scholarly journals 1H-n.m.r. investigation of naturally occurring and chemically oversulphated dermatan sulphates. Identification of minor monosaccharide residues

1990 ◽  
Vol 267 (3) ◽  
pp. 625-630 ◽  
Author(s):  
V Bossennec ◽  
M Petitou ◽  
B Perly
Keyword(s):  
Glucuronic Acid ◽  
Nuclear Overhauser Effect ◽  
Double Quantum ◽  
Dermatan Sulphate ◽  
Proton Proton ◽  
Pig Skin ◽  
Overhauser Effect ◽  
Naturally Occurring ◽  
Iduronic Acid ◽  
Nuclear Overhauser

The 1H-n.m.r. spectra of various dermatan sulphate preparations present, besides the major signals of the basic disaccharide unit, several other minor signals. We have assigned most of them by n.m.r., using two-dimensional proton-proton double-quantum-correlation and nuclear-Overhauser-effect spectroscopy experiments. This allowed us to identify 2-O-sulphated L-iduronic acid and D-glucuronic acid residues as well as 6-sulphated N-acetylgalactosamine (presumably 4-O-sulphated as well). 2-O-Sulphated iduronic acid was present to similar extents (6-10% of total uronic acids) in pig skin dermatan sulphate and pig intestine dermatan sulphate, whereas glucuronic acid represented 17% of the uronic acid of pig skin dermatan sulphate and was virtually absent (1%) from the other preparation. 6-O-Sulphated N-acetylgalactosamine was present in minor amounts in pig intestine dermatan sulphate only. The influence of sulphation of iduronic acid units on their conformation was assessed by using chemically oversulphated pig intestine dermatan sulphate. Introduction of sulphate groups in this unit in dermatan sulphate tends to shift the conformational equilibrium towards the 1C4 conformer.

Applications of the intermolecular nuclear Overhauser effect. II. The operation of solute-site factors in the interaction of polar solutes with the solvent benzene

1983 ◽  
Vol 36 (11) ◽  
pp. 2227 ◽  
Author(s):  
GR Smith ◽  
B Ternai
Keyword(s):  
Nuclear Overhauser Effect ◽  
Proton Relaxation ◽  
Relaxation Rates ◽  
Site Factors ◽  
Aromatic Solvent ◽  
Proton Proton ◽  
Solvent Interactions ◽  
Overhauser Effect ◽  
Polar Solutes ◽  
Nuclear Overhauser

By considering the technique involving the measurement of aromatic solvent-induced shifts, and the models which have been proposed from the results of such measurements, it is suggested that the use of the solvent-induced solute proton intermolecular relaxation rate [(1/T1)solvinter] is a better method to study local solvation of solute molecules. Proton relaxation rates obtained for simple solutes in the solvent benzene are analysed in terms of an interaction parameter I, which treats (1/T1)solvinter] in terms of a proton-proton pair distribution function. The resultant dependence between I and a calculated measure of the local polarity of the observed solute is discussed in terms of previously proposed models of solute-solvent interactions.

scholarly journals An investigation into the solution structures of two self-complementary DNA oligomers, 5′-d(C-G-T-A-C-G) and 5′-d(A-C-G-C-G-C-G-T), by means of nuclear-Overhauser-enhancement measurements

1984 ◽  
Vol 221 (3) ◽  
pp. 723-726 ◽  
Author(s):  
A M Gronenborn ◽  
G M Clore ◽  
B J Kimber
Keyword(s):  
Nuclear Overhauser Effect ◽  
Type Structure ◽  
Dna Oligomers ◽  
Proton Proton ◽  
Solution Structures ◽  
Interproton Distance ◽  
Overhauser Effect ◽  
Distance Data ◽  
Nuclear Overhauser ◽  
Interproton Distances

A 500 MHz 1H-n.m.r. study on two self-complementary alternating pyrimidine-purine oligodeoxyribonucleotides, 5′-d(C-G-T-A-C-G) and 5′-d(A-C-G-C-G-C-G-T), is presented. By using the proton-proton nuclear Overhauser effect virtually complete assignments are obtained and a large number of interproton distances [113 in the case of 5′-d(C-G-T-A-C-G) and 79 in the case of 5′-d(A-C-G-C-G-C-G-T)], both intra- and inter-nucleotide, are determined. The interproton-distance data are consistent with an overall right-handed B-DNA-type structure for both oligonucleotides, in agreement with their B-type c.d. spectra. However, whereas 5′-d(C-G-T-A-C-G) adopts a conventional B-type structure with a mononucleotide repeating unit, the interproton-distance data provide evidence that 5′-d(A-C-G-C-G-C-G-T) has a dinucleotide repeating unit consisting of alternation in glycosidic bond and sugar pucker conformations.

scholarly journals The copolymeric structure of pig skin dermatan sulphate. Characterization of d-glucuronic acid-containing oligosaccharides isolated after controlled degradation of oxydermatan sulphate

1974 ◽  
Vol 143 (2) ◽  
pp. 369-378 ◽  
Author(s):  
Lars-Åke Fransson ◽  
Lars Cöster ◽  
Anders Malmström ◽  
Ingrid Sjöberg
Keyword(s):  
General Formula ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Dermatan Sulphate ◽  
Chondroitinase Abc ◽  
Pig Skin ◽  
Iduronic Acid ◽  
Unsaturated Disaccharide ◽  
Selective Periodate Oxidation

Selective periodate oxidation of unsubstituted l-iduronic acid residues in copolymeric dermatan sulphate chains was followed by reduction-hydrolysis or alkaline elimination. By this procedure the glucuronic acid-containing periods were isolated in oligosaccharide form; general formula: [Formula: see text] Further degradation of these oligosaccharides with chondroitinase-AC yielded three types of products: (a) sulphated trisaccharide containing an unsaturated uronosyl moiety in the non-reducing terminal and a C4 fragment in the reducing terminal, ΔUA-GalNAc-(-SO4)-R; (b) monosulphated, unsaturated disaccharide, ΔUA-GalNAc-SO4 when n is greater than or equal to 2; and (c) N-acetylgalactosamine with or without sulphate. Oligosaccharides containing a single glucuronic acid residue (n=1) comprised more than half of the glucuronic acid-containing oligosaccharides. The terminal N-acetylgalactosamine moiety of the shortest oligosaccharide was largely 4-sulphated, whereas higher oligosaccharides primarily contained 6-sulphated or unsulphated hexosamine moieties in the same position. Moreover, IdUA-SO4-containing oligosaccharides were encountered. These oligosaccharides were resistant to the action of chondroitinase-ABC.

The synthesis and the nuclear magnetic resonance study of β-lactam derivatives of 1,5-benzothiazepines

1988 ◽  
Vol 66 (2) ◽  
pp. 279-282 ◽  
Author(s):  
Aron Szöllösy ◽  
George Kotovych ◽  
Gábor Tóth ◽  
Albert Lévai
Keyword(s):  
Nuclear Overhauser Effect ◽  
Nuclear Magnetic Resonance Study ◽  
Coupling Constants ◽  
Magnetic Resonance Study ◽  
Proton Proton ◽  
Proton Coupling ◽  
Overhauser Effect ◽  
Vicinal Proton ◽  
Nuclear Overhauser ◽  
Derivatives Of

The synthesis and stereochemistry of seven β-lactam derivatives of 1,5-benzothiazepines are presented. The configurational and conformational analysis is based on nuclear Overhauser effect experiments, together with analysis of the vicinal proton–proton coupling constants. In the preferred conformation, the seven-membered ring is in a half-chair. Only for one compound, 2-aza-4-bromo-4-methyl-5,7-diphenyl-8-thiatricyclo[7.4.0.02,5]trideca-Δ1,9,10,12-trien-3-one, were two diastereomers isolated (compounds 6a and 6b). Six of the compounds have the 4S*, 5R*, 7R* configuration while compound 6b has the 4R*, 5R*,7R* configuration.

The conformational analysis of leukotriene D4 in aqueous solution based on high-field nuclear magnetic resonance measurements

1984 ◽  
Vol 62 (8) ◽  
pp. 1640-1645 ◽  
Author(s):  
Makiko Sugiura ◽  
Helmut Beierbeck ◽  
George Kotovych ◽  
Patrice C. Bélanger
Keyword(s):  
Conformational Analysis ◽  
Nuclear Overhauser Effect ◽  
Relaxation Times ◽  
Coupling Constants ◽  
Leukotriene D4 ◽  
Proton Proton ◽  
Proton Coupling ◽  
Overhauser Effect ◽  
Vicinal Proton ◽  
Nuclear Overhauser

The conformational analysis of LTD4 in D2O was carried out based on the analysis of vicinal proton–proton coupling constants, nonselective proton longitudinal relaxation times, and nuclear Overhauser effect data. The H6—C6 to C12 region of the molecule is transoid, the predominant rotamer about C5—C6 is gauche, and two rotamers can be used to describe the rotation about C12—C13. There are three rotamers that can be used to describe the rotation about the C21—C22 bond of cysteine. Finally, chelation between an Yb3+, shift reagents and LTD4 was not observed.

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