Publications by authors named "Shangwei Chen"

18 Publications

  • Page 1 of 1

The inhibitory mechanism of chlorogenic acid and its acylated derivatives on α-amylase and α-glucosidase.

Food Chem 2021 Oct 5;372:131334. Epub 2021 Oct 5.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address:

Due to the poor lipophilicity of chlorogenic acid (CA), five CA derivatives (C2-CA, C4-CA, C6-CA, C8-CA, and C12-CA) with different lipophilicities were synthesized using acylation catalyzed by lipase in present study. The inhibitory activities and mechanisms of CA and its derivatives on α-amylase and α-glucosidase were then determined. Results showed that the inhibitory activities of CA derivatives on α-amylase and α-glucosidase were enhanced as lipophilicity increased, and the inhibitory activities of C12-CA were stronger than those of CA. IC values of C12-CA were 13.30 ± 0.26 μmol/mL for α-amylase and 3.42 ± 0.10 μmol/mL for α-glucosidase. C12-CA possessed the smallest K and K values, and its inhibitory actions on α-amylase and α-glucosidase were stronger than those of CA and the other derivatives. Effects of C12-CA on microenvironments of amino acid residues and secondary structures of α-amylase and α-glucosidase were greater than those of CA and the other derivatives.
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http://dx.doi.org/10.1016/j.foodchem.2021.131334DOI Listing
October 2021

Engineering outer membrane could facilitate better bacterial performance and effectively enhance poly-3-hydroxybutyrate accumulation.

Appl Environ Microbiol 2021 Sep 22:AEM0138921. Epub 2021 Sep 22.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.

Poly-3-hydroxybutyrate (PHB) is an environmentally friendly polymer and can be produced in cells after overexpressing the heterologous gene cluster . The biosynthesis of outer membrane (OM) consumes lots of nutrients and influences cell morphology. Here we engineered OM by disrupting all gene clusters relevant to polysaccharide portion of LPS, colanic acid (CA), flagella or/and fimbria in W3110. All these disruptions benefited PHB production. Especially, disrupting all these OM components improved PHB content to 83.0 wt%, while the wild-type control produced only 1.5 wt% PHB. The improvement was mainly due to the LPS truncation to Kdo-lipid A, which facilitated 82.0 wt% PHB with 25-fold larger cell volume; and disrupting CA facilitated 57.8 wt% PHB. In addition, disrupting LPS facilitated advantageous fermentation features including 69.1% less acetate, 550% higher percentage of autoaggregated cells among the total culture cells, 69.1% less biofilm and higher cellular broken ratio. Further detailed mechanism investigations showed that disrupting LPS caused global regulations on envelope and cellular metabolism: (i) sharply decrease of flagella, fimbria and secretions; (ii) more elastic cell; (iii) much more carbon flux towards acetyl-CoA and cofactors supply including NADP, NAD and ATP; (iv) decrease of byproduct acids but increase of γ-aminobutyric acid by activating σ factor. Disrupting CA, flagella and fimbria also improved the levels of acetyl-CoA and cofactors. The results indicated that engineering OM is an effective strategy to enhance PHB production, and highlighted the applicability of OM engineering to increase microbial cell factory performance. Understanding the detailed influence of OM on cell envelope and cellular metabolism is important for optimizing cell factory and many other microorganisms. This study revealed the applicability of remodeling OM to enhance PHB accumulation as representative inclusion bodies. The knowledge generated in this study provided insights concerning the influence and application of OM engineering, and gave essential references for producing other inclusion bodies or chemicals derived from acetyl-CoA or with the need of cofactor NADPH, NADH or ATP supply, and reducing byproduct acids. This study is promising to provide new ideas for the improvement of microbial cell factories.
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http://dx.doi.org/10.1128/AEM.01389-21DOI Listing
September 2021

Antioxidant activities of chlorogenic acid derivatives with different acyl donor chain lengths and their stabilities during in vitro simulated gastrointestinal digestion.

Food Chem 2021 Apr 20;357:129904. Epub 2021 Apr 20.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address:

In this study, chlorogenic acid (CA) was acylated with vinyl esters of different carbon chain lengths under the action of the lipase Lipozyme RM. Five CA derivatives (C2-CA, C4-CA, C6-CA, C8-CA, and C12-CA) with different lipophilicities were obtained, and their digestive stabilities and antioxidant activities were evaluated. The lipophilicities were positively correlated with the digestive stabilities of CA derivatives. The antioxidant activities of CA derivatives did not change with the reduction of phenolic hydroxyl groups, and their capacity to scavenge 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•) and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) were similar to those of CA. In cellular antioxidant activity (CAA) tests, it was found that the capacity of these derivates to cross cell membranes were enhanced upon enhancing lipophilicity, and their antioxidant activities were improved. C12-CA showed the best antioxidant activity with a median effective dose (EC) of 9.40 μg/mL, which was significantly lower than that of CA (i.e., 29.08 μg/mL).
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http://dx.doi.org/10.1016/j.foodchem.2021.129904DOI Listing
April 2021

Antioxidant Activity of Selenium-Enriched Peptides from the Protein Hydrolysate of Cardamine violifolia.

J Food Sci 2019 Dec 30;84(12):3504-3511. Epub 2019 Oct 30.

State Key Laboratory of Food Science and Technology, Jiangnan Univ., Wuxi, 214122, China.

Cardamine violifolia is a selenium (Se)-enriched plant found in China. In this study, the Se-enriched peptides of C. violifolia (CP) were isolated using a 1 kDa ultrafiltration membrane after enzymatic hydrolysis by alkaline and neutral proteases. The peptides were separated by DEAE-Sepharose FF anion-exchange chromatography and purified using preparative high-performance liquid chromatography (prep-HPLC). The component with the highest antioxidant activity, CPR13, was identified by comparing the 1,1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl (•OH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS •), and superoxide ( ) radical scavenging ability of each fraction. At a concentration of 0.1 mg/mL, the DPPH•, •OH, , and ABTS • scavenging activities of CPR13 were 89.2%, 26.3%, 40.6%, and 42.9%, respectively. Amino acid sequences were obtained by liquid chromatography combined with mass spectrometry as follows: GRVGSSSC, GRAGGSYM, GHPNFKLNCSGG, GTKSCKA, ASSNARDMI, TAGGCYIPI, and KNCALQ. The seleno-amino acids were identified as selenomethionine, methylselenocysteine, and selenocysteine. Correlation analysis among organic Se content, peptide content, and antioxidant activity revealed that organic Se plays a greater role in free radical scavenging than peptides, and that the organic Se content of the Se-enriched peptides was positively correlated with their antioxidant ability (P < 0.05). It indicated that CP has a great potential as natural functional materials for dietary supplement.
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http://dx.doi.org/10.1111/1750-3841.14843DOI Listing
December 2019

Increasing L-threonine production in Escherichia coli by overexpressing the gene cluster phaCAB.

J Ind Microbiol Biotechnol 2019 Nov 16;46(11):1557-1568. Epub 2019 Jul 16.

State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.

L-Threonine is an important branched-chain amino acid and could be applied in feed, drugs, and food. In this study, L-threonine production in an L-threonine-producing Escherichia coli strain TWF001 was significantly increased by overexpressing the gene cluster phaCAB from Ralstonia eutropha. TWF001/pFW01-phaCAB could produce 96.4-g/L L-threonine in 3-L fermenter and 133.5-g/L L-threonine in 10-L fermenter, respectively. In addition, TWF001/pFW01-phaCAB produced 216% more acetyl-CoA, 43% more malate, and much less acetate than the vector control TWF001/pFW01, and meanwhile, TWF001/pFW01-phaCAB produced poly-3-hydroxybutyrate, while TWF001/pFW01 did not. Transcription analysis showed that the key genes in the L-threonine biosynthetic pathway were up-regulated, the genes relevant to the acetate formation were down-regulated, and the gene acs encoding the enzyme which converts acetate to acetyl-CoA was up-regulated. The results suggested that overexpression of the gene cluster phaCAB in E. coli benefits the enhancement of L-threonine production.
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http://dx.doi.org/10.1007/s10295-019-02215-0DOI Listing
November 2019

Activation of colanic acid biosynthesis linked to heterologous expression of the polyhydroxybutyrate pathway in Escherichia coli.

Int J Biol Macromol 2019 May 3;128:752-760. Epub 2019 Feb 3.

Lab of Biorefinery, Shanghai Advanced Research Institute, Chinese Academy of Sciences, No. 99 Haike Road, Pudong, Shanghai 201210, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:

The biosynthesis of colanic acid (CA) in Escherichia coli was known to be activated during growth at low temperature using sub-optimal medium. However, in this study, an E. coli transformant S173-H (S17-3 with plasmid pBhya-CAB) was found to be able to excrete high amount of CA (10.39 g/L) in glucose supplemented Luria-Bertani medium (LBG) when growing at 37 °C. Inoculation of cells in low pH medium was required for the derepression of the CA regulon, another indispensable requirement was the use of high copy number plasmid for over-expression of the heterologous polyhydroxybutyrate (PHB) biosynthesis pathway in S17-3. In addition, S173-H exhibited superior growth performance in LBG, the maximal cell density (OD) of cultures reached 40.0, far exceeding that of any known E. coli strains cultivated under similar conditions. Genomic data mining and transcriptional analysis hinted that the persistent growth or CA production might be modulated by interplaying regulation networks that signal the level of messenger substrate, acetyl-CoA or acetylphosphate. Depletion of these messenger substrates may be triggered by efficient PHB biosynthesis that links to enhanced capability in NADPH regeneration in S17-3, due to mutations on loci at pgi, csrA, or other sites.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.02.004DOI Listing
May 2019

Simultaneous extraction of hydrophobic and hydrophilic bioactive compounds from ginger (Zingiber officinale Roscoe).

Food Chem 2018 Aug 1;257:223-229. Epub 2018 Mar 1.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; National Engineering Research Center for Functional Food, Wuxi 214122, People's Republic of China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China. Electronic address:

Ginger is a commonly used spice around the world. Its bioactive compounds contain hydrophobic gingerols and hydrophilic polysaccharides. Huge physiochemical differences between these compounds and the thermal instability of gingerols impede fast and effective extraction of them using conventional methods. In this research, ionic liquid-based ultrasonic-assisted extraction (ILUAE) was applied to simultaneously extract gingerols and polysaccharides from ginger. Parameters influencing the recovery of gingerols were ionic liquid type, ionic liquid concentration, solid/liquid ratio, ultrasonic power, extraction temperature and extraction time. Compared with traditional methods, LUAE significantly increased the yield of total gingerols and shortened the extraction time. Meanwhile, ginger polysaccharides recovery reached up to 92.82% with ILUAE. Our results indicated that ILUAE has a remarkable capacity to extract gingerols and ginger polysaccharides in one step. Therefore, ILUAE represents a promising technology for simultaneous extraction of hydrophilic and hydrophobic bioactive compounds from plant materials.
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http://dx.doi.org/10.1016/j.foodchem.2018.02.125DOI Listing
August 2018

Chemical components of cold pressed kernel oils from different Torreya grandis cultivars.

Food Chem 2016 Oct 18;209:196-202. Epub 2016 Apr 18.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, PR China. Electronic address:

The chemical compositions of cold pressed kernel oils of seven Torreya grandis cultivars from China were analyzed in this study. The contents of the chemical components of T. grandis kernels and kernel oils varied to different extents with the cultivar. The T. grandis kernels contained relatively high oil and protein content (45.80-53.16% and 10.34-14.29%, respectively). The kernel oils were rich in unsaturated fatty acids including linoleic (39.39-47.77%), oleic (30.47-37.54%) and eicosatrienoic acid (6.78-8.37%). The kernel oils contained some abundant bioactive substances such as tocopherols (0.64-1.77mg/g) consisting of α-, β-, γ- and δ-isomers; sterols including β-sitosterol (0.90-1.29mg/g), campesterol (0.06-0.32mg/g) and stigmasterol (0.04-0.18mg/g) in addition to polyphenols (9.22-22.16μgGAE/g). The results revealed that the T. grandis kernel oils possessed the potentially important nutrition and health benefits and could be used as oils in the human diet or functional ingredients in the food industry.
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http://dx.doi.org/10.1016/j.foodchem.2016.04.053DOI Listing
October 2016

Fingerprint analysis of polysaccharides from different Ganoderma by HPLC combined with chemometrics methods.

Carbohydr Polym 2014 Dec 27;114:432-439. Epub 2014 Aug 27.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address:

A fingerprint analysis method has been developed for characterization and discrimination of polysaccharides from different Ganoderma by high performance liquid chromatography (HPLC) coupled with chemometrics means. The polysaccharides were extracted under ultrasonic-assisted condition, and then partly hydrolyzed with trifluoroacetic acid. Monosaccharides and oligosaccharides in the hydrolyzates were subjected to pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone and HPLC analysis, which will generate unique fingerprint information related to chemical composition and structure of polysaccharides. The peak data were imported to professional software in order to obtain standard fingerprint profiles and evaluate similarity of different samples. Meanwhile, the data were further processed by hierarchical cluster analysis and principal component analysis. Polysaccharides from different parts or species of Ganoderma or polysaccharides from the same parts of Ganoderma but from different geographical regions or different strains could be differentiated clearly. This fingerprint analysis method can be applied to identification and quality control of different Ganoderma and their products.
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http://dx.doi.org/10.1016/j.carbpol.2014.08.048DOI Listing
December 2014

Preparation of molecularly imprinted polymer for use as SPE adsorbent for the simultaneous determination of five sulphonylurea herbicides by HPLC.

Food Chem 2014 May 5;150:106-12. Epub 2013 Nov 5.

Jiangxi Key Laboratory of Natural Products and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, China. Electronic address:

A high selective pre-treatment method for the analysis of sulphonylurea herbicides (SUHs) in rice grain samples based on molecularly imprinted solid-phase extraction (MISPE) was developed. The molecularly imprinted polymers (MIPs) were synthesised with high adsorption capacity and suitable particle size using pyrazosulphuron ethyl (PS) as the template and by screening three porogens and porogen volumes. The resulting MIPs showed high selectivity for PS. The MISPE procedure was developed for the purification and enrichment of PS, bensulphuron methyl (BSM), tribenuron methyl (TBM), metsulphuron methyl (MSM) and nicosulphuron (NS) from a rice grain sample prior to reversed-phase high-performance liquid chromatography (HPLC) analysis. Average recoveries of the PS, NS, MSM and BSM were 95.6%, 88.6%, 87.8% and 89.4%, respectively, but the recovery of TBM was lower (48.2%). This pre-treatment methodology for extracting SUHs was simple and cleaner extractions. The limits of detection ranged from 10.1 to 50.0ngL(-)(1). Five local rice grain samples were analysed by HPLC-MISPE, and PS was detected in all five samples, while BSM was detected in one sample.
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http://dx.doi.org/10.1016/j.foodchem.2013.10.152DOI Listing
May 2014

Ionic liquids based simultaneous ultrasonic and microwave assisted extraction of phenolic compounds from burdock leaves.

Anal Chim Acta 2012 Feb 10;716:28-33. Epub 2011 Mar 10.

State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, PR China.

The ionic liquids based simultaneous ultrasonic and microwave assisted extraction (IL-UMAE) technique was first proposed and applied to isolate compounds. The ionic liquids comprising a range of four anions, five 1-alkyl-3-methylimidazolium derivatives were designed and prepared. The results suggested that varying the anion and cation both had apparent effects on the extraction of phenolics. The results also showed that irradiation power, time and solid-liquid ratio significantly affected the yields. The yields of caffeic acid and quercetin obtained by IL-UMAE were higher than those by regular UMAE. Compared with conventional heat-reflux extraction (HRE), the proposed approach exhibited higher efficiency (8-17% enhanced) and shorter extraction time (from 5h to 30s). The results indicated ILUMAE to be a fast and efficient extraction technique. Moreover, the proposed method was validated by the reproducibility and recovery experiments. The ILUMAE method provided good recoveries (from 96.1% to 105.3%) with RSD lower than 5.2%, which indicated that the proposed method was credible. Based on the designable nature of ionic liquids, and the rapid and highly efficient performance of the proposed approach, ILUMAE provided a new alternative for preparation of various useful substances from solid samples.
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http://dx.doi.org/10.1016/j.aca.2011.03.012DOI Listing
February 2012

Antioxidant activity and chemical composition of the fractions from burdock leaves.

J Food Sci 2010 Jun;75(5):C413-9

State Key Lab. of Food Science and Technology, School of Food Science and Technology, Jiangnan Univ., Wuxi 214122, P.R. China.

The antioxidant activities of each burdock leaves fraction were first investigated alone and in combination with tertiary butylhydroquinone (TBHQ). The burdock leaves extract was fractioned with petroleum ether, ethyl acetate, n-butanol, and water, named as PF, EF, BF, and WF, respectively. The EF exhibited the highest antioxidant activity. Although TBHQ exhibited higher lipid peroxidation inhibitory activity than EF, the reducing power, superoxide anion scavenging capability, DPPH radical and hydroxyl radicals scavenging ability of EF were higher than those of synthetic antioxidant (TBHQ). Moreover, a synergistic antioxidant effect between EF and TBHQ was first demonstrated by isobolographic analysis, indicating that EF dramatically enhances the antioxidant efficiency of TBHQ. For all the fractions, the antioxidant capacity had a significant correlation with total phenolic content. The phenolic compounds of the fractions were then identified, namely chlorogenic acid, o-hydrobenzoic acid, caffeic acid, p-coumaric acid, and rutin. The results indicate that the EF could be used as sources of nature antioxidant in food industry, and allows a decrease of about 4 folds in the amounts of the synthetic compounds used.
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http://dx.doi.org/10.1111/j.1750-3841.2010.01616.xDOI Listing
June 2010

Arginine-chitosan/DNA self-assemble nanoparticles for gene delivery: In vitro characteristics and transfection efficiency.

Int J Pharm 2008 Jul 1;359(1-2):241-6. Epub 2008 Apr 1.

Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.

Chitosan (Cs) is a natural cationic polysaccharide that has shown potential as non-viral vector for gene delivery because of its biocompatibility and low toxicity. However, chitosan used for gene delivery is limited due to its poor water solubility and low transfection efficiency. The purpose of this work was to prepare Arginine-chitosan (Arg-Cs)/DNA self-assemble nanoparticles (ACSNs), and determine their in vitro characteristics and transfection efficiency against HEK 293 and COS-7 cells. Our experimental results showed that the particle size and zeta potential of ACSNs prepared with different N/P ratios were 200-400nm and 0.23-12.25mV, respectively. The in vitro transfection efficiency of ACSNs showed dependence on pH of transfection medium, and the highest expression efficiency was obtained at pH 7.2. The transfection efficiency increased with the ratio of chitosan-amine/DNA phosphate (N/P ratio) from 1 to 5, and reached the highest level with the N/P ratio 5. Effect of plasmid dosage on the transfection efficiency showed the highest transfection efficiency was obtained at 4microg/well for HEK 293 cells and 6microg/well for COS-7 cells. The transfection efficiency of ACSNs was much higher than that of Cs/DNA self-assemble nanoparticles (CSNs). The average cell viability of ACSNs was over 90%. These results suggested that ACSNs could be a safe and effective non-viral vector for gene delivery.
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http://dx.doi.org/10.1016/j.ijpharm.2008.03.037DOI Listing
July 2008

Preparation of molecularly imprinted solid phase extraction using bensulfuron-methyl imprinted polymer and clean-up for the sulfonylurea-herbicides in soybean.

Anal Chim Acta 2008 Apr 14;614(1):112-8. Epub 2008 Mar 14.

State Key Laboratory of Food Science & Technology, Jiangnan University, Jiangsu, Wuxi 214122, China.

A pre-treatment methodology based on the molecularly imprinted solid phase extraction (MI-SPE) procedure was developed for the determination of bensulfuron-methyl (BSM), tribenuron-methyl (TBM), metsulfuron-methyl (MSM) and nicosulfuron (NS) in soybean samples. A molecular imprinted polymer (MIP) was prepared by precipitation polymerization using BSM as the template molecule, alpha-methacrylic acid (MAA) as the functional monomer, trimethylolpropane trimethacrylate (TRIM) as the cross-linker and dichloromethane as the porogen. The binding behaviors of the template BSM and its analogues on the MIP were evaluated by high performance liquid chromatography (HPLC). Then, solid phase extraction (SPE) with a BSM molecularly imprinted polymer (BSM-MIP) as adsorbent was investigated and the optimum loading, washing, and eluting conditions for MI-SPE of the selected BSM, MSM, TBM, and NS were established. The optimized MI-SPE procedure was used to extract the sulfonylureas and a high recovery was obtained in the soybean samples.
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http://dx.doi.org/10.1016/j.aca.2008.03.018DOI Listing
April 2008

Histidylated cationic polyorganophosphazene/DNA self-assembled nanoparticles for gene delivery.

Int J Pharm 2008 Apr 29;353(1-2):277-82. Epub 2007 Nov 29.

Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, China.

Cationic polyorganophosphazene has shown the ability to deliver gene. To obtain more efficient transfection, His(Boc)-OMe bearing histidine moiety was introduced to synthesize a new derivative of cationic polyphosphazenes with another side group of 2-dimethylaminoethylamine (DMAEA). The poly(DMAEA/His(Boc)-OMe)phosphazene (PDHP) and DNA could self-assemble into nanoparticles with a size around 110 nm and zeta potential of +15 mV at the PDHP/DNA ratio of 10:1 (w/w). The maximum transfection efficiency of PDHP/DNA self-assembled nanoparticles (PHSNs) against 293 T cells was much higher than that of poly(di-2-dimethylaminoethylamine) phosphazenes (PDAP)/DNA self-assembled nanoparticles (PASNs) and PEI 25/DNA self-assembled nanoparticles (PESNs) at the polymer/DNA ratio of 10:1, but the cytotoxicity of PDHP assayed by MTT was much lower than that of PDAP and PEI 25. These results suggested that PDHP could be a good candidate with high transfection efficiency and low cytotoxicity for gene delivery.
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http://dx.doi.org/10.1016/j.ijpharm.2007.11.041DOI Listing
April 2008

[Analysis of monosaccharides and uronic acids in polysaccharides by pre-column derivatization with p-aminobenzoic acid and high performance liquid chromatography].

Se Pu 2007 Jan;25(1):75-9

School of Chemistry and Material Engineering of Southern Yangtze University, Wuxi 214036, China.

An ion-pair reversed-phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of carbohydrate and uronic acids was developed. p-Aminobenzoic acid (p-AMBA) was used for pre-column derivatization of the analytes, enabling fluorescence (lambda(ex) = 313 nm, lambda(em) = 358 nm) or ultraviolet (UV at 303 nm) detection. Reaction conditions such as reaction temperature and reaction time were optimized. Atlantis dC18 column with hydrophilic end capping was selected for the separation of derivatives. Effects of mobile phase compositions such as ion pairs and their concentrations and pH on the retention behaviors and separation results of 9 monosaccharides and 2 uronic acids were investigated. Derivatives of fructose, galactose, glucose, mannose, xylose, arabinose, ribose, galacturonic acid, fucose, glucuronic acid and rhamnose were separated within 42 min, applying tetrabutyl ammonium hydrogen bisulfate (TBAHSO4) as the ion pair reagent. The detection limits were between 3.38 x 10(-8) mol/L and 176 x 10(-8) mol/L for fluorescence detection and between 2.55 x 10(-7) mol/L and 13.4 x 10(-7) mol/L for UV detection. Good linearities were obtained with correlation coefficients (r2) above 0.99. The relative standard deviations (RSDs) of the peak area of the derivatives in 12 - 51 h after derivatization were from 2.5% to 3.9%. This method has been applied for the determination of mono-/disaccharides and uronic acids in spirulina polysaccharide after dissolved in trifluoroacetic acid solution (2 mol/L). The results showed this method is suitable for the analysis of monosaccharide compositions in polysaccharides.
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January 2007

[Study on the retention behaviors and analytical methods of polysaccharides from Duanaliella salina by high performance size-exclusion chromatography].

Se Pu 2006 Nov;24(6):560-5

Testing and Analysis Center of Southern Yangtze University, Wuxi 214036, China.

There are many polysaccharides with biological activities including anti-virus and anti-tumor in the residue produced by the extraction of beta-carotene from Duanaliella salina. In this paper, a method of high performance size-exclusion chromatography coupled with refractive index detection has been developed for the relative molecular mass analysis of the polysaccharides isolated from the residue. The effects of salt and pH values of mobile phase on retention behaviors of five polysaccharides fractions were investigated on two HPSEC columns (Waters Ultrahydragel Linear, 7.8 mm i. d. x 300 mm) connected in series. The results showed that 0. 1 mol/L NaAc buffer solution may be utilized as mobile phase during HPSEC under the conditions of column temperature of 45 degrees C and flow rate of 0.9 mL/min to minimize nonspecific interaction of sulfated polysaccharides fraction (PD4a), complex carbohydrate containing oligonucleic acid (PD4b) and acidic polysaccharide fraction (PD1) with the column matrix. In addition, under the conditions the association effect of the polysaccharide molecules was eliminated. Thereby, the polysaccharide molecules were eluted and separated following equilibrium exclusion mechanism mainly. The weight mean molecular masses (M(w)) of five polysaccharide fractions from D. salina determined under optimum chromatographic conditions were 1 548 000 for PD1, 33 000 for PD2, 67 000 for PD3, 424 000 for PD4a and 10 000 for PD4b. For sulfated polysaccharide fraction PD4a, the relative standard deviations were 1.7% and 0.88% for M(w) and peak area, respectively.
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http://dx.doi.org/10.1016/s1872-2059(06)60024-2DOI Listing
November 2006
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