research communications
N-(1-deoxy-β-D-fructopyranos-1-yl)-2-aminoisobutyric acid
and hydrogen bonding inaDepartment of Biochemistry, University of Missouri, Columbia, MO 65211, USA, and bDepartment of Chemistry, University of Missouri, Columbia, MO 65211, USA
*Correspondence e-mail: MossineV@missouri.edu
The title compound, alternatively called D-fructose-2-aminoisobutyric acid (FruAib), C10H19NO7, (I), crystallizes exclusively in the β-pyranose form, with two conformationally non-equivalent molecules [(IA) and (IB)] in the In solution, FruAib establishes an equilibrium, with 75.6% of the population consisting of β-pyranose, 10.4% β-furanose, 10.1% α-furanose, 3.0% α-pyranose and <0.7% the acyclic forms. The carbohydrate ring in (I) has the normal 2C5 chair conformation and the amino acid portion is in the zwitterion form. Bond lengths and valence angles compare well with the average values from related pyranose structures. All carboxyl, hydroxy and ammonium groups are involved in hydrogen bonding and form a three-dimensional network of infinite chains that are connected through homodromic rings and short chains. Intramolecular hydrogen bonds bridge the amino acid and sugar portions in both molecules. A comparative Hirshfeld surfaces analysis of FruAib and four other sugar–amino acids suggests an increasing role of intramolecular heteroatom interactions in crystal structures with an increasing proportion of C—H bonds.
Keywords: crystal structure; fructosamine; Maillard reaction; D-fructose-2-aminoisobutyric acid; hydrogen bonding; Hirshfeld surface analysis.
CCDC reference: 1583254
1. Chemical context
D-Fructose-amino acids are derivatives of fructosamine and represent the major fraction of the early Maillard reaction products which form non-enzymatically both in processed foods and in vivo (Mossine & Mawhinney, 2010). Naturally occurring D-fructose-amino acids act as intermediates in the formation of food aroma and colour, while elevated fructosamine content in humans has been linked to the development of diabetic complications and tissue damage. Synthetic fructosamine derivatives have been offered as lectin blockers and antioxidants that might stimulate immune system (Tarnawski, Kuliś-Orzechowska & Szelepin, 2007), be potentially useful in prevention of cancer metastasis (Mossine et al., 2010), or neuroinflammation (Song et al., 2016). The chemical and biological reactivity of fructosamines stems from their structural instability. Thus, in solutions, fructosamine derivatives rapidly establish a equilibrium between several cyclic and acyclic forms (Kaufmann et al., 2016), as exemplified in Fig. 1 for the title compound. The acyclic tautomers, while present in minute (<1%) proportions, are responsible for chemical transformations of fructosamines in numerous redox, isomerization, or degradation reactions. The cyclic conformers are responsible for the carbohydrate recognition by proteins such as transporters or enzymes, and thus define a number of biological activities of fructosamines (Mossine & Mawhinney, 2010).
As a part of our structure–activity studies, we have prepared D-fructose-2-aminoisobutyric acid (FruAib), a structural analogue of an efficient blocker of galectins-1, −3 and −4, D-fructose-L-leucine (Mossine et al., 2008). In this work, we report on the molecular and of FruAib, C10H19NO7 (I), with an emphasis on hydrogen-bonding patterns in the structure. A comparative Hirshfeld surfaces analysis of FruAib and four other sugar-amino acids is also completed.
2. Structural commentary
Crystalline FruAib has two conformationally nonequivalent molecules, (IA) and (IB), in the The molecular structures and atomic numbering are shown in Figs. 2 and 3. The molecules may be considered as conjugates of a carbohydrate, 1-amino-1-deoxy-D-fructose, and an amino acid, 2-aminoisobutyric acid, which are joined through the common amino group. The β-D-fructopyranose rings of the carbohydrate portions in both (IA) and (IB) exist in the 2C5 chair conformation, with puckering parameters Q = 0.582 Å, q = 177.7°, and f = 224° for (IA) and Q =0.565 Å, q = 175.5°, and f = 268° for (IB). These parameters correspond to a conformation with the lowest energy possible for fructose (French et al., 1997), with (IB) providing a better fit. The bond distances and the valence angles are close to the average values for a number of crystalline pyranose structures (Jeffrey & Taylor, 1980). In the solution of FruAib, the β-D-pyranose anomer dominates the equilibrium, at 76.6%, as follows from the 13C NMR spectrum (Fig. 1, Supporting Table S1). In the 1H NMR spectrum of the major anomer (see Section 5), the vicinal proton–proton coupling constants J3,4 = 9.8 Hz and J4,5 = 3.4 Hz indicate H4 is in the trans disposition to H3 and in the gauche disposition to H5. Hence, the predominant conformation of FruAib in solution is the 2C5 β-D-fructopyranose, as well.
The amino acid portions of both (IA) and (IB) are in the zwitterion form with a positively charged tetrahedral secondary ammonium nitrogen and a negatively charged deprotonated carboxyl group. Each molecule has three intramolecular interactions (Table 1), two of which bridge the carboxylate, ammonium, and the carbohydrate portions of the molecules. The intramolecular hydrogen-bonding patterns differ in the molecules. Thus, in (IB), the string of short heteroatom contacts stretches from O4B through O7B and can be denoted in terms of the S23(5) pattern descriptor. In (IA), the intramolecular hydrogen bonding is fragmented between the shorter zwitterionic bridge O7A⋯H1NA⋯O6A [the S12(3) pattern] and the O2A—H⋯O3A contact. In the 1H NMR spectrum of FruAib (see Section 5), the two protons attached to C1 produce two distinct signals at 3.297 and 3.210 ppm, with J1A,1B = −12.7 Hz. The inequality of these protons indicates around the C1—C2 and C1—C7 bonds, thus suggesting that the intramolecular hydrogen bonds retain the structure in solution (Mossine et al., 1994). There are non-equivalences in carboxylate C—O distances that are observed in both molecules and which could be attributed to unequal participation of the oxygen atoms in hydrogen bonding. In (IA), O8A is involved in a three-center hydrogen-bonding interaction, with H⋯O8A distances of 1.79 and 1.98 Å, while for the O7A interaction, the distances are 1.91 and 2.30 Å (Table 1), which explains the elongation of the C8A—O8A bond (1.260 Å), as compared to the C8A—O7A distance (1.249 Å). Similar considerations can be applied to (IB), where O7B is involved in two short heteroatom contacts and O8B participates in only one (Table 1), hence the difference in the C8B—O7B (1.263 Å) and C8B—O8B (1.241 Å) bond lengths.
3. Supramolecular features
FruAib crystallizes in the triclinic P1, with two non-equivalent molecules per The molecular packing of (I) features infinite chains of hydrogen bonds spiralling along the a axis (Fig. 4). The basic hydrogen-bonding patterns are depicted in Fig. 5 and include the main infinite chain pattern C55(12); in the crystal, these infinite chains are connected through homodromic rings [R44(8)] and short chains [D12(5) and D(4)]. Thus, hydrogen bonds form a three-dimensional network of short heteroatomic contacts throughout the crystal of (I). In addition, there are a number of close C—H⋯O contacts that may qualify as weak hydrogen bonds (Table 2). Interestingly, molecule (IA) provides most of donors for these contacts.
|
4. Database survey
Search of SciFinder, Google Scholar, and the Cambridge Structural Database (Groom et al., 2016) by both structure and chemical names revealed no previous structural description of D-fructose-2-aminoisobutyric acid: thus the compound appears to be novel. The D-fructosamine portion of the molecule is more interesting for a structure comparison survey due to its conformational instability and practical significance to food and health sciences. The most closely related structures are D-fructose-glycine (FruGly, CCDC 1307697; Mossine et al., 1995) and D-fructose-L-proline (FruPro, CCDC 628806, 628807, 631528; Tarnawski, Ślepokura et al., 2007). These D-fructose-amino acids crystallize in the 2C5 β-pyranose conformations and exist as as well, with the intramolecular hydrogen bonding that necessarily involves the amino acid carboxylate, the ammonium group and one hydroxy group donated by the carbohydrate moiety. However, none of these structures features the involvement of the pyranose ring O6 in the intramolecular hydrogen bonding found in (IA). On the other hand, (IB) is structurally close to both FruGly (Mossine et al., 1995) and FruPro (Tarnawski, Ślepokura et al., 2007). In the molecules, the conformations around the C1—C2 bond are trans–gauche, with respective values of the N—C1—C2—O6 torsion angle falling into the 165–177° range and are stabilized with the similar intramolecular hydrogen-bonding pattern O3⋯H1N⋯O7.
A compendium of structures close to (I) is presented in Table 3. In addition to FruPro and FruGly, two structures isomeric to FruGly were included: D-galactose-glycine (GalGly, CCDC123625; Mossine et al., 1996) and D-glucose-glycine (GlcGly, CCDC123624; Mossine et al., 1996). In sugar-amino acids, as demonstrated in Table 3, an increase in the proportion of C—H bonds leads to an increase in number of intramolecular hydrogen bonds. Such tendency towards the `internalization' of hydrogen bonding was also noticed as a result of a comparative analysis of the `fingerprint plots' based on the calculated Hirshfeld surfaces (Spackman & Jayatilaka, 2009) and delineated for the O⋯H/H⋯O contacts (Fig. 6). Table 3 lists the relative abundances of these contacts calculated for (IA), (IB) and structurally close sugar-amino acids. There is an obvious trend towards decrease in the proportion of intermolecular O⋯H contacts as the number of the C—H bonds in the structure increases, although a total number of hydrogen-bonds per molecule increases as well.
|
5. Synthesis and crystallization
2-Aminoisobutyric acid (2.1 g, 0.02 mol), D-glucose (9 g, 0.05 mol), and sodium acetate (0.82 g, 0.01 mol) were dissolved in 100 ml of a methanol/glycerol (3:1) mixture and refluxed for 3 h. The reaction progress was monitored by TLC on silica. The reaction mixture was diluted with 900 ml of water and passed through a column charged with 80 ml of Amberlite IRN-77 (H+-form). The target compound was then eluted with 0.2 M pyridine, and fractions containing pure FruAib were pooled and evaporated. The residue was redissolved in 100 ml of water, decolorized with 0.5 g of and evaporated to a syrup. The latter was dissolved in 30 ml of ethanol and made nearly cloudy with dropwise addition of acetone. Crystallization occurred within a week at room temperature. Yield 2.0 g (38%, based on starting Aib). Major (β-pyranose anomer) peaks (ppm) in the 13C NMR spectrum in D2O: 179.35 (C8); 98.33 (C2); 72.39 (C4); 72.21 (C3); 71.79 (C5); 67.00 (C7); 66.68 (C6); 51.72 (C1); 24.66, 24.47 (C9, C10). See Supporting Table S1 for minor peak assignments in the spectrum. Major signals (ppm) and resolved coupling constants (Hz) in the 1H NMR spectrum: 4.038 (dd, H6B); 4.021 (m, H5); 3.903 (dd, H4); 3.784 (d, H3); 3.775 (dd, H6A); 3.297 (d, H1B); 3.210 (d, H1A); 1.517 (s, 3H10); 1.512 (s, 3H9); J1A,1B = −12.7; J3,4 = 9.8; J4,5 = 3.4; J5,6A = 1.3; J6A,6B = −12.9.
6. Refinement
Crystal data, data collection and structure . Hydroxy and nitrogen-bound H atoms were located in difference-Fourier analyses and were allowed to refine fully. Other H atoms were placed at calculated positions and treated as riding, with C—H = 0.98 Å (methyl), 0.99 Å (methylene) or 1.00 Å (methine) and with Uiso(H) = 1.2Ueq(methine or methylene) or 1.5Ueq(methyl). As a result of the unrealistic value obtained for the Flack parameter [−0.5 (3) for 2254 quotients (Parsons et al., 2013)], the of the ring system (2R,3S,4R,5R) was assigned on the basis of the known configuration for the starting compound D-glucose (McNaught, 1996).
details are summarized in Table 4
|
Supporting information
CCDC reference: 1583254
https://doi.org/10.1107/S2056989017018060/zs2396sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989017018060/zs2396Isup2.hkl
Data collection: APEX2 (Bruker, 1998); cell
SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2017 (Sheldrick, 2015); molecular graphics: X-SEED (Barbour, 2001) and Mercury (Macrae et al., 2008); software used to prepare material for publication: CIFTAB (Sheldrick, 2008) and publCIF (Westrip, 2010).C10H19NO7 | Z = 2 |
Mr = 265.26 | F(000) = 284 |
Triclinic, P1 | Dx = 1.494 Mg m−3 |
a = 5.8008 (19) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.636 (3) Å | Cell parameters from 4131 reflections |
c = 10.676 (4) Å | θ = 2.8–27.6° |
α = 87.766 (3)° | µ = 0.13 mm−1 |
β = 86.330 (4)° | T = 100 K |
γ = 82.042 (4)° | Plate, colourless |
V = 589.5 (3) Å3 | 0.25 × 0.20 × 0.08 mm |
Bruker APEXII CCD area detector diffractometer | 4927 reflections with I > 2σ(I) |
ω scans | Rint = 0.022 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | θmax = 27.6°, θmin = 1.9° |
Tmin = 0.86, Tmax = 0.99 | h = −7→7 |
6952 measured reflections | k = −12→12 |
5160 independent reflections | l = −13→13 |
Refinement on F2 | Hydrogen site location: mixed |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.033 | w = 1/[σ2(Fo2) + (0.0439P)2 + 0.1P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.081 | (Δ/σ)max < 0.001 |
S = 1.03 | Δρmax = 0.30 e Å−3 |
5160 reflections | Δρmin = −0.22 e Å−3 |
377 parameters | Absolute structure: Flack x determined using 2254 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013) |
3 restraints | Absolute structure parameter: −0.5 (3) |
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. |
x | y | z | Uiso*/Ueq | ||
N1A | 0.4852 (3) | 0.7001 (2) | 0.59886 (18) | 0.0140 (4) | |
C1A | 0.2937 (4) | 0.6814 (2) | 0.6955 (2) | 0.0155 (4) | |
H1A1 | 0.258387 | 0.583790 | 0.696105 | 0.019* | |
H1A2 | 0.150865 | 0.745067 | 0.675402 | 0.019* | |
O2A | 0.5882 (3) | 0.6392 (2) | 0.84699 (16) | 0.0201 (4) | |
C2A | 0.3701 (4) | 0.7143 (2) | 0.8240 (2) | 0.0149 (4) | |
O3A | 0.1611 (3) | 0.54217 (18) | 0.93040 (17) | 0.0200 (4) | |
C3A | 0.1796 (4) | 0.6889 (2) | 0.9256 (2) | 0.0160 (4) | |
H3A | 0.027565 | 0.743040 | 0.902764 | 0.019* | |
O4A | 0.0554 (3) | 0.7173 (2) | 1.14090 (17) | 0.0235 (4) | |
C4A | 0.2446 (4) | 0.7366 (2) | 1.0515 (2) | 0.0166 (4) | |
H4A | 0.388769 | 0.676038 | 1.077616 | 0.020* | |
O5A | 0.0858 (3) | 0.9847 (2) | 1.01890 (19) | 0.0256 (4) | |
C5A | 0.2914 (4) | 0.8897 (2) | 1.0402 (2) | 0.0173 (5) | |
H5A | 0.356155 | 0.914273 | 1.119767 | 0.021* | |
O6A | 0.3959 (3) | 0.85831 (17) | 0.81688 (15) | 0.0185 (3) | |
C6A | 0.4700 (4) | 0.9059 (3) | 0.9321 (2) | 0.0208 (5) | |
H6A1 | 0.492827 | 1.005718 | 0.921278 | 0.025* | |
H6A2 | 0.621286 | 0.851162 | 0.951912 | 0.025* | |
O7A | 0.2928 (3) | 0.95121 (17) | 0.51308 (16) | 0.0205 (4) | |
C7A | 0.4156 (4) | 0.7112 (2) | 0.4646 (2) | 0.0140 (4) | |
O8A | 0.1246 (3) | 0.86077 (17) | 0.35794 (16) | 0.0204 (4) | |
C8A | 0.2629 (4) | 0.8535 (2) | 0.4449 (2) | 0.0147 (4) | |
C9A | 0.6394 (4) | 0.7138 (3) | 0.3809 (2) | 0.0190 (5) | |
H9A1 | 0.718756 | 0.791634 | 0.404061 | 0.028* | |
H9A2 | 0.600415 | 0.726203 | 0.292846 | 0.028* | |
H9A3 | 0.742340 | 0.625157 | 0.392235 | 0.028* | |
C10A | 0.2936 (4) | 0.5854 (2) | 0.4386 (2) | 0.0176 (5) | |
H10A | 0.386894 | 0.499035 | 0.467924 | 0.026* | |
H10B | 0.276226 | 0.581322 | 0.348147 | 0.026* | |
H10C | 0.139289 | 0.595194 | 0.483013 | 0.026* | |
N1B | 0.9798 (3) | 0.1994 (2) | 0.51896 (19) | 0.0148 (4) | |
C1B | 0.7661 (4) | 0.1679 (2) | 0.4597 (2) | 0.0162 (4) | |
H1B1 | 0.628379 | 0.230040 | 0.494220 | 0.019* | |
H1B2 | 0.742314 | 0.069761 | 0.481061 | 0.019* | |
O2B | 0.9828 (3) | 0.10708 (18) | 0.26199 (16) | 0.0177 (3) | |
C2B | 0.7867 (4) | 0.1888 (2) | 0.3164 (2) | 0.0153 (4) | |
O3B | 1.0020 (3) | 0.39052 (17) | 0.31557 (16) | 0.0179 (3) | |
C3B | 0.7993 (4) | 0.3425 (2) | 0.2743 (2) | 0.0147 (4) | |
H3B | 0.660381 | 0.401144 | 0.314343 | 0.018* | |
O4B | 0.7785 (3) | 0.50320 (19) | 0.09278 (18) | 0.0220 (4) | |
C4B | 0.7840 (4) | 0.3599 (2) | 0.1331 (2) | 0.0157 (4) | |
H4B | 0.923045 | 0.303446 | 0.090998 | 0.019* | |
O5B | 0.3592 (3) | 0.39757 (19) | 0.13899 (18) | 0.0212 (4) | |
C5B | 0.5615 (4) | 0.3074 (3) | 0.0932 (2) | 0.0178 (5) | |
H5B | 0.564638 | 0.306047 | −0.000506 | 0.021* | |
O6B | 0.5737 (3) | 0.15023 (18) | 0.28044 (16) | 0.0184 (3) | |
C6B | 0.5487 (4) | 0.1611 (3) | 0.1472 (2) | 0.0196 (5) | |
H6B1 | 0.396939 | 0.132758 | 0.129061 | 0.023* | |
H6B2 | 0.673214 | 0.095284 | 0.105088 | 0.023* | |
O7B | 0.7832 (3) | 0.45290 (18) | 0.59469 (17) | 0.0248 (4) | |
C7B | 0.9506 (4) | 0.2216 (2) | 0.6593 (2) | 0.0158 (4) | |
O8B | 0.6794 (4) | 0.3715 (2) | 0.78640 (18) | 0.0301 (5) | |
C8B | 0.7867 (4) | 0.3608 (2) | 0.6822 (2) | 0.0174 (5) | |
C9B | 1.1926 (4) | 0.2407 (3) | 0.7005 (3) | 0.0241 (5) | |
H9B1 | 1.299035 | 0.153209 | 0.689055 | 0.036* | |
H9B2 | 1.180988 | 0.264886 | 0.789159 | 0.036* | |
H9B3 | 1.252503 | 0.316092 | 0.649424 | 0.036* | |
C10B | 0.8641 (5) | 0.0944 (3) | 0.7269 (2) | 0.0221 (5) | |
H10D | 0.705980 | 0.087100 | 0.702985 | 0.033* | |
H10E | 0.862555 | 0.104968 | 0.817864 | 0.033* | |
H10F | 0.968250 | 0.009301 | 0.703146 | 0.033* | |
H1NA | 0.536 (5) | 0.778 (3) | 0.613 (3) | 0.016 (7)* | |
H2OB | 1.012 (6) | 0.032 (3) | 0.303 (3) | 0.021 (7)* | |
H2NA | 0.599 (5) | 0.616 (3) | 0.607 (3) | 0.019 (7)* | |
H5OA | 0.040 (6) | 1.015 (4) | 1.082 (4) | 0.027 (9)* | |
H5OB | 0.311 (6) | 0.453 (4) | 0.082 (4) | 0.032 (9)* | |
H3OA | 0.030 (7) | 0.539 (4) | 0.951 (3) | 0.029 (9)* | |
H4OA | 0.086 (7) | 0.750 (4) | 1.208 (4) | 0.045 (11)* | |
H2OA | 0.590 (6) | 0.555 (4) | 0.840 (3) | 0.033 (9)* | |
H4OB | 0.852 (10) | 0.549 (5) | 0.138 (5) | 0.074 (15)* | |
H2NB | 1.090 (5) | 0.124 (3) | 0.507 (3) | 0.017 (7)* | |
H1NB | 1.021 (6) | 0.276 (4) | 0.478 (3) | 0.029 (8)* | |
H3OB | 1.114 (7) | 0.365 (4) | 0.261 (4) | 0.045 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1A | 0.0143 (9) | 0.0143 (9) | 0.0131 (9) | −0.0003 (7) | −0.0011 (7) | −0.0013 (7) |
C1A | 0.0159 (10) | 0.0182 (11) | 0.0124 (10) | −0.0020 (8) | 0.0001 (8) | −0.0009 (8) |
O2A | 0.0173 (8) | 0.0212 (9) | 0.0204 (9) | 0.0038 (7) | −0.0035 (6) | −0.0043 (7) |
C2A | 0.0162 (10) | 0.0133 (10) | 0.0150 (10) | −0.0010 (8) | −0.0018 (8) | −0.0020 (8) |
O3A | 0.0232 (9) | 0.0181 (8) | 0.0197 (8) | −0.0070 (7) | 0.0012 (7) | −0.0010 (7) |
C3A | 0.0196 (11) | 0.0155 (10) | 0.0129 (10) | −0.0019 (8) | 0.0001 (8) | −0.0012 (8) |
O4A | 0.0285 (9) | 0.0306 (10) | 0.0135 (8) | −0.0125 (8) | 0.0040 (7) | −0.0050 (7) |
C4A | 0.0183 (11) | 0.0174 (11) | 0.0144 (11) | −0.0040 (9) | 0.0002 (8) | −0.0008 (9) |
O5A | 0.0301 (10) | 0.0236 (9) | 0.0199 (9) | 0.0087 (8) | −0.0009 (8) | −0.0050 (8) |
C5A | 0.0217 (11) | 0.0157 (11) | 0.0147 (11) | −0.0024 (9) | −0.0006 (8) | −0.0033 (9) |
O6A | 0.0255 (9) | 0.0161 (8) | 0.0145 (8) | −0.0054 (7) | 0.0011 (6) | −0.0018 (6) |
C6A | 0.0246 (12) | 0.0197 (11) | 0.0197 (12) | −0.0078 (9) | 0.0005 (9) | −0.0054 (9) |
O7A | 0.0259 (9) | 0.0160 (8) | 0.0188 (8) | 0.0021 (7) | −0.0040 (7) | −0.0038 (7) |
C7A | 0.0158 (10) | 0.0153 (10) | 0.0109 (10) | −0.0015 (8) | −0.0014 (8) | −0.0007 (8) |
O8A | 0.0221 (9) | 0.0177 (8) | 0.0212 (9) | 0.0011 (7) | −0.0076 (7) | 0.0001 (7) |
C8A | 0.0149 (10) | 0.0152 (10) | 0.0131 (10) | −0.0006 (8) | 0.0029 (8) | −0.0001 (8) |
C9A | 0.0178 (11) | 0.0208 (11) | 0.0169 (11) | 0.0004 (9) | 0.0030 (9) | 0.0005 (9) |
C10A | 0.0210 (11) | 0.0152 (10) | 0.0171 (11) | −0.0028 (9) | −0.0028 (9) | −0.0033 (9) |
N1B | 0.0150 (9) | 0.0152 (9) | 0.0138 (9) | −0.0004 (7) | −0.0006 (7) | −0.0013 (8) |
C1B | 0.0148 (10) | 0.0182 (11) | 0.0155 (11) | −0.0021 (8) | −0.0011 (8) | 0.0003 (8) |
O2B | 0.0199 (8) | 0.0157 (8) | 0.0160 (8) | 0.0030 (6) | −0.0002 (6) | −0.0006 (7) |
C2B | 0.0144 (10) | 0.0159 (11) | 0.0153 (11) | −0.0014 (8) | −0.0012 (8) | −0.0003 (9) |
O3B | 0.0170 (8) | 0.0211 (8) | 0.0171 (8) | −0.0072 (7) | −0.0007 (7) | −0.0023 (7) |
C3B | 0.0129 (10) | 0.0155 (10) | 0.0158 (11) | −0.0023 (8) | −0.0003 (8) | −0.0005 (8) |
O4B | 0.0236 (9) | 0.0201 (9) | 0.0236 (9) | −0.0073 (7) | −0.0063 (7) | 0.0068 (7) |
C4B | 0.0138 (10) | 0.0173 (11) | 0.0156 (11) | −0.0016 (8) | −0.0004 (8) | 0.0008 (8) |
O5B | 0.0153 (8) | 0.0230 (9) | 0.0242 (9) | −0.0002 (7) | −0.0014 (7) | 0.0055 (7) |
C5B | 0.0162 (11) | 0.0234 (12) | 0.0142 (11) | −0.0032 (9) | −0.0023 (8) | −0.0011 (9) |
O6B | 0.0180 (8) | 0.0213 (8) | 0.0174 (8) | −0.0063 (6) | −0.0033 (6) | 0.0001 (7) |
C6B | 0.0202 (11) | 0.0194 (11) | 0.0200 (12) | −0.0037 (9) | −0.0045 (9) | −0.0029 (9) |
O7B | 0.0320 (10) | 0.0188 (8) | 0.0197 (9) | 0.0081 (7) | 0.0022 (7) | 0.0017 (7) |
C7B | 0.0181 (11) | 0.0168 (11) | 0.0116 (10) | 0.0008 (8) | −0.0008 (8) | −0.0003 (8) |
O8B | 0.0396 (12) | 0.0237 (9) | 0.0224 (10) | 0.0062 (8) | 0.0097 (8) | −0.0014 (7) |
C8B | 0.0178 (11) | 0.0159 (10) | 0.0176 (11) | 0.0023 (9) | −0.0018 (9) | −0.0028 (9) |
C9B | 0.0194 (12) | 0.0299 (13) | 0.0225 (12) | 0.0021 (10) | −0.0069 (9) | −0.0063 (10) |
C10B | 0.0266 (13) | 0.0206 (12) | 0.0173 (11) | 0.0007 (10) | 0.0018 (9) | 0.0028 (9) |
O2A—C2A | 1.399 (3) | O3B—H3OB | 0.86 (4) |
O3A—C3A | 1.431 (3) | C4A—H4A | 1.0000 |
O4A—C4A | 1.435 (3) | O4B—H4OB | 0.84 (6) |
O6A—C2A | 1.415 (3) | C5A—H5A | 1.0000 |
O6A—C6A | 1.440 (3) | O5B—H5OB | 0.83 (4) |
O7A—C8A | 1.250 (3) | C6A—H6A2 | 0.9900 |
O8A—C8A | 1.259 (3) | C6A—H6A1 | 0.9900 |
N1A—C1A | 1.492 (3) | C9A—H9A3 | 0.9800 |
N1A—C7A | 1.510 (3) | C9A—H9A1 | 0.9800 |
O2A—H2OA | 0.82 (4) | C9A—H9A2 | 0.9800 |
O3A—H3OA | 0.78 (4) | C10A—H10C | 0.9800 |
O4A—H4OA | 0.83 (4) | C10A—H10B | 0.9800 |
O5A—H5OA | 0.76 (4) | C10A—H10A | 0.9800 |
C1A—C2A | 1.526 (3) | C1B—C2B | 1.535 (3) |
N1A—H1NA | 0.87 (3) | N1B—H2NB | 0.91 (3) |
N1A—H2NA | 0.98 (3) | N1B—H1NB | 0.90 (4) |
C2A—C3A | 1.536 (3) | C2B—C3B | 1.541 (3) |
O2B—C2B | 1.398 (3) | C3B—C4B | 1.517 (3) |
C3A—C4A | 1.524 (3) | C4B—C5B | 1.540 (3) |
O3B—C3B | 1.423 (3) | C5B—C6B | 1.512 (4) |
C4A—C5A | 1.535 (3) | C7B—C10B | 1.526 (3) |
O4B—C4B | 1.427 (3) | C7B—C8B | 1.551 (3) |
C5A—C6A | 1.519 (3) | C7B—C9B | 1.535 (3) |
O5B—C5B | 1.431 (3) | C1B—H1B1 | 0.9900 |
O6B—C2B | 1.418 (3) | C1B—H1B2 | 0.9900 |
O6B—C6B | 1.437 (3) | C3B—H3B | 1.0000 |
C7A—C8A | 1.541 (3) | C4B—H4B | 1.0000 |
C7A—C10A | 1.529 (3) | C5B—H5B | 1.0000 |
C7A—C9A | 1.531 (3) | C6B—H6B1 | 0.9900 |
O7B—C8B | 1.262 (3) | C6B—H6B2 | 0.9900 |
O8B—C8B | 1.240 (3) | C9B—H9B1 | 0.9800 |
C1A—H1A1 | 0.9900 | C9B—H9B2 | 0.9800 |
C1A—H1A2 | 0.9900 | C9B—H9B3 | 0.9800 |
N1B—C1B | 1.500 (3) | C10B—H10D | 0.9800 |
N1B—C7B | 1.517 (3) | C10B—H10E | 0.9800 |
O2B—H2OB | 0.83 (3) | C10B—H10F | 0.9800 |
C3A—H3A | 1.0000 | ||
C2A—O6A—C6A | 112.33 (18) | C7A—C10A—H10C | 109.00 |
C1A—N1A—C7A | 115.41 (17) | C7A—C10A—H10A | 110.00 |
C2A—O2A—H2OA | 112 (2) | C7A—C10A—H10B | 109.00 |
C3A—O3A—H3OA | 104 (3) | H10A—C10A—H10B | 109.00 |
C4A—O4A—H4OA | 107 (3) | H10A—C10A—H10C | 109.00 |
C5A—O5A—H5OA | 107 (3) | H10B—C10A—H10C | 109.00 |
C7A—N1A—H1NA | 106 (2) | C7B—N1B—H2NB | 107 (2) |
C7A—N1A—H2NA | 107.4 (19) | C7B—N1B—H1NB | 111 (2) |
H1NA—N1A—H2NA | 115 (3) | H2NB—N1B—H1NB | 112 (3) |
N1A—C1A—C2A | 108.99 (18) | N1B—C1B—C2B | 111.65 (18) |
C1A—N1A—H1NA | 108 (2) | C1B—N1B—H2NB | 106.7 (19) |
C1A—N1A—H2NA | 105.3 (18) | C1B—N1B—H1NB | 106 (2) |
O2A—C2A—O6A | 107.46 (18) | O2B—C2B—O6B | 113.03 (17) |
O6A—C2A—C1A | 105.52 (16) | O6B—C2B—C1B | 102.24 (17) |
O6A—C2A—C3A | 109.62 (16) | O6B—C2B—C3B | 108.88 (17) |
C1A—C2A—C3A | 109.73 (18) | C1B—C2B—C3B | 112.86 (16) |
O2A—C2A—C1A | 110.90 (17) | O2B—C2B—C1B | 112.22 (18) |
O2A—C2A—C3A | 113.29 (17) | O2B—C2B—C3B | 107.61 (18) |
O3A—C3A—C2A | 107.71 (16) | O3B—C3B—C2B | 111.53 (18) |
O3A—C3A—C4A | 111.05 (17) | O3B—C3B—C4B | 112.03 (18) |
C2A—C3A—C4A | 109.56 (18) | C2B—C3B—C4B | 110.23 (16) |
O4A—C4A—C3A | 107.02 (18) | O4B—C4B—C3B | 111.32 (17) |
C3A—C4A—C5A | 110.21 (17) | C3B—C4B—C5B | 110.08 (18) |
O4A—C4A—C5A | 112.35 (17) | O4B—C4B—C5B | 108.48 (19) |
O5A—C5A—C4A | 112.39 (19) | O5B—C5B—C4B | 110.2 (2) |
O5A—C5A—C6A | 108.72 (18) | O5B—C5B—C6B | 108.56 (19) |
C4A—C5A—C6A | 109.36 (18) | C4B—C5B—C6B | 109.76 (19) |
O6A—C6A—C5A | 111.20 (19) | O6B—C6B—C5B | 113.0 (2) |
C2B—O6B—C6B | 113.45 (17) | N1B—C7B—C8B | 108.36 (17) |
N1A—C7A—C8A | 108.17 (16) | C8B—C7B—C9B | 107.71 (18) |
C8A—C7A—C10A | 113.58 (19) | C8B—C7B—C10B | 113.61 (19) |
C9A—C7A—C10A | 111.62 (18) | C9B—C7B—C10B | 110.7 (2) |
N1A—C7A—C9A | 107.01 (18) | N1B—C7B—C9B | 106.01 (19) |
N1A—C7A—C10A | 108.96 (16) | N1B—C7B—C10B | 110.12 (17) |
C8A—C7A—C9A | 107.24 (18) | O8B—C8B—C7B | 116.38 (19) |
O7A—C8A—O8A | 126.3 (2) | O7B—C8B—O8B | 127.0 (2) |
O7A—C8A—C7A | 117.51 (19) | O7B—C8B—C7B | 116.61 (19) |
O8A—C8A—C7A | 116.13 (18) | N1B—C1B—H1B1 | 109.00 |
N1A—C1A—H1A2 | 110.00 | N1B—C1B—H1B2 | 109.00 |
C2A—C1A—H1A1 | 110.00 | C2B—C1B—H1B1 | 109.00 |
C2A—C1A—H1A2 | 110.00 | C2B—C1B—H1B2 | 109.00 |
H1A1—C1A—H1A2 | 108.00 | H1B1—C1B—H1B2 | 108.00 |
N1A—C1A—H1A1 | 110.00 | O3B—C3B—H3B | 108.00 |
C1B—N1B—C7B | 115.17 (17) | C2B—C3B—H3B | 108.00 |
C2B—O2B—H2OB | 110 (2) | C4B—C3B—H3B | 108.00 |
O3A—C3A—H3A | 109.00 | O4B—C4B—H4B | 109.00 |
C4A—C3A—H3A | 109.00 | C3B—C4B—H4B | 109.00 |
C2A—C3A—H3A | 110.00 | C5B—C4B—H4B | 109.00 |
C3B—O3B—H3OB | 107 (3) | O5B—C5B—H5B | 109.00 |
O4A—C4A—H4A | 109.00 | C4B—C5B—H5B | 109.00 |
C5A—C4A—H4A | 109.00 | C6B—C5B—H5B | 109.00 |
C3A—C4A—H4A | 109.00 | O6B—C6B—H6B1 | 109.00 |
C4B—O4B—H4OB | 113 (3) | O6B—C6B—H6B2 | 109.00 |
C4A—C5A—H5A | 109.00 | C5B—C6B—H6B1 | 109.00 |
O5A—C5A—H5A | 109.00 | C5B—C6B—H6B2 | 109.00 |
C6A—C5A—H5A | 109.00 | H6B1—C6B—H6B2 | 108.00 |
C5B—O5B—H5OB | 110 (3) | C7B—C9B—H9B1 | 109.00 |
C5A—C6A—H6A2 | 109.00 | C7B—C9B—H9B2 | 110.00 |
O6A—C6A—H6A2 | 109.00 | C7B—C9B—H9B3 | 109.00 |
O6A—C6A—H6A1 | 109.00 | H9B1—C9B—H9B2 | 109.00 |
C5A—C6A—H6A1 | 109.00 | H9B1—C9B—H9B3 | 109.00 |
H6A1—C6A—H6A2 | 108.00 | H9B2—C9B—H9B3 | 110.00 |
C7A—C9A—H9A2 | 109.00 | C7B—C10B—H10D | 109.00 |
C7A—C9A—H9A1 | 109.00 | C7B—C10B—H10E | 110.00 |
H9A1—C9A—H9A3 | 109.00 | C7B—C10B—H10F | 109.00 |
C7A—C9A—H9A3 | 109.00 | H10D—C10B—H10E | 109.00 |
H9A1—C9A—H9A2 | 109.00 | H10D—C10B—H10F | 109.00 |
H9A2—C9A—H9A3 | 109.00 | H10E—C10B—H10F | 109.00 |
C6A—O6A—C2A—O2A | −61.2 (2) | C9A—C7A—C8A—O8A | 89.4 (2) |
C6A—O6A—C2A—C1A | −179.57 (18) | C10A—C7A—C8A—O7A | 147.9 (2) |
C6A—O6A—C2A—C3A | 62.3 (2) | N1A—C7A—C8A—O7A | 26.8 (3) |
C2A—O6A—C6A—C5A | −61.7 (2) | N1A—C7A—C8A—O8A | −155.48 (19) |
C1A—N1A—C7A—C10A | −53.2 (2) | C1B—N1B—C7B—C10B | 56.0 (2) |
C1A—N1A—C7A—C8A | 70.7 (2) | C1B—N1B—C7B—C8B | −68.8 (2) |
C1A—N1A—C7A—C9A | −174.04 (18) | C1B—N1B—C7B—C9B | 175.78 (18) |
C7A—N1A—C1A—C2A | −163.70 (16) | C7B—N1B—C1B—C2B | 163.55 (16) |
N1A—C1A—C2A—O6A | 64.6 (2) | N1B—C1B—C2B—O6B | 178.40 (16) |
N1A—C1A—C2A—C3A | −177.35 (16) | N1B—C1B—C2B—C3B | −64.8 (2) |
N1A—C1A—C2A—O2A | −51.4 (2) | N1B—C1B—C2B—O2B | 57.0 (2) |
O2A—C2A—C3A—O3A | −59.4 (2) | O2B—C2B—C3B—O3B | −61.3 (2) |
O6A—C2A—C3A—O3A | −179.43 (17) | O6B—C2B—C3B—O3B | 175.87 (17) |
O6A—C2A—C3A—C4A | −58.5 (2) | O6B—C2B—C3B—C4B | −59.0 (2) |
C1A—C2A—C3A—O3A | 65.1 (2) | C1B—C2B—C3B—O3B | 63.1 (2) |
C1A—C2A—C3A—C4A | −173.98 (16) | C1B—C2B—C3B—C4B | −171.81 (19) |
O2A—C2A—C3A—C4A | 61.5 (2) | O2B—C2B—C3B—C4B | 63.8 (2) |
O3A—C3A—C4A—C5A | 173.44 (18) | O3B—C3B—C4B—C5B | −179.66 (18) |
C2A—C3A—C4A—O4A | 177.02 (16) | C2B—C3B—C4B—O4B | 175.84 (18) |
O3A—C3A—C4A—O4A | −64.1 (2) | O3B—C3B—C4B—O4B | −59.3 (2) |
C2A—C3A—C4A—C5A | 54.6 (2) | C2B—C3B—C4B—C5B | 55.5 (2) |
O4A—C4A—C5A—C6A | −172.33 (18) | O4B—C4B—C5B—C6B | −173.64 (18) |
C3A—C4A—C5A—O5A | 67.8 (2) | C3B—C4B—C5B—O5B | 67.9 (2) |
O4A—C4A—C5A—O5A | −51.5 (2) | O4B—C4B—C5B—O5B | −54.1 (2) |
C3A—C4A—C5A—C6A | −53.1 (2) | C3B—C4B—C5B—C6B | −51.6 (2) |
O5A—C5A—C6A—O6A | −67.5 (2) | O5B—C5B—C6B—O6B | −68.2 (2) |
C4A—C5A—C6A—O6A | 55.5 (3) | C4B—C5B—C6B—O6B | 52.4 (2) |
C6B—O6B—C2B—C3B | 60.3 (2) | N1B—C7B—C8B—O7B | −27.2 (3) |
C2B—O6B—C6B—C5B | −58.7 (2) | N1B—C7B—C8B—O8B | 155.3 (2) |
C6B—O6B—C2B—O2B | −59.3 (2) | C9B—C7B—C8B—O7B | 87.1 (2) |
C6B—O6B—C2B—C1B | 179.89 (18) | C9B—C7B—C8B—O8B | −90.4 (3) |
C9A—C7A—C8A—O7A | −88.3 (2) | C10B—C7B—C8B—O7B | −149.9 (2) |
C10A—C7A—C8A—O8A | −34.4 (3) | C10B—C7B—C8B—O8B | 32.6 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1NA···O6A | 0.86 (3) | 2.40 (3) | 2.813 (3) | 110 (2) |
N1A—H1NA···O7A | 0.86 (3) | 2.30 (3) | 2.674 (2) | 107 (2) |
O2B—H2OB···O8Ai | 0.84 (3) | 1.78 (3) | 2.596 (3) | 165 (3) |
N1A—H2NA···O7B | 0.98 (3) | 1.78 (3) | 2.743 (3) | 169 (3) |
O5A—H5OA···O2Bii | 0.76 (4) | 2.14 (4) | 2.886 (3) | 168 (4) |
O5B—H5OB···O3Aiii | 0.83 (4) | 1.99 (4) | 2.804 (3) | 165 (3) |
O2A—H2OA···O3A | 0.82 (4) | 2.62 (3) | 2.847 (2) | 97 (3) |
O3A—H3OA···O4Biv | 0.78 (4) | 2.08 (4) | 2.785 (3) | 149 (3) |
O4A—H4OA···O8Av | 0.84 (4) | 2.00 (4) | 2.822 (3) | 170 (4) |
O2A—H2OA···O8B | 0.82 (4) | 1.87 (4) | 2.657 (3) | 161 (4) |
O4B—H4OB···O3B | 0.84 (4) | 2.51 (4) | 2.886 (2) | 108 (3) |
O4B—H4OB···O4Avi | 0.84 (5) | 2.14 (5) | 2.864 (3) | 145 (5) |
N1B—H2NB···O7Ai | 0.90 (3) | 1.91 (3) | 2.795 (3) | 168 (3) |
N1B—H1NB···O3B | 0.90 (4) | 2.02 (4) | 2.800 (3) | 144 (3) |
N1B—H1NB···O7B | 0.90 (4) | 2.40 (3) | 2.681 (3) | 100 (2) |
O3B—H3OB···O5Bvii | 0.86 (4) | 1.92 (4) | 2.717 (3) | 154 (4) |
Symmetry codes: (i) x+1, y−1, z; (ii) x−1, y+1, z+1; (iii) x, y, z−1; (iv) x−1, y, z+1; (v) x, y, z+1; (vi) x+1, y, z−1; (vii) x+1, y, z. |
D—H···A | D—H | H···A | D···A | D—H···A | Symmetry code |
C1A—H1A1···O3A | 0.99 | 2.56 | 2.909 (3) | 101 | |
C4A—H4A···O4B | 1.00 | 2.63 | 3.608 (3) | 167 | x, y, z + 1 |
C9A—H9A1···O8A | 0.98 | 2.55 | 3.313 (3) | 135 | x + 1, y, z |
C9A—H9A3···O3B | 0.98 | 2.66 | 3.575 (3) | 156 | |
C9A—H9A3···O7B | 0.98 | 2.68 | 3.381 (3) | 129 | |
C10A—H10A···O7B | 0.98 | 2.72 | 3.451 (3) | 132 | |
C10A—H10B···O3B | 0.98 | 2.64 | 3.076 (3) | 107 | x - 1, y, z |
C5B—H5B···O8A | 1.00 | 2.41 | 3.355 (3) | 156 | x, y, z - 1 |
C6B—H6B2···O5A | 0.99 | 2.61 | 3.556 (3) | 161 | x + 1, y - 1, z |
C10B—H10E···O5A | 0.98 | 2.71 | 3.517 (3) | 140 | x + 1, y - 1, z |
C10B—H10F···O7A | 0.98 | 2.70 | 3.443 (3) | 133 | x + 1, y - 1, z |
Notes: (*) All sugar-amino acids are in the pyranose form and all have four hydroxy, one carboxyl and one ammonium group, and one pyranose ring oxygen; (**)hydrogen-bond selection criteria: D···A < 2.9 Å; H···A < 2.7 Å; D—H···A >95°. |
Structure* | No. of CH/CH2/CH3 groups (total C—H) | No. of intra/inter hydrogen-bonds** | % of O···H/H···O contacts on Hirshfeld surface | Reference |
GalGly | 3/3/0 (9) | 2/6 | 55.7 | Mossine et al. (1996) |
GlcGly | 3/3/0 (9) | 3/6 | 57.6 | Mossine et al. (1996) |
FruGly | 3/3/0 (9) | 2/6 | 51.6 | Mossine et al. (1995) |
FruAib (IA) | 3/2/2 (13) | 3/5 | 44.0 | This work |
FruAib (IB) | 3/2/2 (13) | 3/5 | 45.9 | This work |
FruPro·H2O | 4/5/0 (14) | 3/6 | 49.2 | Mossine et al. (2007) |
FruPro·2H2O | 4/5/0 (14) | 3/6 | 49.3 | Tarnawski, Ślepokura et al. (2007) |
FruPro·MeOH | 4/5/1 (17) | 4/5 | 40.2 | Tarnawski, Ślepokura et al. (2007) |
carbon | α-pyranose | β-pyranose | α-furanose | β-furanose | |
C1 | 51.55 | 51.72 | 49.81 | 51.35 | |
C2 | 99.08 | 98.33 | 104.65 | 101.85 | |
C3 | 73.12 | 72.21 | 85.26 | 80.64 | |
C4 | 74.85 | 72.39 | 78.69 | 77.17 | |
C5 | 68.74 | 71.79 | 85.32 | 83.78 | |
C6 | 65.80 | 66.68 | 63.63 | 64.76 | |
C7 | n.r. | 67.00 | 66.76 | 66.85 | |
C8 | n.r. | 179.35 | 179.37 | 179.46 | |
C9 or C10 | 24.55 | 24.66 | 24.64 | 24.64 | |
C9 or C10 | 24.16 | 24.47 | 24.36 | 24.43 | |
References | |||||
% for FruAib | 3.0 | 75.6 | 10.1 | 10.4 | This work |
% for D-Fru | 2.1 | 68.6 | 5.7 | 23.0 | Kaufmann et al., 2016 |
% for FruGly | 5 | 66 | 15 | 14 | Mossine et al., 1994 |
% for FruAla | 5.1 | 71.5 | 10.8 | 11.6 | Kaufmann et al., 2016 |
% for FruPro | 4.2 | 64.8 | 12.9 | 16.9 | Kaufmann et al., 2016 |
Acknowledgements
The authors thank Dr Shaokai Jiang for assistance with acquiring NMR spectra.
Funding information
Funding for this research was provided by: University of Missouri Agriculture Experiment Station Chemical Laboratories.
References
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker. (1998). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
French, A. D., Dowd, M. K. & Reilly, P. J. (1997). J. Mol. Struct. Theochem, 395–396, 271–287. CrossRef CAS Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CSD CrossRef IUCr Journals Google Scholar
Jeffrey, G. A. & Taylor, R. (1980). J. Comput. Chem. 1, 99–109. CrossRef CAS Web of Science Google Scholar
Kaufmann, M., Meissner, P. M., Pelke, D., Mügge, C. & Kroh, L. W. (2016). Carbohydr. Res. 428, 87–99. CrossRef CAS PubMed Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
McNaught, A. D. (1996). Pure Appl. Chem. 68, 1919–2008. CrossRef CAS Web of Science Google Scholar
Mossine, V. V., Barnes, C. L., Glinsky, G. V. & Feather, M. S. (1996). Carbohydr. Res. 284, 11–24. CrossRef CAS PubMed Google Scholar
Mossine, V. V., Barnes, C. L. & Mawhinney, T. P. (2007). J. Carbohydr. Chem. 26, 249–266. CrossRef CAS Google Scholar
Mossine, V. V., Glinsky, G. V., Barnes, C. L. & Feather, M. S. (1995). Carbohydr. Res. 266, 5–14. CSD CrossRef CAS PubMed Web of Science Google Scholar
Mossine, V. V., Glinsky, G. V. & Feather, M. S. (1994). Carbohydr. Res. 262, 257–270. CrossRef CAS PubMed Google Scholar
Mossine, V. V., Glinsky, V. V. & Mawhinney, T. P. (2008). In Galectins, Klyosov, A. A., Platt, D. & Witczak, Z. J., Eds. John Wiley & Sons, pp. 235–270. Google Scholar
Mossine, V. V., Glinsky, V. V. & Mawhinney, T. P. (2010). In The Maillard Reaction: Interface between Aging, Nutrition and Metabolism, edited by M. C. Thomas and J. Forbes, pp. 170–179. Royal Society of Chemistry. Google Scholar
Mossine, V. V. & Mawhinney, T. P. (2010). Adv. Carbohydr. Chem. Biochem. 64, 291–402. CrossRef CAS PubMed Google Scholar
Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249–259. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Song, H., Lu, Y., Qu, Z., Mossine, V. V., Martin, M. B., Hou, J., Cui, J., Peculis, B. A., Mawhinney, T. P., Cheng, J., Greenlief, C. M., Fritsche, K., Schmidt, F. J., Walter, R. B., Lubahn, D. B., Sun, G. Y. & Gu, Z. (2016). Sci. Rep. 6, 35323. CrossRef PubMed Google Scholar
Spackman, M. A. & Jayatilaka, D. (2009). CrystEngComm, 11, 19–32. Web of Science CrossRef CAS Google Scholar
Tarnawski, M., Kuliś-Orzechowska, R. & Szelepin, B. (2007). Int. Immunopharmacol. 7, 1577–1581. CrossRef PubMed CAS Google Scholar
Tarnawski, M., Ślepokura, K., Lis, T., Kuliś-Orzechowska, R. & Szelepin, B. (2007). Carbohydr. Res. 342, 1264–1270. CrossRef PubMed CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.