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Objective: To study the relative molecular mass and composition of Ligustrum lucidum polysaccharide purified by dialysis, and provide the theories for the relationship between the biological activity and the internal composition. Methods: In this paper, L. lucidum as an object was studied. Polysaccharide was isolated by water extraction and ethyl alcohol precipitation and purified by Sevage method, hydrogen peroxide and dialysis. After the acidolysis of trifluoroacetic acid, the molecular weight was measured by GPC, and the composition of polysaccharide was analyzed by HPLC-RID. Results: The Mw of polysaccharide was 10 721, and the Mn of polysaccharide was 10 673. L. lucidum polysaccharide consisted of glucose, rhamnose, and arabinose, the molar ratio of these monosaccharide was 9.148.105.18. Conclusion: The purified polysaccharide composition is more homogeneous, and the monosaccharides of polysaccharides was easily analyzed by HPLC-RID without column derivatization.
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The flower of Hibiscus syriacus has good ornamental and edible-medicinal values.In this study,four samples of two varieties,namely white multiple petals flower and pink multiple petals flower,were selected as test materials.And the optimum extraction conditions,relative molecular weight,monosaccharide composition and antioxidant activity of polysaccharides in flower were investigated.Through single factor experiment and response surface,the optimal extract conditions of polysaccharide were designed as follows:extraction temperature at 96.8℃,ratio of material to liquid of 43.5∶1 m L·g~(-1),extraction time of 3.1 h.Polysaccharides of H.syriacus flowers were analyzed by high performance gel chromatography.The average molecular masses of the 4 polysaccharide samples were1.49×10~5,1.25×10~5,1.01×10~5,1.37×10~5,respectively.Polysaccharides of H.syriacus flowers were mainly composed of glucose,mannose,galactose,rhamnose and arabinose by pre-column derivatization HPLC.The ratio of galactose was the highest in five monosaccharide,and the ratio of galactose to glucose was 1.656-4.496.In addition,crude polysaccharides of H.syriacus flowers showed potential antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)assay,total reducing capacity assay and ABTS assay in vitro,and its antioxidant effect showed a good dose-effect relationship with the concentration of crude polysaccharides.Among the tested varieties,polysaccharides of pink multiple petals flower and white multiple petals flower had the same molecular masses and monosaccharides composition,but the antioxidant activity of the polysaccharides of pink multiple petals flower was higher than that of the white flowers.The results of this study can provide a theoretical basis for the application of H.syriacus flower in the field of functional foods.
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Antioxidants , Chemistry , Pharmacology , Flowers , Chemistry , Hibiscus , Chemistry , Monosaccharides , Chemistry , Phytochemicals , Chemistry , Pharmacology , Pigmentation , Polysaccharides , Chemistry , PharmacologyABSTRACT
Objective To optimize the conditions for the synthetic process of iron sucrose complex (ISC), via the investigation of the effects of reaction temperature (X1), reaction time (X2), amount of alkali (X3), and amount of sucrose (X4) on the relative molecular mass of the ISC product. Methods According to the experimental results for the single factor, the conditions dealing with the X1, X2, X3, and X4 parameters for the preparation of ISC were optimized by the Box-Behnker design combined with the response surface methodology using the weight average relative molecular mass of ISC as an indicator, and analyzed with gel permeation chromatography. Results The reaction temperature and the amount of alkali had a significant effect on the weight average relative molecular mass of ISC. The influence of the four factors in the descending order was as follows:X3＞X1＞X2＞X4. In the designed experimental conditions, theresponsevaluedecreasedwiththeincreaseofbothreactiontemperaturesandalkaliamounts. Conclusion Theresponse surface methodology could provide the relationship between the response values and variables via the minimum number experiments to obtain the optimized conditions for the preparation of ISCs.
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Background: ß-glucans (1-3: 1-4) are soluble fibers applied to foods due to their technological properties (water binding capacity, viscosity, emulsification and stabilization) and their beneficial effects on health. The functional properties of ß-glucans can be lost during the extraction and purification processes. The high viscosity of ß-glucans is related to a high molecular weight and its physiological properties in the intestine. Therefore, to characterize the fiber after its extraction and purification is fundamental to understand its possible applications in foods. Objectives: characterize ß-glucans extracted (EßG) and compare them with three commercial ß-glucans (CßG-A, CßG-B and CßG-C) to identify its possible applications in foods and to evaluate if enzymatic purification affects molecular and structurally the ß-glucans. Methods: barley ß-glucans were extracted (EßG), characterized by chemical analyzes, rheological behavior, and color, and compared to three commercial ß-glucans samples. Then, the extract was purified and its structural and molecular characteristics were calculated. Results: EßG contained 64.38 ± 3.54% of ß-glucans, high starch contamination (12.70 ± 1.73%), high content of calcium (8894 mg/kg), pseudoplastic behavior, and dark color (L* = 52.77 ± 0.7). All commercial samples showed low starch contamination, lighter color, and Newtonian behavior. After purification starch and protein contamination decreased (0.85 ± 0.46% and 5.50 ± 0.12% respectively), increased the content of ßG (69.45 ± 0.81%) and increased brightness (L* = 92.60 ± 1.70). Purified ß-glucans (PßG) showed a molar weight of 690 ± 1.6 kDa and species with degree polymerization 3 (DP3) to 11 (DP11) were identified on the structure. Conclusions: EßG extracts before the purification presented a high viscosity and contamination. The enzymatic purification process was effective and allowed to maintain a high molar mass of PßG and its distinctive molecular structures (species with DP3 and DP4). The commercial samples CßG-A and CßG-B showed a low content of ß-glucans. Finally, CßG-C presented the best physicochemical and rheological properties for its subsequent application in food.
Antecedentes: los ß-glucanos (1-3: 1-4) son fibras solubles aplicadas a los alimentos debido a sus propiedades tecnológicas (capacidad de retención de agua, viscosidad, emulsificación y estabilización) y a sus efectos beneficiosos en la salud. Las propiedades funcionales de los ß-glucanos pueden perderse durante los procesos de extracción y purificación. La alta viscosidad de los ß-glucanos está relacionada con un alto peso molecular y con sus propiedades fisiológicas en el intestino. Por lo tanto, caracterizar la fibra después de su extracción y purificación es fundamental para comprender sus posibles aplicaciones en alimentos. Objetivos: caracterizar ß-glucanos extraídos (EßG) y compararlos con tres marcas comerciales (CßG-A, CßG-B y CßG-C) para identificar su futura aplicación en alimentos y evaluar si la purificación enzimática afecta molecular y estructuralmente los ß-glucanos. Métodos: se extrajeron ß-glucanos de cebada (EßG), caracterizados por análisis químicos, comportamiento reológico y color, y se compararon con tres muestras comerciales. Posteriormente, el extracto (EßG) se purificó y se identificaron sus características estructurales y su peso molecular. Resultados: EßG contenía 64.38 ± 3.54% de ß-glucanos, alta contaminación con almidón (12.70 ± 1.73%), alto contenido de calcio (8894 mg / kg), comportamiento pseudoplástico y color oscuro (L* = 52.77 ± 0.7). Todas las muestras comerciales mostraron una baja contaminación con almidón, color más claro y comportamiento newtoniano. Después de la purificación de EßG, la contaminación con almidón y proteína disminuyó (0.85 ± 0.46% y 5.50 ± 0.12%, respectivamente), aumentó el contenido de ßG (69.45 ± 0.81%) y aumentó su luminosidad (L* = 92.60 ± 1.70). Los ß-glucanos purificados (PßG) mostraron un peso molar de 690 ± 1,6 kDa y se identificaron en la estructura especies con grado de polimerización desde 3 (GP3) hasta 11 (GP11). Conclusiones: los EßG antes de la purificación presentaron alta viscosidad y contaminación. El proceso de purificación enzimática fue efectivo y permitió mantener una alta masa molar de la fibra y sus estructuras moleculares características (especies con GP3 y GP4). Las muestras comerciales CßG-A y CßG-B mostraron un bajo contenido de ß-glucanos. Finalmente, la CßG-C presentó las mejores propiedades fisicoquímicas y reológicas para su posterior aplicación en alimentos.
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Humans , beta-Glucans , Viscosity , Dietary Fiber , Whole Foods , Molecular WeightABSTRACT
In order to provide new information on polysaccharide in Dendrobium officinale flowers,the monosaccharide composition and relative molecular mass distribution of 11 families of flowers were investigated and analyzed by high performance gel filtration chromatography (HPGFC) and pre-column derivatization ultra performance liquid chromatography (UPLC) in this study. Then cluster analysis was carried out for the monosaccharide peak areas by utilizing SPSS 19.0 software. The results showed that the polysaccharides of all the above 11 hybrid families of D. officinale flower were separated into three fractions (DOP-1, DOP-2 and DOP-3) with the average relative molecular mass of 5.53×105, 3.49×105 and 2.12×105. The polysaccharides in 11 different families were mainly composed of glucose, mannose, galactose, galacturonic acid and arabinose; mannose had the highest proportion among them, with mannose/glucose ratio of 0.302-3.335. Additionally, the relative contents of various monosaccharides in different families varied. 11 families of D. officinale flower could be classified into four categories according to their monosaccharide components and relative contents. In this study, the relative molecular mass distribution and monosaccharide composition of polysaccharides in D. officinale flowers were defined, which can provide foundations for its resource utilization．.
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Heparosan is the start point for chemoenzymatic synthesis of heparin and it is of great significance to efficiently synthesize heparosan in microorganisms. The effects of overexpressing key enzyme genes of the UDP-glucuronic acid (UDP-GlcUA) pathway (pgcA, gtaB and tuaD) or the UDP-N-acetyl-glucosamine (UDP-GlcNAc) pathway (glmS, glmM and glmU) on the heparosan production and molecular mass were analyzed in the constructed heparosan-producing Bacillus subtilis ((1.71±0.08) g/L). On this basis, heparosan production was increased to (2.89±0.11) g/L with the molecular mass of (75.90±1.18) kDa through co-overexpressing the tuaD, gtaB, glmU, glmM and glmS genes in shake flask cultivation. In the 3 L fed-batch fermentation, heparosan production was improved to (7.25±0.36) g/L with the molecular mass of (46.66±2.71) kDa, providing the potential for heparosan industrial production.
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ABSTRACT:Objective To explore the effects of virus interleukin‐10 (vIL‐10 ) on different expressions of MHC‐I antigen processing “the operon” .Methods We collected nasopharyngeal carcinoma cells (CNE‐1 and CNE‐2) treated by vIL‐10 at different time points ,and detected the changes of MHC‐I antigen processing “the operons” (TAP‐1 ,TAP‐2 ,LMP‐2 ,LMP‐7 and HLA‐I) by RT‐PCR and Western blot .Results ① mRNA level :There was no difference in the expression of TAP‐1 in CNE‐1 and CNE‐2 cells at various time points .The expressions of TAP‐2 and LMP‐2 in CNE‐1 and CNE‐2 did not change at 1 ,4 ,6 ,12 h ,but downregulated and even disappeared at 24 h .The expression of LMP‐7 in CNE‐1 decreased 4 h after vIL‐10 was added ,and that in CNE‐2 decreased at 6 h .The expression of HLA‐I in CNE‐1 and CNE‐2 showed significant decrease at 24 h .② Protein expression :The expression of TAP‐1 in CNE‐1 and CNE‐2 showed significant decrease at 24 h .The expression of TAP‐2 in CNE‐1 and CNE‐2 was gradually downregulated at different time points .The expressions of LMP‐2 and LMP‐7 in CNE‐2 were gradually downregulated at different periods ,while that in CNE‐1 was only decreased at 12 h .The expression of HLA‐I in CNE‐1 and CNE‐2 was gradually downregulated ,but there was no significant difference at each period in CNE‐1 ,while the expression of HLA‐I in CNE‐2 at 24 h was significantly downregulated .Conclusion vIL‐10 can inhibit the expression of MHC‐I antigen processing “the operon” in NPC in the time‐dependent manner .
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Objective To analyze the structures and molecular weight distributions of the capsular polysaccharides from 6 serotypes of pneumococcus .Methods The structures of pneumococcal capsular pol-ysaccharides of 6 serotypes were analyzed by 1 H nuclear magnetic resonance ( NMR) .Chemical shifts of all characteristic protons were investigated to analyze polysaccharide integrity and inter -assay consistency .High performance size exclusion chromatography-multi angle laser light scattering ( HPSEC-MALLS) was used to measure the molecular weights .Results The chemical shifts of all characteristic protons of the pneumococ-cal capsular polysaccharides of 6 serotypes were consistent with the standard chemical shift .The weight-aver-age molecular mass of the pneumococcal capsular polysaccharides ranged from 7.182×104 g/mol(for serotype 19A) to 1.273×106 g/mol(for serotype 9V)examined by HPSEC-MALLS.Conclusion The structures and molecular weight distributions of pneumococcal capsular polysaccharides could be rapidly and effectively ana -lyzed by 1 H NMR and HPSEC-MALLS.Moreover, C-PS and acetate contained in capsular polysaccharides could also be detected .HPSEC-MALLS is an applicable method for the quantitative analysis of molar mass distributions in different serotypes of pneumococcal capsular polysaccharides . Although 1 H NMR and HPSEC-MALLS have been accepted as the quality control measurements by WHO , to use them as the re-placements of the traditional QC method still needs further investigation .
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To determine the number average molecular mass of chitosan-oligosaccharide by u-sing the acetylacetone's method based on the color-producing reaction with amino terminal . Via the tests on the repetitiveness, accuracy and the stability, supposed this method was reliable. At the same time, the contrastive results of HPLC and the traditional K3Fe(CN)6 method indicate that the acetylacetone method was more suitable for the determination of chitosan-oligosaccharide molecular mass.
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Objective To observe the bacteriostatic effect of chitosan lactate with different relative molecular masses in vitro. Methods The MICs of the chitosans lactate with different relative molecular masses against the usual pathogens were detected,and the MBCS against two standard strains were also determined. Levofloxacin hydrochloride was used as a control drug. Results The MIC90 of chitosan lactate with 10,30,50kDa against 50 strains of gram-positive cocci and 50 strains of gram-negative bacilli were 0.5,1~4,0.5~4mg?mL-1 and 1~4,0.5~1 ,0.5~4mg?mL-1,respectively. The MIC90 of levofloxacin hydrochloride against the 50 strains of gram-positive cocci and 50 strains of gram-negative bacilli were 4～8 and 8～16?g?mL-1,respectively. ATCC 25923 strain of S.aureus and ATCC 25922 strain of E.coli could be killed by 10kDa chitosan lactate in the concentration of 4mg?mL-1. The MBCS of levofloxacin hydrochloride against ATCC25923 strain of S.aureus and ATCC 25922 strain of E.coli were 2 and 4?g?mL-1,respectively. Conclusion The 4 species of the experimental bacteria could be inhibited by the chitosan lactate with 10,30 and 50kDa Mr in vitro,but the inhibitory effect of the chitosan lactate with 10kDa Mr was stronger among them. ATCC 25923 strain of S.aureus and ATCC25923 strain of E.coli could be killed only by 10kDa chitosan lactate in vitro,not by others.
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Objective To determine the purity,composition and antitumor activities of polysaccharide AHP-12 from abalone harslet.Methods Its purity was checked by HPLC with TSK-GEL G4000PWXL column and agarose gel electrophoresis;Molecular weight was determined by gel filtration chromatography;Sulfate content was identified by gelatine nephelometry and aminohexose content by chromatometry;Gas chromatograph was applied to determine monosaccharide composition;Antitumor activities were investigated by MTT method.Results AHP-12 from abalone harslet was a homogeneous polysaccharide both measured by molecular weight and electric property;The molecular weight was about 3?105;It was contained sulfate 13.07% and aminohexose 4.98%;AHP-12 was composed of rhamnose,fucose and galactose(the ratio in mole is 1∶2.2∶1.7);the activity determined by MTT method showed it could hamper the growth of HeLa cell.Conclusion AHP-12 was extracted and purified from abalone harslet.It was a homogeneous polysaccharide,which contained sulfate and aminopolysaccharide,and with weak antitumor activities in vitro.
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Objective To study the relationship between fucoidans structure and their antioxidant activities. Method Fucoidans (HF) were extracted from Laminaria japonica and was separated by anion exchange chromatography on DEAE-Cellulose 52 column (2.5?40 cm), and two fractions HF1 and HF2 were obtained. Fucoidans of low molecular weight (LF) was made after hydrolysis of HF by hydrochloric acid and purification by ultrafiltration. Chemical methods and gas chromatography were used to analyse the sugar composition of these polysaccharides; and infrared spectrum was utilized to determine their structure. The activity of inhibiting hydroxyl radical (?O H ) was evaluated by means of Fenton reaction. Results In HF1, 18.834% uronic acid, 44.197% L-fucose, 31.193% D-galactose and 24.612% D-mannose were detected. As to HF2, 5.878% uronic acid, 81.119% L-fucose and 18.881% D-mannose were found. L-fucose content in LF was 13.033%, equal to 32.084% of that in HF 40.621%. Both in HF1 and LF, sulfate groups were at the C-2 and C-4 positions of L-fucose, while in HF2, sulfate groups only at C-4 position. The concentration of fucoidans inhibiting 50% ?O H (IC50) was 7.6, 5.2 and 8.9 mg/ml for HF, HF1 and HF2 respectively. Nevertheless, LF approximately lost this activity. Conclusion The molecular weight, content and composition of sugar and the combining sites of sulfate groups were found to be related with the activity of inhibiting ?O H radical in fucoidans.