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Yan J.-K.,Jiangsu University | Yan J.-K.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Wang Y.-Y.,Jiangsu University | Ma H.-L.,Jiangsu University | And 3 more authors.
Ultrasonics Sonochemistry | Year: 2016

In this study, a high-molecular-weight polysaccharide PL-N isolated from the alkaline extract of Phellinus linteus mycelia was degraded by ultrasound. Results showed that ultrasound treatment at different ultrasonic intensities decreased the intrinsic viscosity and molecular weight of PL-N, as well as narrowed the molecular weight distribution. A larger reduction in intrinsic viscosity and molecular weight was caused by a higher ultrasonic intensity. The degradation kinetics model was fitted to (1/Mt - 1/M0) = k·t, and the reaction rate constant (k) increased with increasing ultrasonic intensity. Ultrasound degradation did not change the primary structure of PL-N, and scanning electron microscopy analysis indicated that the morphology of the original PL-N was different from that of degraded PL-N fractions. Antioxidant activity assays in vitro indicated that the degraded PL-N fraction with low molecular weight had stronger hydroxyl radical scavenging capacity and higher TEAC and FRAP values. © 2015 Elsevier B.V. All rights reserved.


Yan J.-K.,Jiangsu University | Yan J.-K.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Ma H.-L.,Jiangsu University | Ma H.-L.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | And 6 more authors.
Food Chemistry | Year: 2014

Regioselective oxidation was applied to commercial curdlan for the preparation of its water-soluble derivatives with improved antioxidant activities, using a 4-acetamido-2, 2, 6, 6-tetramethylpiperidine-1-oxyl radical/NaClO/NaClO2 system at pH 4.8 and 40 °C. The structural features, molecular properties, and chain conformations of the oxidised curdlans were determined using Fourier transform (FT) infrared and FT Raman spectroscopy, carbon nuclear magnetic resonance, X-ray diffraction, and size-exclusion chromatography with multi-angle laser-light scattering analyses. The C6 primary hydroxyls of curdlan were successfully oxidised into carboxylate groups with less depolymerization, and no aldehyde groups were formed during oxidation. The crystalline region of curdlan was destroyed after oxidation. The oxidised curdlans formed random coils in aqueous solution, and the chain became more flexible and expanded with increasing carboxylate contents from 2.07 mmol/g to 4.87 mmol/g. The high polyglucuronic acid derivative (Cur-24) showed the best antioxidant activity in TEAC and FRAP assays, thus it could be explored as novel potential antioxidants for dietary and therapeutic applications. © 2013 Elsevier Ltd. All rights reserved.


Wang Z.-B.,Jiangsu University | Wang Z.-B.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Chen B.-B.,Jiangsu University | Luo L.,Jiangsu University | And 3 more authors.
Journal of the Taiwan Institute of Chemical Engineers | Year: 2016

In this paper, three water-soluble polysaccharides (PS-D1, PS-D2, and PS-D3) isolated and purified from Pueraria lobata roots were characterized and their biological activities were evaluated. Results showed that PS-D1 was a neutral heteropolysaccharide comprised glucose and fructose in a molar ratio of 24.4:1.0 with a weight-average molecular weight (M w) of 62kDa, while PS-D2 and PS-D3 were both acidic heteropolysaccharides consisting of glucose, fructose, arabinose and glucose, fructose, galactose, arabinose in a molar ratio of 54.5:1.0:1.0 and 61.0:1.0:2.7:2.4 with M ws of 159 and 385kDa, respectively. Amongst of them, PS-D3 had the highest uronic acid content (∼12.4%), carbohydrate content (∼88.9%) and M w. All the three polysaccharides exhibited as random coils or large aggregates in aqueous solution. In vitro antioxidant activity tests indicated that PS-D3 showed the strongest scavenging capacities on hydroxyl (79.6%) and DPPH (60%) radicals at 3.0mg/ml, and exhibited the highest antioxidant activity with a Trolox equivalent antioxidant capacity of 53.8μmol Trolox/g and a ferric reducing ability of plasma of 56.9μmol Fe2+/g. Moreover, the inhibitory activity on advanced glycation end-products (AGEs) formation of PS-D3 was 59.1% at 0.8mg/ml. These results indicated that PS-D3 with prominent antioxidant capability showed pronounced non-enzymatic glycation inhibition activity in vitro. © 2016 Taiwan Institute of Chemical Engineers.


Zhang H.,Jiangsu University | Ma H.,Jiangsu University | Ma H.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Liu W.,Jiangsu University | And 6 more authors.
Carbohydrate Polymers | Year: 2014

In this study, a novel flat-plate ultrasound technology was developed to stimulate polysaccharides production from Phellinus igniarius mycelial fermentation. Three-factor-three-level Box-Behnken design was used to optimize ultrasonic treatment time, duty cycle time and culture time for a high yield of P. igniarius polysaccharides (PIPS). Optimal conditions were found to be ultrasound treatment time 65 min, duty cycle time 25 s, and culture time 3.8 d that gave a maximum PIPS yield of 1.8002 g/L, which increased ∼22.64% compared with the control (without any ultrasound). PIPS mainly contained low-molecular weight (MW) polysaccharides (3.1 kDa, 80%) composed of glucose, rhamnose and mannose in a molar ratio of 11.0:14.0:1.0. PIPS with higher carbohydrate and uronic acid contents exhibited strong antioxidant activities in vitro. Laser scanning confocal microscope (LSCM) observations suggested that ultrasound could change the morphology and structure of P. igniarius mycelium, and accelerate the transfer of nutrients and metabolites. © 2014 Elsevier Ltd.


Wang Z.-B.,Jiangsu University | Wang Z.-B.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Pei J.-J.,Jiangsu University | Ma H.-L.,Jiangsu University | And 4 more authors.
Carbohydrate Polymers | Year: 2014

Three partially purified polysaccharides were extracted from Phellinus linteus mycelia using hot water, 1% (NH4)2C 2O4, and 1.25 M NaOH/0.05% NaBH4, and the extracts were named PL-W, PL-A, and, PL-N respectively. PL-N mainly comprised xylose and arabinose with a high molecular weight (Mw) and the highest carbohydrate and uronic acid contents. PL-W and PL-A were mainly composed of glucose with high and low Mw fractions in various ratios. All three polysaccharides existed as compact coils in aqueous solutions and exhibited strong scavenging capacity and antioxidant activities in a concentration-dependent manner. The polysaccharides also had high uronic acid and carbohydrate contents and strong antioxidant activities. The Mws, monosaccharide compositions, and chemical structures of the polysaccharides also affected their antioxidant activities. PL-A and PL-N had better antioxidant activities and could thus be developed as potential natural antioxidant agents for applications in food additives and biomedical industries. © 2014 Elsevier Ltd. All rights reserved.


Yana J.-K.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Cai P.-F.,Jiangsu University | Cao X.-Q.,Jiangsu University | Maa H.-L.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | And 3 more authors.
Carbohydrate Polymers | Year: 2013

A facile, simple, and eco-friendly method using 4-acetamido-2,2,6,6- tetramethypiperidine-1-oxyl radical-oxidized curdlan (Oc) as both reducing and stabilizing agents was developed for the fabrication of silver nanoparticles (AgNPs) from silver nitrate (AgNO3). The structure, morphology, and particle size of the as-prepared AgNPs were investigated by ultraviolet-visible spectroscopy, transmission electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, and dynamic laser light scattering. The well-dispersed AgNPs were sphere like with a mean diameter of 15 nm. Their formation was dependent on reaction duration, reaction temperature, Oc concentration, and AgNO3 concentration. Fourier transform-infrared and Raman spectra demonstrated that the as-prepared AgNPs can readily bind covalently with the carboxylate groups of Oc through the strong monodentate interaction in the reaction medium. © 2013 Elsevier Ltd. All rights reserved.


Yan J.-K.,Jiangsu University | Yan J.-K.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Yan J.-K.,South China University of Technology | Cai P.-F.,Jiangsu University | And 4 more authors.
Journal of Inorganic and Organometallic Polymers and Materials | Year: 2013

In the present work, the interaction between bovine serum albumin (BSA) and as-synthesized silver nanoparticles (Oc-AgNPs) by using 4-acetamido-TEMPO-oxidized curdlan (Oc), as a reducing and stabilizing agent, was studied through fluorescence quenching method, ultraviolet visible spectrum (UV-Vis), and circular dichroism measurement. The results presented clearly indicate that the intrinsic fluorescence of BSA molecule was effectively quenched after the interaction with Oc-AgNPs by a static mechanism, which is further confirmed by UV-Vis analysis. The apparent binding constant (K), number of binding sites (n), and dissociation equilibrium constant (KD) were calculated to be 7.5 × 105 M-1, 1.03, and 3.0 ± 0.6 μM, respectively. Furthermore, a conformational change of BSA was also observed when the Oc-AgNPs-BSA interactant formed. © 2013 Springer Science+Business Media New York.


Yan J.-K.,Jiangsu University | Yan J.-K.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Pei J.-J.,Jiangsu University | Ma H.-L.,Jiangsu University | And 3 more authors.
Carbohydrate Polymers | Year: 2015

In this study, high-intensity ultrasound (20 kHz), a simple, effective and without any additive method, was used to the degradation of carboxylic curdlan (Cc) produced by 4-acetamido-TEMPO-mediated oxidation. The effects of ultrasound on molecular properties, structure and chain conformations of Cc were investigated by viscometry, size-exclusion chromatography with multiangle laser-light scattering (SEC-MALLS) analysis, as well as FTIR and NMR spectroscopies. The results indicated that the intrinsic viscosity [η] and the weight-average molecular weight (Mw) of Cc decreased obviously after ultrasound, and a uniform and narrow distribution of degradation product was obtained. The z-average radius of gyrations (Rg) firstly increased and then decreased as the sonication time prolonged. Ultrasound destroyed the hydrogen bonds resulting in the transition from compact random coil conformation to more flexible and even shorter extended chains. Ultrasonic treatment could not alter the primary chemical structure of Cc molecules according to the structural analysis by FTIR and NMR spectroscopies. Degradation kinetics based on Schmid model was applied to estimate the degradation rate constant k. It was found that the k value of Cc decreased with increasing the polymer concentration from 0.05 to 0.2% (w/v). © 2014 Elsevier Ltd. All rights reserved.


Pei J.-J.,Jiangsu University | Wang Z.-B.,Jiangsu University | Wang Z.-B.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Ma H.-L.,Jiangsu University | And 3 more authors.
Carbohydrate Polymers | Year: 2015

A novel high molecular weight polysaccharide (PL-N1) was isolated from alkaline extract of the cultured Phellinus linteus mycelia. The weight average molecular weight (Mw) of PL-N1 was estimated at 343,000 kDa. PL-N1 comprised arabinose, xylose, glucose, and galactose in the molar ratio of 4.0:6.7:1.3:1.0. The chemical structure of PL-N1 was investigated by FTIR and NMR spectroscopies and methylation analysis. The results showed that the backbone of PL-N1 comprised (1 → 4)-linked β-D-xylopyranosyl residues, (1 → 2)-linked α-D-xylopyranosyl residues, (1 → 4)-linked α-D-glucopyranosyl residues, (1 → 5)-linked β-D-arabinofuranosyl residues, (1 → 4)-linked β-D-xylopyranosyl residues which branched at O-2, and (1 → 4)-linked β-D-galactopyranosyl residues which branched at O-6. The branches consisted of (1 →)-linked α-D-arabinofuranosyl residues. Antitumor activity assay in vitro showed that PL-N1 could inhibit the growth of HepG2 cells to a certain extent in a dose-dependent manner. Thus, PL-N1 may be developed as a potential, natural antitumor agent and functional food. © 2014 Elsevier Ltd. All rights reserved.


Yan J.-K.,Jiangsu University | Wang W.-Q.,Hong Kong Polytechnic University | Ma H.-L.,Jiangsu University | Ma H.-L.,Physical Processing of Agricultural Products Key Laboratory of Jiangsu Province | Wu J.-Y.,Hong Kong Polytechnic University
Molecules | Year: 2013

EPS-1 was an exopolysaccharide produced by the medicinal fungus Cordyceps sinensis (Cs-HK1). In the present study, EPS-1 was sulfated with chlorosulfonic acid (CSA)-pyridine (Pyr) at different volume ratios, yielding four sulfated derivatives, SEPS-1A, B, C and D, with different degrees of substitution (DS: 0.25-1.38) and molecular weights (17.1-4.1 kDa). The sulfation of EPS-1 occurred most frequently at the C-6 hydroxyl groups due to their higher reactivity. In aqueous solution, the native EPS-1 formed random coils or aggregated networks, but the sulfated derivatives formed single helices. The antioxidant activities of the sulfated EPS-1 derivatives for scavenging hydroxyl radicals (·OH) and 2,2-Azinobis-3-ehtylbenzothiazolin-6-sulfonic acid radicals (ABTS·+) were significantly increased with increasing DS and decreasing molecular weight (MW). Sulfation has thus been shown to be an effective and favorable strategy for improving the physico-chemical properties and bioactivities of fungal polysaccharides. © 2013 by the authors.

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