Gas chromatographic-mass spectrometric characterisation of plant gums in samples from painted works of art

This paper presents an analytical GC-MS procedure to study the chemical composition of plant gums, determining aldoses and uronic acids in one step. The procedure is based on the silylation of aldoses and uronic acids, released from plant gums by microwave assisted hydrolysis, and previously converted into the corresponding diethyl-dithioacetals and diethyl-dithioacetal lactones. Using this method only one peak for each compound is obtained, thus providing simple and highly reproducible chromatograms. The analytical procedure was optimised using reference samples of raw plant gums (arabic, karaya, ghatti, guar, locust bean and tragacanth, cherry, plum and peach gums), commercial watercolours and paint layers prepared according to ancient recipes at the Opificio delle Pietre Dure of Florence (Italy). To identify gum media in samples of unknown composition, a decisional schema for the gum identification and the principal component analysis of the relative sugar percentage contents were employed. The procedure was used to study samples collected from wall paintings from Macedonian tombs (4th-3rd centuries bc) and from the Mycenaean "Palace of Nestor" (13th century bc) in Pylos, Greece. The presence of carbohydrates was ascertained and plant gum binders (fruit and a mixture of tragacanth and fruit tree gums) were identified in some of the samples.     

Separation of trimethylsilylated oximes of monosaccharides by capillary gas-liquid chromatography

Summary Trimethylsilylated oximes (TMS-oximes) of arabinose, fucose, galactose, glucose, mannose, rhamnose, xylose, glucuronic acid, and galacturonic acid were prepared using a two-step derivatization procedure. The TMS-oximes were separated and quantitated by gas-liquid chromatography using a 25-m fused-silica capillary column coated with crosslinked methylsilicone stationary phase. Starting with dried sugar extract, the entire procedure can be accomplished within 2 hours.     

Use of specific polysaccharide‐immobilized monodisperse poly(glycidyl methacrylate) core–silica shell microspheres for affinity purification of lectins

Immobilization of polysaccharides (yeast mannan and gum arabic) on the macroporous poly(glycidyl methacrylate) monodisperse microspheres coated with silica (SiO₂)‐containing amino groups on the surface was used to prepare affinity sorbents for lectin purification. The efficiency of isolating mannose specific Pisum sativum lectin was demonstrated on sorbent with immobilized yeast mannan and that of galactose specific Glycine hispida lectin on sorbent with immobilized gum arabic. The microspheres with immobilized polysaccharides can be used for selecting an affinity sorbent for purification of other mannose‐ and galactose‐specific lectins. In contrast to yeast mannan, the gum arabic immobilized on the microspheres possesses much narrower specificity and is suitable for purification of only those galactose specific lectins which interact well with l ‐rhamnose or l ‐arabinose. The synthesized macroporous particles are capable of immobilizing 50 mg of polysaccharide per 1 g of the matrix, which is 10 times higher than the capacity of epoxy‐activated Sepharose 6B. That makes it possible to obtain the same lectin quantity using a column of 10 times smaller volume. Another advantage of novel affinity sorbents comparing corresponding Sepharose gels is the possibility of sorbent drying after use. Copyright © 2014 John Wiley & Sons, Ltd.     

Advances in identification of plant gums in cultural heritage by thermally assisted hydrolysis and methylation

Plant gums are present in works of art as binding media for watercolours and adhesives for cellulosic substrates. Thermally assisted hydrolysis and methylation (THM) in combination with analytical pyrolysis coupled to GC/MS has been applied to the characterisation of plant gums typically used in artworks. THM products from standard samples of arabic gum, tragacanth gum and cherry gum were characterised. The main products identified are permethylated and partially methylated aldonic acids, characteristic of specific epimeric sugars. Aldonic acids were formed by alkaline hydrolysis of free reducing sugars and of reducing polysaccharide terminal groups, while methylation occurs during pyrolysis. The presence of these characteristic markers allows gum identification. A systematic analysis of all the parameters that can affect the marker yields was performed. In particular, the influence of pyrolysis temperature, reagent concentration and contact time between tetramethylammonium hydroxide and sample were studied, and different kinds of sample preparation procedures were tested. Some analyses on real watercolours were performed, and gum binders were classified using the peak area ratio of the main monosaccharide markers.     

超高效液相色谱-串联质谱法测定螺旋藻多糖的单糖组成

建立了同时测定螺旋藻多糖水解产物中鼠李糖、木糖、阿拉伯糖、果糖、甘露糖、葡萄糖、半乳糖、甘露醇、核糖、岩藻糖、葡萄糖醛酸、半乳糖醛酸12种糖类化合物的超高效液相色谱-串联质谱分析方法。螺旋藻样品经超声波辅助提取,用三氟乙酸水解,经Waters Acquity BEH Amide色谱柱(100 mm×2.1 mm,1.7μm)分离,以10mmol/L甲酸铵和10 mmol/L甲酸铵-乙腈为流动相,在电喷雾电离源负离子(ESI-)模式下,用多反应监测(MRM)模式检测。结果表明,12种糖类化合物的定量限为0.005~0.15 mg/kg,线性范围为0.05~5 mg/L。按照样品中每种糖本底含量的50%、100%、150%进行添加,回收率为80.21%~121.6%。应用该方法对螺旋藻样品进行分析,结果发现:大部分样品都能检测到岩藻糖、半乳糖、阿拉伯糖、鼠李糖、葡萄糖、果糖、木糖、核糖,含量在0.3~889.4 mg/g之间。此外,测定的15个样品中岩藻糖、半乳糖、阿拉伯糖、鼠李糖、葡萄糖、果糖、木糖、核糖是共有组分,含量差异较大,但在所有样品中均未检测到甘露醇和甘露糖。该方法的建立可为阐明螺旋藻多糖的结构组成及其活性提供技术支撑及基础数据。     

用毛细管气相色谱法测定多糖中单糖的组成

报道了测定多糖中单糖组成的糖醇乙酸酯的毛细管气相色谱分析方法。使用ＯＶ－２２５毛细管气相色谱柱分离了１１种单糖的糖醇乙酸酯衍生物,在０．２～１．６８ｇ／Ｌ质量浓度范围内,１１种单糖定量校正曲线的线性关系廊。应用该法测定了胡麻我发多糖和少 我中单糖的组成。为这些药物多糖的基础研究提供了有用的信息。     

Structural analysis of the gum polysaccharide from anacardium occidentale

The gum exudate from Anacardium occidentale contains galactose (61 %), arabinose (14 %), rhamnose (7 %), glucose (8 %) and glucuronic acid (5 %) in addition to small amounts (<2 %) of each of mannose, xylose and 4-0 methylglucuronic acid. Contrary to earlier findings, the main aldobiuronic acid present is 6-O-(β-D-glucopyranosyluronic acid)-D-galactose; smaller amounts of the 4-O-methyl analogue are also present. Mild acid hydrolysis showed only two galactobioses, 3-O-β-D-galactopyranosyl-D-galactose (major

component) and 6-O-β-D-galactopyranosyl-D-galactose (minor component). Degraded gum A, prepared by controlled acid hydrolysis, contained galactose, glucose, and uronic acid. A Smith-degradation of degraded gum A gave degraded gum B, which contained only galactose. Sequential Smith-degradations of Anacardium occidentale gum, and methylation analyses of the gum and of its degradation products indicated a highly-branched galactan framework consisting of chains of β-(1–3)-linked D-galactose residues branched and interspersed with β-(1–6) linkages. Arabinose is present as end-groups or in short (1–2)-linked chains up to five units long. Glucose, rhamnose, mannose xylose, and uronic acid are all present as end-groups.     

The question of the structure of a triterpene glycoside fromSaponaria officinalis

Conclusions 1. It has been shown that saponaside D is a decaoside of gypsogenin.2. It has been established that the carbohydrate moiety attached to the hydroxyl group of the aglycone comprises galactose, arabinose, xylose, rhamnose, and glucuronic acid and that attached to the carboxyl group of gypsogenin comprises galactose, glucose, xylose, fucose, and rhamnose.3. It has been shown that glucuronic acid is attached directly to the hydroxyl of the gypsogenin by a -glycosidic linkage and a fucose residue is attached directly to the carboxyl group.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 6, pp. 494–498, 1969     

Emulsifying,Flocculating, and Physicochemical Properties of Exopolysaccharide Produced by Cyanobacterium Nostoc flagelliforme

The emulsifying, flocculating, and physicochemical properties of purified exopolysaccharide (EPS) of terrestrial cyanobacterium Nostoc flagelliforme cultured in liquid media were investigated. The EPS was defined as heteropolysaccharide composed by 41.2 % glucose, 21.1 % galactose, 21.0 % mannose, 2.5 % fructose, 3.6 % ribose, 1.7 % xylose, 0.6 % arabinose, 3.0 % rhamnose, 0.9 % fucose, and 4.3 % glucuronic acid. The EPS possessed higher intrinsic viscosity than other cyanobacterial strains as reported and displayed pseudoplastic behavior in aqueous solution. The EPS produced more stable emulsions with tested hydrocarbons and oils than xanthan gum, and the emulsification indexes with n-hexadecane, liquid paraffin, and peanut oil were higher than 50 %, indicating the strong emulsion-stabilizing capacity. The EPS showed peak flocculating rates of 93.5 and 86.1 % in kaolin and MgO suspension, respectively, and exhibited a better flocculation performance than Al₂(SO₄)₃ and xanthan gum. These results demonstrated that the EPS of N. flagelliforme was a very promising candidate for numerous industrial applications, as it had higher intrinsic viscosity, good emulsification activity, and excellent flocculation capability.     

Monosaccharide-NAIM derivatives for D-, L-configurational analysis

The D-, L-enantiomeric pairs of common monosaccharides (xylose, ribose, rhamnose, arabinose, fucose, glucose, mannose, galactose, N-acetylgalactosamine, glucuronic acid and galacturonic acid) were derivatized with 2,3-naphthalenediamine to form the corresponding D-, L-aldo-NAIM derivatives. A simple and facile capillary electrophoretic method was established for sugar composition analysis by simultaneously determining the migration times of these aldo-NAIMs using borate buffer at high pH (100 mM, pH 9.0). The methodology is also applicable to sialic acid (ketose monosaccharides). The quantitation level of the proposed method was in the 10~500 ppm range and the LOD was 1 ppm. The enantioseparation of D, L pairs of aldo-NAIMs were also achieved by using modified sulfated-α-cyclodextrin as the chiral selector in phosphate buffer (300 mM, pH 3.0). In addition, the combination by reductive amination of amino-aldo-NAIM agent and D-, L-enantiomeric pairs of monosaccharides formed a diastereomeric pair for saccharide configuration analysis. Aldo-NAIM derivatives are thus shown to be rapid and efficient agents for analyzing saccharide compositions and configurations with good linearity and short analysis times via capillary electrophoresis.     

An Acidic Polysaccharide from Tribulus terrestris

An aqueous acidic polysaccharide, named rhamnogalacturonan (designated as TIP-D2) was isolated from Tribulus terrestris L by means of DEAE-cellulose chromatography and gel filtration. The molecular mass of TTP-D2 was estimated to be 26 KDa by gel filtration.TTP-D2 is composed of galacturonic acid, rhamnose, arabinose, galactose,fucose,mannose,xylose and glucose in a ratio of 71.4:13.5:5.6:4.9:3.1:1.9:1.9:1.0. The main chain structure of TTP-D2 was elucidated as an acidic hetero-polysaccaride with the connection of α-(1-4) galacturonic acid with α-（1-3) rhamnose by GC analysis of partially hydrolyzed products and determination of ^1H,^13C-NMR spectra.     

Gas chromatographic determination of polysaccharide gums in foods after hydrolysis and derivatization

A gas chromatographic method was evaluated for the determination of food grade gums in dairy products, salad dressings and meat sauces. The gums studied were tragacanth, karaya, ghatti, carob, guar, arabic and xanthan gum. The extraction method included removal of fat followed by starch degradation then precipitation of protein. The isolated gums were hydrolysed with trifluoroacetic acid and the resulting neutral monosaccharides converted to their aldonitrile acetate derivatives for determination by gas chromatography. Recoveries from thirteen different commodities averaged 85%. However, the recovery of guar gum from ice cream and cold pack cheese was 42 and 50%, respectively. In a comparison of enzyme hydrolysis and iodine complexation for the removal of starch the former was simpler and provided cleaner extracts than the iodine treatment. Both gave similar results.     

Polysaccharides from the stems ofAlthea nudiflora

From the heart of the stems of the hollyhockAlthea nudiflora (Lindl.) Boiss., growing on the territory of Southern Kazakhstan we have isolated a polysaccharide (yield 5%) containing residues of glucuronic and galacturonic acids (totalling 42%), and also of glucose, rhamnose, galactose, arabinose, xylose (traces) and mannose (traces). From the bark of the stems of this plant we have isolated a polysaccharide (yield 1.8%) consisting of a branched polymer composed of residues of rhamnose, glucose, and arabinose (22:17:2) and also of glucuronic and galacturonic acids (totalling 30%). In the products of the methylation of this polysaccharide previously reduced at the COOH groups we have established the presence of 2,3,4-tri-O-methylrhamnose, 3,4-di-O-methylrhamnose, 2,3,4,6-tetra-O-methylglucose, 2,6-di-O-methylglucose, and a mixture of 2,3,6-tri-O-methylglucose and 2,3,6-tri-O-methylgalactose (1:10:14:5:7).V. L. Komarov Botanical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 145–148, March–April, 1980.     

Comparative Analysis of Polysaccharides from Two Ecological Types of Leymus chinensis

Leymus chinensis(Trin.) Tzvel., widely distributed at eastern Eurasian steppe and divided into gray-green type and yellow-green type, has different stress resistance to environment. In the present study, the water-soluble polysaccharides from two ecotypes of L. chinensis were analyzed in detail, and the differences between polysaccharides from the two ecotypes of L. chinensis in the yield, monosaccharide composition, molecular weight and structure were clarified. The polysaccharides of L. chinensis were composed of both neutral and acidic polysaccharides. The neutral polysaccharides contained mannose, glucose, galactose, xylose and arabinose, and mainly consisted of β-1,4-Glcp, α-1,3-Galp and α-1,2-Xylp residues. The acidic polysaccharides contained mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and arabinose. However, the yields, monosaccharides contents and the molecular weights of the polysaccharides from the two ecotypes of L. chinensis were different. Moreover, the resistance type(gray-green type) of L. chinensis contained a number of α-1,3-Manp and reducing end of β-Glcp residues, and much more O-methyl groups than normal type(yellow-green type) of L. chinensis. The differences of the polysaccharides of the two ecotypes of L. chinensis might be due to the long-term environmental adaptability of plant, and the differences of the polysaccharides might influence the stress resistance of L. chinensis.     

柱前衍生化-高效液相色谱法分析木糖结晶母液的单糖组成

采用1-苯基-甲基-吡唑啉酮(PMP)柱前衍生化-反相高效液相色谱(HPLC)法建立了8种常见单糖的分离模式,并用于木糖结晶母液单糖组成的定量分析.结果表明:木糖结晶母液至少由甘露糖、鼠李糖、纤维二糖、葡萄糖、半乳糖、木糖、阿拉伯糖及岩藻糖8种单糖组成,其中以葡萄糖、半乳糖、木糖和阿拉伯糖为主.以峰高定量,8种单糖的浓...     

Optimized hydrolysis and analysis of Radix Asparagi polysaccharide monosaccharide composition by capillary zone electrophoresis

Using orthogonal design, optimized conditions for the hydrolysis of the polysaccharide from Radix Asparagi were determined, as well as its monosaccharide composition. Optimized hydrolysis conditions were a temperature of 100°C in 1.5 M sulfuric acid solution for 5 h. The resulting monosaccharides were derivatized with 1‐phenyl‐3‐methyl‐5‐pyrazolone, then separated by capillary zone electrophoresis in 40 mM sodium tetraborate buffer (pH 10.1), and detected by ultraviolet absorption at 245 nm. Results indicate that the polysaccharide from Radix Asparagi is composed of xylose, arabinose, glucose, rhamnose, mannose, galactose, glucuronic acid, and galacturonic acid, which differs from published findings. Moreover, xylose, glucuronic acid, and galacturonic acid have not been previously reported in Radix Asparagi polysaccharide. This method is simple, fast, and yields a highly efficient separation. As well, these findings can be applied to quality control of Radix Asparagi and for in‐depth study of the biological activity of Radix Asparagi polysaccharide.     

离子色谱-脉冲安培法测定芦荟多糖中7种单糖的含量

采用水提醇沉法提取芦荟鲜叶中的多糖，经三氟乙酸水解，利用Dionex CarboPac PA10高效阴离子色谱柱分离，氢氧化钠梯度淋洗，积分脉冲安培检测，建立了芦荟多糖中岩藻糖、鼠李糖、阿拉伯糖、半乳糖、葡萄糖、甘露糖和木糖7种常见单糖的测定方法。结果表明：7种单糖在线性范围内的相关系数（R²）均高于0.997，检出限为0.007~0.024 mg/L，加标回收率为97.5%~102.5%，相对标准偏差（RSD）为0.1%~4.8%。该法简单、快速、灵敏、准确，可用于芦荟多糖中单糖含量的测定和多糖组成的研究。     

A new glycoprotein SPG-8700 isolated from sweet potato with potential anti-cancer activity against colon cancer

A new small molecule glycoprotein SPG-8700 with potential anti-colorectal cancer activity was firstly separated by tracking of bioactivity from a new sweet potato variety Zhongshu-1. Matrix-assisted laser desorption ionization mass spectrometry, high-performance liquid chromatography and amino acid analyzer were applied separately to determine the molecular weight and compositions of this glycoprotein. Flow cytometry analysis and western blotting analysis were employed to explore it’s mechanism of the anti-colorectal cancer. The molecular weight of glycoprotein was 8703.8D (SPG-8700). Relative sugar and protein contents in SPG-8700 were 73.4 and 26.6%, comprising more than 6 types of sugars (mannose, rhamnose, glucuronic acid, glucose, galactose and arabinose with a proportion of 1:6.9:7.3:1.5:46:21). Further results indicated that SPG-8700 promoted apoptosis in HCT-116 cells through regulating the expression of Bcl-2 and Bax and had no effect on the growth of normal cells.     

氨基苯甲酸衍生化高效液相色谱法 分析多糖中的单糖及糖醛酸组成

衍生反相离子对色谱法同时分离检测多糖中单糖及糖醛酸组成的方法,筛选出适合于p-AMBA糖衍生物分离的色谱柱,考察了流动相组成对9种单糖和两种糖醛酸的p-AMBA衍生化产物的保留值及分离的影响,优化了反应温度和反应时间等衍生化条件,并应用优化的分析方法测定了螺旋藻中的单糖和糖醛酸的组成。采用紫外检测时,方法的检出限为 (2.55～13.4)×107mol/L;采用荧光检测时,方法的检出限为(3.38～176)×108 mol/L。     

Determination of the compositions of polysaccharides from Chinese herbs by capillary zone electrophoresis with amperometric detection

In this paper, capillary zone electrophoresis with amperometric detection (CZE-AD) was applied to determine the compositions of hetero-polysaccharides from Chinese herbs, Angelica sinensis and flax by analyzing their hydrolyzed monosaccharides: fucose, galactose, glucose, arabinose, rhamnose and xylose. Under the selected optimum conditions, the six monosaccharides could be perfectly separated within 25 min and showed significant current responses at copper electrodes. The linear ranges of the six monosaccharides were all from 5.0 x 10(-6) to 2.0 x 10(-4) mol L(-1) and their detection limits were lower or near 1.0 x 10(-6) mol L(-1) (S/N = 3). Experiments showed that the Angelica sinensis polysaccharide was composed of fucose, galactose, glucose, arabinose, rhamnose and xylose (mole ratio 1.0:13.6:15.0:8.7:21.3:3.7), and the flax polysaccharide was composed of galactose, glucose and arabinose (mole ratio 1.0:4.98:1.1). The purity of these polysaccharides leached by the introduced leaching method was 98.3 and 97.6%, respectively. Analyzing polysaccharides by this method has some merits of speed, simple instrumentation and operation, high sensitivity and high reproducibility.