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1.
Water‐soluble polysaccharides from coarse green tea were separated by anion‐exchange chromatography into five fractions (fraction A [FA], fraction B, fraction C [FC], fraction D and fraction E). Two of these fractions, FA and FC, contained significant glucokinase‐stimulating activity (P < 0.05). The major component, FC, showed the most activity, and thus, was further purified by gel filtration chromatography, thereby obtaining fraction C‐1 (FC‐1) and fraction C‐2 (FC‐2). The biological activity of the two fractions was investigated, and FC‐1 displayed higher glucokinase‐stimulating activity (P < 0.01). Chemical tests combined with IR and UV spectroscopy revealed that FC‐1 is an acidic polysaccharide without conjugation to protein. Sugars of FC‐1 are composed of rhamnose, arabinose, mannose, glucose and galactose in the ratio of 12.57:22.95:4.4:39.34:20.77. Uronic acid analysis by ion chromatography showed that FC‐1 contains 8% galacturonic acid, and its molecular weight was estimated to be approximately 6 × 104 using a Sephacryl S200 column. These results are different from the observations previously reported, therefore suggesting that FC‐1 is a novel polysaccharide.  相似文献   

2.
Mesona blumes gum can be isolated into a neutral polysaccharide (NMBG) and an acidic polysaccharide (AMBG). The yield of AMBG can be up to 90% (w/w). AMBG with a molecular weight of 6566 Da is composed of galactose, glucose, mannose, xylose, arabinose, rhamnose and galacturonic acid in the molar ratio 2.66:1:0.37:2.29:12.5:5.99:23.5. Structural features of the purified AMBG were investigated by a combination of chemical and instrumental analysis, such as periodate oxidation, Smith degradation, methylation, and 13C and 1H NMR. It was found that AMBG possessed a (1 → 4)‐α‐galacturonan backbone with some insertions of (1 → 2)‐α‐L ‐Rhap residues. The branches of arabinogalactan, arabinan, galactan and xylan were all attached to the backbone via O‐4 of α‐L ‐Rhap residues. In addition, some α‐L ‐Rhap residues on the backbone terminated with α‐L ‐Araf and some O‐6 in galacturonic acid residues were acetylated or methyl esterified. The molecular structure of AMBG at different concentrations was observed by atomic force microscopy (AFM). It was found that AMBG showed spherical lumps at 1 µg mL?1 but an irregular worm‐like shape at 10 µg mL?1, which indicated that the viscosity of AMBG might be caused by its notable molecular aggregation. Copyright © 2007 Society of Chemical Industry  相似文献   

3.
In the present study, crude polysaccharides from Ziziphus Jujuba cv. Muzao were isolated and purified using DEAE cellulose-52 and Sephadex G-100 size-exclusion chromatography; four fractions were collected, namely GZMP-1, GZMP-2, GZMP-3, and GZMP-4. The molecular weights of these four fractions were measured to be 111.2, 95.1, 84.2, and 571.4 kDa, respectively, using high-performance gel permeation chromatography. Gas chromatography analysis of the monosaccharide composition confirmed that GZMP-1 was composed of rhamnose, arabinose, glucose, and galactose. Rhamnose, arabinose, and galactose were the main components present in GZMP-2 and GZMP-3, whereas GZMP-4 was composed of only rhamnose and arabinose. Scanning electron microscopy showed relatively smooth surfaces for GZMP-1 and GZMP-4, whereas GZMP-2 and GZMP-3 had more folds on their surfaces. Fourier transform infrared spectroscopy analyses indicated that GZMP-1 and ZMP mainly had α-type glycosidic linkages. The in vitro antioxidant activities of the polysaccharides revealed that jujube polysaccharides exhibit remarkable antioxidant activity, and can scavenge DPPH radical and OH radical in a concentration-dependent manner. The results of this work suggest that polysaccharides from Z. Jujuba cv. Muzao have potential to be used as functional food and in the development of natural antioxidant drug carriers.  相似文献   

4.
Cell wall polysaccharides (CWP) of two types of melons were isolated and purified. Fractionations were performed using cyclohexanetrans-1,2-diamine tetraacetate (CDTA), Na2CO3, guanidinium thiocyanate (GTC) and KOH. Alditol acetate derivatives of neutral sugars from each CWP fraction were prepared and analysed by gas chromatography. Trifluoro-acetic acid insoluble fractions were analysed colorimetrically and uronic acid was determined. The CDTA and Na2CO3 fractions were found to be composed of typical pectic materialscontaining primarily galacturonic acid with the neutral sugars arabinose, galactose, rhamnose and a smaller amount of xylose. As maturity increased, CDTA fraction yields increased, though total neutral sugar CWP compositions decreased. GTC and KOH fractions were typical of hemicellulose, and contained principally xylose, glucose, galactose, mannose and fucose, with very small amounts of uronic acid, arabinose and rhamnose. The residues contained principally glucose and galactose, with smaller amounts of mannose, xylose, arabinose and fucose. With the exception of xylose and glucose, all neutral sugars decreased significantly during ripening in both the Cantaloupe and Honey Dew melons. Total uronic acid did not change as maturity increased, except for Cantaloupe, where total uronic acid decreased from the ripe to overripe stages. Relationships between firmness, drip loss and other composition measurements, as well as the total CWP sugar composition, were also determined. Only the CDTA fraction yields were negatively correlated with the changes in firmness of both melons and positively correlated with changes in drip loss as maturity increased.  相似文献   

5.
Abstract: The water‐soluble crude polysaccharide tea flower polysaccharide (TFP), obtained from tea (Camellia sinensis) flower by boiling‐water extraction and ethanol precipitation, was fractionated by Sephadex G‐100 column chromatography, giving 2 polysaccharide fractions termed TFP‐1 and TFP‐2. The structural features of TFP‐1 and TFP‐2 were investigated by high‐performance liquid chromatography (HPLC), gel‐permeation chromatography (GPC), rheometer, infrared (IR) spectra, nuclear magnetic resonance (NMR) spectroscopy, atomic force microscope (AFM), and scanning electron microscope (SEM). Results indicated that TFP‐1 was composed of glucose: xylose: rhamnose: galactose = 1.0:1.2:0.81:0.98 with a molecular weight of 167.5 KDa, while TFP‐2 comprised glucose: xylose: rhamnose: arabinose = 1.0:0.76:2.3:2.3 with a molecular weight of 10.1 KDa. The 1H NMR revealed that TFP‐1 contained α‐L‐Rhap, α‐D‐Galp, α‐D‐GalpNAc, α‐D‐Xylp, α‐D‐Glcp, and β‐D‐Glcp residues, while TFP‐2 was illustrated to have α‐L‐Rhap, α‐L‐Arap, α‐D‐Xylp, α‐D‐Glcp, and α‐D‐GlcpNAc residues. Antioxidant activities of these fractions were investigated using various in vitro assay systems compared with ascorbic acid. In conclusion, TFP‐2 exhibited the higher antioxidant activities and could be explored as a novel potential antioxidant. Practical Application: At present, commonly low‐grade tea is preferred to extract the tea polysaccharide, to take full advantage of tea flower resource to extract polysaccharides can greatly reduce the cost of tea products. Thus, the search for plant‐derived biomaterials from this study could generate natural value‐added products from underutilized tea plant waste and used as a medicinal agent against chronic health problems, such as cancers, aging, and atherosclerosis caused by reactive free radicals that produced from oxidation.  相似文献   

6.
Using hot water extraction, a large number of polysaccharides were obtained from Cucurbita maxima. A DEAE‐Sepharose CL‐6B chromatography column was used to isolate the major polysaccharides from C. maxima. Two fractions were obtained (LP2‐1 and LP2‐2). LP2‐1 and LP2‐2 consisted of neutral polysaccharides (MW: 1.02 × 104 and 4.32 × 108 g mol?1, respectively) comprised mainly of galactose units. Analyses by FT‐IR spectrometry, partial acid hydrolysis, periodate oxidation, Smith degradation and GC‐MS indicated that LP2‐1 consisted of 85.3% (1→4) glycosidic linkages and 1.7% (1→3) or (1→6) glycosidic linkages. The LP2‐1 backbone consisted of (1→4)‐linked galactose units, which occasionally branched at O6 or O3. The branches were composed of (1→4)‐linked galactose and terminated with galactose (13%). Two sulphated derivatives (SLP2‐1 and SLP2‐2) with variable degrees of sulphation (DS) were obtained by the sulphur trioxide–pyridine method, without degradation of the polysaccharide. DS of PL2‐1 and PL2‐2 was 0.19 and 0.20, respectively.  相似文献   

7.
Much research has been carried out over the years examining cell wall glucans from Saccharomyces cerevisiae and this study further examines aspects of the binding of (1r?4)‐α‐D‐glucan in the yeast cell wall, using a number of isolation techniques as well as monoclonal antibodies able to recognize a mixed (1r?4)‐α‐D‐glucan/(1r?6)‐β‐D‐glucan. Extraction of purified glucan, from S. cerevisiae cell wall, with 0.1N HCl, at 80°C for 6 h, released into the solution (1r?4)‐α‐D‐glucan and (1r?6)‐β‐D‐glucan as the major polysaccharides, along with an insoluble pellet highly enriched in (1r?3)‐β‐D‐glucan. The released (1r?4)‐α‐D‐glucan was composed of a high molecular size >100 kDa fraction (7.2% w/w) and a medium 5–50 kDa polysaccharide (10.2% w/w), with the (1r?4)‐α‐D‐glucan covalently bound to the (1r?6)‐β‐D‐glucan. The average molar ratio of the α:β glucan was 47: 53 in this mixed polysaccharide. The structure of this polysaccharide was different from the structure of plant starch or animal glycogen as monoclonal antibodies specific to yeast (1r?4)‐α‐D‐glucan/(1r?6)‐β‐D‐glucan did not recognize the plant starch or animal glycogen standards.  相似文献   

8.
The gum from Hymenaea courbaril (Caesalpiniaceae) produced gum at seed level. The gum is soluble in water, dextrorotatory and less viscous than the gum from Cyamopsis tetragonolobus (guar gum). The polysaccharide, isolated from this gum, contains galactose, glucose, xylose and arabinose. The preparation of degraded products by acid hydrolysis and Smith-degradation process led to obtain degraded gums A and B, and the polysaccharides I and II. Chemical methods in combination with 1D NMR (1H, 13C, DEPT-135) and 2D NMR (COSY, HMQC and HMBC) were applied. The backbone is a xylogalactan; β-d-galactose and β-d-xylose residues are 4-O- and 2-O-linked, respectively. The branches are constituted by xylose, arabinose and galactose. It was also observed 4,6-di-O-substituted galactose residues. This work shows interesting structural features of the polysaccharide isolated from H. courbaril gum.  相似文献   

9.
BACKGROUND: The maltogenic amylase from Bacillus stearothermophilus (BSMA) is a valuable biocatalyst that has been used to transglycosylate natural glycosides to improve solubility. To ensure safety, BSMA was produced in Bacillus subtilis, using new shuttle vector‐based expression vectors. The transglycosylation of puerarin was also conducted with crude BSMA and analyzed. RESULTS: Two expression systems, each containing one of the promoters from the genes encoding Bacillus licheniformis maltogenic amylase (BLMA) and an α‐amylase from B. subtilis NA64 (amyR2), were constructed. The amyR2 promoter system was chosen as the best system; it yielded 107 mg of pure BSMA from a 2 L culture. In the transglycosylation reactions of puerarin using crude BSMA, relative amounts for maltosyl‐α‐(1 → 6)‐puerarin, glucosyl‐α‐(1 → 6)‐puerarin, glucosyl‐α‐(1 → 3)‐puerarin, and puerarin were determined as 26:18:7:49. A two‐step purification process, including gel permeation chromatography, yielded 1.7 g of the transfer products from 3 g of puerarin. CONCLUSION: The crude BSMA produced from a host generally recognized as safe (B. subtilis) can be used to transglycosylate various functional compounds. The expression system developed in this study will be helpful for the production of other food‐grade enzymes by B. subtilis. Copyright © 2010 Society of Chemical Industry  相似文献   

10.
采用热水浸提法从香薷中得到多糖提取物,然后采用乙醇分级沉淀法纯化香薷多糖,收集得到乙醇体积分数为20%、30%、40%、50%、60%、70% 条件下析出的多糖沉淀物。之后经Sevag 法脱除多糖中的游离蛋白,得到纯化后的6 个香薷多糖组分HMP-1、HMP-2、HMP-3、HMP-4、HMP-5 和HMP-6。应用紫外和红外光谱检测HMP-1、HMP-2、HMP-3、HMP-4、HMP-5 和HMP-6 的光谱性质,测定糖含量、可溶性蛋白质含量和糖醛酸含量,并用气相色谱法测定单糖组成。结果表明:HMP-1、HMP-2、HMP-3、HMP-4、HMP-5和HMP-6 均为酸性多糖,蛋白含量较高。HMP-1 和HMP-2 主要含有阿拉伯糖和葡萄糖,HMP-3 主要含有阿拉伯糖、葡萄糖、半乳糖和核糖,HMP-4 主要含有阿拉伯糖、葡萄糖和半乳糖,HMP-5 和HMP-6 主要含有阿拉伯糖、葡萄糖、半乳糖和甘露糖。此外,6 个多糖组分均含有少量的鼠李糖、木糖,但单糖间物质的量比相差较大。  相似文献   

11.
A large number of polysaccharides present in the leaves of Taxus chinensis var. mairei were successively extracted with hot water after preliminary treatments. The ion-exchange and gel-permeation chromatography was used to isolate and purify the major polysaccharides to afford a complex water-soluble polysaccharide, named T1 with a molecular mass of 3.44 × 10Da determined by HPGPC. T1 consisted of 2,4-di-O-methyl-mannose, rhamnose, arabinose, xylose, galactose, mannose, galacturonic acid and glucuronic acid in a molar ratio of 2:5:24:9:3:46:1:10, and the acetyl content was estimated to be 2.1%. On the basis of methylation analysis, periodate and chromium trioxide oxidations, Smith degradation, graded acid hydrolysis, and NMR and IR spectroscopy, T1 possessed a 1,3,6-linked β-d-Manp main chain, substituted by mannose, arabinose, galactose, xylose, rhamnose, 2,4-di-O-methyl-mannose, galacturonic acid, and glucuronic acid residues. These contained non-reducing end-units of mannose, arabinose, xylose, 2,4-di-O-methyl-mannose, and glucuronic acid. This is the first report on isolation of an acid heteropolysaccharide from Taxus species.  相似文献   

12.
A rapid and sensitive method was optimized and validated for the separation and quantification of derivatized monosaccharides in polysaccharide from Potentilla anserine L. using 1-naphthyl-3-methyl-5-pyrazolone (NMP) as precolumn derivatization reagent by capillary zone electrophoresis (CZE). On the basis of the optimum conditions, nine NMP-derivatized monosaccharides achieve baseline resolution within 16 min. The developed method has been successfully applied to analyze component monosaccharides of three Potentilla anserine L. samples, which were obtained by gradational precipitation with 50, 70, and 90% aqueous ethanol, respectively. The polysaccharide precipitated from 50% ethanol solvent was composed of fucose, mannose, xylose, glucuronic acid, glucose, rhamnose, galacturonic acid, galactose, arabinose in molar proportion of 1:1.65:1.99:5.08:7.38:8.14:13.05:27.41:39.02; the corresponding molar proportions for polysaccharide obtained from 70% ethanol solvent were 1:1.64:1.65:4.52:13.96:9.13:26.30:10.52:18.00; fucose and galacturonic acid were not found in the polysaccharide precipitated from 90% ethanol solvent, and mannose, xylose, glucuronic acid, glucose, rhamnose, galactose and arabinose were determined with molar proportion of 1:0.87:1.77:2.78:1.69:2.58:2.49. Quantitative recoveries of the component monosaccharides in the polysaccharide were in the range of 93.3–105.1% and the relative standard deviation (RSD) values fell within 3.4–6.3%, respectively. The results demonstrated that the proposed CZE method was precise and sensitive for the analysis of the composition of polysaccharide.  相似文献   

13.
A highly purified type I arabinogalactan (AG) from soybean meal was prepared. It contained galactose, arabinose, galacturonic acid and rhamnose in a 52:41:4:3 molar ratio and had Mw 124,000 g/mol. Methylation analysis and 13C NMR spectroscopy indicated that AG is constituted by a (1→4)-linked β-Galp main chain with substituents of α-Araf at O-3, which are in turn substituted at O-5, O-3,5, and O-2,5. It is probably linked to O-4 of some rhamnosyl units of a type I rhamnogalacturonan, formed by repeating (1→4)-α-D-GalpA-(1→2)-α-L-Rhap groups. AG significantly inhibited ethanol-induced gastric lesions in rats at an ED50 of 35 mg/kg, indicating that it has a gastroprotective effect.  相似文献   

14.
Genes encoding l ‐arabinose transporters in Kluyveromyces marxianus and Pichia guilliermondii were identified by functional complementation of Saccharomyces cerevisiae whose growth on l ‐arabinose was dependent on a functioning l ‐arabinose transporter, or by screening a differential display library, respectively. These transporters also transport d ‐xylose and were designated KmAXT1 (arabinose–xylose transporter) and PgAXT1, respectively. Transport assays using l ‐arabinose showed that KmAxt1p has Km 263 mm and Vmax 57 nm /mg/min, and PgAxt1p has Km 0.13 mm and Vmax 18 nm /mg/min. Glucose, galactose and xylose significantly inhibit l ‐arabinose transport by both transporters. Transport assays using d ‐xylose showed that KmAxt1p has Km 27 mm and Vmax 3.8 nm /mg/min, and PgAxt1p has Km 65 mm and Vmax 8.7 nm /mg/min. Neither transporter is capable of recovering growth on glucose or galactose in a S. cerevisiae strain deleted for hexose and galactose transporters. Transport kinetics of S. cerevisiae Gal2p showed Km 371 mm and Vmax 341 nm /mg/min for l ‐arabinose, and Km 25 mm and Vmax 76 nm /mg/min for galactose. Due to the ability of Gal2p and these two newly characterized transporters to transport both l ‐arabinose and d ‐xylose, one scenario for the complete usage of biomass‐derived pentose sugars would require only the low‐affinity, high‐throughput transporter Gal2p and one additional high‐affinity general pentose transporter, rather than dedicated d ‐xylose or l ‐arabinose transporters. Additionally, alignment of these transporters with other characterized pentose transporters provides potential targets for substrate recognition engineering. Accession Nos: KmAXT1: GZ791039; PgAXT1: GZ791040 Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

15.
After removal of water-soluble pectin from senescent Idared apples, an additional sizable pectin fraction could be extracted using Na2EDTA under nondegradative conditions. This chelator-soluble fraction did not appear to owe its insolubility in the cell wall solely to molecular charge. The galacturonic acid-rich polymers of chelator-soluble pectin were notably lower in arabinose galactose and rhamnose residues than those of water-soluble pectin.  相似文献   

16.
Mango is a tropical fruit with sweet taste and desirable flavor. Mango seed polysaccharides (MSP) were extracted in this work and the extraction conditions were optimized by response surface methodology. A mathematical model was built with high fitness and the optimal conditions to obtain the highest MSP yield were 9.0 ml/g of solvent/material ratio, 174 min of time and 89 °C of temperature. The monosaccharides occurred in MSP I were determined to be arabinose, rhamnose, mannose, galactose, and glucose. Besides these monosaccharides, fructose was detected as the major monosaccharide in MSP II, which relative molar percentage was 60.9%. In MSP I, mannose and galactose constructed the backbone. However, their percentage sum was only 20.7% in MSP II. Arabinose, rhamnose, and mannose were detected to have only one type of glycosidic linkage, which attended in linear structure. →2)-Fru-(1,4→ was the unique linkage for fructose, and it built the branched structure. A dose-dependent behavior was observed for DPPH radical scavenging activity of MSPs I and II. Amongst, MSP I showed a better antioxidant activity than MSP II.  相似文献   

17.
以山梨醇作内标,羟胺吡啶和BSTFA 1%TMCS为衍生化剂,采用GC法同时测定了国内外21种牌号卷烟中的木糖、阿拉伯糖、鼠李糖、果糖、甘露糖、半乳糖、葡萄糖、蔗糖、麦芽糖、天门冬氨酸、天门冬酰胺、丙二醇、丙三醇、乳酸、丙二酸、苹果酸、柠檬酸和磷酸。结果显示:①丙二醇和阿拉伯糖的RSD>10%,乳酸、天门冬酰胺、鼠李糖、半乳糖和麦芽糖的RSD>5%,其它成分的RSD<5%;②除丙二酸、半乳糖、鼠李糖、丙三醇和阿拉伯糖的回收率介于70%~75%外,其它组分的回收率>80%;③在所分析的卷烟样品中,进口混合型卷烟中柠檬酸、天门冬氨酸、天门冬酰胺、丙二醇和丙三醇含量较国产烤烟型卷烟的高,而糖类的含量则普遍较低,其它成分差别不大。  相似文献   

18.
The proximate composition of defatted edible groundnut flour, processed and unprocessed, has been determined. The flour contains about 38% total carbohydrates of which oligosaccharides account for 18%, starch 12.5%, hemicelluloses A and B 0.5 and 3.5% respectively and fibre (cellulose) 4.5%. Sucrose 13.90 and 14.55%, raffinose 0.89 and 0.92%, stachyose 1.56 and 1.60%, and verbascose 0.41 and 0.42% represent the oligosaccharide fractions (from 70% alcoholic extract) of unprocessed and processed flour, respectively. In addition the unprocessed flour also contained glucose 0.80% and fructose 0.41 % along with two unidentified spots 0.70%. Hemicellulose A consisted of glucose, arabinose, and xylose (4 : 0.5 : 0.1) whereas hemicellulose B had galacturonic acid, glucose, galactose, arabinose and xylose (1 : 4: 1 : 12 : 6). The fibre fraction on hydrolysis yielded predominantly glucose with only traces of galacturonic acid and rhamnose. The presence of verbascose and xylose in groundnuts has not been previously reported.  相似文献   

19.
阿里红中多糖的分离纯化及其组分分析   总被引:1,自引:1,他引:0  
目的对阿里红中的多糖进行分离纯化,并对得到的两种多糖组分进行基础结构分析。方法阿里红经水提醇沉法除蛋白后,再经DEAE纤维素-52、Sepharose CL-6B和葡聚糖凝胶Sephadex G-100柱层析分离纯化得到两种多糖组分FOPS-a和FOPS-b。采用凝胶过滤法分析其纯度和相对分子量,经气相色谱法分析其单糖组成,并对多糖组分进行部分酸水解,高碘酸氧化和Smith降解分析。结果分离纯化得到的阿里红多糖组分FOPS-a、FOPS-b的相对分子质量为199 kDa和87 kDa。单糖组成均为甘露糖、阿拉伯糖、半乳糖。FOPS-a主链单糖残基为甘露糖,末端残基和分支单糖残基为阿拉伯糖、半乳糖、甘露糖和鼠李糖;FOPS-b主链单糖残基为甘露糖,末端残基和分支单糖残基为阿拉伯糖、半乳糖、甘露糖和葡萄糖。结论该研究可为阿里红多糖的开发与利用提供技术参考。  相似文献   

20.
Considering the medicinal and edible properties of Physalis pubescens L. fruit, the plant has a long history of cultivation in China. In the current study, a novel polysaccharide (PPL-1) was successfully obtained from P. pubescens fruits using multi-column techniques. The chemical characterisation of the polysaccharide was achieved by acid hydrolysis, determination of weight average molecular mass, thermogravimetric and Smith degradation analyses, in addition to ultraviolet, Fourier transform infrared spectroscopy, one- and two-dimensional nuclear magnetic resonance spectroscopy. According to the structural analyses, PPL-1 consisted of rhamnose, arabinose, fructose, mannose and glucose with a relative molar ratio of 0.39:0.12:0.02:0.03:0.44. The average molecular weight of PPL-1 was 7.3 kDa and it was mainly composed of (1 → 3) and (1 → 6) linkages. PPL-1 exhibited not only scavenging effects on 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals but also hydrogen peroxide-induced oxidative stress in SH-SY5Y cells effectively by decreasing malondialdehyde content and increasing total antioxidant capacity, superoxide dismutase and glutathione peroxidase activity levels.  相似文献   

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