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Methyl [beta]-D-galactopyranosyl-(1[rightwards arrow]4)-[beta]-D-xylopyran­oside, C12H22O10, (II), crystallizes as colorless needles from water with positional disorder in the xylopyranosyl (Xyl) ring and no water mol­ecules in the unit cell. The inter­nal glycosidic linkage conformation in (II) is characterized by a [varphi]' torsion angle (C2'Gal-C1'Gal-O1'Gal-C4Xyl) of 156.4 (5)° and a [psi]' torsion angle (C1'Gal-O1'Gal-C4Xyl-C3Xyl) of 94.0 (11)°, where the ring atom numbering conforms to the convention in which C1 denotes the anomeric C atom, and C5 and C6 denote the hy­droxy­methyl (-CH2OH) C atoms in the [beta]-Xyl and [beta]-Gal residues, respectively. By comparison, the inter­nal linkage conformation in the crystal structure of the structurally related disaccharide, methyl [beta]-lactoside [methyl [beta]-D-galactopyrano­syl-(1[rightwards arrow]4)-[beta]-D-glucopyran­oside], (III) [Stenutz, Shang & Serianni (1999). Acta Cryst. C55, 1719-1721], is characterized by [varphi]' = 153.8 (2)° and [psi]' = 78.4 (2)°. A comparison of [beta]-(1[rightwards arrow]4)-linked disaccharides shows considerable variability in both [varphi]' and [psi]', with the range in the latter (~38°) greater than that in the former (~28°). Inter-residue hydrogen bonding is observed between atoms O3Xyl and O5'Gal in the crystal structure of (II), analogous to the inter-residue hydrogen bond detected between atoms O3Glc and O5'Gal in (III). The exocyclic hy­droxy­methyl conformations in the Gal residues of (II) and (III) are identical (gauche-trans conformer).

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270111048347/tp3005sup1.cif
Contains datablocks II, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270111048347/tp3005IIsup2.hkl
Contains datablock II

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S0108270111048347/tp3005sup3.pdf
Supplementary material

CCDC reference: 866750

Comment top

The N-linked glycans of human glycoproteins are characterized by a common pentasaccharide core, Man3GlcNAc2, containing three D-mannose (Man) and two N-acetyl-D-glucosamine (GlcNAc) residues, with the terminal β-GlcNAc-(14)-β-GlcNAc portion linked to L-asparagine side chains of the protein (Taylor & Drickamer, 2003). In contrast, the modes of attachment of O-linked glycans to proteins are more diverse, with N-acetyl-D-galactosamine, D-glucose, D-galactose, D-mannose or D-xylose covalently attached via the side chains of L-serine and L-threonine (Voet & Voet, 2011). For example, in the proteoglycans, chrondroitin sulfate polysaccharide chains are covalently attached to core protein via a β-GlcA-(13)-β-Gal-(13)-β-Gal-(14)-β-Xyl tetrasaccharide, (I), with the terminal β-Xyl residue linked to L-serine (Nadanaka & Kitagawa, 2008). The residues comprising this linkage tetrasaccharide may be O-sulfated or O-phosphorylated. In this report, the crystal structure of the β-Gal-(14)-β-Xyl substructure of (I) has been determined in the form of its methyl glycoside, namely, methyl β-D-galactopyranosyl-(14)-β-D-xylopyranoside, (II). This new structure complements those of other structurally related β-(14)-linked disaccharides reported previously, including methyl β-D-galactopyranosyl-(14)-β-D-glucopyranoside, (III) (Stenutz et al., 1999), methyl β-D-galactopyranosyl-(14)-α-D-glucopyranoside, (IV) (Pan et al., 2005), methyl β-L-galactopyranosyl-(14)-β-D-glucopyranoside, (V) (Pan et al., 2006), methyl β-D-galactopyranosyl-(14)-α-D-mannopyranoside, (VI) (Hu et al., 2010), methyl β-D-galactopyranosyl-(14)-β-D-allopyranoside, (VII) (Zhang et al., 2010), and methyl β-D-glucopyranosyl-(14)-β-D-glucopyranoside, (VIII) (Ham & Williams, 1970).

Methyl β-D-galactopyranosyl-(14)-β-D-xylopyranoside, (II), was prepared by a chemical route (see supplementary material for synthetic details). After purification by chromatography, (II) was crystallized from water to give microcrystals devoid of water. In this report, the crystal structure of (II) is compared with that of the structurally related methyl disaccharide β-D-galactopyranosyl-(14)-β-D-glucopyranoside [methyl β-lactoside, (III); Stenutz et al., 1999] (Table 2).

The crystal structure of (II) exhibits elements of disorder not observed in those of (III) and other β-(14)-linked disaccharides (Pan et al., 2005, 2006; Hu et al., 2010; Zhang et al., 2010; Ham & Williams, 1970). This disorder is located exclusively within the Xyl residue, and modeling of the diffraction data yielded major (~70%) and minor (~30%) components. Atoms in the latter are denoted with the suffix A throughout this article. The observed disorder has been attributed to an oscillation of the Xyl ring perpendicular to the plane of the ring, translating into librational motion across the β-(14) linkage. This behavior appears to be a characteristic feature of crystals of (II); data obtained from different samples of crystals yielded the same disorder. Why disorder in the glycosidic linkage appears in crystals of (II) and not in those of other β-(14) linked disaccharides including (III) is unclear, but ring geometry and/or substituent effects in the Xyl ring, or packing considerations, probably play a role. The glycosidic linkages in other β-(14) linked disaccharides are constrained by inter-residue hydrogen bonding between atoms O3 and O5'. Lack of an exocyclic CH2OH group in the Xyl ring of (II) may allow this hydrogen bonding in a wider range of linkage conformations, thus leading to linkage disorder in the solid state. Whether this putative difference plays a functional role in the O-linkages of glycoproteins involving β-Xyl remains uncertain.

The presence of disorder in crystals of (II) complicates a quantitative analysis of molecular parameters such as bond lengths, angles and torsions due to averaging effects on the electron densities (and corresponding displacement ellipsoids) used to determine the structure. This fact is evident, for example, when comparing the C4—C5 bond length in (II) with that in (III), where a difference of ~0.04 Å is observed (Table 2). In contrast, inspection of the X-ray structure of methyl β-xylopyranoside, (IX) (Takagi & Jeffrey, 1977), shows a C4—C5 bond of 1.519 Å, in better agreement with the corresponding bond length in (III) than in (II).

For the major component of (II), the C1—O1—C6 bond angle is 118.3 (9)°, statistically larger than the value of 113.7 (2)° found in (III), with the latter value similar to the corresponding value found in methyl β-xylopyranoside, (IX) (113.0°). In contrast, the internal C1'—O1'—C4 bond angle in (II) is 113.6 (7)°, similar to the corresponding value found in (III) [116.2 (2)°; Table 2]. This internal glycosidic bond angle is typically larger than that associated with the terminal methyl glycosides, presumably due to greater steric strain present in the internal linkage. The normal value of this angle in (II) suggests that the internal glycosidic torsion angles in (II) (i.e. ϕ' and ψ') are probably minimally affected by the presence of disorder in the Xyl residue. This conclusion is supported by the similar bond lengths observed in the Gal residues of (II) and (III) (Table 2).

Cremer–Pople (CP) puckering parameters for the pyranosyl ring constituents of (II) and (III) are shown in Table 3 (Cremer & Pople, 1975; Boeyens, 1978; Spek, 2009). The β-Gal ring in both structures adopts a chair conformation with similar θ and ϕ values, indicating similar degrees and directions for the slight distortion towards the C3TBC1 conformation (TB = twist-boat). The β-Xyl ring of (II) and β-Glc ring of (III) show the same degree of distortion, with the former slightly skewed towards C3,O5B (B = boat) and the latter towards O5TBC2. In contrast, the crystal structure of methyl β-D-galactopyranoside, (X) (Takagi & Jeffrey, 1979), has θ = 5.89° and ϕ = 346.6°, indicating a direction of distortion (O5TBC2) different from that in the Gal residues of (II) and (III). CP parameters for methyl β-D-xylopyranoside, (IX), and methyl β-D-glucopyranoside, (XI) (Jeffrey & Takagi, 1979), are very similar (θ = 7–8° and ϕ = 36–38°), indicating a direction of distortion in (IX) similar to that in the Xyl reside of (II) but a direction of distortion in (XI) different from that found in the Glc residue of (III). However, it must be noted that the distortion in (II) is highly dependent on the model used to treat the disorder. Examination of the electron-density map of the disorder shows no evidence for discrete regions of electron density corresponding to the separate components, so it is highly probable that the β-Xyl ring of (II) is dynamic, making the distortion difficult to quantify reliably.

The exocyclic hydroxymethyl conformation in the Gal residues of (II) and (III) is similar, with O5'—C5'—C6'—O6' torsion angles near 60°, corresponding to the gauche–trans (gt) conformation. This behavior is similar to that found in methyl β-D-galactopyranoside, (X).

The internal glycosidic linkage conformation in (II) differs from that in (III), with the difference associated more with ψ' than with ϕ'; the ϕ' values differ by ~3°, whereas the ψ' values differ by ~16°. Table 4 summarizes the ϕ' and ψ' values observed in a series of β-(14)-linked disaccharides for which crystal structures have been reported. In this comparison, torsion angles involving heavy atoms were used to define ϕ' and ψ', namely, C2'—C1'—O1'—C4 for ϕ' and C1'—O1'—C4—C3 for ψ'. It is noteworthy that considerable variability in both ϕ' and ψ' is observed, with that for ψ' (37.7°) larger than that for ϕ' (28.4°). These findings, although confined to a relatively small data set, show that the stereoelectronic (exo-anomeric) effect does not severely constrain the ϕ' torsion angle in these linkages; presumably, crystal packing forces are strong enough to rotate the C1'—O1' bond in order to minimize the packing energy. The comparatively greater variability in ψ' is presumably caused by different non-bonded (steric) effects that are structure-dependent, although packing forces may also contribute. Disaccharide (V) was excluded from this comparison since it contains an L-Gal residue and thus its internal glycosidic linkage is structurally distinct from the others.

Internal (inter-residue) hydrogen bonding occurs in (II) between atom O3 of the Xyl residue and atom O5' of the Gal residue. The O3···O5' internuclear distances of 2.729 (5) and 2.803 (13) Å (major and minor component, respectively) in the two O3 (O3/O3A) positions show that two hydrogen-bonding geometries are possible; this observation suggests some plasticity in the overall conformation in accommodating this type of intramolecular hydrogen bond. It is noteworthy that all of the disaccharides in Table 4 contain this hydrogen bond except (V) and (VII). The major-component hydroxy atom O3 also has a long inter-residue contact with methoxy atom O6'.

All hydroxy H atoms in the Gal moiety of (II) are involved as donors in intermolecular hydrogen bonds. In the Xyl residue, both atoms O2 and O3 are hydrogen-bond donors, whereas atom O2A is not well located to form a hydrogen bond with nearby acceptors. Atom O3 is involved as a donor in an inter-residue hydrogen bond with atom O5'. Atoms O1 and O2 of the Xyl residue are not involved as acceptors, whereas atoms O3 and O5 serve as mono-acceptors. Atoms O1', O2', O4' and O5' of the Gal residue are not involved as acceptors in intermolecular hydrogen bonds, while atom O3' serves as a mono-acceptor.

The overall packing motif of (II) is a three-dimensional network of hydrogen-bonded molecules (Fig. 2). The interaction of atom O2' with ring atom O5ii forms chains related by the screw axis parallel to the c axis [symmetry code: (ii) -x + 1/2, -y + 2, z + 1/2]. These chains are linked to other chains related by screw axes parallel to the a axis through the hydrogen bonds from atoms O4' to O3iv, O2 to O4'i and O6' to O3'i [symmetry codes: (i) x - 1/2, -y + 3/2, -z + 2; (iv) x + 1/2, -y + 3/2, -z + 2]. These screw axes are translated along the a axis with respect to the others. Lastly, atom O3' forms a hydrogen bond with atom O6'iii related by the screw axis parallel to the b axis [symmetry code: (iii) x + 1/2, -y + 3/2, -z + 1]. The disordered methoxy atom C6 and the minor component hydroxy atom O2A are oriented towards a void space within the lattice.

Related literature top

For related literature, see: Boeyens (1978); Cremer & Pople (1975); Flack (1983); Gruzman et al. (2008); Ham & Williams (1970); Hooft et al. (2008); Hu et al. (2010); Nadanaka & Kitagawa (2008); Ning et al. (2003); Pan et al. (2005, 2006); Podlasek et al. (1995); Schmidt & Michel (1985); Spek (2009); Stenutz et al. (1999); Takagi & Jeffrey (1977, 1979); Taylor & Drickamer (2003); Tropper et al. (1992); Voet & Voet (2011); Wu & Serianni (1991); Zhang et al. (2010).

Experimental top

The crystal structure of (II) was determined on a sample prepared chemically by the eight-step synthesis described in the supplementary material; the relevant literature references are: Schmidt & Michel (1985); Wu & Serianni (1991); Podlasek et al. (1995); Tropper et al. (1992); Gruzman et al. (2008); Ning et al. (2003). [Please confirm added text] Disaccharide (II) was crystallized from water to give colorless needle-like microcrystals.Due to the growth of the compound as microcrystals, conservatively estimated at 10 microns in thickness and the presence of only light atoms within the sample synchrotron radiation was a necessity for the determination of the structure. Standard laboratory instruments only yielded data suitable for a low quality preliminary structure.

Refinement top

Examination of the xylose moiety showed positional disorder in the peripheral atoms and close inspection of the displacement ellipsoids demonstrated that the entire ring was affected. The positions for atoms in the major and minor components were determined initially by location of the major component and subsequent refinement of these sites at less than full occupancy, enhancing the difference Fourier map which displayed the location of the minor component atoms. The occupancies of the major and minor components were refined and summed to unity, yielding an approximately 0.70:0.30 ratio. The minor component was restrained to have bond distances and angles similar to those of the major component to within a small error (s.u. = 0.02 Å or 0.02°). The major and minor components were both refined with anistropic displacement parameters, with displacement parameters of adjacent atoms restrained to have similar Uij values in the two disorder components.

H atoms were initially located from a difference Fourier map and subsequently included as riding atoms in geometrically idealized positions, with C—H = 0.98–1.00 Å and O—H = 0.84 Å. For all H atoms, Uiso(H) = kUeq(parent), where k = 1.5 for methyl groups and 1.2 for all other H atoms. Hydroxy H atoms were permitted to rotate but not tilt.

The assignment of the absolute configuration was based on the known configuration of the disaccharide from the synthesis. Refinement of the Flack x parameter [x = 0.6 (9); Flack, 1983] and Bayesian analysis of Bijvoet pairs of reflections [y = 0.4 (4); Hooft et al., 2008] did not yield a conclusive analysis of the correct absolute configuration. The structure was ultimately refined as a racemic twin with a twin fraction of approximately 0.58.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Sheldrick, 2008), POV-RAY (Cason, 2003) and DIAMOND (Brandenburg, 2009); software used to prepare material for publication: XCIF (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure of (II), with the atom-numbering scheme. Displacement ellipsoids are depicted at the 50% probability level.
[Figure 2] Fig. 2. The hydrogen-bonding network for (II), viewed along the c axis. The minor disorder component has been omitted for clarity. Dashed lines represent hydrogen bonds.
Methyl β-D-galactopyranosyl-(14)-β-D-xylopyranoside top
Crystal data top
C12H22O10F(000) = 696
Mr = 326.30Dx = 1.481 Mg m3
Orthorhombic, P212121Synchrotron radiation, λ = 1.23990 Å
Hall symbol: P 2ac 2abCell parameters from 3223 reflections
a = 13.7878 (14) Åθ = 3.0–44.4°
b = 22.892 (2) ŵ = 0.52 mm1
c = 4.6367 (5) ÅT = 150 K
V = 1463.5 (3) Å3Needle, colourless
Z = 40.08 × 0.01 × 0.01 mm
Data collection top
Bruker APEXII
diffractometer
2300 independent reflections
Radiation source: synchrotron1900 reflections with I > 2σ(I)
Channel-cut Si-<111> crystal monochromatorRint = 0.073
Detector resolution: 8.33 pixels mm-1θmax = 45.3°, θmin = 3.0°
combination of ω and ϕ scansh = 1515
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 2008)
k = 2626
Tmin = 0.566, Tmax = 0.749l = 55
11197 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.067H-atom parameters constrained
wR(F2) = 0.158 w = 1/[σ2(Fo2) + (0.0515P)2 + 2.2462P]
where P = (Fo2 + 2Fc2)/3
S = 1.16(Δ/σ)max < 0.001
2300 reflectionsΔρmax = 0.35 e Å3
298 parametersΔρmin = 0.27 e Å3
299 restraintsAbsolute structure: Flack (1983), 920 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.6 (9)
Crystal data top
C12H22O10V = 1463.5 (3) Å3
Mr = 326.30Z = 4
Orthorhombic, P212121Synchrotron radiation, λ = 1.23990 Å
a = 13.7878 (14) ŵ = 0.52 mm1
b = 22.892 (2) ÅT = 150 K
c = 4.6367 (5) Å0.08 × 0.01 × 0.01 mm
Data collection top
Bruker APEXII
diffractometer
2300 independent reflections
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 2008)
1900 reflections with I > 2σ(I)
Tmin = 0.566, Tmax = 0.749Rint = 0.073
11197 measured reflectionsθmax = 45.3°
Refinement top
R[F2 > 2σ(F2)] = 0.067H-atom parameters constrained
wR(F2) = 0.158Δρmax = 0.35 e Å3
S = 1.16Δρmin = 0.27 e Å3
2300 reflectionsAbsolute structure: Flack (1983), 920 Friedel pairs
298 parametersAbsolute structure parameter: 0.6 (9)
299 restraints
Special details top

Experimental. 2,3,4,6-Tetra-O-acetyl-α-D-galactopyranosyl trichloroacetimidate (4).

D-Galactose (1) (1.20 g, 6.67 mmol) was dissolved in pyridine (40 ml), and acetic anhydride (6.25 ml, 66.7 mmol) was added. The reaction mixture was stirred at room temperature overnight and concentrated in vacuo to afford the per-O-acetylated D-galactopyranose (2). Compound 2 was deacetylated at C1 with benzylamine (0.87 ml, 8.00 mmol) in THF (40.0 ml) to afford 3. After purification, compound 3 was converted to the corresponding trichloroacetimidate with trichloroacetonitrile and 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU), as described by Schmidt & Michel (1985), affording 4 (1.96 g, 4.00 mmol, 60%).

Methyl β-D-xylopyranoside (6).

D-Xylose (5) (1.00 g, 6.67 mmol) was dissolved in anhydrous methanol (40 ml), dry Dowex 50W × 8 (200–400 mesh) (H+) ion-exchange resin (2.0 g) was added, and the suspension was refluxed for 2 d. After filtration to remove the resin, the solution was concentrated at 30°C in vacuo to dryness and the residue was dissolved in a minimum quantity of distilled water and applied to a column (2.5 cm × 50 cm) containing Dowex 1 × 8 (200–400 mesh) ion-exchange resin in the OH- form (Wu & Serianni, 1991; Podalesk et al., 1995). The column was eluted with distilled decarbonated water (1.0 ml min-1), and fractions (18 ml) were collected and assayed by TLC (silica gel; spots detected by charring after spraying with 1% (w/v) CeSO4 – 2.5% (w/v) (NH4)6Mo7O24 – 10% aqueous H2SO4 reagent) (Tropper et al., 1992). Fractions containing glycosides were pooled and evaporated to dryness at 30 °C in vacuo to afford pure methyl β-D-xylopyranoside (0.60 g) and methyl β-D-xylopyranoside (6) (0.30 g). Compound 6 was crystallized from methanol.

Methyl 2,3-O-isopropylidene-β-D-xylopyranoside (7).

To a sealed flask containing methyl β-D-xylopyranoside (6) (1.00 g, 6.10 mmol) were added dry N,N-dimethylformamide (DMF) (10 ml), methanol (0.20 ml) and acetyl chloride (40 µl). 2-Methoxypropene (1.40 ml) was then added dropwise to the ice-cold reaction mixture over 10 min. The reaction mixture clarified and was stirred for 2 h at room temperature. CH2Cl2 (100 ml) was added and the solution was extracted with NaHCO3 solution (0.1 M, 50 ml) and water (50 ml). The NaHCO3 solution phase and water phase were back-extracted with CH2Cl2. The organic solutions were combined and dried over anhydrous Na2SO4, then concentrated in vacuo to a syrup. Purification by flash chromatography on a silica gel column (eluant: hexanes/ethyl acetate, 1.5:1) afforded 7 (0.95 g, 4.66 mmol, 76%) (Gruzman et al., 2008).

Methyl β-D-4-O-(2,3,4,6-tetra-O-acetyl-galactopyranosyl)-2,3-O-isopropylidene-β-D-xylopyranoside (8).

Donor 4 (1.30 g, 2.65 mmol) and acceptor 7 (0.50 g, 2.45 mmol) were dissolved in anhydrous CH2Cl2 (20 ml) after drying under high vacuum, and the solution was treated with molecular sieves (4 Å) (1.0 g). A catalytic amount of trimethylsilyltriflate (15 ml, 0.08 mmol) was added under N2 at 0°C. After stirring for 2 h at room temperature, additional trimethylsilyltriflate (15 µl, 0.08 mmol) was added and the reaction mixture was stirred at room temperature overnight. The reaction mixture was quenched with the addition of triethylamine (30 µl) and the molecular sieves were removed by filtration. The solution was concentrated and purified by flash chromatography on a silica gel column (eluant: hexanes/ethyl acetate, 2:1) to afford 8 (0.68 g, with some impurity). Compound 8 was then dissolved in methanol (20 ml), and acetyl chloride (40 µl) was added at 0°C. The reaction mixture was stirred for 1 h at room temperature, concentrated in vacuo, and purified on a silica gel column to obtain methyl β-D-4-O-(2,3,4,6-tetra-O-acetyl-galactopyranosyl)-β-D-xylopyranoside (9) (0.37 g, 0.75 mmol, 30% for two steps).

Methyl β-D-galactopyranosyl-(14)-β-D-xylopyranoside (II).

Compound 9 (350 mg, 0.71 mmol) was dissolved in methanol (10 ml) saturated with NH3 (Ning et al., 2003). After 16 h, the solution was concentrated to a syrup at 30°C in vacuo. The residue was dissolved in \sim0.5 ml of water and the solution was applied to a column (2.5 × 100 cm) containing Dowex 50 × 8 (200–400 mesh) ion-exchange resin in the Ca2+ form (Tropper et al., 1992). The column was eluted with distilled decarbonated water at \sim1.5 ml min-1, and fractions (8 ml) were collected and assayed by TLC (Gruzman et al., 2008). Fractions 20–24 were pooled and concentrated at 30°C in vacuo to give (II) (0.21 g, 0.64 mmol, 90%).

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Three, low-angle reflections were omitted from the refinement (1 0 2), (0 1 2) and (0 0 1) due to a zero recorded intensity, presumably a result of a detector overload during data collection.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
O10.1217 (6)0.9916 (4)0.5119 (19)0.051 (2)0.692 (9)
O20.1190 (4)0.8860 (3)0.8253 (18)0.0364 (16)0.692 (9)
H20.12450.85040.78540.044*0.692 (9)
O30.0564 (3)0.82478 (18)0.7192 (15)0.0385 (17)0.692 (9)
H30.09690.80730.82340.046*0.692 (9)
O50.0409 (7)0.9952 (4)0.5174 (18)0.041 (2)0.692 (9)
C10.0431 (6)0.9749 (4)0.674 (2)0.038 (2)0.692 (9)
H1A0.04570.99120.87380.046*0.692 (9)
C20.0390 (5)0.9096 (3)0.675 (2)0.0323 (19)0.692 (9)
H2A0.04470.89650.46960.039*0.692 (9)
C30.0560 (5)0.8853 (3)0.790 (2)0.0281 (18)0.692 (9)
H3A0.05610.88931.00490.034*0.692 (9)
C40.1446 (8)0.9163 (5)0.671 (4)0.0286 (19)0.692 (9)
H4A0.15370.90300.46700.034*0.692 (9)
C50.1298 (7)0.9807 (5)0.665 (3)0.035 (2)0.692 (9)
H5A0.12710.99580.86540.043*0.692 (9)
H5B0.18520.99960.56650.043*0.692 (9)
C60.1556 (8)1.0506 (5)0.538 (3)0.073 (4)0.692 (9)
H6A0.21211.05620.41240.110*0.692 (9)
H6B0.10391.07760.47960.110*0.692 (9)
H6C0.17391.05840.73810.110*0.692 (9)
O1A0.1223 (13)0.9986 (7)0.637 (4)0.046 (3)0.308 (9)
O2A0.1134 (10)0.9065 (8)0.973 (4)0.044 (4)0.308 (9)
H2AA0.11860.93581.08010.053*0.308 (9)
O3A0.0595 (9)0.8394 (5)0.971 (4)0.055 (4)0.308 (9)
H3AA0.11560.82771.01200.066*0.308 (9)
O5A0.0451 (14)1.0031 (8)0.606 (4)0.034 (3)0.308 (9)
C1A0.0373 (13)0.9800 (8)0.743 (6)0.037 (2)0.308 (9)
H1A10.03480.99530.94490.045*0.308 (9)
C2A0.0360 (11)0.9155 (8)0.773 (5)0.036 (3)0.308 (9)
H2A10.04860.89560.58430.044*0.308 (9)
C3A0.0627 (12)0.8981 (7)0.900 (5)0.035 (3)0.308 (9)
H3A10.06990.92011.08460.042*0.308 (9)
C4A0.1426 (19)0.9199 (11)0.699 (10)0.031 (3)0.308 (9)
H4A10.13500.90710.49380.037*0.308 (9)
C5A0.1351 (16)0.9854 (11)0.742 (6)0.033 (3)0.308 (9)
H5A10.13420.99500.95000.040*0.308 (9)
H5B10.19091.00540.65110.040*0.308 (9)
C6A0.1502 (17)1.0565 (8)0.714 (6)0.053 (5)0.308 (9)
H6A10.21011.06690.61290.079*0.308 (9)
H6B10.09861.08380.65970.079*0.308 (9)
H6C10.16091.05860.92280.079*0.308 (9)
O1'0.2330 (2)0.90369 (13)0.8255 (8)0.0300 (8)
O2'0.4330 (2)0.91350 (14)0.6523 (8)0.0416 (10)
H2'0.44650.93910.77570.050*
O3'0.5459 (2)0.81092 (16)0.7860 (8)0.0389 (8)
H3'0.58350.81880.64900.047*
O4'0.4093 (2)0.74209 (15)1.0721 (8)0.0355 (9)
H4'0.46070.72361.10470.043*
O5'0.24811 (19)0.80457 (13)0.8259 (7)0.0292 (7)
O6'0.1379 (2)0.70430 (16)0.7108 (9)0.0421 (9)
H6'0.10220.70110.85670.051*
C1'0.2871 (3)0.85764 (19)0.7055 (12)0.0292 (11)
H1'A0.28070.85750.49070.035*
C2'0.3936 (3)0.86334 (19)0.7935 (12)0.0304 (11)
H2'A0.40000.86691.00760.037*
C3'0.4479 (3)0.80961 (19)0.6827 (11)0.0296 (11)
H3'A0.44940.81140.46730.036*
C4'0.3999 (3)0.7519 (2)0.7717 (11)0.0299 (11)
H4'A0.43150.71900.66520.036*
C5'0.2929 (3)0.75388 (19)0.6931 (12)0.0309 (11)
H5'A0.28640.75690.47880.037*
C6'0.2379 (3)0.7006 (2)0.7970 (13)0.0404 (13)
H6'A0.26750.66490.71440.048*
H6'B0.24210.69791.00970.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.030 (3)0.047 (3)0.075 (5)0.004 (3)0.012 (4)0.014 (4)
O20.018 (2)0.030 (3)0.062 (5)0.000 (2)0.013 (3)0.005 (3)
O30.020 (3)0.018 (2)0.078 (5)0.0008 (18)0.001 (3)0.001 (3)
O50.025 (2)0.039 (3)0.060 (5)0.004 (3)0.002 (3)0.008 (3)
C10.020 (3)0.035 (3)0.060 (5)0.002 (3)0.002 (3)0.002 (3)
C20.017 (3)0.034 (3)0.046 (4)0.002 (3)0.007 (3)0.000 (3)
C30.019 (3)0.027 (3)0.038 (4)0.000 (3)0.004 (3)0.004 (3)
C40.017 (3)0.030 (3)0.039 (5)0.001 (3)0.006 (3)0.003 (3)
C50.022 (3)0.030 (3)0.055 (6)0.001 (3)0.005 (3)0.001 (4)
C60.041 (5)0.061 (6)0.117 (10)0.019 (5)0.003 (7)0.020 (7)
O1A0.025 (4)0.039 (5)0.074 (7)0.007 (4)0.003 (6)0.005 (6)
O2A0.033 (7)0.053 (9)0.046 (9)0.004 (7)0.009 (6)0.011 (7)
O3A0.044 (7)0.045 (7)0.074 (9)0.007 (6)0.011 (6)0.016 (6)
O5A0.018 (4)0.028 (4)0.056 (6)0.004 (4)0.004 (5)0.001 (5)
C1A0.019 (4)0.035 (4)0.058 (5)0.001 (4)0.003 (4)0.003 (4)
C2A0.023 (4)0.035 (4)0.051 (5)0.002 (4)0.003 (4)0.005 (5)
C3A0.027 (4)0.030 (5)0.048 (6)0.003 (4)0.006 (5)0.001 (5)
C4A0.021 (4)0.031 (5)0.042 (6)0.001 (4)0.002 (4)0.001 (5)
C5A0.020 (4)0.030 (5)0.049 (6)0.001 (4)0.004 (5)0.001 (5)
C6A0.042 (9)0.025 (8)0.091 (14)0.014 (7)0.001 (11)0.021 (10)
O1'0.0175 (15)0.0314 (17)0.041 (2)0.0034 (13)0.0012 (14)0.0032 (15)
O2'0.0284 (17)0.0354 (19)0.061 (3)0.0062 (16)0.0104 (18)0.0006 (18)
O3'0.0172 (15)0.054 (2)0.045 (2)0.0006 (16)0.0013 (15)0.0143 (19)
O4'0.0244 (17)0.045 (2)0.037 (2)0.0067 (16)0.0102 (16)0.0043 (16)
O5'0.0164 (14)0.0294 (16)0.042 (2)0.0004 (14)0.0047 (14)0.0033 (16)
O6'0.0242 (16)0.050 (2)0.052 (2)0.0104 (16)0.0093 (16)0.0102 (19)
C1'0.022 (2)0.030 (3)0.036 (3)0.005 (2)0.003 (2)0.003 (2)
C2'0.021 (2)0.032 (3)0.038 (3)0.003 (2)0.007 (2)0.001 (2)
C3'0.019 (2)0.031 (3)0.039 (3)0.002 (2)0.002 (2)0.007 (2)
C4'0.025 (2)0.034 (3)0.031 (3)0.005 (2)0.001 (2)0.001 (2)
C5'0.022 (2)0.033 (3)0.038 (3)0.002 (2)0.007 (2)0.000 (2)
C6'0.028 (2)0.035 (3)0.058 (4)0.005 (2)0.014 (2)0.000 (3)
Geometric parameters (Å, º) top
O1—C11.373 (9)O2—H20.8400
O1—C61.434 (11)O3—H30.8400
O2—C21.413 (8)C1—H1A1.0000
O3—C31.424 (8)C2—H2A1.0000
O5—C51.443 (8)C3—H3A1.0000
O5—C11.444 (8)C4—H4A1.0000
C1—C21.495 (9)C5—H5A0.9900
C2—C31.519 (8)C5—H5B0.9900
C3—C41.518 (9)C6—H6A0.9800
C4—O1'1.443 (17)C6—H6B0.9800
C4—C51.489 (9)C6—H6C0.9800
O1A—C1A1.339 (15)O2A—H2AA0.8400
O1A—C6A1.427 (15)O3A—H3AA0.8400
O2A—C2A1.429 (15)C1A—H1A11.0000
O3A—C3A1.384 (15)C2A—H2A11.0000
O5A—C1A1.405 (14)C3A—H3A11.0000
O5A—C5A1.449 (15)C4A—H4A11.0000
C1A—C2A1.483 (15)C5A—H5A10.9900
C2A—C3A1.536 (15)C5A—H5B10.9900
C3A—C4A1.527 (17)C6A—H6A10.9800
C4A—O1'1.43 (4)C6A—H6B10.9800
C4A—C5A1.516 (16)C6A—H6C10.9800
O1'—C1'1.406 (5)O2'—H2'0.8400
O2'—C2'1.429 (6)O3'—H3'0.8400
O3'—C3'1.434 (5)O4'—H4'0.8400
O4'—C4'1.417 (6)O6'—H6'0.8400
O5'—C1'1.441 (5)C1'—H1'A1.0000
O5'—C5'1.452 (6)C2'—H2'A1.0000
O6'—C6'1.439 (5)C3'—H3'A1.0000
C1'—C2'1.530 (6)C4'—H4'A1.0000
C2'—C3'1.529 (6)C5'—H5'A1.0000
C3'—C4'1.535 (6)C6'—H6'A0.9900
C4'—C5'1.520 (6)C6'—H6'B0.9900
C5'—C6'1.516 (7)
C1—O1—C6118.3 (9)O1'—C4A—C3A107 (2)
C5—O5—C1111.6 (7)C5A—C4A—C3A101.2 (17)
O1—C1—O5105.5 (7)O5A—C5A—C4A106.2 (16)
O1—C1—C2108.1 (7)C1'—O1'—C4A119.7 (17)
O5—C1—C2107.0 (7)C1'—O1'—C4113.6 (7)
O2—C2—C1110.7 (6)C4A—O1'—C46 (2)
O2—C2—C3111.0 (6)C1'—O5'—C5'110.5 (3)
C1—C2—C3113.5 (6)O1'—C1'—O5'106.3 (3)
O3—C3—C4111.5 (7)O1'—C1'—C2'109.9 (4)
O3—C3—C2106.2 (6)O5'—C1'—C2'109.1 (3)
C4—C3—C2113.2 (7)O2'—C2'—C3'107.8 (4)
O1'—C4—C5108.8 (11)O2'—C2'—C1'108.1 (4)
O1'—C4—C3113.9 (10)C3'—C2'—C1'108.2 (4)
C5—C4—C3111.0 (7)O3'—C3'—C2'109.4 (4)
O5—C5—C4110.6 (8)O3'—C3'—C4'109.6 (4)
C1A—O5A—C5A113.0 (14)C2'—C3'—C4'113.0 (4)
O1A—C1A—O5A114.9 (16)O4'—C4'—C5'109.2 (4)
O1A—C1A—C2A111.1 (14)O4'—C4'—C3'111.2 (4)
O5A—C1A—C2A114.0 (14)C5'—C4'—C3'109.1 (4)
O2A—C2A—C1A101.2 (14)O5'—C5'—C6'107.2 (4)
O2A—C2A—C3A112.0 (14)O5'—C5'—C4'109.6 (4)
C1A—C2A—C3A107.8 (13)C6'—C5'—C4'112.6 (4)
O3A—C3A—C4A119.2 (15)O6'—C6'—C5'110.1 (4)
O3A—C3A—C2A108.4 (13)O1'—C4A—H4A1114.1
C4A—C3A—C2A108.7 (17)C5A—C4A—H4A1114.1
O1—C1—H1A112.0C3A—C4A—H4A1114.1
O5—C1—H1A112.0O5A—C5A—H5A1110.5
C2—C1—H1A112.0C4A—C5A—H5A1110.5
O2—C2—H2A107.1O5A—C5A—H5B1110.5
C1—C2—H2A107.1C4A—C5A—H5B1110.5
C3—C2—H2A107.1H5A1—C5A—H5B1108.7
O3—C3—H3A108.6O1A—C6A—H6A1109.5
C4—C3—H3A108.6O1A—C6A—H6B1109.5
C2—C3—H3A108.6H6A1—C6A—H6B1109.5
O1'—C4—H4A107.7O1A—C6A—H6C1109.5
C5—C4—H4A107.7H6A1—C6A—H6C1109.5
C3—C4—H4A107.7H6B1—C6A—H6C1109.5
O5—C5—H5A109.5C2'—O2'—H2'109.5
C4—C5—H5A109.5C3'—O3'—H3'109.5
O5—C5—H5B109.5C4'—O4'—H4'109.5
C4—C5—H5B109.5C6'—O6'—H6'109.5
H5A—C5—H5B108.1O1'—C1'—H1'A110.5
O1—C6—H6A109.5O5'—C1'—H1'A110.5
O1—C6—H6B109.5C2'—C1'—H1'A110.5
H6A—C6—H6B109.5O2'—C2'—H2'A110.9
O1—C6—H6C109.5C3'—C2'—H2'A110.9
H6A—C6—H6C109.5C1'—C2'—H2'A110.9
H6B—C6—H6C109.5O3'—C3'—H3'A108.2
C1A—O1A—C6A116.0 (16)C2'—C3'—H3'A108.2
C2A—O2A—H2AA109.5C4'—C3'—H3'A108.2
C3A—O3A—H3AA109.5O4'—C4'—H4'A109.1
O1A—C1A—H1A1105.2C5'—C4'—H4'A109.1
O5A—C1A—H1A1105.2C3'—C4'—H4'A109.1
C2A—C1A—H1A1105.2O5'—C5'—H5'A109.1
O2A—C2A—H2A1111.8C6'—C5'—H5'A109.1
C1A—C2A—H2A1111.8C4'—C5'—H5'A109.1
C3A—C2A—H2A1111.8O6'—C6'—H6'A109.6
O3A—C3A—H3A1106.6C5'—C6'—H6'A109.6
C4A—C3A—H3A1106.6O6'—C6'—H6'B109.6
C2A—C3A—H3A1106.6C5'—C6'—H6'B109.6
O1'—C4A—C5A105 (3)H6'A—C6'—H6'B108.2
C6—O1—C1—O581.4 (11)O1'—C4A—C5A—O5A178 (2)
C6—O1—C1—C2164.5 (9)C3A—C4A—C5A—O5A70 (3)
C5—O5—C1—O1179.7 (7)C5A—C4A—O1'—C1'146.6 (15)
C5—O5—C1—C265.4 (9)C3A—C4A—O1'—C1'106 (2)
O1—C1—C2—O266.9 (10)C5A—C4A—O1'—C4133 (11)
O5—C1—C2—O2179.8 (7)C3A—C4A—O1'—C4120 (11)
O1—C1—C2—C3167.5 (7)C5—C4—O1'—C1'141.6 (8)
O5—C1—C2—C354.2 (9)C3—C4—O1'—C1'94.0 (11)
O2—C2—C3—O366.8 (8)C5—C4—O1'—C4A51 (10)
C1—C2—C3—O3167.8 (7)C3—C4—O1'—C4A73 (10)
O2—C2—C3—C4170.6 (9)C4A—O1'—C1'—O5'84.1 (11)
C1—C2—C3—C445.2 (11)C4—O1'—C1'—O5'85.7 (6)
O3—C3—C4—O1'74.2 (13)C4A—O1'—C1'—C2'158.0 (10)
C2—C3—C4—O1'166.2 (8)C4—O1'—C1'—C2'156.4 (5)
O3—C3—C4—C5162.7 (10)C5'—O5'—C1'—O1'174.3 (3)
C2—C3—C4—C543.0 (15)C5'—O5'—C1'—C2'67.3 (4)
C1—O5—C5—C466.5 (10)O1'—C1'—C2'—O2'68.6 (5)
O1'—C4—C5—O5178.8 (9)O5'—C1'—C2'—O2'175.2 (4)
C3—C4—C5—O552.8 (14)O1'—C1'—C2'—C3'174.8 (4)
C6A—O1A—C1A—O5A75 (3)O5'—C1'—C2'—C3'58.6 (5)
C6A—O1A—C1A—C2A153 (2)O2'—C2'—C3'—O3'68.9 (5)
C5A—O5A—C1A—O1A175.6 (18)C1'—C2'—C3'—O3'174.4 (4)
C5A—O5A—C1A—C2A54 (2)O2'—C2'—C3'—C4'168.8 (4)
O1A—C1A—C2A—O2A61 (2)C1'—C2'—C3'—C4'52.0 (5)
O5A—C1A—C2A—O2A166.8 (18)O3'—C3'—C4'—O4'52.7 (5)
O1A—C1A—C2A—C3A179.1 (18)C2'—C3'—C4'—O4'69.6 (5)
O5A—C1A—C2A—C3A49 (2)O3'—C3'—C4'—C5'173.3 (4)
O2A—C2A—C3A—O3A60 (2)C2'—C3'—C4'—C5'51.0 (5)
C1A—C2A—C3A—O3A170.6 (17)C1'—O5'—C5'—C6'171.6 (4)
O2A—C2A—C3A—C4A169.0 (19)C1'—O5'—C5'—C4'65.8 (5)
C1A—C2A—C3A—C4A59 (2)O4'—C4'—C5'—O5'66.0 (5)
O3A—C3A—C4A—O1'56 (3)C3'—C4'—C5'—O5'55.8 (5)
C2A—C3A—C4A—O1'179 (2)O4'—C4'—C5'—C6'53.3 (5)
O3A—C3A—C4A—C5A166 (2)C3'—C4'—C5'—C6'175.0 (4)
C2A—C3A—C4A—C5A69 (3)O5'—C5'—C6'—O6'60.7 (5)
C1A—O5A—C5A—C4A65 (2)C4'—C5'—C6'—O6'178.7 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O4i0.842.272.997 (7)146
O3—H3···O50.842.092.729 (5)133
O3—H3···O60.842.482.978 (6)119
O3A—H3AA···O50.842.092.803 (13)143
O2—H2···O5ii0.841.882.714 (9)169
O2—H2···O5Aii0.842.032.86 (2)169
O3—H3···O6iii0.841.902.653 (5)148
O4—H4···O3iv0.841.912.720 (6)163
O4—H4···O3Aiv0.842.012.795 (13)154
O6—H6···O3i0.841.852.678 (5)169
Symmetry codes: (i) x1/2, y+3/2, z+2; (ii) x+1/2, y+2, z+1/2; (iii) x+1/2, y+3/2, z+1; (iv) x+1/2, y+3/2, z+2.

Experimental details

Crystal data
Chemical formulaC12H22O10
Mr326.30
Crystal system, space groupOrthorhombic, P212121
Temperature (K)150
a, b, c (Å)13.7878 (14), 22.892 (2), 4.6367 (5)
V3)1463.5 (3)
Z4
Radiation typeSynchrotron, λ = 1.23990 Å
µ (mm1)0.52
Crystal size (mm)0.08 × 0.01 × 0.01
Data collection
DiffractometerBruker APEXII
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(SADABS; Sheldrick, 2008)
Tmin, Tmax0.566, 0.749
No. of measured, independent and
observed [I > 2σ(I)] reflections
11197, 2300, 1900
Rint0.073
θmax (°)45.3
(sin θ/λ)max1)0.573
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.067, 0.158, 1.16
No. of reflections2300
No. of parameters298
No. of restraints299
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.35, 0.27
Absolute structureFlack (1983), 920 Friedel pairs
Absolute structure parameter0.6 (9)

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Sheldrick, 2008), POV-RAY (Cason, 2003) and DIAMOND (Brandenburg, 2009), XCIF (Sheldrick, 2008) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O4'i0.842.272.997 (7)145.5
O3—H3···O5'0.842.092.729 (5)133.0
O3—H3···O6'0.842.482.978 (6)118.9
O3A—H3AA···O5'0.842.092.803 (13)142.5
O2'—H2'···O5ii0.841.882.714 (9)169.4
O2'—H2'···O5Aii0.842.032.86 (2)169.3
O3'—H3'···O6'iii0.841.902.653 (5)147.7
O4'—H4'···O3iv0.841.912.720 (6)162.6
O4'—H4'···O3Aiv0.842.012.795 (13)154.2
O6'—H6'···O3'i0.841.852.678 (5)168.6
Symmetry codes: (i) x1/2, y+3/2, z+2; (ii) x+1/2, y+2, z+1/2; (iii) x+1/2, y+3/2, z+1; (iv) x+1/2, y+3/2, z+2.
Comparison of structural parameters in (II) and (III) top
Bond distances and(II)*(III)
internuclear contacts (Å)
C1–C21.495 (9)1.516 (3)
C2–C31.519 (8)1.519 (3)
C3–C41.518 (9)1.531 (3)
C4–C51.489 (9)1.530 (3)
C5–C61.508 (3)
C1'–C2'1.530 (6)1.527 (3)
C2'–C3'1.529 (6)1.531 (3)
C3'–C4'1.535 (6)1.521 (3)
C4'–C5'1.520 (6)1.521 (3)
C5'–C6'1.516 (7)1.511 (3)
C1–O11.373 (9)1.384 (3)
C1–O51.444 (8)1.413 (3)
C2–O21.413 (8)1.418 (3)
C3–O31.424 (8)1.421 (3)
C5–O51.443 (8)
C6–O61.424 (3)
C1'–O1'1.406 (5)1.387 (3)
C1'–O5'1.441 (5)1.425 (3)
C2'–O2'1.429 (6)1.414 (3)
C3'–O3'1.434 (5)1.422 (3)
C4'–O4'1.417 (6)1.423 (3)
C5'–O5'1.452 (6)1.432 (3)
C6'–O6'1.439 (5)1.426 (3)
C4–O1'1.443 (17)1.437 (3)
O3···O5'2.729 (5)2.764 (2)
O3···O6'2.978 (6)
Bond angles (°)
C1'–O1'–C4113.6 (7)116.2 (2)
C1–O1–C6118.3 (9)113.7 (2)
Torsion angles (°)
C2–C1–O1–C6 (ϕ)164.5 (9)164.2 (2)
O5–C1–O1–C6 (ϕ)-81.4 (11)-77.4 (3)
C2'–C1'–O1'–C4 (ϕ')156.4 (5)153.8 (2)
O5'–C1'–O1'–C4 (ϕ')-85.7 (6)-88.4 (2)
C1'–O1'–C4–C3 (ϕ')94.0 (11)78.4 (2)
C1'–O1'–C4–C5 (ϕ')-141.6 (8)-161.3 (2)
H1'A–C1'–O1'–C4 (ϕ')34.331.9
C1'–O1'–C4–H4A (ϕ')-25.2-43.7
O5'–C5'–C6'–O6' (ϕ')60.7 (5) (gt)57.4 (2) (gt)
Note: (a) only parameters pertaining to the major component are reported. gt is gauche–trans.
Cremer–Pople puckering parameters in (II), (III) and (IX)–(XI)a top
Compoundθ (°)ϕ (°)Q (Å)q2 (Å)q3 (Å)
(II), βGalp7.3 (5)14 (4)0.596 (5)0.078 (5)0.591 (5)
(II), βXylp13.9 (10)6(5)0.551 (11)0.131 (10)0.535 (11)
(III), βGalp4.84 (19)28.0 (3)0.595 (2)0.049 (2)0.593 (2)
(III), βGlcp11.9 (2)341.3 (13)0.558 (2)0.116 (2)0.546 (2)
(IX), βXylp8.1736.40.57950.08240.5737
(X), βGalp5.89346.70.58240.05970.5793
(XI), βGlcp6.9137.90.59720.07180.5928
Note: (a) s.u. values were not provided in the original reports for (III), (IX), (X) and (XI).
Comparison of ϕ' and ψ' glycosidic torsion angles in several β-(14)-linked disaccharides top
CompoundC2'-C1'-O1'-C4, ϕ' (°)C1'-O1'-C4-C3, ψ' (°)
βGal(14)βXylOCH3, (II)156.4 (5)94.0 (11)
βGal(14)βGlcOCH3, (III)153.8 (2)78.4 (2)
βGal(14)αGlcOCH3, (IV)148.1 (1)93.5 (1)
β-L-Gal(14)βGlcOCH3, (V)-146.19 (12)111.14 (13)
βGal(14)αManOCH3, (VI)173.1 (2)115.2 (2)
βGal(14)βAllOCH3, (VII)144.74 (10)77.55 (13)
βGlc(14)βGlcOCH3, (VIII)a152.080.3
See text for literature references to individual disaccharide X-ray reports. Note: (a) s.u. values not reported in original report.
 

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