Determination Of Monosaccharides Research Articles

A Rapid and Accurate UHPLC Method for Determination of Monosaccharides in Polysaccharides of Different Sources of Radix Astragali and Its Immune Activity Analysis.

With the escalating demand for Astragalus polysaccharides products developed from Radix Astragali (RA), the necessity for quality control of polysaccharides in RA has become increasingly urgent. In this study, a specific method for the simultaneous determination of seven monosaccharides in polysaccharides extracted from Radix Astragali (RA) has been developed and validated using ultra-performance liquid chromatography equipped with an ultraviolet detector (UHPLC-UV) for the first time. The 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatizations were separated on a C18 column (Waters ACQUITYTM, Milfor, MA, USA, 1.8 µm, 2.1 × 100 mm) using gradient elution with a binary system of 5 mm ammonium formate (0.1% formic acid)-acetonitrile for 24 min. Additionally, seven monosaccharides showed good linear relationships (R2, 0.9971-0.9995), adequate precision (RSD < 4.21%), and high recoveries (RSD < 4.70%). The established method was used to analyze 109 batches of RA. Results showed that the Astragalus polysaccharides (APSs) mainly consist of mannose (Man), rhamnose (Rha), glucose (Glu), galactose (Gal), arabinose (Ara), xylose (Xyl); and fucose (Fuc); however, their composition was different among RA samples from different growth patterns, species, growth years, and origins, and the growth mode of RA and the age of wild-simulated RA can be accurately distinguished by principal component analysis (PCA). In addition, the immunological activity of APSs were also evaluated jointly by measurement of the NO release with RAW264.7, with the results showing that APSs have a promoting effect on the release of NO and exhibit a significant correlation with Man, Glu, Xyl, and Fuc contents. Accordingly, the new established monosaccharides analytical method and APS-immune activity determination in this study can provide a reference for quality evaluation and the establishment of quality standards for RA.

Characterization of Mannoprotein Structural Diversity in Wine Yeast Species.

The structure of yeast cell wall (CW) mannoproteins (MPs) influences their impact on wine properties. Yeast species produce a diverse range of MPs, but the link between properties and specific structural features has been ill-characterized. This study compared the protein and polysaccharide moieties of MP-rich preparations from four strains of four different enologically relevant yeast species, named Saccharomyces boulardii (SB62), Saccharomyces cerevisiae (SC01), Metschnikowia fructicola (MF77), and Torulaspora delbrueckii (TD70), and a commercial MP preparation. Monosaccharide determination revealed that SB62 MPs contained the highest mannose/glucose ratio followed by SC01, while polysaccharide size distribution analyses showed maximum molecular weights ranging from 1349 kDa for MF77 to 483 kDa for TD70. Protein identification analysis led to the identification of unique CW proteins in SB62, SC01, and TD70, as well as some proteins shared between different strains. This study reveals MP composition diversity within wine yeasts and paves the way toward their industrial exploitation.

Development of a joint derivatization protocol for the unequivocal identification of the monosaccharide composition in four dendrobium polysaccharides and free monosaccharide by GC-MS.

The determination of monosaccharides is crucial for studying the structure of polysaccharides and the composition of free monosaccharides in living organisms. Based on previous derivatization gas chromatography-mass spectrometry (GC-MS) methods, we aimed to develop a novel analytical protocol for better quantifying monosaccharides. In this study, sugar alcohol acetylation, saccharonitrile acetylation, silylation and a combination of sugar alcohols acetylation and saccharonitrile acetylation were compared. The optimal method was verified with the monosaccharide determination of four polysaccharides and four free monosaccharides from Dendrobium. The results showed that the novel combined derivatization method was superior to the other three methods in terms of content analysis of monosaccharides. Furthermore, it possessed good linearity (all calibration curves showed relative coefficients ≥ 0.999), sensitivity, precision (relative standard deviation < 2%), and accuracy (recovery, 95.7-105%). Finally, the novel method established in this study was successfully employed in determining the monosaccharide composition of four polysaccharides and four free monosaccharide samples from Dendrobium.

An efficient mixed enzymes-assisted mechanical bio-extraction of polysaccharides from Dendrobium officinale and determination of monosaccharides by HPLC-Q-TOF/MS

The mixed enzymes-assisted mechanical bio-extraction method was first used to extract polysaccharides from Dendrobium officinale. Different parameters including the ratio of enzyme, the amount of enzyme, the grinding time, the extraction time and the solid/liquid ratio were investigated by single factor experiments and multifactorial experiments. Through the response surface methodology the optimal extraction conditions were obtained with the ratio of cellulase to pectinase was 2: 1 and total amount of enzyme was 0.23 mg, the grinding time of 11.48 min, the extraction time of 5.99 min. The obtained polysaccharide extracts were hydrolyzed and derivatized and then injected into high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF/MS) for monosaccharide composition analysis. After optimization of the chromatographic conditions (including mobile phase and column), twelve monosaccharides were successfully determined within 20 min. The proposed method provided satisfactory linearity with the correlation coefficients higher than 0.99, suitable recoveries (81.46–114.92 %), acceptable reproducibility ranging from 0.06 % to 4.77 %, low limits of detection (0.70–45.45 ng/mL). Compared with other methods, this method makes the extraction efficiency much higher and has the advantages of simple operation, environmental friendliness and mild extraction conditions. Therefore, this method can be used for the extraction of polysaccharides from plants and the determination of monosaccharides and has the potential to be used in more areas.

Comparative monosaccharide profiling for taxon differentiation: An example of Icelandic edible seaweeds

Edible seaweeds are usually sold as flakes or even powers, and morphological identification of seaweed taxa is difficult. Water-soluble polysaccharides (WSPs) in edible seaweeds are not only interesting functional food ingredients (e.g. gel-forming property, health benefits), but also useful for seaweed taxon differentiation. The current study aims to explore the utility of monosaccharide profiling of WSPs in seaweed differentiation. We developed a high-performance liquid chromatography-photodiode array detection for monosaccharide determination, and characterized monosaccharide profiles of WSPs from five edible seaweeds sold in Iceland (i.e. kombu Iceland – Laminaria hyperborea, sugar kelp – Saccharina latissima, dulse – Palmaria palmata and two types of nori labelled as Porphyra sp. and Pyropia sp.). Monosaccharide profiling data reflected both the complexity and quantitative differences of WSPs. The seaweed dulse showed the highest concentrations of total sugar (ca. 16 mM), followed by kombu (ca. 12 mM). From monosaccharide profiling of red algae, it was found that galactose (ca. 81–87% of total sugars) and xylose (ca. 65–77% of total sugars) are the dominant sugars in nori and dulse, respectively, which reflected the presence of galactans and xylans. In brown algae (i.e. kombu and sugar kelp), glucose (ca. 64–83%) and fucose (13–20%) are the main sugars, and they represent laminarins and fucoidans. The principal component analysis of sugar profiles showed the useful patterns ‘for seaweed taxon differentiation. The dendrogram resulting from hierarchical cluster analysis is congruent with phylogenetic tree, implying the chemotaxonomic value of seaweed monosaccharide profiles. This tool will be more useful in authentication of seaweed taxa when morphological and genetic identifications are not available.

Synthesis of naphthalimide-type chemsensor and its application in quality evaluation for polygonatum sibiricum Red.

The premise and key of ensuring the safety and effectiveness of traditional Chinese medicine (TCM) is to construct appropriate quality evaluation system of TCM. This study aimed to establish a pre-column derivatization HPLC method for achieving the quality control of Polygonatum sibiricum by reacting synthesized 4-hydrazino-1,8-naphthalimide (HAN) with diverse monosaccharides from the hydrolytic product of P. sibiricum polysaccharides (PSPs), followed by HPLC separation. The HAN was synthesized based on a CuI-catalyzed cross-coupling reaction in water, and then employed as a novel chemosensor that reacts with reducing sugars. Good separation was achieved at a detection wavelength of 448 nm using an ZORBAX SB-C8 column under a gradient elution at a flow rate of 0.5 ml/min within 12 min. The monosaccharide compositions of PSP mainly include two hexoses [glucose (Glc), galactose (Gal)] and two hexuronic acids [glucuronic acid (GlcA) and galacturonic acid (GalA)], and the molar ratio of Glc, Gal, GlcA and GalA is 16.67:52.94:10.58:19.81. The verified HPLC method, possessing excellent precision and good accuracy, successfully achieved rapid qualitative and quantitative determination for PSP. Additionally, the HAN displayed fluorescence enhancement through “push–pull” mode, and fluorescence decreased through “pull–pull” mode after binding to monosaccharides, which is a potential for fluorescence determination of different monosaccharides.

The investigation on the characteristic metabolites of Lactobacillus plantarum RLL68 during fermentation of beverage from by-products of black tea manufacture

At present, lactic acid bacteria (LAB) fermentation is commonly considered as an effective strategy to remarkably drive the improvement of flavor and nutritional value, and extend shelf-life of fermented foods. In this study, the by-product of tea manufacture, including broken tea segments and tea stalk, was used to produce fermented tea beverages. In addition, the residual components of matrices and bacterial metabolites were measured, as well as the sensory quality of the beverage was evaluated. Subsequently, the determination of monosaccharides, volatile aroma profile, free amino acids, biogenic amines and organic acids, and several functional substances involving γ-aminobutyric acid (GABA), polyphenols, caffeine and L-theanine were carried out. The results revealed that glucose, fructose, mannose and xylose are principal carbon source of Lactobacillus plantarum RLL68 during the fermentation; moreover, the abundance of aromatic substances is varied dramatically and the characteristic flavors of the beverages, particularly fermentation for 48 h and 72 h, are imparted with sweet and fruity odor on the basis of initial nutty and floral odor; Meanwhile, the organoleptic qualities of fermented beverages is also enhanced. Furthermore, the levels of organic acids and GABA are elevated, while the bitter amino acids, as well as some bioactive substances including tea polyphenols and L-theanine are declined; Besides, the caffeine level almost remains constant, and quite low levels of various biogenic amines are also observed. The results of this study will provide the theoretical basis to steer and control the flavor and quality of the fermented tea beverages in the future.

A capillary electrophoresis method for the determination of soluble monosaccharides in Ginkgo biloba leaves.

A method for the simultaneous determination of six monosaccharides by pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone and capillary electrophoresis was developed in this work. The derivatization (i.e., reaction temperature, capillary electrophoresis duration, and extraction number) and separation (i.e., pH and buffer concentration) conditions for capillary electrophoresis were optimized. Results showed that the limits of detection under optimal conditions were in the range of 0.036-0.35mg/L with a mean correlation coefficient >0.99. The recoveries were in the range of 87.3-108.49%, and the relative standard deviations of intra- and inter-day variations were in the ranges of 2.2-3.8 and 3.2-5.0%, respectively. The method was successfully applied to the analysis of six free monosaccharides in three types of Ginkgo biloba leaves.

Quality Distinguish of Red Ginseng from Different Origins by HPLC–ELSD/PDA Combined with HPSEC–MALLS–RID, Focus on the Sugar-Markers

Red ginseng (RG) has been extensively utilized in Asian countries due to its pharmacological effects. For the quality evaluation of RG, small molecules, such as ginsenosides, have been widely considered as candidates of its quality markers (Q-markers), and various analytical techniques have been developed in order to identify these compounds. However, despite the efforts to analyze the hydrophobic constituents, it is worth pointing out that about 60% of the mass of RG is made of carbohydrates, including mono-, oligo- and polysaccharides. Consequently, the quality differentiation and identification of RG from the perspective of sugar-markers should be focused. High performance liquid chromatography and evaporative light scattering detector (HPLC–ELSD) method for the determination of disaccharides in RG was established. Furthermore, high performance size exclusion chromatography–multi-angle laser light scattering–refractive index detector (HPSEC–MALLS–RID) for the determination of molecular weight and high performance liquid chromatography photodiode array (HPLC–PDA) for the determination of compositional monosaccharides in RG polysaccharides were also established. HPLC–ELSD/PDA combined with HPSEC–MALLS–RID could be used to determine the contents of disaccharides, molecular weights, and compositional monosaccharides of RG polysaccharides, which could be used for quality control, and this is a new view on the sugar marker to quality differentiation of various origins of RG.

Determination and analysis of monosaccharides in Polygonatum cyrtonema Hua polysaccharides from different areas by ultra-high-performance liquid chromatography quadrupole trap tandem mass spectrometry.

We wanted to explore a new method for the determination of monosaccharides in Polygonatum cyrtonema Hua polysaccharide using the ultra‐high‐performance liquid chromatography quadrupole trap tandem mass spectrometry. In this study, hydrochloric acid was used instead of trifluoroacetic acid to hydrolyze polysaccharides, and hydrolysis time was greatly reduced from 5–9 h to 1 h. The 1‐phenyl‐3‐methyl‐5‐pyrazolone was used for pre‐column derivatization of monosaccharides. The parameters of linearity (R 2 > 0.999), stability (1.63–2.52%), intra‐day and inter‐day precision (0.69–0.95%, 1.81–2.77%), repeatability (1.89–2.65%), and recovery (97.63–102.24%) of the method were verified. Satisfactory validation results showed this method could be used to determine the target components. The results indicated the polysaccharide contained glucose, mannose, rhamnose, galactose, ribose, and arabinose. Technique for order preference by similarity to an ideal solution and principal component analysis were used to build an evaluation model based on the monosaccharide composition. The evaluation results showed that the samples from the Qingyang County of Anhui Province were the best when the monosaccharides were used as the evaluation index. Therefore, a new method was established to detect the monosaccharide content of polysaccharides from Polygonatum cyrtonema Hua and comprehensively evaluate the quality of Chinese medicines with polysaccharides as the main active ingredient.

Determination of Monosaccharides, Disaccharide and Uronic Acids in Laminaria japonica by High Performance Anion Exchange Chromatography with Pulsed Amperometric Detection

Determination of Monosaccharides, Disaccharide and Uronic Acids in Laminaria japonica by High Performance Anion Exchange Chromatography with Pulsed Amperometric Detection

Determination of Cellulose Degree of Polymerization in Historical Papers with High Lignin Content.

Determination of cellulose degree of polymerization (DP) is one of the most commonly used methods in paper degradation studies, performed either by a standardized method using viscometry (as average degree of polymerization (DPv)) or size-exclusion chromatography (SEC) (as weight average molecular mass (Mw)). Due to the insolubility of papers with high lignin content in cupriethylenediamine (CED), such as groundwood papers, viscometric determination is not possible; therefore, pretreatment is required to allow subsequent dissolution of the papers. In this study, the pretreatment of historical papers containing groundwood with sodium chlorite in acetic acid was investigated, which enables dissolution of the paper samples in CED and determination of the cellulose average degree of polymerization by viscometry (DPv). Kappa number was determined to estimate the lignin content in the papers. The suitability of SEC UV-VIS analysis for determination of Mw in papers with high lignin content had been verified before it was used as a comparative method for viscometry. Using SEC, changes in the weight average molecular mass (Mw) of cellulose tricarbanilate (CTC) derivative during delignification were evaluated. The results indicate that no significant depolymerization occurred in the selected samples under the studied delignification conditions, which was additionally confirmed with determination of monosaccharides by ion chromatography. The results of the Mw determinations by SEC and DPv by viscometry are in good correlation, justifying the use of viscometry after chlorite/acetic acid pretreatment to determine the cellulose average degree of polymerization in historical papers with high lignin content.

(General Student Poster Session Winner - 2nd Place) Synthesis and Comparative Electrochemical Study of Mixed Metal Oxides Derived from Hydrotalcites Modified with Copper (II) and Nickel (II)

At present, the use of heterogeneous catalysts together with environmentally friendly methodologies has been increasing for the synthesis of value-added products.[1] Schiff bases (SB) and their derivatives are very versatile compounds of great importance in the fine chemical industry since they are widely used in various chemistry fields such as, pharmaceutical, clinical, pharmacological, electrochemical, catalytic, photochemical and luminescence. [2-4] On the other hand, the use of mixed metal oxides (MMO) derived from hydrotalcites (LDHs) as catalysts has been increased in organic chemistry. In this work, we synthetized, characterized, and employed MMOs modified with Cu (II) and Ni (II) as catalyst in the synthesis of SB derived from 2-aminothizoles and aromatic aldehydes. The MMOs synthetized were labeled as NixMMO and CuyMMO (x and y, denotes the percentage of substitution of Mg (II) ions by Ni (II) or Cu (II) ions). The electrochemical behavior of these MMOs were determined by cyclic voltammetry and chronoamperometry using a system of three electrodes: Ag/AgCl electrode (reference electrode), Pt wire (counter electrode) and carbon paste electrode (CPE) modified with MMOs (working electrode) in an electrochemical cell. The analysis was carried out employing NaOH (0.1 mol L-1) and NaCl (0.05 mol L-1) as electrolytic. [5] The electrochemical behavior of these MMO were compared with the catalytic results obtained in the synthesis of SB determining the influence of the metal substituted on the catalysts.[1] Vargas, J. M., Henrique, L., Morelato, T., Ortega, J. O., Boscolo, M., & Metzker, G. (2020). Upgrading 1-butanol to unsaturated, carbonyl and aromatic compounds: a new synthesis approach to produce important organic building blocks. Green Chemistry, 22, 2365-2369[2] Muhammad, A. R., Necmi, Dege., Onur, E. D., Tuğgan, Ağar., & Sajjad, H. S. (2020). Synthesis of two new Schiff bases; crystal structure, Hirshfeld surface analysis, density functional theory and molecular docking. Molecular Structure, 1226, 129330.[3]Revenga, M., Robledo, S., Martínez, E., González, M., Colina, A., Herase, A., Parientea, F., & Lorenzo, E. (2020). Direct determination of monosaccharides in honey by coupling a sensitive new Schiff base Ni complex electrochemical sensor and chemometric tools. Sensors and Actuators B: Chemical, 312. 127848.[4] Maza, S., Kijatkin, C., Bouhidel, Z., Pillet, S., Schaniel, D., Imlau, M., Guillot, B., Cherouana, A., & Bendeif, E. (2020). Synthesis, structural investigation and NLO properties of three. Journal of Molecular Structure, 1219, 128492.[5] Aguilar, V., Gonzalez, I., & Valente, J. S. (2011). Comparative Electrochemical Study of MgZnGa and ZnGaAl Hydrotalcites. ECS Transactions, 36, 247–256.

WOOD COMPONENTS AS SOURCES OF PENTO-CONTAINING RAW MATERIALS FOR SYNTHESIS OF USEFUL COMPOUNDS, PRODUCTS AND REAGENTS

The paper considers the main components and products of wood processing, agricultural waste, pulp and paper industry waste and qualifies them as sources of pentose-containing resource-renewable domestic raw materials. The article describes in detail the structural components of wood as a natural polymer, which contains aromatic and carbohydrate parts. It is noted that these poly-mers are promising as raw materials for the production of useful chemical products. The role of lignin, cellolose and hemicellulose in the design of mechanical and structural properties of wood is considered. The article considers the features of the sulfonation reactions of the lignin monomer unit depending on the pH of the medium: acidic, neutral and alkaline. There are three main reac-tions that occur simultaneously with lignin in the process of wood delignification during sulfite cooking, such as the sulfonation reaction, the hydrolytic destruction reaction, and the condensation reaction. It is shown that the lignin-hemicellulose matrix contains three types of interconnected mesh structures: the lignin itself; a network of covalent bonds of lignin with hemicelluloses, and a network whose structure is obtained due to the hydrogen bond and the forces of the physical inter-action of lignin and hemicelluloses. The features of chemical transformations of the monomeric aromatic link of lignosulfonate – phenylpropane unit in the processes of wood delignification, the main chemical reactions of wood raw material delignification under the conditions of sulfite and neutral-sulfite brews are shown. The method of quantitative determination of monosaccharides in the composition of the carbohydrate part is proposed.

Determination of monosaccharides in Lycium barbarum fruit polysaccharide by an efficient UHPLC-QTRAP-MS/MS method.

Pre-column derivatisation using 1-phenyl-3-methyl-5-pyrazolone (PMP) is a common method for monosaccharide determination. Herein, a specific ultra-high-performance liquid chromatography quadrupole trap tandem mass spectrometry (UHPLC-QTRAP-MS/MS) method was developed and used for the determination of monosaccharide composition of Lycium barbarum polysaccharide (LBP). Exploration of a new efficient method for monosaccharide determination. In our study, hydrochloric acid was used to hydrolyse the polysaccharide obtained from L. barbarum fruits. Principal component analysis (PCA) and technique for order of preference by similarity to ideal solution (TOPSIS) analysis were used for comprehensive evaluation of the samples. The results showed that LBP was composed of seven monosaccharides: galactose, arabinose, mannose, rhamnose, xylose, ribose, and glucose. The linear relationship of the seven monosaccharides was optimum within a certain concentration range. Quantitative recoveries of the seven monosaccharides from the samples ranged from 94.76% to 102.11%. A rapid quantitative detection method was established, in which the hydrolysis time was reduced from 12h to 2h. By using LBP as one of the indexes to evaluate the quality of L. barbarum, L. barbarum from Zhongning County, Ningxia Province, was identified as having the best quality among the varieties tested. The UHPLC-QTRAP-MS/MS pre-column derivatisation method used in this study was simple, accurate, and sensitive, with good repeatability, and can be used for quality evaluation and origin distinction of L. barbarum and other medicinal plants.

Determination of monosaccharides hydrolyzed from polysaccharides in activated sludge by ion chromatography-mass spectrometry with online pretreatment of column switching technique.

The simultaneous determination of monosaccharides present in the activated sludge would be crucial to understand the water treatment mechanism. Herein, an ion chromatography-mass spectrometry (IC-MS) with online pretreatment of column switching technique was proposed to analyze monosaccharides hydrolyzed from extracellular polysaccharides in the activated sludge. When the matrix was eliminated in the first dimension, monosaccharides were immediately identified by IC-MS. The improved ionization efficiency was achieved with the addition of T-joint prior to MS. During the performance test, our established method showed excellent detection limits ranging from 0.34 to 2.15μg/L for all sugar targets. Great linearity (R ≥ 0.9955) was also achieved using this method in the range from 0.01 to 5mg/L. Furthermore, the average recoveries were obtained between 84.82 and 113.46%. RSDs for peak areas and retention times were determined as 3.76% and 0.27%, respectively. Finally, this approach provided a rapid, convenient, and practical determination of monosaccharides in the activated sludge, which would be helpful for the analysis of monosaccharides derived from other biological samples.

Properties of fiberboards produced from kermes oak (Quercuscoccifera L.) and brutian pine (Pinusbrutia Ten.) woods

In this study the utilization of kermes oak Quercus coccifera L. wood, which could be used as an industrial raw material for the production of fiberboard, was investigated. In the experimental design, boards were produced from mixtures of kermes oak and brutian pine Pinus brutia Ten. fibers in ratios of 0:100, 25:75, 50:50, 75:25, and 100:0. The chemical and thermal characteristics of the fibers used were determined, and the effects of these characteristics on the physical and mechanical properties of the produced fiberboards were revealed. The main chemical component analysis indicated that kermes oak fibers contained higher quantities of extractives, α-cellulose, and hemicelluloses and a lower quantity of lignin compared to the brutian pine fibers. Analyses of the main chemical components were supported by Fourier transform infrared spectroscopic analyses and gas chromatographic determination of monosaccharides. The pH determination showed that kermes oak fibers were more acidic than the brutian pine fibers. Thermogravimetric analysis indicated that kermes oak fibers had higher thermal stability than brutian pine fibers. An increase in kermes oak in the fiber mixture raised water absorption and thickness swelling TS but reduced the modulus of elasticity MOE , modulus of rupture MOR , and internal bond IB strength of the produced boards. The boards produced with 25% kermes oak fibers met the requirements of standard TS-EN 622-5 in terms of TS, MOE, MOR, and IB strength for load-bearing applications in dry conditions.

Direct determination of monosaccharides in honey by coupling a sensitive new Schiff base Ni complex electrochemical sensor and chemometric tools

The determination and quantification of saccharides is of considerable importance in the food industry among other fields. In this work, we describe for the first time the preparation of the Schiff base Ni complex, NiII-(N,N’-bis(2,3-dihydroxybenzylidene)-1,2-diaminobenzene) (Ni(II)-2,3dhS) obtained by reaction of the tetradentate Schiff base ligand containing ortho quinone functional groups (N,N’-bis(2,3-dihydroxybenzylidene)-1,2-diaminobenzene) and Ni2+, as well as its application in the development of an electrochemical sensor. Coupled to chemometric tools, the sensor allowed the direct determination of glucose and fructose in honey, without the need of previous separation steps or chromatographic techniques. For this purpose, the new Schiff base Ni complex has been electropolymerized onto screen-printed electrodes modified with carbon nanotubes. The electropolymerization process has been exhaustively characterized by operando spectroelectrochemical techniques to confirm the generation of the desired polymer. The resulting modified electrodes present a strong electrocatalytic activity towards the oxidation of glucose and fructose in alkaline solution and have been employed in combination with partial least squares regression (PLSR) to resolve mixtures of glucose and fructose in a complex matrix, as honey. The multivariate model was based on PLSR analysis and showed good predictive capability for the two analytes in sample standard honey with an average error of 8% and relative standard deviations below 9%.

Analysis of monosaccharide composition in polysaccharides from Lycium barbarum L. by precolumn labeling under mild conditions and high-performance liquid chromatography coupled with mass spectrometry

A method for the separation, identification, and determination of fructose and various aldehyde monosaccharides was established by precolumn labeling with 1-phenyl-3-methyl-5-pyrazolone (PMP) and high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The separation was performed on a Kromasil-C18 column (100 mm×4.6 mm, 3.5 μm) with gradient elution. The detection was performed by electrospray ionization mass spectrometry in selected ion monitoring (SIM) mode. In this study, the derivatization mechanism of PMP-labeled fructose was proposed under mild NH3·H2O conditions. The suggested method showed good linearity in the corresponding mass concentration ranges, with the correlation coefficients (r2) > 0.9947. The limits of detection (LODs) and limits of quantification (LOQs) were in the ranges 0.003 to 0.05 mg/L and 0.01 to 0.15 mg/L, respectively. The recoveries in spiked Lycium barbarum L. samples were 65.1% to 116.2%, with relative standard deviations (RSDs) of less than 10.2%. By virtue of its simplicity, high sensitivity, and good repeatability, the method could be successfully applied to the analysis of the monosaccharide composition in polysaccharides of Lycium barbarum L. from four planting areas. Results showed that the isolated polysaccharides comprise mannose, fructose, rhamnose, galactose, glucose, xylose, arabinose, and ribose. The concentration distribution of various monosaccharides differed notably depending on the planted environmention. The proposed method is expected to be of great significance in standardizing the quality control of polysaccharides.

Selection of the Optimal conditions for analysis of plant active Pharmaceutical Inulin Ingredients by Thin-layer Chromatography to develop the draft for the National Monograph “Inulin”

Inulin is a representative of the class of soluble dietary fibers. One of the stated methods for identification of substances in the monograph “Inulin” of the British Pharmacopoeia 2010 (??) is the method of thin-layer chromatography (TLC), in the State Pharmacopoeia of Ukraine (SPhU) the method of TLC for identification of plant active pharmaceutical ingredients (API) of inulin is absent. The Pharmacopoeia provides only quality requirements of such monosaccharides as “Fructose”, “Anhydrous glucose”, “Glucose, monohydrate”, “Anhydrous lactose”, “Lactose monohydrate”. The experimental studies were conducted using nine herbal substances of inulin obtained from plant sources such as chicory, Jerusalem artichoke and agave and two standard substances of inulin with chicory and dahlia. Identification and determination of related impurities of plant API of inulin using TLC were performed according to the method of the monograph “Inulin” of the BP and the method of determination of monosaccharides given in the SPhU. The optimal conditions for the chromatographic determination have been chosen; validation of the method using indicators of specificity, robustness and precision has been conducted. The validated method for analysis of plant API of inulin using TLC has been proposed to be included into the draft for the monograph “Inulin” of the SPhU in the sections “Identification” and “Test for purity”.