The Crystal and Molecular Structure of alpha-Xylose.

Hordvik, Asbjørn; Hassel, O.; Seppälä, Ilkka J.; Hedberg, Kenneth; Schaumburg, Kjeld; Ehrenberg, L.

doi:10.3891/acta.chem.scand.25-2175

Cited by 31 publications

(14 citation statements)

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“…The ring has an almost ideal chair form as demonstrated by the dihedral angles, Table 2. The interatomic distances and interbond angles agree reasonably with those in 7-xylopyranose (Hordvik, 1971) although the spread of values is greater than might have been expected, probably due to the relatively unfavourable parameter to observation ratio. (6) 106.2 (4) O (8) (6) 0(8) Table 2 and Table 4 the dihedral angle about the bond J-K is the angle the bond K-L is rotated from the 1JK plane.…”

Section: O-(8-d-xylopyranosyl)-l-serine and Its Copper(ii) Complexsupporting

confidence: 64%

The crystal and molecular structure of O-(β-D-xylopyranosyl)-L-serine and its copper(II) complex

Delbaere¹,

Kamenar²,

Prout³

1975

Acta Crystallogr Sect B

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The crystal structures of O-(fl-D-xylopyranosyl)-L-serine (monoclinic a=6.05, b=9-53, c=9-43 A, ?,=94.5°; space group P2~, Mo Ka radiation, linear diffractometer data, 907 independent reflexions, final R 0.058) and bis-[O-(fl-D-xylopyranosyl)-L-serinato]copper(II) (tetragonal a=9.82, c=21.28 A; space group P43212, Mo Ke radiation, linear diffractometer data, 733 independent reflexions, final R 0.093) have been determined and refined by the full-matrix least-squares method. The dimensions and conformation of the molecules are discussed.The carbohydrate-peptide bond in a number of complex macromolecules, e.g. heparin, chondroitin sulphates, is known to consist of a fl-O-glycoside between xylose and serine (xyl-ser) (Lindahl & Roden, 1965). Xyl-ser has been synthesised by Lindberg & Silvander (1965), Derevitskaya, Vafina & Kochetkov (1967) and Higham, Kent & Fisher (1968).The fl-configuration of the glycosidic bond was assigned from nuclear magnetic resonance data from chromatographically pure, crystalline xyl-ser (in D20 at 100 Hz) (Delbaere, Higham, Kamenar, Kent & Prout, 1972) who also reported the alkaline degradation of xyl-ser and the catalysis of this degradation by copper(II). The structures of xyl-ser and its copper complex were determined to study the conformation of xyl-ser and the effect of coordination with copper-(II). These structures have appeared in a preliminary report (Delbaere et al., 1972). Experimental PreparationsCrystals of xyl-ser and its copper complex were supplied by Dr P. W. Kent. Structure analysisFor each compound preliminary cell dimensions and the space group were determined from Weissenberg and precession photographs. The cell dimensions were refined and X-ray intensities measured on a linear diffractometer with Mo Ka radiation and balanced flters (xyl-ser: 907 independent reflexions, layers The structure xyl-ser was determined by direct methods. The reflexions 120, 370 and 521 were fixed at 0 to define the origin. ~1 relationships indicated that the phase of 040 was n and ~2 relationships that if the l phase of 237 was a then that of 2112 would be 2a; a was given the value n/4 and application of the tangent formula gave phases for a set of E's that yielded an E map in which the 16 largest peaks corresponded to the xyl-ser molecule. The trial model was refined by the full-matrix least-squares method first with isotropic then anisotropic temperature factors. Hydrogen atoms were found from a difference map at R = 0.066 but not refined. The refinement converged after six cycles at R = 0.058. Unit weights were used.The structure of copper xyl-ser was determined by the heavy-atom method. The trial structure obtained was refined by full-matrix least-squares calculations with isotropic temperature factors. The Fo map at R = 0.156 showed C(3) partially resolved into two maxima and 0(3) clearly resolved into two well separated peaks. These atoms and C(2), 0(2), C(4) and 0(4) all had anomalously high temperature factors, but all atoms other than 0(3) and C(3) were clearly resolved single ma...

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Section: O-(8-d-xylopyranosyl)-l-serine and Its Copper(ii) Complexsupporting

confidence: 64%

The crystal and molecular structure of O-(β-D-xylopyranosyl)-L-serine and its copper(II) complex

Delbaere¹,

Kamenar²,

Prout³

1975

Acta Crystallogr Sect B

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“…Despite the sensitivity reached in the experiment, no traces belonging to β-pyranose forms have been detected. This is in accordance with the fact that the rotational spectra of laser ablated crystalline D-xylose should reflect the α form found in the crystalline sample [266]. The interconversion between α and β anomers is usually a solvent-mediated reaction and would not occur that easily during the laser ablation process or in the gas phase [269].…”

Section: -Deoxy-d-ribose and Ribosementioning

confidence: 54%

“…Xylose exists predominantly in the pyranose form in the condensed phase [210,233,234,266], and it is believed to maintain this structure in the gas phase [267]. The pyranose structures have two enantiomers designated as α and β depending on the OH group position at the chiral C 1 .…”

Section: -Deoxy-d-ribose and Ribosementioning

confidence: 99%

Microwave Spectroscopy of Biomolecular Building Blocks

Alonso

López

2014

Topics in Current Chemistry

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Microwave spectroscopy, considered as the most definitive gas phase structural probe, is able to distinguish between different conformational structures of a molecule, because they have unique spectroscopic constants and give rise to distinct individual rotational spectra.Previously, application of this technique was limited to molecular specimens possessing appreciable vapor pressures, thus discarding the possibility of studying many other molecules of biological importance, in particular those with high melting points, which had a tendency to undergo thermal reactions, and ultimately degradation, upon heating.Nowadays, the combination of laser ablation with Fourier transform microwave spectroscopy techniques, in supersonic jets, has enabled the gas-phase study of such systems. In this chapter, these techniques, including broadband spectroscopy, as well as results of their application into the study of the conformational panorama and structure of biomolecular building blocks, such as amino acids, nucleic bases, and monosaccharides, are briefly discussed, and with them, the tools for conformational assignation - rotational constants, nuclear quadrupole coupling interaction, and dipole moment.

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“…were remeasured, since the values reported by Hordvik (1971) were 0.3% greater than the neutron diffraction values. The contents of the unit cell are shown in Fig.…”

mentioning

confidence: 95%

“…The atomic coordinates from the X-ray determination (Hordvik, 1971) were used as the initial values for separate refinement of (I) and (II) by fullmatrix least squares, minimizing ~ wIF2o -k2F212 (Busing, Martin & Levy, 1962). A difference Fourier map revealed the positions of all hydrogen atoms.…”

mentioning

confidence: 99%

α-L-Xylopyranose: a neutron diffraction refinement

Takagi¹

1979

Acta Crystallogr Sect B

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The Crystal and Molecular Structure of alpha-Xylose.

Cited by 31 publications

References 0 publications

The crystal and molecular structure of O-(β-D-xylopyranosyl)-L-serine and its copper(II) complex

The crystal and molecular structure of O-(β-D-xylopyranosyl)-L-serine and its copper(II) complex

Microwave Spectroscopy of Biomolecular Building Blocks

α-L-Xylopyranose: a neutron diffraction refinement

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