Identification and Quantification of Monosaccharides from Fungal Cell Walls and Exopolysaccharides by Gas Chromatography Coupled to Mass Spectrometry

The fungal cell wall and secreted exopolysaccharides play an important role in the interactions between fungi and their environment. Despite their central role in fungal biology, ecology, and host-pathogen interactions, the composition of these polymers and their synthetic pathways are not well understood. The protocols presented in this article describe an approach to isolate fungal cell wall polysaccharides and to identify and quantify the monosaccharide composition of these polymers by gas chromatography-mass spectrometry (GC-MS). © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: O-methyl trimethylsilyl monosaccharide derivatives composition analysis by GC-MS Support Protocol: Fungal cell wall extraction.

Purification, Structural Characterization, and Anti-Inflammatory Effects of a Novel Polysaccharide Isolated from Orostachys fimbriata

The present study elucidated the structural characteristics and anti-inflammatory activity of a novel polysaccharide isolated from Orostachys fimbriata, which is a traditional Chinese medicinal plant. O. fimbriata polysaccharide (OFP) was extracted and subsequently purified by chromatography using a DEAE cellulose-52 and Sephadex G-75 column. The molecular weight was determined as 6.2 kDa. HPGPC and monosaccharide composition analysis revealed a homogeneous polysaccharide containing only Glc. Chromatography and spectral analysis showed that the possible chemical structure consisted of →4)-α-Glcp-(1→ and a small quantity of →4,6)-β-Glcp-(1→ in the main chain and →6)-β-Glcp-(1→, α-Glcp-(1→, and β-Glcp-(1→ in the side chain. Morphological analysis using scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicated that OFP had a multi-branched structure, and the sugar chain molecules of polysaccharide appeared aggregated. OFP was found to exhibit anti-inflammatory activity by reducing the secretion of inflammatory factors in RAW264.7 cells and by decreasing the extent of xylene-induced ear swelling in mice.

Toxicological assessment of Opuntia dillenii (Ker Gawl.) Haw. cladode methanol extract, fractions and its alpha pyrones: Opuntiol and opuntioside

ETHNOPHARMACOLOGICAL RELEVANCE

The edible plant Opuntia dillenii (Ker Gawl.) Haw. commonly known as Nagphana, belongs to the Cactaceae family. It is traditionally used to treat various ailments including inflammation, gastric ulcers, diabetes, hepatitis, asthma, whooping cough and intestinal spasm.

AIM OF THE STUDY

Despite its traditional use in various countries, detailed toxicological studies of O. dillenii cladode are few. Thus in the current study, toxicity of O. dillenii cladode derived methanol extract, fractions and its α-pyrones: opuntiol and opuntioside have been addressed.

METHODS

The test agents were assessed using both in vitro and in vivo toxicity assays. MTT on human embryonic kidney cell line (HEK-293), tryphan blue exclusion in rat neutrophils, Cytokinesis-B block micronucleus (CBMN) in human lymphocytes and genomic DNA fragmentation using agarose gel electrophoresis were performed. In acute toxicity test, mice orally received extract (5 g/kg) for 7 days followed by measurements of relative organ weight, biochemical (blood profile, liver and kidney function test) and histological studies (liver and kidney) were carried out. Rat bone marrow micronucleus genotoxicity assay was also conducted.

RESULTS

O. dillenii derived test agents were non-cytotoxic and had no effect on the integrity of DNA. Methanol extract (5 g/kg) orally administered in mice did not cause any significant change in relative organ weights, biochemical parameters and liver and kidney histology as compared to vehicle control. In parallel, extract did not stimulate micronuclei formation in rat bone marrow polychromatic erythrocytes.

CONCLUSION

These results led to conclude that edible O. dillenii extract is non-toxic via the oral route and appears to be non-cyto-, hepato-, nephro- or genotoxic, thereby supporting its safe traditional use against various ailments. Therefore, opuntiol and opuntioside may serve as lead compounds in designing new drug(s) derived from edible plants.

Recovery of Anthocyanins and Monosaccharides from Grape Marc Extract by Nanofiltration Membranes

Wastewaters and by-products generated in the winemaking process are important and inexpensive sources of value-added compounds that can be potentially reused for the development of new products of commercial interest (i.e., functional foods). This research was undertaken in order to evaluate the potential of nanofiltration (NF) membranes in the recovery of anthocyanins and monosaccharides from a clarified Carménère grape marc obtained through a combination of ultrasound-assisted extraction and microfiltration. Three different flat-sheet nanofiltration (NF) membranes, covering the range of molecular weight cut-off (MWCO) from 150 to 800 Da, were evaluated for their productivity as well as for their rejection towards anthocyanins (malvidin-3-O-glucoside, malvidin 3-(acetyl)-glucoside, and malvidin 3-(coumaroyl)-glucoside) and sugars (glucose and fructose) in selected operating conditions. The selected membranes showed differences in their performance in terms of permeate flux and rejection of target compounds. The NFX membrane, with the lowest MWCO (150–300 Da), showed a lower flux decay in comparison to the other investigated membranes. All the membranes showed rejection higher than 99.42% for the quantified anthocyanins. Regarding sugars rejection, the NFX membrane showed the highest rejection for glucose and fructose (100 and 92.60%, respectively), whereas the NFW membrane (MWCO 300–500 Da) was the one with the lowest rejection for these compounds (80.57 and 71.62%, respectively). As a general trend, the tested membranes did not show a preferential rejection of anthocyanins over sugars. Therefore, all tested membranes were suitable for concentration purposes.

A New, Quick, and Simple Protocol to Evaluate Microalgae Polysaccharide Composition

In this work, a new methodological approach, relying on the high specificity of enzymes in a complex mixture, was developed to estimate the composition of bioactive polysaccharides produced by microalgae, directly in algal cultures. The objective was to set up a protocol to target oligomers commonly known to be associated with exopolysaccharides' (EPS) nutraceutical and pharmaceutical activities (i.e., rhamnose, fucose, acidic sugars, etc.) without the constraints classically associated with chromatographic methods, while maintaining a resolution sufficiently high to enable their monitoring in the culture system. Determination of the monosaccharide content required the application of acid hydrolysis (2 M trifluoroacetic acid) followed by NaOH (2 M) neutralization. Quantification was then carried out directly on the fresh hydrolysate using enzyme kits corresponding to the main monosaccharides in a pre-determined composition of the polysaccharides under analysis. Initial results showed that the enzymes were not sensitive to the presence of TFA and NaOH, so the methodology could be carried out on fresh hydrolysate. The limits of quantification of the method were estimated as being in the order of the log of nanograms of monosaccharides per well, thus positioning it among the chromatographic methods in terms of analytical performance. A comparative analysis of the results obtained by the enzymatic method with a reference method (high-performance anion-exchange chromatography) confirmed good recovery rates, thus validating the closeness of the protocol. Finally, analyses of raw culture media were carried out and compared to the results obtained in miliQ water; no differences were observed. The new approach is a quick, functional analysis method allowing routine monitoring of the quality of bioactive polysaccharides in algal cultures grown in photobioreactors.

Enhanced separation and analysis of low abundant soy proteins by dual washing extraction process

Soybean seeds provide a rich source of proteins, fats, carbohydrates, and micronutrients. Extraction and analysis of low abundant soybean seed proteins are challenging because of its complex seed composition. For characterizing various proteins, it is paramount to remove the other interfering components, primarily oils, and carbohydrates. In the present study, we used a sequential dual washing process initially with hexane to remove oil and non-polar interferences, followed by 80% ethanol washing to remove about 60% of the total soluble sugars. The extracted soluble sugars were quantified using a newly developed and validated high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD). This newly developed combined washings process significantly enhanced the separation of both low molecular weight and low abundant proteins using 1D (one dimensional)- and 2D (two dimensional) gel electrophoresis. The separated proteins were trypsinized and analyzed by using Bruker amazon speed ion trap mass spectrometer equipped with an ESI source. This combined washing process allowed the identification of 18 additional low abundant soy proteins as compared to the simple hexane washed samples. This purification process will allow researchers to identify and investigate the role of low molecular weight and low abundant proteins as it relates to plant functions, nutrition, and health.

[High-efficiency separation and analysis of monosaccharides in Pueraria polysaccharides by pressurized capillary electrochromatography]

Pueraria polysaccharides have been proven to possess biological activities such as bacteriostasis, anti-oxidative, anti-tumor, and immunity boosting activities. The variation in the structure, composition, and amount of monosaccharides in these polysaccharides may lead to different spatial structures and biological activities. Therefore, extraction of Pueraria polysaccharides and determination of the monosaccharide composition are of great significance for activity analysis and quality control. Direct detection of saccharides is difficult because they are strongly polar and do not show absorption in the ultraviolet region. At present, the commonly used methods for saccharide detection are liquid chromatography-ultraviolet detection, gas chromatography-ultraviolet detection, and mass spectrometry. Pressurized capillary electrochromatography is a high-efficiency microseparation technology. In this study, two kinds of Pueraria polysaccharides were extracted by an ultrasonic-assisted method, and response surface methodology was performed to explore the conditions for ultrasonic-assisted extraction of polysaccharides from Pueraria. The interaction effects of four factors, the liquid-solid ratio, ultrasonic extraction time, ultrasonic extraction temperature, and ultrasonic power, on the extraction rate of the polysaccharides were analyzed. By combining the optimal conditions predicted by the software and the actual equipment conditions, the optimal extraction conditions for Pueraria polysaccharides were chosen as follows:ultrasonic extraction temperature, 90℃; liquid-solid ratio of Pueraria thomsonii Benth, 20 mL/g; liquid-solid ratio of Pueraria lobata Ohwi, 40 mL/g; ultrasonic extraction time, 30 min; ultrasonic power, 180 W. Through data fitting, the multiple quadratic regression equation of the four factors on the extraction rate of Pueraria polysaccharides was established. A novel method based on pressurized capillary electrochromatography for the separation and analysis of eight neutral monosaccharides has been established. The monosaccharides were derivatized by the 1-phenyl-3-methyl-5-pyrazolone pre-column derivatization method. The separation conditions for these monosaccharides were explored, and the buffer concentration, buffer pH, applied voltage, type of chromatographic column, and mobile phase ratio were optimized. Finally, the established pressurized capillary electrochromatography-ultraviolet detection method was applied to the detection and identification of two kinds of actual Pueraria polysaccharide samples. The results of response surface analysis showed that among the four experimental factors, ultrasonic extraction temperature had the greatest influence on the extraction rate of polysaccharides from the two kinds of Pueraria, followed by the liquid-solid ratio; the influence of the ultrasonic extraction time and ultrasonic power was relatively weak. The experimental conditions were determined as follows:the separation of eight neutral monosaccharide derivatives could be realized within 24 min on a Halo-2.7 μm core-shell C18 capillary column with acetonitrile-50 mmol/L ammonium acetate aqueous solution (18:82, v/v, pH 4.1) as the mobile phase, by detection at 250 nm under an applied voltage of-20 kV. The separation and detection speeds and the column efficiency achieved with this method were much better than those obtained with the traditional liquid chromatography method. The results show that the proposed method has a good linear relationship and good repeatability. The separation and identification results for the actual samples showed that the polysaccharides of Pueraria thomsonii Benth were mainly composed of glucose, mannose, rhamnose, and fucose in the molar ratio 1.00:0.16:0.14:0.07. The polysaccharides of Pueraria lobata Ohwi were mainly composed of glucose and mannose in the molar ratio 1.00:0.70. This study provides a novel method for the rapid and efficient separation and detection of neutral monosaccharides, and serves as a reference for analyzing the monosaccharide composition of Pueraria polysaccharides.

The heteropolysaccharide of Mangifera indica fruit: Isolation, chemical profile, complexation with β-lactoglobulin and antioxidant activity

A 91 kDa heteropolysaccharide (F2) was isolated from Mangifera indica fruit via extraction with H₂O, purification by C₂H₅OH, starch removal and ion exchange chromatography. This polymer was made up mostly of Ara, Gal, Glc, Rha, Xyl, and GalA in a 37: 29: 9:3:2:19 molar proportion. It inherited a small backbone containing GalpA and Rhap units substituted with very large side chains containing differently linked Ara and Gal units plus esterified gallic acid (GA) residue. Several enzymes generated oligosaccharides including (i) Ara_2-10Ac_6-22, (ii) Gal_1-8Ac_5-26 and (iii) GA₁Gal₁Ac₇ were characterized. This polysaccharide, which showed dose dependent antioxidant activity, exhibited synergism with gallic acid, and formed a complex (K = 1.2 × 10⁶ M^-1) with β-lactoglobulin. Accordingly, H₂O treatment produces a polysaccharide with desired biochemical properties; this could be effective in designing innovative functional food with flexible makeup.

Arsenosugar standards extracted from algae: Isolation, characterization and use for identification and quantification purposes

Sulfate (SO4-sug) and sulfonate (SO3-sug) arsenosugar standard solutions were obtained using preparative liquid chromatography. Several commercial algae samples were characterized (total contents and speciation) to select the most appropriate in relation to their arsenosugar contents. Water extracts from the selected sample (Fucus vesiculosus) were fractionated using a Hamilton PRP-X100 preparative column, and the presence of arsenic species in the isolated fractions was ascertained by IC-ICP-MS. Two of the fractions successfully presented only one arsenic species corresponding to sulfate and sulfonate arsenosugars at suitable concentrations. To unequivocally confirm the presence of both compounds, high-resolution mass spectrometry (ESI-TOF/MS) was used and the exact mass determined with errors lower than 0.5 ppm. The standard solutions obtained were successfully used to identify and quantify SO4-sug and SO3-sug in several edible algae samples purchased in local market. Total arsenic content for analyzed samples ranged from 34 to 57 mg kg-1, concentration values found for SO3-sug ranged from 5 to 36 mg As kg-1 and SO4-sug was only found in fucus with a concentration of 9.3 mg As kg-1.

Vaccine Quality Ensured by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection

Many important vaccines use bacterial capsular polysaccharides, or shorter polysaccharides or oligosaccharides, derived from the capsular polysaccharides, conjugated to protein. It is imperative that manufacturers understand the carbohydrate composition of these vaccines and deliver a product with a consistent polysaccharide or polysaccharide conjugate composition and content. High-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) is a major technique used to understand the carbohydrate composition of these vaccines and ensure product quality. HPAE-PAD separates and detects carbohydrates without analyte derivatization. This paper describes the basics of the HPAE-PAD technique and then reviews how it has been applied to Haemophilus influenzae type b, pneumococcal, meningococcal, group B streptococcal, and Salmonella polysaccharide and corresponding conjugate vaccines.

Microwave-assisted hydrothermal extraction of non-structural carbohydrates and hemicelluloses from tobacco biomass

Microwave-assisted hydrothermal extraction of non-structural carbohydrates and hemicelluloses from tobacco biomass was investigated. Non-structural carbohydrates extraction was optimized by an Optimal design. The maximum yields for the leaf and stem were 118.57 mg/g and 120.33 mg/g biomass, respectively. The extracted stem residue was further treated for hemicelluloses extraction. A temperature of 200 °C without holding was proved to be the most efficient condition to produce a hemicelluloses yield of 105.15 mg/g. GPC results showed that the Mw values of precipitated hemicelluloses decreased from 143.5 kDa to 13.25 kDa with increasing temperature and holding time, while the un-precipitated fraction were ranging from 11.83 to 4.88 kDa. Monosaccharide analysis revealed that hemicelluloses extracted at lower temperature are heterogeneous compositional type, including xylan, glucuronoxylan and xylanglucan, while the ratio of xylose increased significantly (up to 72.64%) with increasing temperature. The developed microwave-assisted hydrothermal extraction process opens new avenues for a sustainable tobacco-based biorefinery.

Fluorescent Probes for Sugar Detection

Herein, a new class of polymerizable boronic acid (BA) monomers are presented, which are used to generate soft hydrogels capable of accurate determination of saccharide concentration. By exploiting the interaction of these cationic BAs with an anionic fluorophore, 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (pyranine), a two-component sugar-sensing system was realized. In the presence of such cationic BAs ( o-BA, m-BA, and p-BA), the fluorescence of pyranine becomes quenched because of the formation of a nonfluorescent BA-fluorophore complex. Upon addition of saccharides, formation of a cyclic boronate ester results in dissociation of the nonfluorescent complex and recovery of the pyranine fluorescence. The response of this system was examined in solution with common monosaccharides, such as glucose, fructose, and galactose. Subsequent polymerization of the BA monomers yielded cross-linked hydrogels which showed similar reversible recovery of fluorescence in the presence of glucose.

Chemical and bioactivity screening of subcritical water extracts of chokeberry (Aronia melanocarpa) stems

Subcritical water extracts of chokeberry (Aronia melanocarpa) stems were chemically and biologically characterised. Chemical profile was defined by GC-MS analysis whereas anti-oxidant, anti-diabetic and tyrosinase-inhibitory activities of the extracts were investigated by in vitro assays. Antioxidant activity assays revealed strong activity against DPPH radical (IC₅₀ = 0.1 mg/mL) and reducing power (IC₅₀ = 0.25 mg/mL). The extracts demonstrated remarkable amylase (0.59 mmol ACAE/g) and glucosidase (7.50 mmol ACAE/g) inhibitory effects. Anti-tyrosinase activity of aronia stem extracts obtained by subcritical water was calculated to be 15.87 mg KAE/g extract. GC-MS analysis of chokeberry stem subcritical water extracts revealed the presence of different chemical classes. The compounds present in the highest concentrations were polyols arabitol (13.7%), xylitol (3.5%), and glycerol (1.96%), as well as sugars such as fructose (3.04%), ribose (1.99%) and xylulose (1.18%).

A Modified GC-MS Analytical Procedure for Separation and Detection of Multiple Classes of Carbohydrates

A modified GC-MS analytical procedure based on trimethylsilyl-dithioacetal (TMSD) derivatization has been established for a simultaneous determination of thirteen carbohydrates. Different from previous approaches, the current GC-MS method was featured by a powerful practicability for simultaneous detection of aldoses, uronic acids, ketoses, and amino sugars; simplifying GC-MS chromatograms and producing a single peak for each derivatized sugar, as well as high resolution, sensitivity, and repeatability. An additional liquid-liquid extraction from derivatization mixtures was performed not only to increase the detection sensitivity of amino sugars but also to decrease the by-products of derivatization. Contrarily, three amino sugars were detected at a very low intensity or not detected at all. The effect of time on monosaccharide- mercaptalated reaction was systematically investigated. The effect of trimethylsilylation on the formation of TMSD was also optimized. The established GC-MS based on TMSD derivatization was suitable for complex carbohydrate analysis and has been successfully applied for the detection of free carbohydrates in water extracts of Anemarrhena asphodeloides roots and determination of monosaccharides in Glossy ganoderma polysaccharides.

Plant Cell Walls: Isolation and Monosaccharide Composition Analysis

Plant cell walls have important roles during all phases of plant growth and development. Polysaccharides are the major components of the primary walls surrounding growing plant cells, together with small amounts of protein and minerals. Secondary walls that are deposited when a cell has ceased to grow are also composed predominantly of polysaccharides, although lignin may account for up to 20% w/w of these walls. The types of polysaccharides and their structure and abundance often vary greatly in the cell walls of different plant species, different cell types, and different developmental stages. Significant changes in structure and composition of cell wall have been described in various types of plant senescence. Here we describe a general method for the isolation of cell wall polysaccharides as their alcohol-insoluble residues (AIR) and procedures for the determination of the neutral and acidic monosaccharides present in the wall.

C-glycosides from the stems of Calophyllum membranaceum

Three new C-glycosides, calophymembransides D-F (1-3), were isolated from the stems of Calophyllum membranaceum Gardn. et Champ.. The structures were assigned on the basis of spectroscopic data. RXRα transcriptional inhibition and α-glucosidase inhibition assays indicated that all the isolates were inactive.

Unexpected features of exponentially growing Tobacco Bright Yellow-2 cell suspension culture in relation to excreted extracellular polysaccharides and cell wall composition

This article presents a new insight about TBY-2 cells; from extracellular polysaccharides secretion to cell wall composition during cell suspension culture. In the medium of cells taken 2 days after dilution (end of lag phase), a two unit pH decrease from 5.38 to 3.45 was observed and linked to a high uronic acid (UA) amount secretion (47.8%) while, in 4 and 7 day-old spent media, pH increased and UA amounts decreased 35.6 and 42.3% UA, respectively. To attain deeper knowledge of the putative link between extracellular polysaccharide excretion and cell wall composition, we determined cell wall UA and neutral sugar composition of cells from D2 to D12 cultures. While cell walls from D2 and D3 cells contained a large amount of uronic acid (twice as much as the other analysed cell walls), similar amounts of neutral sugar were detected in cells from lag to end of exponential phase cells suggesting an enriched pectin network in young cultures. Indeed, monosaccharide composition analysis leads to an estimated percentage of pectins of 56% for D3 cell wall against 45% D7 cell walls indicating that the cells at the mid-exponential growth phase re-organized their cell wall linked to a decrease in secreted UA that finally led to a stabilization of the spent medium pH to 5.4. In conclusion, TBY-2 cell suspension from lag to stationary phase showed cell wall remodeling that could be of interest in drug interaction and internalization study.

Identification of a flavonoid C-glycoside as potent antioxidant

Flavonoids have been documented to have good antioxidant activities in vitro. However, reports on the cellular antioxidant activities of flavonoid C-glycosides are very limited. In this work, an apigenin C-glycoside was purified from Artocarpus heterophyllus by column chromatography and was identified to be 2″-O-β-D-xylosylvitexin by nuclear magnetic resonance spectroscopy. The cellular antioxidant activity and anticancer activity of 2″-O-β-D-xylosylvitexin were evaluated for the first time. The quantitative structure-activity relationship was analysed by molecular modeling. Apigenin presented an unexpected cellular antioxidation behaviour. It had an antioxidant activity at low concentration and a prooxidant activity at high concentration, whereas 2″-O-β-D-xylosylvitexin showed a dose-dependent cellular antioxidant activity. It indicated that C-glycosidation improved the cellular antioxidation performance of apigenin and eliminated the prooxidant effect. The ortho-dihydroxyl at C-3'/C-4' and C-3 hydroxyl in the flavonoid skeleton play important roles in the antioxidation behaviour. The cell proliferation assay revealed a low cytotoxicity of 2″-O-β-D-xylosylvitexin.

A two-stage pretreatment process using dilute hydrochloric acid followed by Fenton oxidation to improve sugar recovery from corn stover

A two-stage pretreatment process is proposed in this research in order to improve sugar recovery from corn stover. In the proposed process, corn stover is hydrolyzed by dilute hydrochloric acid to recover xylose, which is followed by a Fenton reagent oxidation to remove lignin. 0.7wt% dilute hydrochloric acid is applied in the first stage pretreatment at 120°C for 40min, resulting in 81.0% xylose removal. Fenton reagent oxidation (1g/L FeSO4·7H2O and 30g/L H2O2) is performed at room temperature (about 20°C) for 12 has a second stage which resulted in 32.9% lignin removal. The glucose yield in the subsequent enzymatic hydrolysis was 71.3% with a very low cellulase dosage (3FPU/g). This two-stage pretreatment is effective due to the hydrolysis of hemicelluloses in the first stage and the removal of lignin in the second stage, resulting in a very high sugar recovery with a low enzyme loading.

Rapid preparation of functional polysaccharides from Pyropia yezoensis by microwave-assistant rapid enzyme digest system

This study describes a simple preparation of functional polysaccharides from Pyropia yezoensis using a microwave-assistant rapid enzyme digest system (MAREDS) with various carbohydrases, and evaluates their antioxidative effects. Polysaccharide hydrolysates were prepared using MAREDS under different hydrolytic conditions of the carbohydrases and microwave powers. Polysaccharides less than 10kDa (Low molecular weight polysaccharides, LMWP, ≤10kDa) were efficiently obtained using an ultrafiltration (molecular weight cut-off of 10kDa). MAREDS increases AMG activation via an increased degree of hydrolysis; the best AMG hydrolysate was prepared using a 10:1 ratio of substrate to enzyme for 2h in MAREDS with 400W. LMWP consisted of galactose (27.3%), glucose (64.5%), and mannose (8.3%) from the AMG hydrolysate had stronger antioxidant effects than the high molecular weight polysaccharides (>10kDa). We rapidly prepared functional LMWPs by using MAREDS with carbohydrases, and suggest that LMWP might be potentially a valuable algal polysaccharide antioxidant.

Chemical Structure and Immunomodulating Activities of an α-Glucan Purified from Lobelia chinensis Lour

A neutral α-glucan, named BP1, with a molecular mass of approximately 9.45 kDa, was isolated from Lobelia chinensis by hot-water extraction, a Q-Sepharose Fast Flow column and Superdex-75 column chromatography. Its chemical structure was characterized by monosaccharide analysis, methylation analysis and analysis of its FT-IR, high performance gel permeation chromatography (HPGPC) and 1D/2D-NMR spectra data. The backbone of BP1 consists of →₆α-d-Glcp¹→6,3α-d-Glcp¹→(₆α-d-Glcp¹)x-6,3α-d-Glcp¹-(₆α-d-Glcp¹)y→. The side chains were terminal α-d-Glcp¹→ and α-d-Glcp¹→ (₆α-d-Glcp¹)z→₄α-d-Glcp¹→₃α-d-Glcp¹→₄α-d-Glcp¹→ (x + y + z = 5), which are attached to the backbone at O-3 of 3,6α-d-Glcp¹. The results of the effect of BP1 on mouse macrophage cell line RAW 264.7 indicate that BP1 enhances the cell proliferation, phagocytosis, nitric oxide production and cytokine secretion in a dose-dependent manner. Because the inhibitor of Toll-like receptor 4 blocks the BP1-induced secretion of TNF-α and IL-6, we hypothesize that α-glucan BP1 activates TLR4, which mediates the above-mentioned immunomodulating effects.

3-O-β-D-Glucopyranosyltheobroxide from Aerial Parts of Cowpea (Vigna unguiculata)

Theobroxide has been isolated from culture filtrates of Lasiodiplodia theobromae as a potato tuber-inducing compound. In this study, the metabolism of theobroxide was investigated using cowpea as an experimental model and [2H3-7]theobroxide as a substrate for analyzing a metabolite, which revealed that theobroxide applied exogenously to the roots was converted into 3-O-β-D-glucopyranosyltheobroxide.

Antioxidant and immunomodulatory properties of polysaccharides from Allanblackia floribunda Oliv stem bark and Chromolaena odorata (L.) King and H.E. Robins leaves

BACKGROUND

Many plant polysaccharides have shown high antioxidant and immunostimulating properties and can be explored as novel molecules with biological properties that can potentially improve immune function. The objective of this work was to characterize soluble and cell wall polysaccharides isolated from the stem bark of Allanblackia floribunda and Chromolaena odorata leaves and to evaluate their antioxidant and immunomodulatory properties.

METHODS

Three polysaccharide fractions: soluble polysaccharides (PoS), pectins (Pec) and hemicelluloses (Hem) were extracted from A. floribunda stem bark and C. odorata leaves. These samples were analysed for their proteins, phenolic compounds and total sugar contents. The monosaccharide composition was determined by gas chromatography and arabinogalactan proteins content in PoS was evaluated by rocket electrophoresis. The in vitro antioxidant activities were evaluated by 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-bis-3-éthylbenzylthiazoline-6-sulphonic acid (ABTS) radical scavenging assays and ferrous ions chelating activity. Immunomodulatory activities were performed on the peripheral blood mononuclear cells (PBMCs) using proliferation and enzyme linked immunospot (ELISPOT) method to determine the production of an interferon-gamma.

RESULTS

The characterization of the various fractions showed varied metabolites in each plant. In PoS fractions, Ara and Gal were the major monosaccharides found, indicating that arabinogalactans are the primary macromolecules. Hem fractions contained predominantly Xyl and GalA for A. floribunda and Xyl (upto 80 %) for and C. odorata. A. floribunda Hem fraction and C. odorata PoS fraction showed significant DPPH and ABTS radical scavenging activities and immunostimulatory activity via stimulation of PBMC and production of IFN-γ in a dose-dependent manner.

CONCLUSION

The results obtained from this study support the ethnomedicinal use of the stem bark of A. floribunda and leaves of C. odorata. Further research is necessary to have supporting evidence that the antioxidative and immunomodulative activities of these fractions are really connected to the polysaccharides and not polyphenols.

Centrifugal partition chromatography in a biorefinery context: Separation of monosaccharides from hydrolysed sugar beet pulp

A critical step in the bioprocessing of sustainable biomass feedstocks, such as sugar beet pulp (SBP), is the isolation of the component sugars from the hydrolysed polysaccharides. This facilitates their subsequent conversion into higher value chemicals and pharmaceutical intermediates. Separation methodologies such as centrifugal partition chromatography (CPC) offer an alternative to traditional resin-based chromatographic techniques for multicomponent sugar separations. Highly polar two-phase systems containing ethanol and aqueous ammonium sulphate are examined here for the separation of monosaccharides present in hydrolysed SBP pectin: l-rhamnose, l-arabinose, d-galactose and d-galacturonic acid. Dimethyl sulfoxide (DMSO) was selected as an effective phase system modifier improving monosaccharide separation. The best phase system identified was ethanol:DMSO:aqueous ammonium sulphate (300gL(-1)) (0.8:0.1:1.8, v:v:v) which enabled separation of the SBP monosaccharides by CPC (200mL column) in ascending mode (upper phase as mobile phase) with a mobile phase flow rate of 8mLmin(-1). A mixture containing all four monosaccharides (1.08g total sugars) in the proportions found in hydrolysed SBP was separated into three main fractions; a pure l-rhamnose fraction (>90%), a mixed l-arabinose/d-galactose fraction and a pure d-galacturonic acid fraction (>90%). The separation took less than 2h demonstrating that CPC is a promising technique for the separation of these sugars with potential for application within an integrated, whole crop biorefinery.

A new glucosidic phthalide from Helichrysum microphyllum subsp. tyrrhenicum from La Maddalena Island (Sardinia, Italy)

In this study, we reported the analysis of the medium polarity fraction obtained from an accession of Helichrysum microphyllum subsp. tyrrhenicum from La Maddalena Island. Besides several compounds already evidenced in this species and related genera, i.e. micropyrone (1), arzanol (2), helipyrone (3), acetyl-bitalin derivatives (4, 5), gnaphaliol (6), caffeic acid (7), ursolic acid (8), 7-O-β-(D-glucopyranosyl)-5-methoxy-1(3H)-isobenzofuranone (9), gnaphaliol-9-O-β-D-glucopyranoside (11) and gnaphaliol-3-O-β-D-glucopyranoside (12), the presence of a new glycosidic phthalide, 6-O-β-(D-glucopyranosyl)-4-methoxy-1(3H)-benzofuranone (10), was evidenced for the first time, which resulted in a structural isomer of compound (9). The occurrence of this new benzofuranone derivative is an additional evidence of the deep intraspecific variability expressed by this species, which was also stated for the non-volatile components, and may be a distinctive trait of the population growing on La Maddalena Island.

Biorefining strategy for maximal monosaccharide recovery from three different feedstocks: eucalyptus residues, wheat straw and olive tree pruning

This work proposes the biorefining of eucalyptus residues (ER), wheat straw (WS) and olive tree pruning (OP) combining hydrothermal pretreatment (autohydrolysis) with acid post-hydrolysis of the liquid fraction and enzymatic hydrolysis of the solid fraction towards maximal recovery of monosaccharides from those lignocellulose materials. Autohydrolysis of ER, WS and OP was performed under non-isothermal conditions (195-230°C) and the non-cellulosic saccharides were recovered in the liquid fraction while cellulose and lignin remained in the solid fraction. The acid post-hydrolysis of the soluble oligosaccharides was studied by optimizing sulfuric acid concentration (1-4%w/w) and reaction time (10-60 min), employing a factorial (2(2)) experimental design. The solids resulting from pretreatment were submitted to enzymatic hydrolysis by applying commercial cellulolytic enzymes Celluclast® 1.5L and Novozyme® 188 (0.225 and 0.025 g/g solid, respectively). This strategy provides high total monosaccharide recovery or high glucose recovery from lignocellulosic materials, depending on the autohydrolysis conditions applied.

Ameliorative effects of physcion 8-O-β-glucopyranoside isolated from Polygonum cuspidatum on learning and memory in dementia rats induced by Aβ1-40

CONTEXT

Polygonum cuspidatum Sieb. Et Zucc. (Polygonaceae) has been traditionally used in folk medicine to treat various diseases.

OBJECTIVE

This study investigates the ameliorative effects of physcion 8-O-β-glucopyranoside (PSG) isolated from P. cuspidatum on learning and memory in dementia rats induced by Aβ1-40.

MATERIALS AND METHODS

Dementia rats were prepared by intracerebroventricular injection of Aβ1-40. PSG (5, 10, 20, and 40 mg/kg/d, for 5 d) was administered orally. Ameliorative activity of PSG in dementia rats was evaluated by the Morris water maze (MWM) test, and its mechanisms were explored by evaluating AchE activity, levels of DA, NE, and 5-HT in hippocampus, and drebrin protein expressions in hippocampus.

RESULTS

Our results indicated that PSG (5, 10, 20, and 40 mg/kg/d) significantly inhibited the prolonged latency in dementia rats (p < 0.05), and inhibitory rates were 16.5, 22.7, 33.0, and 44.8% after 5 d of learning, indicating that PSG improves learning and memory of dementia rats. Furthermore, PSG significantly decreased AchE activity (10, 20, and 40 mg/kg/d; p < 0.05), increased 5-HT (20 and 40 mg/kg/d, p < 0.05), NE (10, 20, and 40 mg/kg/d; p < 0.05), and DA levels (5, 10, 20, and 40 mg/kg; p < 0.05) in the hippocampus. Additionally, PSG obviously decreased the Aβ contents in hippocampus (10, 20, and 40 mg/kg/d; p < 0.05), and up-regulated drebrin protein expressions (5, 10, 20, and 40 mg/kg/d; p < 0.05).

CONCLUSIONS

PSG can significantly enhance learning and memory in Aβ1-40-induced dementia rats, and the mechanisms may be related to increase levels of Ach, 5-HT, NE, and DA, decrease Aβ contents, and up-regulation of drebrin proteins in hippocampus.

Evaluation of Salacia species as anti-diabetic natural resources based on quantitative analysis of eight sulphonium constituents: a new class of α-glucosidase inhibitors

INTRODUCTION

Stems and roots of Salacia genus plants have been used in Ayurveda as a specific remedy for early stage diabetes. Previous investigations identified four sulphonium sulphates, that is, salacinol (1), kotalanol (3), ponkoranol (5) and salaprinol (7), as the compounds responsible for the anti-diabetic activity. Their desulphonates (2, 4, 6 and 8) were also isolated as active constituents. Two separate quantitative analytical protocols, that is, for 1 and 3 and for 2 and 4, have been developed recently.

OBJECTIVE

To: validate the two analytical protocols with respect to all eight sulphoniums; evaluate the quality of a variety of Salacia samples collected in different geographical regions, that is, Thailand, Sri Lanka and India; and determine their distribution in each part of the plant, that is, stems/roots, leaves and fruits.

METHODS

Analyses of four sulphonium sulphates in 32 Salacia extracts were carried out on an Asahipak NH2P-50 column, and those of the corresponding desulphonates were conducted on an Inertsil ODS-3 column.

RESULTS

Neokotalanol (4) was the major constituent in Salacia samples from Thailand, whereas 1 was the primary constituent in extracts of the stems/roots of plants from Sri Lanka and India. These sulphoniums were only present in trace amounts in leaves and fruits of the plants.

CONCLUSION

Two analytical protocols were successfully applied to analyse 32 Salacia samples, and revealed that sulphoniums (1-8) had characteristic distributions due to the plant part and/or due to geographical region.

Stability of toxic arsenic species and arsenosugars found in the dry alga Hijiki and its water extracts

The achievement of reliable results in speciation analysis requires not only sensitive techniques but also sureness of species stability. Therefore, it is necessary to carry out stability studies because it is important to know with absolute certainty that there is not any species transformation during sample treatment and/or storage. Although several procedures have been recommended for the preservation of species integrity, there is no general agreement, as arsenic species stability depends on the sample matrix, the concentration level and the sample treatment procedure, so it is necessary to assess the arsenic species stability for each case. Thus, the present paper reports the stability tests of arsenic species carried out on the commercially available edible alga Hijiki (Hizikia fusiformis), from Japan, in both the dry sample and its water extracts, which were stored in amber glass and polystyrene containers at -18 and +4°C in the dark. Extractions were carried out with deionized water by microwave-assisted extraction, at a temperature of 90°C and three extraction steps of 5 min each, whereas arsenic speciation analysis was performed by anion exchange high performance liquid chromatography-photo-oxidation-hydride generation-atomic fluorescence spectrometry. The results obtained for the dry alga showed that the arsenic species present in it (arsenate (As(V)), dimethylarsinic acid (DMA) and the arsenosugars glycerol (Gly-sug), phosphate (PO4-sug), sulfonate (SO3-sug) and sulfate (SO4-sug)) were stable for at least 12 months when the sample was stored in polystyrene containers at +20°C in the dark. Regarding water extracts, the best storage conditions consisted of the use of polystyrene containers and a temperature of +4°C, for a maximum storage time of seven days. Therefore, the immediate analysis of Hijiki water extracts would not be necessary, and they could be stored for one week before analysis, ensuring arsenic species stability. This information about species integrity in extracts is especially useful when the sample treatment for arsenic species extraction is time-consuming.

[Discussion on polysaccharide determination methods in new Chinese drug research]

According to existing problems in polysaccharide determination methods in new Chinese drug applications, the method suitability, chemical reference selection, components interference and method research were introduced. The author suggests that suitable determination method should be selected according to the structure and property of the polysaccharide, and validated. Some influent factors should be examined to assure the accuracy of the method, such as the stability and using amount of the visualizing reagent, visualizing time, maximum detection wavelength etc. Monosaccharide and other water soluble components should be removed from polysaccharide sample, and suitable reference substance and detection wavelength should be selected. It should pay attention to mutual interference of neutral and acidic saccharide, and use inhibitor to eliminate the interference. Because the slopes of the standard curves are different for different monosaccharide, it is proposed that the types and ratios of the monosaccharide in heteroglycan should be understood, and mixed reference substance solution in the ratio is prepared for determination.

[Separation, purification and primary reverse cholesterol transport study of Cordyceps militaris polysaccharide]

The authors designed to separate, purify and determine the monosaccharide composition of the polysaccharide from Cordyceps militaris, and study its effect on reverse cholesterol transport in vivo by isotope tracing assay. Polysaccharides were separate and purify by ion exchange column Q-sepharose Fast Flow and size exclusion column Sephacryl S200HR; the molecular weight and monosaccharide composition of the polysaccharides were determined by high performance gel permeation chromatography and high performance liquid chromatography coming with pre-column derivation, respectively. Finally, three purified polysaccharides CMBW1, CMBW2 and CMYW1 were obtained, their total carbohydrate contents were 87%, 89%, 95%, respectively; their protein contents were 6.5%, 1.3%, 2.8%, respectively; their molecular weights were 772.1, 20.9, 13.2 kDa, respectively; CMBW1 was composed of mannose, glucosamine, rhamnose, glucuronic acid, glucose, galactose and arabinose with a molar ratio of 7.25: 0.17: 1.29: 0.23: 6.30: 11.08: 0.79; CMBW2 was composed of mannose, glucosamine, galactose and arabinose with a molar ratio of 2.40: 0.16: 2.92: 0.24; CMYW1 was composed of mannose, glucosamine, glucuronic acid and glucose with a molar ratio of 0.59: 0.57: 0.45: 25.61. Polysaccharide at 50 mg x kg(-1) could significantly improve the transport of 3H- cholesterol to blood and excretion from feces. All of the three purified polysaccharides CMBW1, CMBW2 and CMYW1 were heteropolysaccharide; and they could improve reverse cholesterol transport in vivo, the underlying mechanisms are being studied.

Alditols and monosaccharides from sorghum vinegar can attenuate platelet aggregation by inhibiting cyclooxygenase-1 and thromboxane-A2 synthase

ETHNOPHARMACOLOGICAL RELEVANCE

Vinegar has been used as both a common seasoning and a traditional Chinese medicine. Sorghum vinegar is an excellent source of physiological substances with multiple health benefits.

AIM OF THIS STUDY

To evaluate the antiplatelet aggregation activity of alditols and monosaccharides extracted from sorghum vinegar and analysis its mechanism.

MATERIALS AND METHODS

Alditol and monosaccharide extract (AME) from sorghum vinegar was first evaluated for antiplatelet activity using the turbidimetric method. Blood was collected from healthy volunteer donors. The platelet aggregation was induced by arachidonic acid (AA), collagen, adenosine diphosphate (ADP) and thrombin in vitro. AME was divided into three experimental groups with the concentration were 0.10, 0.25 and 0.50 mg/mL. In order to determine the inhibitory activity of AME on COX1, TXS and TXA2 production experiments were conducted using the COX1, TXS and TXB2 EIA kit. Computational docking was used to find the docking pose of monosaccharides and alditols with COX1.

RESULTS

AME showed significant induction of antiplatelet activity by arachidonic acid (AA), collagen, adenosine diphosphate (ADP) and thrombin in a concentration-dependent manner (p<0.05). AME (0.50 mg/mL) reduced the AA-induced aggregation rate to 10.35%±0.46%, which was comparable to acetylsalicylic acid (aspirin, ASA) (0.50 mg/mL, 6.35%±0.58%), a medical standard. Furthermore, AME strongly inhibited cyclooxygenase-1 (COX1) and thromboxane-A2 synthase (TXS), and subsequently attenuated thromboxane-A2 (TXA2) production. These findings indicated that AME attenuates platelet aggregation through the AA metabolism pathway. Computational docking showed that alditols (L-erythritol, L-arabitol, xylitol and D-sorbitol), monosaccharides (D-glucopyranose, D-fructofuranonse, D-xylopyranose, D-galactopyranose and D-ribose), ethyl glucoside and 3,4-(methylenedioxy) mandelic acid could dock directly into the active site of COX1.

CONCLUSION

Alditols and monosaccharides from sorghum vinegar inhibit multiple steps in the platelet aggregation pathway, and may be beneficial for the treatment of cardiovascular diseases.

Analysis of phenolic acids of Jerusalem artichoke (Helianthus tuberosus L.) responding to salt-stress by liquid chromatography/tandem mass spectrometry

Plant phenolics can have applications in pharmaceutical and other industries. To identify and quantify the phenolic compounds in Helianthus tuberosus leaves, qualitative analysis was performed by a reversed phase high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) and quantitative analysis by HPLC. Ten chlorogenic acids (CGAs) were identified (3-o-caffeoylquinic acid, two isomers of caffeoylquinic acid, caffeic acid, p-coumaroyl-quinic acid, feruloylquinic acid, 3,4-dicaffeoyquinic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid) by comparing their retention times, UV-Vis absorption spectra, and MS/MS spectra with standards. In addition, four other phenolic compounds, including caffeoyl glucopyranose, isorhamnetin glucoside, kaempferol glucuronide, and kaempferol-3-o-glucoside, were tentatively identified in Helianthus tuberosus leaves for the first time. The 3-o-caffeoylquinic acid (7.752 mg/g DW), 4,5-dicaffeoylquinic acid (5.633 mg/g DW), and 3,5-dicaffeoylquinic acid (4.900 mg/g DW) were the major phenolic compounds in leaves of Helianthus tuberosus cultivar NanYu in maturity. The variations in phenolic concentrations and proportions in Helianthus tuberosus leaves were influenced by genotype and plant growth stage. Cultivar NanYu had the highest concentration of phenolic compounds, in particular 3-o-caffeoylquinic acid and 4,5-dicaffeoylquinic acid compared with the other genotypes (wild accession and QingYu). Considering various growth stages, the concentration of total phenolics in cultivar NanYu was higher at flowering stage (5.270 mg/g DW) than at budding and tuber swelling stages. Cultivar NanYu of Helianthus tuberosus is a potential source of natural phenolics that may play an important role in the development of pharmaceuticals.

[Comparison of monosaccharide composition of capsular polysaccharides in Streptococcus suis serotype 1, 2, 14 and 1/2]

OBJECTIVE

There are one-way or two-way cross-reactions among Streptococcus suis serotype 1, 2, 1/2 and 14, the reason to which was unknown.

METHODS

The capsular polysaccharides of serotype 14 and 1/2 were purified on Sephacryl S-300 column and identified by phenol-sulphuric acid method and dot-ELISA. The molecular weight of the serotype 14 and 1/2 capsular polysaccharides was revealed as 487.38 kDa and 512.72 kDa by high performance gel permeation chromatography, respectively.

RESULTS

The monosaccharide composition of serotype 14 and 1/2 capsular polysaccharides was determined as Glc/Gal/GlcNAc/Rha/Neu5Ac (1: 2.94 : 1.35 : 0.24 : 0.37) and Glc/Gal/GlcNAc/GalNAc/Rha/Neu5Ac (1 : 1.67 : 1.05 : 0.93: 0.72 : 0.7) by pre-column derivatization high performance liquid chromatography, fluorescent labeling HPLC and NMR, respectively. These were compared with the composition of serotype 1 and 2 capsular polysaccharides. Glc, GlcN, Gal and Neu5Ac was contained in the capsular polysaccharides of serotype 1, 2 14 and 1/2. But there is no prominent correlation between the monosaccharide composition and cross-reactions. The cross-reactions among them could be induced by the structure of the capsular polysaccharides and/or the other components on the cell wall.

Sugar Esters from Globularia orientalis

From the methanolic extract of the underground parts of Globularia orientalis, a new antioxidant sugar ester was isolated. The structure of the new compound, globularitol (1), was identified as 6-O-feruloyl-β-ᴅ-glucopyranosyl-(156)-glucitol by spectroscopic methods (1D and 2D NMR, ESI- and FAB-MS) and confirmed by chemical means.

Coumarins from Edgeworthia chrysantha

A new coumarin, edgeworic acid (1), was isolated from the flower buds of Edgeworthia chrysantha, together with the five known coumarins umbelliferone (2), 5,7-dimethoxycoumarin (3), daphnoretin (4), edgeworoside C (5), and edgeworoside A (6). Their structures were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences (1H-1H COSY, HSQC and HMBC), in combination with acetylation reactions.

Two new secondary metabolites from Xylaria sp. cfcc 87468

A new isocoumarin glycoside, 3R-(+)-5-O-[6'-O-acetyl]-α-d-glucopyranosyl-5-hydroxymellein (1), and a new phenylethanol glycoside, (−)-phenylethyl-8-O-α-l-rhamno-pyranoside (2), were isolated from the ethyl acetate extract of the fungus Xylaria sp. cfcc 87468, together with five known steroids, β-sitosterol (3), stigmast-4-en-3-one (4), ergosterol (5), (22E)-cholesta-4,6,8(14),22-tetraen-3-one (6), and 4α-methyl- ergosta-8(14),24(28)-dien-3β-ol (7). The structures of compounds 1 and 2 were elucidated by MS, extensive 1D and 2D NMR spectroscopy, and the circular dichroism (CD) spectroscopy.

[Chemical constituents from flowers of Paeonia lactiflora]

OBJECTIVE

To study the chemical constituents of Paeonia lactiflora flowers.

METHODS

[corrected] The chemical constituents were isolated and purified by various chromatography methods,and the structures were identified by physicochemical and modem spectroscopic.

RESULTS

11 compounds were identified as gallic acid(1),methyl gallate(2),ethyl gallate(3),1,2,3,6-tetragalloyl-beta-D-glucopyranoside(4), 1,2,3,4,6-pentagalloyl-beta-D-glucopyranoside(5), quercetin-3-O-glucoside-6"-gallate(6), kaempferol-3-O-glucoside-6"-gallate(7), 1-O-galloyl-beta-D-glucose (8), kaempferol-3, 7-di-O-beta-D-glucoside(9), paeoniflorin(10) and albiflorin(11).

CONCLUSIONS

Compounds 1-8, 10 and 11 are obtained from the flowers of Paeonia lactiflora for the first time,compounds 6 and 7 are obtained from Paeonia genus for the first time.

[Antifungal and antiviral substances of Pseudomonas chlororaphis subsp. aureofaciens strains--components of gaupsin]

Phenazine-1-carboxylic, 2-hydroxy-phenazine-carboxylic acid and 2-hydroxy-phenazine active against phytopathogenic fungi were detected in fermentation broth of Pseudomonas chlororaphis subsp.aureofaciens strains UCM B-111 and UCM B-306--components of insectofungicide biopreparation gaupsin using chromato-mass-spectrometric methods; strain B-306 produced antifungal antibiotic pyrrolnitrin together with phenazines. Supernatants of fermentation broth of P chlororaphis subsp. aureofaciens B-111 and B-306 strains grown in King A medium and exopolymers preparations obtained from these supernatants using evaporation, dialysis and liophylisation were highly active against tobacco mosaic virus (TMV). At a dose of 10 mg/ml they reduced TMV infectivity by 76-96%, at concentrations 1 and 0.1 mg/ml the antiviral effect was decreased to 40-62 and 14-27%, respectively. Dialysis did not influence the antiviral activity of isolated preparations. The latter contained 2-7.6 % of carbohydrates including neutral monosaccharides: fucose, mannose, galactose and glucose.

[Chemical constituents from Lysimachia circaeoides]

OBJECTIVE

To study the chemical constituents from Lysimachia circaeoides.

METHODS

The column chromatographic techniques were applied to isolate the constituents. EI-MS and NMR were used to identify the structures.

RESULTS

Eight compounds were isolated and identified from the extract of L. circaeoides and their structures were elucidated as kaempferol (1), beta-daucosterol (2), beta-sitosterol (3), quercetin (4), luteolin (5), quercetin-3-O-beta-D-galactoside (6), kaempferol-3-O-beta-D-glucoside (7) and rutin (8).

CONCLUSION

Compounds 1 - 8 are isolated from this plant for the first time.

Simultaneous acetic acid separation and monosaccharide concentration by reverse osmosis

This study aimed to investigate the feasibility and efficiency of simultaneous acetic acid separation and sugar concentration in model lignocellulosic hydrolyzates by reverse osmosis. The effects of operation parameters such as pH, temperature, pressure and feed concentration on the solute retentions were examined with a synthetic xylose–glucose–acetic acid model solution. Results showed that the monosaccharides were almost completely rejected at above 20 bar, while the acetic acid retention increased with the increase in pH and pressure, and decreased with the temperature increase. The maximum separation factors of acetic acid over xylose and glucose reached as high as 211.5 and 228.4 at pH 2.93 (the initial pH of model lignocellulosic hydrolyzates), 40 °C and 20 bar. Furthermore, the concentration and diafiltration process were employed at optimal operation conditions. Consequently, a high sugar concentration and a beneficially lower acetic acid concentration were simultaneously achieved by reverse osmosis.

Sulfite (SPORL) pretreatment of switchgrass for enzymatic saccharification

SPORL (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) pretreatment was applied to switchgrass and optimized through an experimental design using Response Surface Methodology within the range of temperature (163-197 °C), time (3-37 min), sulfuric acid dosage (0.8-4.2% on switchgrass), and sodium sulfite dosage (0.6-7.4% on switchgrass). Performance of SPORL was compared with that of dilute acid (DA) and alkali (AL) in switchgrass pretreatment. Results indicated that SPORL pretreatment improved the digestibility of switchgrass through sufficiently removing hemicellulose, partially dissolving lignin, and reducing hydrophobicity of lignin by sulfonation. The removal of hemicellulose was more critical to substrate digestibility than the removal of lignin during SPORL pretreatment. SPORL pretreated switchgrass had better enzymatic digestibility than DA and AL pretreated ones. The SPORL pretreated switchgrass could be hydrolyzed by 83% within 48 h with 15 FPU (filter paper unit) cellulase and 30 CBU (cellobiose unit) β-glucosidase/g cellulose.

Determination of mono-, di-, and oligosaccharides by capillary electrophoresis with capacitively coupled contactless conductivity detection

Saccharides and chitooligosaccharides can be separated in electrophoretic conditions by raising the pH of the medium, which renders the corresponding alcoholate forms. These anionic species can be separated and detected with capacitively coupled contactless conductivity detection as negative peaks because of their low mobilities when compared to the hydroxyl mobility, which is the main co-ion in the background electrolyte. Three methods for different matrixes are presented in this chapter.

Determination of monosaccharides derivatized with 2-aminobenzoic Acid by capillary electrophoresis

Reducing monosaccharides were derivatized with 2-aminobenzoic acid (2-AA) through reductive amination using sodium cyanoborohydride as a reductant, and the derivatives were separated by capillary zone electrophoresis with UV detection using 50 mM sodium phosphate (pH 5.5) or 150 mM sodium borate-50 mM sodium phosphate (pH 7.0) running buffer. The derivatives of monosaccharides, which are major components of various carbohydrate materials, were completely separated within 25 min.

Structural and chemical characterization of hardwood from tree species with applications as bioenergy feedstocks

Eucalypt species are a group of flowering trees widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key tree species. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of tree species for use as biorefinery feedstocks.

Producing high sugar concentrations from loblolly pine using wet explosion pretreatment

We present quantitative analysis of pretreatment for obtaining high conversion and release of sugars from loblolly pine. We use wet explosion (WEx): wet oxidation followed by steam explosion and enzymatic hydrolysis (EH) at high dry matter to solubilize sugars. WEx was conducted at 25% (w/w) solids in presence of oxygen at pressures 6.5-7.2 bar, temperatures 170-175°C and residence time from 20 to 22.5 min. EH of pretreated samples was performed by Cellic® Ctec2 (60 mg protein/g cellulose) and Cellic® Htec2 enzymes (10% of Ctec2) at 50°C for 72 h. At the optimal WEx condition 96% cellulose and nearly 100% hemicellulose yield were obtained. The final concentrations of monomeric sugars were 152 g/L of glucose, 67 g/L of xylose, and 67 g/L of minor sugars (galactose, arabinose and mannose). Compared to previous work WEx seems to be superior for releasing high concentrations of monomeric sugars.

Bioactive constituents of Clausena lansium and a method for discrimination of aldose enantiomers

Glycosides, clausenosides A and B, and carbazole alkaloids, clausenaline A, claulamine A, and claulamine B, together with 50 known compounds, were isolated from the stems of Clausena lansium. Their structures were determined by means of spectroscopic methods, including that of CD and 1D/2D NMR analysis. Claulamine A has a 1-oxygenated carbazole skeleton with a rare 2,3-lactone ring, and claulamine B represents an hitherto unknown acetal carbazole alkaloid. Thirty-one of the isolated known compounds were evaluated in various assays for anti-inflammatory activity. Among them, imperatorin, isoheraclenin, and osthol exhibited selective and potent inhibition of formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation, and lansiumarin C also decreased nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production in lipopolysaccharide (LPS)-induced macrophages. In addition, a modified HPLC method of pre-column derivatization was developed that is more practical for simultaneous analysis of aldose enantiomers as compared to the literature method. The absolute configurations of the sugar moieties in clausenosides A and B were determined with this modified method.

Plasmolysis effects and osmotic potential of two phylogenetically distinct alpine strains of Klebsormidium (Streptophyta)

The osmotic potential and effects of plasmolysis were investigated in two different Klebsormidium strains from alpine habitats by incubation in 300-2,000 (3,000) mM sorbitol. Several members of this genus were previously found to tolerate desiccation in the vegetative state yet information was lacking on the osmotic potentials of these algae. The strains were morphologically determined as Klebsormidium crenulatum and Klebsormidium nitens. These species belong to distinct clades, as verified by phylogenetic analysis of the rbcL gene. K. crenulatum is part of to the K. crenulatum/mucosum ('F' clade) and K. nitens of the 'E2' clade. Plasmolysis occurred in K. crenulatum at 800 mM sorbitol (961 mOsmol kg(-1), Ψ = -2.09 MPa) and in K. nitens at 600 mM sorbitol (720 mOsmol kg(-1), Ψ = -1.67 MPa). These are extraordinarily high osmotic values (very negative osmotic potentials) compared with values reported for other green algae. In K. crenulatum, the maximum photosynthetic rate (Pmax) in the light-saturated range was 116 μmol O(2) h(-1) mg(-1) chl a. Incubation in 1,000 mM sorbitol decreased Pmax to 74.1% of the initial value, whereas 2,000 mM sorbitol (Ψ = -5.87 MPa) lead to an almost complete loss of oxygen production. In K. nitens, Pmax was 91 μmol O(2) h(-1) mg(-1) chl a under control conditions and incubation in 800 mM sorbitol did not decrease Pmax, 2,000 mM sorbitol decreased Pmax only to about 62.6% of the initial value whereas 3,000 mM sorbitol stopped oxygen evolution. This indicated a broader amplitude for photosynthesis in the examined strain of K. nitens. Control samples and samples plasmolysed for 3 h in 800 mM sorbitol (K. nitens), 1,000 mM sorbitol (K. crenulatum), or 2,000 mM sorbitol were investigated by transmission electron microscopy after chemical or high-pressure freeze fixation. In cells undergoing plasmolysis the protoplasts were retracted from the cell wall, the cytoplasm appeared dense, vacuoles were small and fragmented, and the cytoplasm was filled with ribosomes. Thin cytoplasmic strands were connected to the cell wall; 2,000 mM sorbitol increased the effect. The content of soluble carbohydrates in these two strains was investigated by HPLC, as this is one known mechanism for cells to maintain high osmotic pressure of the cytosol. Both Klebsormidium species contained diverse soluble carbohydrates, including a dominant mixed peak of unidentified oligosaccharides, and more minor amounts of raffinose, sucrose, glucose, xylose, galactose, mannose, inositol, fructose, glycerol, mannitol, and sorbitol. The total content of soluble carbohydrates was approximately 1.2% of the dry weight, indicating that this is not a major factor contributing to the high osmotic potential in these strains of Klebsormidium.

[Chemical constituents from stems of Lonicera macranthoides]

OBJECTIVE

To study the chemical constituents of Lonicera macranthoides.

METHODS

Many chromatography means were used in separation and purification, and the structures of all compounds were identified by the means of spectroscopic analysis (MS, 1H-NMR, 13C-NMR) and physicochemical properties.

RESULTS

13 compounds were elucidated as beta-sitosterol (1), daucosterol (2), chlorogenic acid (3), luteolin (4), quercetin (5), diosmetin-7-O-beta-D-glucoside (6), kaempferol-3-O-beta-D-glucoside (7), 3,4-O-di-caffeoylquinic acid methylester (8), 1,3-O-di-caffeoylquinic acid (9), scopoletin (10), macranthoidin B (11), macranthoidin A (12), eriodictyol (13).

CONCLUSION

The compounds 6,7 and 13 are obtained from this plant for the first time.

Profiling of phenolics from Tephrosia cinerea

An HPLC-ESIMS(n) method, based on high-performance liquid chromatography coupled to electrospray positive ionization multistage ion trap mass spectrometry, has been used to rapidly identify and guide the isolation of phenolic constituents from the methanol extract of the aerial parts of T. cinerea. On the basis of the results of the online screening by HPLC-ESIMS (n), 17 phenolic constituents, including two new compounds, namely demethylapollinin 7- O- β-D-glucopyranoside (1) and cineroside A (17), were isolated, and their structures were unambiguously assigned by the extensive use of 1D- and 2D-NMR experiments.