Structural characterization of arabinogalactan-II and pectin from Urtica cannabina.

Comparative analysis of extracellular and cell wall glycans from Urtica cannabina leaves was performed using chemical methods, GC, GC-MS, 1D, and 2D NMR spectroscopy. The structures of extracellular AG-II and cell wall AG-II are similar. The units are typical for AG-IIs: β-GlcpA-4-OMe-(1→, Rhap-(1 → 4)-β-GlcpA-(1→, attached to β-Galp at O-6, as well as arabinan chains attached to β-Galp at O-3.

Characterization of the carbapenem-resistant clinical reference isolate BAL062 (CC2:KL58:OCL1): resistance properties and capsular polysaccharide structure.

The carbapenem-resistant isolate BAL062 is a clinical reference isolate used in several recent experimental studies. It is from a ventilator-associated pneumonia (VAP) patient in an intensive care unit at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam in 2009. Here, BAL062 was found to belong to the B sub-lineage of global clone 2 (GC2) isolates in the previously reported outbreak (2008 and 2012) of carbapenem-resistant VAP at the HTD.

Design and synthesis of phosphoryl-substituted steroidal pyridazines (Pho-STPYRs) as potent estrogen receptor alpha inhibitors: targeted treatment of hormone-dependent breast cancer cells.

Estrogen receptor alpha (ERα) is an important target for the discovery of new therapeutic drugs against hormone-dependent breast cancer. A series of phosphoryl-substituted steroidal pyridazines (Pho-STPYRs) were synthesized and biologically evaluated as potent ERα inhibitors. Pho-STPYRs showed cytotoxicity against breast cancer cells with IC values of 5.

New lactate- and pyruvate-containing polysaccharide and rhamnomannan with xylose residues from the cell wall of Rathayibacter oskolensis VKM Ac-2121.

The cell wall of endophytic strain Rathayibacter oskolensis VKM Ac-2121 (family Microbacteriaceae, class Actinomycetes) was found to contain neutral and acidic glycopolymers. The neutral polymer is a block-type rhamnomannan partially should be substitutied by xylose residues, [→2)-α-[β-D-Xylp-(1 → 3)]-D-Manp-(1 → 3)-α-D-Rhap-(1→] [→2)-α-D-Manp-(1 → 3)-α-D-Rhap-(1→]. The acidic polymer has branched chain, bearing lactate and pyruvate residues, →4)-α-D-[S-Lac-(2-3)-α-L-Rhap-(1 → 3)]-D-Manp-(1 → 3)-α-D-[4,6-R-Pyr]-D-Galp-(1 → 3)-β-D-Glcp-(1 →.

Structural studies of the O polysaccharides from the lipopolysaccharides of Azospirillum thiophilum BV-S and Azospirillum griseum L-25-5w-1.

Diazotrophic bacteria of the genus Azospirillum are known widely, because they are ubiquitous in the rhizosphere and can promote the growth and performance of nonlegume plants. Recently, more Azospirillum species have been isolated from sources other than plants or soil. We report the structures of the O polysaccharides (OPSs) from the lipopolysaccharides of the type strains A.

Synthesis and ab initio conformational investigation of a series of model sulfated α-L-iduronopyranosides.

Due to the all-axial orientation of the OH-groups in the C chair conformation considered standard for L-hexapyranosides, including l-iduronopyranoside - a component of many biologically and medically significant sulfated glycans, these monosaccharides can be anticipated to display unusual conformations upon the introduction of bulky and charged substituents. Herein we describe the synthesis of a series of iduronopyranoside derivatives with varying sulfation patterns, which were studied computationally using the DLPNO-MP2 approach and by means of analyzing their chemical shifts to ascertain the effects sulfation has on the conformation of the iduronopyranoside ring.

Structure, Physicochemical Properties and Biological Activity of Lipopolysaccharide from the Rhizospheric Bacterium T1Kr02, Containing d-Fucose Residues.

Lipopolysaccharides (LPSs) are major components of the outer membranes of Gram-negative bacteria. In this work, the structure of the O-polysaccharide of T1Kr02 was identified by nuclear magnetic resonance (NMR), and the physical-chemical properties and biological activity of LPS were also investigated. The NMR analysis showed that the O-polysaccharide has the following structure: →2)-β-d-Fuc-(1→3)-β-d-Fuc-(1→.

Fucosylated Chondroitin Sulfates with Rare Disaccharide Branches from the Sea Cucumbers and : Structures and Influence on Hematopoiesis.

Two fucosylated chondroitin sulfates were isolated from the sea cucumbers and using a conventional extraction procedure in the presence of papain, followed by anion-exchange chromatography on DEAE-Sephacel. Their composition was characterized in terms of quantitative monosaccharide and sulfate content, and structures were mainly elucidated using 1D- and 2D-NMR spectroscopy. As revealed by the data of the NMR spectra, both polysaccharides along with the usual fucosyl branches contained rare disaccharide branches α-D-GalNAc46-(1→2)-α-L-Fuc34 → attached to -3 of the GlcA of the backbone ( = H or SO).

Stereocontrolled Synthesis and Conformational Analysis of a Series of Disaccharides α,β-d-GlcA-(1→3)-α-L-Fuc.

D-Glucuronic acid is a fundamental building block of many biologically important polysaccharides, either in its non-substituted form or bearing a variety of substituents, among them sulfates. We have previously performed a study of the effects of exhaustive sulfation on the conformational behavior of β-gluronopyranosides. Herein, we report an investigation comparing α- and β-derivatives of this monosaccharide within the title disaccharides using NMR and quantum chemistry approaches.

The K70 and K9 capsular polysaccharides consist of related K-units linked by the same Wzy polymerase and cleaved by the same phage depolymerases.

Bacteriophage show promise for the treatment of infections that resist all therapeutically suitable antibiotics. Many tail-spike depolymerases encoded by phage that are able to degrade capsular polysaccharide (CPS) exhibit specificity for the linkage present between K-units that make up CPS polymers. This linkage is formed by a specific Wzy polymerase, and the ability to predict this linkage using sequence-based methods that identify the Wzy at the K locus could assist with the selection of phage for therapy.

Pectic polysaccharides of black radish taproots: Extraction, structural characterization.

The mixtures of starch and pectin were isolated by sequential extraction of the pulp and peel of black radish taproots Raphanus sativus L. with cold, hot and acidified water, solutions of ammonium oxalate, sodium carbonate and sodium hydroxide. The polysaccharide fractions obtained with ammonium oxalate solutions from the pulp and peel of the taproots gave the highest yields.

A highly branched novel galactofuranan in the cell wall of Clavibacter tesselarius VKM Ac-1406.

The structures of two cell wall glycopolymers were studied in the plant pathogenic bacterium Clavibacter tesselarius VKM Ac-1406 (family Microbacteriaceae, order Micrococcales, class Actinomycetes). The predominant polymer was a novel (1 → 6)-linked β-d-galactofuranan with a highly branched repeating unit, α-L-Rhap-(1 → 3)-α-D-Galp-(1 → 2)-[α-L-Rhap-(1 → 3)]-α-D-Fucp-(1 →, at O-2 on every second galactofuranose residue. The second polymer present in small amounts was acidic with the repeating unit, →3)-α-D-Galp-(1 → 3)-α-D-[4,6-S-Pyr]-Manp-(1 → 3)-α-D-Manp-[2OAc]-(1→, and was reported in all Clavibacter species investigated to date.

Glycosaminoglycans from the Starfish : Structures and Influence on Hematopoiesis.

Crude anionic polysaccharides extracted from the Pacific starfish were purified by anion-exchange chromatography. The main fraction having MW 14.5 kDa and dispersity 1.

Structure of the O-specific polysaccharide of Ochrobactrum endophyticum KCTC 42485 containing 3-(3-hydroxy-2,3-dimethyl-5-oxoprolyl)amino-3,6-dideoxy-d-galactose.

Ochrobactrum endophyticum (syn. Brucella endophytica) is an aerobic species of Alphaproteobacteria isolated from healthy roots of Glycyrrhiza uralensis. Here we report the structure of the O-specific polysaccharide obtained by mild acid hydrolysis of the lipopolysaccharide of the type strain KCTC 42485:→3)-α-l-FucpNAc-(1→3)-β-d-QuipNAc-(1→2)-β-d-Fucp3NAcyl-(1→ where Acyl is 3-hydroxy-2,3-dimethyl-5-oxoprolyl.

A novel cell wall galactofuranan in Clavibacter phaseoli VKM Ac-2641.

A glycopolymer of novel structure was found in the cell wall of plant pathogen Clavibacter phaseoli VKM Ac-2641 (family Microbacteriaceae, class Actinomycetes). The glycopolymer was (1 → 6)-linked β-d-galactofuranan with side branched trisaccharide, α-D-Manp-(1 → 2)-[α-D-Manp-(1 → 3)]-α-D-Ribf-(1→ at O-2 on every second galactofuranose residue. The galactofuranan structure was established by chemical and NMR spectroscopic methods using one- and two-dimensional techniques H,H COSY, TOCSY, ROESY and H,C HSQC, HMBC.

Complete chemical structure of the K135 capsular polysaccharide produced by Acinetobacter baumannii RES-546 that contains 5,7-di-N-acetyl-8-epipseudaminic acid.

A structurally diverse capsular polysaccharide (CPS) in the outer cell envelope plays an important role in the virulence of the important bacterial pathogen, Acinetobacter baumannii. More than 75 different CPS structures have been determined for the species to date, and many CPSs include isomers of a higher sugar, namely 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid. Recently, a novel isomer having the d-glycero-l-manno configuration (5,7-di-N-acetyl-8-epipseudaminic acid; 8ePse5Ac7Ac) has been identified in the CPS from A.

Polysaccharides of : Extraction, Structural Characterization and Antioxidant Activity.

The above-ground part of the was found to contain ~13% (/) of polysaccharides extractable with water and aqueous solutions of ammonium oxalate and sodium carbonate. The fractions extracted with aqueous sodium carbonate solutions had the highest yield. The polysaccharides of majority fractions are characterized by similar monosaccharide composition; namely, galacturonic acid and arabinose residues are the principal components of their carbohydrate chains.

Overclocking Nitronyl Nitroxide Gold Derivatives in Cross-Coupling Reactions.

Nitronyl nitroxides are functional building blocks in cutting-edge research fields, such as the design of molecular magnets, the development of redox and photoswitchable molecular systems and the creation of redox-active components for organic and hybrid batteries. The key importance of the nitronyl nitroxide function is to translate molecular-level-optimized structures into nano-scale devices and new technologies. In spite of great importance, efficient and versatile synthetic approaches to these compounds still represent a challenge.

Epinephrine extensively changes the biofilm matrix composition in C01 isolated from human skin.

The importance of the impact of human hormones on commensal microbiota and microbial biofilms is established in lots of studies. In the present investigation, we continued and extended the research of epinephrine effects on the skin commensal C01 and its biofilms, and also the matrix changes during the biofilm growth. Epinephrine in concentration 4.

Fucose-Rich Sulfated Polysaccharides from Two Vietnamese Sea Cucumbers and : Structures and Anticoagulant Activity.

Fucosylated chondroitin sulfates (FCSs) and , as well as fucan sulfates (FSs) and were isolated from the sea cucumbers and , respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods.

Synthesis and evaluation of avermectin-imidazo[1,2-a]pyridine hybrids as potent GABA receptor modulators.

The γ-aminobutyric acid type A (GABA) receptors are pentameric transmembrane protein complexes. They have attracted extensive attention from the scientific community due to their significant pharmacological potential. Here we report the first synthesis of avermectin-imidazo[1,2-a]pyridine hybrids promising as GABA receptor positive allosteric modulators (PAMs).

Capsule-Targeting Depolymerases Derived from Prophage Regions.

In this study, several different depolymerases encoded in the prophage regions of genomes have been bioinformatically predicted and recombinantly produced. The identified depolymerases possessed multi-domain structures and were identical or closely homologous to various proteins encoded in other genomes. This means that prophage-derived depolymerases are widespread, and different bacterial genomes can be the source of proteins with polysaccharide-degrading activities.