjustment than NaOH/H2SO4 solution. Low concentrations of cations and anions had no effects on the degradation efficiency of DMP. High concentrations of SO4(2-), NO3(-) and HPO4(2-) had no remarkable effects on ozonation. But high concentrations of Cl(-) and HCO3(-) inhibited the degradation and the inhibitory effect of HCO3(-) was stronger than Cl(-). The degradation efficiency of DMP was only 50.5% and 26.2%, respectively, after 40 min under 7 097 mg x L(-1) of Cl(-) and 6 093 mg x L(-1) of HCO3(-).

Production and in vitro antioxidant activity of exopolysaccharide by a mutant, Cordyceps militaris SU5-08.

Cordyceps militaris SU5-08 was derived from an initial strain (C. militaris SU5) by ultraviolet mutagenesis of protoplasts, and the extraction parameters for C. militaris SU5-08 exopolysaccharide (EPS) produced during submerged culture were optimized. The extraction rate of EPS was 1919.16±165.27 mg/l, which was 120.38±11.36% higher than that of C. militaris SU5. The in vitro scavenging effects of EPS of C. militaris SU5-08 on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at a dosage of 5 g/l were 63.64±3.52%, 75.27±5.16%, and 6.46±5.03%, respectively. The reducing power of EPS of C. militaris SU5-08 was 0.21±0.01. The results suggest that the EPS of C. militaris SU5-08 can be used as a potential antioxidant which enhances adaptive immune responses.