Abstract-An NMR study of proton chemical shift patterns of known linear a-D D-glucopyranose di-and trisaccharide structures was carried out. Chemical shift patterns for (a1?2)-, (a1?3)-, (a1?4)-and (a1?6)-linked D D-glucose residues were analysed and compared to literature data. Using these data, a 1 H NMR structural-reporter-group concept was formulated to function as a tool in the structural analysis of a-D D-glucans.

This study was aimed at finding structural requirements for the interaction of the acyl chain of endocannabinoids with cannabinoid receptors, membrane transporter protein, and fatty acid amide hydrolase (FAAH). To this end, the flexibility of the acyl chain was restricted by introduction of an 1-hydroxy-2Z,4E-pentadiene system in anandamide (N-arachidonoylethanolamine, AEA) and 2-arachidonoylglycerol (2-AG) at various positions using different lipoxygenases. This brought about selectivity and attenuated the binding potency of AEA and 2-AG. Although the displacement constants were modest, 15(S)-hydroxy-eicosa-5Z,8Z,11Z,-13E-tetraenoyl-N-(2-hydroxyethyl)amine was found to bind selectively to the CB 1 receptor, whereas its 1-arachidonoyl-sn-glycerol analogue and 13(S)-hydroxy-octadeca-9Z,11E-dienoyl-N-(2-hydroxyethyl)amine could selectively bind to the CB 2 receptor. 11(S)-Hydroxy-eicosa-5Z,8Z,12E,14Z-tetraenoyl-N-(2-hydroxyethyl)amine did not bind to either receptor, whereas 12(S)-hydroxy-eicosa-5Z,8Z,10E,14Z-tetraenoyl-N-(2-hydroxyethyl)amine did bind to both CB receptors with an affinity similar to that of AEA. All oxygenated anandamide derivatives were good inhibitors of FAAH (low micromolar K i ) but were ineffective on the AEA transporter. 2-AG rapidly isomerizes into 1(3)-arachidonoyl-sn-glycerol. Both 1-and 3-arachidonoyl-snglycerol did not bind to either CB receptor and did not interfere with AEA transport. Thus, after it is isomerized, 2-AG is inactivated, thereby decreasing effective concentrations of 2-AG. Analysis of 1 H NMR spectra revealed that chloroform did not induce notably different conformations in the acyl chain of 15(S)-hydroxy-eicosa-5Z,8Z,11Z,13E-tetraenoic acid as compared with water. Molecular dynamics (MD) simulations of AEA and its analogues in the presence of explicit water molecules revealed that a tightly folded conformation of the acyl chain is not the only requirement for CB 1 binding. Structural details of the C 2 -C 15 loop, such as an sp 2 carbon at position 11, are necessary for receptor binding. The MD simulations may suggest that the average orientations of the pentyl tail of AEA and 12(S)-hydroxy-eicosa-5Z,8Z,-10E,14Z-tetraenoyl-N-(2-hydroxyethyl)amine are different from that of the low-affinity, inactive ligands.

Assembly of a protective cyst wall by Giardia is essential for the survival of the parasite outside the host intestine and for transmission among susceptible hosts. The structure of the G. intestinalis filamentous cyst wall was studied by chemical methods, mass spectrometry, and (1)H nuclear magnetic resonance spectroscopy. Isolated cyst wall material contains carbohydrate and protein in a ratio of 3:2 (w/w), and the carbohydrate moiety is composed of a beta(1-3)-N-acetyl-D-galactopyranosamine homopolymer. Conformational analysis by molecular dynamics and persistence length calculations of GalNAc oligomers in solution demonstrated a flexible structure consisting of left- and right-handed helical elements. It is most likely that in the solid state, the polysaccharide forms ordered helices or possibly multiple helical structures having strong interchain interactions. The highly insoluble nature of the Giardia cyst wall must be due to these strong interchain interactions and, probably, a strong association between the carbohydrate and the protein moiety.

The EUROCarbDB project is a design study for a technical framework, which provides sophisticated, freely accessible, open-source informatics tools and databases to support glycobiology and glycomic research. EUROCarbDB is a relational database containing glycan structures, their biological context and, when available, primary and interpreted analytical data from high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance experiments. Database content can be accessed via a web-based user interface. The database is complemented by a suite of glycoinformatics tools, specifically designed to assist the elucidation and submission of glycan structure and experimental data when used in conjunction with contemporary carbohydrate research workflows. All software tools and source code are licensed under the terms of the Lesser General Public License, and publicly contributed structures and data are freely accessible. The public test version of the web interface to the EUROCarbDB can be found at .

Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone that is involved in the maintenance of the corpus luteum in early pregnancy. Glycosylation at Am52 of its a subunit (ahCG) is essential for signal transduction, whereas the N-glycan at Am78 stabilizes the structure of the protein.In this study, an almost complete 'H-NMR and a partial "C-NMR spectral assignment for the amino acids and the N-glycans of ahCG and of an enzymatically deglycosylated form, which had a single GlcNAc residue at each of its two glycosylation sites, has been achieved. The secondary structure of ahCG in solution, which was determined based on NOE data, is partially similar to that of the a subunit in the crystal structure of hCG, but large structural differences are found for amino acid residues 33-58.In the crystal structure of hCG, residues 33-37 and 54-58 of the a subunit are part of an intersubunit seven-stranded b-barrel and residues 41 -47 constitute a 3,,,-helix. In contrast, in free ahCG in solution, amino acids 33-58 are part of a large disordered loop, indicating that in intact hCG interactions with the /I subunit of hCG stabilize the conformation of the 0: subunit. The NMR data of ahCG and its deglycosylated counterpart are very similar, indicating that removal of carbohydrate residues other than GlcNAc-1 does not notably affect the conformation of the protein part. However, numerous 'H-NOES between the GlcNAc-1 residue at Am78 and several amino acid residues show that this GlcNAc residue is tightly packed against the protein, being an integral part of the structure of the IX subunit. 'H-NOES across the glycosidic linkages of the glycan, resonance-line widths, and 'H and I3C chemical shifts of the other monosaccharides suggest that the remainder of the glycans at Asn78, and the glycans at Asn.52 are largely extended in solution.

The existence of an HO-3 .

The exopolysaccharide of Lactobacillus delbrückii subsp. bulgaricus rr, isolated from skimmed milk, is a heteropolymer of D-galactopyranosyl, D-glucopyranosyl, and L-rhamnopyranosyl residues in the molar ratio 5:1:1. The structure was established by linkage analysis and 1D and 2D NMR spectroscopy of the native polysaccharide, in combination with characterisation of oligosaccharide fragments, obtained by Smith degradation and partial acid hydrolysis, using methylation analysis, EIMS, and 1D and 2D 1H NMR spectroscopy. The polysaccharide has a branched heptasaccharide repeating unit with the following structure: -->2)-[beta-D-Galp-(1-->3)]-alpha-D-Galp-(1-->3)- beta-D-Glcp-(1-->3)-[beta-D-Galp-(1-->4)]-beta-D-Galp-(1-->4)-[alpha-L- Rhap-(1-->3)]-alpha-D-Galp-(1-->.

From the latex of Jatropha curcas L. (Euphorbiaceae) a novel cyclic octapeptide was isolated, which we named curcacycline A. The compound was found to contain one threonine, one valine, two glycine, and four leucine residues. By two-dimensional ~H-NMR spectroscopy (HOHAHA and ROESY), its sequence was determined to be GiyLLeu2-Leu3-Gly4-ThrS-Val6-LeuT-Leu sGly% Curcacycline A displays a moderate inhibition of (i) classical pathway activity of human complement and (ii) proliferation of human T-cells.and two-dimensional 1H-NMR spectroscopy (HOHAHA and ROESY). Experimental Plant materialJatropha curcas L. plants grown as hedges in Jepara (near Kudus, Java, Indonesia) were identified. Crude latex was obtained by cutting off leaf stalks, adding a few drops of EtOH to prevent the latex from excessive foaming. The latex was stored at -20°C until use.