Determination of carbohydrates in the herbal antidiabetic mixtures by GC-MC

Due to the wide range of biologically active substances, the herbal mixtures can influence the development of diabetes mellitus and its complications. Carbohydrates attract particular attention due to their hypoglycemic, hypolipidemic, anticholesterolemic, antioxidant, antiinflammatory and detoxifying activities. The aim of this study was to investigate the content of carbohydrates through their monomeric composition in the herbal mixture samples: a) Urtica dioica leaf, Cichorium intybus roots, Rosa majalis fruits, Elymys repens rhizome, Taraxacum officinale roots, b) Arctium lappa roots, Elymys repens rhizome, Zea mays columns with stigmas, Helichrysum arenarium flowers, Rosa majalis fruits, c) Inula helenium rhizome with roots, Helichrysi arenarium flowers, Zea mays columns with stigmas, Origanum vulgare herb, Rosa majalis fruits, Taraxacum officinale roots, d) Cichorium intybus roots, Elymys repens rhizome, Helichrysum arenarium flowers, Rosa majalis fruits, Zea mays columns with stigmas and e) Urtica dioica leaf, Taraxacum officinale roots, Vaccinium myrtillus leaf, Rosa majalis fruits, Mentha piperita herb, which were used in Ukrainian folk medicine for the prevention and treatment of diabetes mellitus type 2.The carbohydrates were separated by gas chromatography-mass spectrometry after conversion into volatile aldononitrile acetate derivatives. The monomeric composition of polysaccharides was studied after their hydrolysis to form monosaccharides and poly-alcohols.Quantitative analyses of free carbohydrates showed that the predominant sugars were fructose, glucose and disaccharide – sucrose, in all samples. Concerning the determination of polysaccharide monomers after hydrolysis, glucose was the most abundant in all samples. The chromatographic study revealed a number of polyalcohols that are important for the treatment and prevention of progression of diabetes mellitus and its complications, namely, mannitol, pinitol and myo-inositol.

Adhesive Performance of Acrylic Pressure-Sensitive Adhesives from Different Preparation Processes

A series of pressure-sensitive adhesives (PSAs) was prepared using a constant monomeric composition and different preparation processes to investigate the best combination to obtain the best balance between peel resistance, tack, and shear resistance. The monomeric composition was a 1:1 combination of two different water-based acrylic polymers—one with a high shear resistance (A) and the other with a high peel resistance and tack (B). Two different strategies were applied to prepare the adhesives: physical blending of polymers A and B and in situ emulsion polymerization of A + B, either in one or two steps; in this last case, by polymerizing A or B first. To characterize the polymer, the average particle size and viscosity were analyzed. The glass transition temperature (Tg) was determined by differential scanning calorimetry (DSC). The tetrahydrofuran (THF) insoluble polymer fraction was used to calculate the gel content, and the soluble part was used to determine the average sol molecular weight by means of gel permeation chromatography (GPC). The adhesive performance was assessed by measuring tack as well as peel and shear resistance. The mechanical properties were obtained by calculating the shear modulus and determination of maximum stress and the deformation energy. Moreover, an adhesive performance index (API) was designed to determine which samples are closest to the requirements demanded by the self-adhesive label market.

Protein modeling

Proteins are essential and versatile polymers consisting of sequenced amino acids that often possess an organized three-dimensional arrangement, (a result of their monomeric composition), which determines their biological role in cellular function. Proteins are involved in enzymatic catalysis; they participate in genetic information decoding and transmission processes, in cell recognition, in signaling, and transport of substances, in regulation of intra and extracellular conditions, and other functions.

Delignification of Cistus ladanifer Biomass by Organosolv and Alkali Processes

Residues of Cistus ladanifer obtained after commercial steam distillation for essential oil production were evaluated to produce cellulose enriched solids and added-value lignin-derived compounds. The delignification of extracted (CLRext) and extracted and hydrothermally pretreated biomass (CLRtreat) was studied using two organosolv processes, ethanol/water mixtures (EO), and alkali-catalyzed glycerol (AGO), and by an alkali (sodium hydroxide) process (ASP) under different reaction conditions. The phenolic composition of soluble lignin was determined by capillary zone electrophoresis and by Py-GC/MS, which was also used to establish the monomeric composition of both the delignified solids and isolated lignin. The enzymatic saccharification of the delignified solids was also evaluated. The ASP (4% NaOH, 2 h) lead to both the highest delignification and enzymatic saccharification (87% and 79%, respectively). A delignification of 76% and enzymatic hydrolysis yields of 72% were obtained for AGO (4% NaOH) while EO processes led to lower delignification (maximum lignin removal 29%). The residual lignin in the delignified solids were enriched in G- and H-units, with S-units being preferentially removed. The main phenolics present in the ASP and AGO liquors were vanillic acid and epicatechin, while gallic acid was the main phenolic in the EO liquors. The results showed that C. ladanifer residues can be a biomass source for the production of lignin-derivatives and glucan-rich solids to be further used in bioconversion processes.

Structure and chemical composition of exopolysaccharides of frost-damaged sugar beet

In this research paper, development of a procedure of isolation of exopolysaccharides from frost-damaged beet and an analysis of structural and chemical composition of polymers isolated from sugar beet of different origin are presented. Total acid hydrolysis degradation integrated with HPAEC-ED analysis has been utilized to confirm the monomeric composition of the separated polysaccharides. The implementation of NMR spectral analysis and SEC chromatography of the structure of exopolysaccharides has been investigated. The results demonstrate that the chemical composition and structure of exopolysaccharides depend on their origin. Typical exopolysaccharides from Central European beet roots consist mainly of glucose monomers – and they have low branched structure – about 90% of α-1,6 linkage which is typical for dextran. The exopolysaccharides isolated from Swedish beet are characterized by 50–60% fructose monomers. They contain only about 65% α-1,6 linkages. Exopolysaccharides extracted from various origin beet differ in average molecular mass. The molecular distribution is not normal.

Comparative study of chromatographic methods for the analysis of exopolysaccharides from archaeal biofilms

<p>Microorganisms, such as archaea, favour life in a biofilm rather than the planktonic form of life. A biofilm is defined as a community of microorganisms embedded in a self-produced matrix of hydrated extracellular polymeric substances (EPS), mainly polysaccharides (PS), proteins and extracellular DNA. The polysaccharides form a three-dimensional network, which provides stability of the biofilm and mediates the adhesion to surfaces. [1] Analysis of the monomeric composition of PS requires chromatographic separation and identification by mass spectrometry (MS).</p> <p>A comparative study of different chromatographic methods for the analysis of the monomeric composition of exopolysaccharides from archaeal biofilms from Sulfolobus acidocaldarius has been carried out. For this study, different chromatographic separation methods, such as supercritical fluid chromatography (SFC), hydrophilic interaction liquid chromatography (HILIC) reversed-phase liquid chromatography (RP-LC) and gas chromatography (GC), each coupled to mass spectrometry, were developed and compared by means of separation performance and sensitivity, using authentic standards.</p> <p>The study revealed, that each method features distinct advantages and disadvantages over the other methods. For example, when using SFC-MS, no derivatization is necessary and soft ionization conditions can be used. [2] However, the HILIC-MS and RP-LC-MS methods show significantly greater separation performances for the analysis of the monosaccharide composition. [3] All investigated methods show similar quantification limits in the sub-mg/L range.</p> <p>Finally, the developed chromatographic methods were applied to real biofilm samples of the thermoacidophilic archaeon Sulfolobus acidocaldarius. To determine the monomeric composition of the exopolysaccharides from these archaeal biofilms, the extracellular polymeric substances were extracted from the biofilm and then the PS were hydrolyzed.</p> <p> </p> <p>Literature:</p> <p>[1] H.-C. Flemming, Nat. Microbiol. Rev. 2010, 8, 623 - 633. [2] M. Lafosse, J. Chromatogr. A, 1996, 720, 61-73. [3] V. Sieber, J. Chromatogr. A, 2014, 1350, 44–50.</p>

CONTENT OF EXTRACTIVE SUBSTANCES AND POLYSACCHARIDES IN FRUIT BODIES OF GRIFOLA FRON-DOSA CULTIVATED ON LIGNOCELLULUS SUBSTRATES DEPENDING ON EXTRACTION METHODS

The work is devoted to a comparative analysis of the quantitative content of extractives and water-soluble polysaccharides isolated from the fruit bodies of mushrooms Grifola frondosa depending on the extraction methods. As objects of study used strain of fungi G. frondosa 2639, isolated from commercial mycelium. It was established that the yield of fungi in polypropylene bags (volume up to 4500 cm3) was 36.37%, differing little from the yield of fruit bodies in glass containers (volume 800–1000 cm3). Using the hydrolysis of extraction products it was found that the methods of extracting the fruit bodies of G. frondosa with water lead to the extraction of polysaccharides of different composition. It was established that when using extraction methods in the Soxhlet apparatus, boiling and maceration (25.0±1.0 °C), the yield of extractive substances from the fruit bodies of G. frondosa was within the literature data interval and amounted to 6.04, 5.81 and 3.45%, respectively. It was shown that the highest content of water-soluble polysaccharides in the fruit bodies of G. frondosa was found using the extraction method in the Soxhlet apparatus – 14.92 %, differing from boiling and maceration methods (25.0±1.0 °C) in 1.15 and 1.33 times. By HPLC it was found that when maceration extraction was used (25.0±1.0 °C) and boiling, the monomeric composition of the polysaccharides of the fruit bodies of G. frondosa is mainly glucose, mannose, fucose and rhamnose in a ratio of 1.0 : 0.9 : 0.4 : 1.3, respectively. During extraction in the Soxhlet apparatus, their ratio was 1.0 : 1.2 : 0.5 : 1.9.

Novel ionic liquids-based extraction method that preserves molecular structure from cutin

The biopolyester cutin is ubiquitous in land plants, building the polymeric matrix of the plant’s outermost defensive barrier - the cuticle. Cutin influences many biological processes in planta however due to its complexity and highly branched nature, the native structure remains partially unresolved. Our aim was to define an original workflow for the purification and systematic characterisation of the molecular structure of cutin. To purify cutin we tested the ionic liquids cholinium hexanoate and 1-butyl-3-methyl-imidazolium acetate. The ensuing polymers are highly esterified, amorphous and have the typical monomeric composition as demonstrated by solid state NMR, complemented by spectroscopic (GC-MS), thermal (DSC) and x-ray scattering (WAXS) analyses. A systematic study by solution-state NMR of cryogenically milled cutins extracted from Micro-Tom tomatoes (the wild type and the gpat6 and cus1 mutants) was undertaken. Their molecular structures, relative distribution of ester aliphatics, free acid end-groups and free hydroxyl groups, differentiating between those derived from primary and secondary esters, were solved. The acquired data demonstrate the existence of free hydroxyl groups in cutin and reveal novel insights on how the mutations impact the esterification arrangement of cutin. Compared to conventional approaches, the usage of ionic liquids for the study of plant polyesters opens new avenues since simple modifications can be applied to recover a biopolymer carrying distinct types/degrees of modifications (e.g. preservation of esters or cuticular polysaccharides), which in combination with the solution NMR methodologies developed here, constitutes now essential tools to fingerprint the multi-functionality and the structure of cutin in planta.

Leaf cuticle analyses: implications for the existence of cutan/non-ester cutin and its biosynthetic origin

Background and Aims The cuticle of a limited number of plant species contains cutan, a chemically highly resistant biopolymer. As yet, the biosynthesis of cutan is not fully understood. Attempting to further unravel the origin of cutan, we analysed the chemical composition of enzymatically isolated cuticular membranes of Agave americana leaves. Methods Cuticular waxes were extracted with organic solvents. Subsequently, the dewaxed cuticular membrane was depolymerized by acid-catalysed transesterification yielding cutin monomers and cutan, a non-hydrolysable, cuticular membrane residue. The cutan matrix was analysed by thermal extraction, flash pyrolysis and thermally assisted hydrolysis and methylation to elucidate the monomeric composition and deduce a putative biosynthetic origin. Key Results According to gas chromatography–mass spectrometry analyses, the cuticular waxes of A. americana contained primarily very-long-chain alkanoic acids and primary alkanols dominated by C32, whereas the cutin biopolyester of A. americana mainly consisted of 9,10-epoxy ω-hydroxy and 9,10,ω-trihydroxy C18 alkanoic acids. The main aliphatic cutan monomers were alkanoic acids, primary alkanols, ω-hydroxy alkanoic acids and alkane-α,ω-diols ranging predominantly from C28 to C34 and maximizing at C32. Minor contributions of benzene-1,3,5-triol and derivatives suggested that these aromatic moieties form the polymeric core of cutan, to which the aliphatic moieties are linked via ester and possibly ether bonds. Conclusions High similarity of aliphatic moieties in the cutan and the cuticular wax component indicated a common biosynthetic origin. In order to exclude species-specific peculiarities of A. americana and to place our results in a broader context, cuticular waxes, cutin and cutan of Clivia miniata, Ficus elastica and Prunus laurocerasus leaves were also investigated. A detailed comparison showed compositional and structural differences, indicated that cutan was only found in leaves of perennial evergreen A. americana and C. miniata, and made clear that the phenomenon of cutan is possibly less present in plant species than suggested in the literature.