13C–13C spin-coupling constants in crystalline 13C-labeled saccharides: conformational effects interrogated by solid-state 13C NMR spectroscopy

Zhang, Wenhui; Yoon, Misun; Meredith, Reagan J; Zajíček, Jaroslav; Oliver, Allen G.; Hadad, Matthew J.; Frey, M. H.; Carmichael, Ian; Serianni, Anthony S.

doi:10.1039/c9cp03228b

Cited by 12 publications

(21 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to the reported results, a careful analysis of the candidate structures revealed two main different conformers of 110, A and B. Interestingly, conformer B represented the main conformation of svetamicin A, while conformer A, which was not in agreement with the NMR data, represented the minor conformer. Taken together, the reported data supported the 2S,3S,4R structure as the most probable absolute configuration of svetamicin A. reproduced from Zhang, et al [374] with the permission of the American Chemical Society Reproduced from Zhang, et al [374] with the permission of the American Chemical Society Reproduced with minor editing privilege from Zhang, et al [375] with the permission of the Royal Society of Chemistry S C H E M E 1 5 Chemical structures of the selectively 13 C-labeled mono-and disaccharides, and the 2 J C1ÀC3 value measured in each compound by the solution-and solid-state 13 C NMR. Blue circles, and the superscripts on compound numbers, denote the labeled carbons.…”

Section: Bioorganic Compoundssupporting

confidence: 58%

“…Recently, Zhang, et al [ 375 ] calculated contour plots of the 1 J (C1‐C2) values of β ‐D‐glucopyranose and established their primary dependence on the C 1 –C 2 –O 2 –H torsion angle and secondary effects of rotation around the C 3 –O 3 , C 4 –O 4 , C 5 –C 6 , and C 6 –O 6 bonds, which is shown in Figure 48. The basic finding of that study was that 1 J (C1‐C2) exhibited a dynamic range of about 7 Hz, which was due to the effect of rotation around the C 2 –O 2 bond, being essentially unaffected by the rotation around other bonds.…”

Section: Computational 1h and 13c Nmr In Stereochemical Studies Of In...mentioning

confidence: 99%

“…Two‐dimensional contour plots of calculated 1 J (C1‐C2) values in β ‐D‐glucopyranose showing a primary dependence on the C1–C2–O2–H torsion angle and secondary effects of rotating around the C 3 –O 3 (a), C 4 –O 4 (b), C 5 –C 6 (c), and the C 6 –O 6 (d) bonds. Reproduced with minor editing privilege from Zhang, et al [ 375 ] with the permission of the Royal Society of Chemistry…”

Section: Computational 1h and 13c Nmr In Stereochemical Studies Of In...mentioning

confidence: 99%

“…Recently, Zhang, et al [375] calculated contour plots of the 1 J (C1-C2) values of β-D-glucopyranose and established their primary dependence on the C 1 -C 2 -O 2 -H torsion F I G U R E 3 8 Docking of PI3Kα-selective inhibitor and mTOR-selective inhibitor with the crystal structures of human PI3Kα and mTOR showing hydrogen bonds and surface maps. For details, see original publication.…”

Section: Carbohydratesmentioning

confidence: 99%

See 3 more Smart Citations

Computational¹H and¹³C NMR in structural and stereochemical studies

Krivdin

2022

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

Present review outlines the advances and perspectives of computational 1H and 13C NMR applied to the stereochemical studies of inorganic, organic, and bioorganic compounds, involving in particular natural products, carbohydrates, and carbonium ions. The first part of the review briefly outlines theoretical background of the modern computational methods applied to the calculation of chemical shifts and spin–spin coupling constants at the DFT and the non‐empirical levels. The second part of the review deals with the achievements of the computational 1H and 13C NMR in the stereochemical investigation of a variety of inorganic, organic, and bioorganic compounds, providing in an abridged form the material partly discussed by the author in a series of parent reviews. Major attention is focused herewith on the publications of the recent years, which were not reviewed elsewhere.

show abstract

Section: Bioorganic Compoundssupporting

confidence: 58%

Section: Computational 1h and 13c Nmr In Stereochemical Studies Of In...mentioning

confidence: 99%

Section: Computational 1h and 13c Nmr In Stereochemical Studies Of In...mentioning

confidence: 99%

Section: Carbohydratesmentioning

confidence: 99%

See 2 more Smart Citations

Computational¹H and¹³C NMR in structural and stereochemical studies

Krivdin

2022

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

show abstract

“…Emerging work is also being carried out to understand the relationship between the homonuclear 13 C− 13 C J-couplings and the structure of glycans in solution 104,105 and solids. 107 These couplings helped to alleviate the assignment ambiguities in our sample. Peak splitting is not observed for the terminal sites (such as C 1 and C 6 in glucose) that only have a single neighboring carbon but observed for all remaining sites (such as C 2 −C 5 in glucose) that have two neighboring carbons.…”

Section: ■ Results and Discussionmentioning

confidence: 95%

Identification and Quantification of Glycans in Whole Cells: Architecture of Microalgal Polysaccharides Described by Solid-State Nuclear Magnetic Resonance

et al. 2021

View full text Add to dashboard Cite

Microalgae are photosynthetic organisms widely distributed in nature and serve as a sustainable source of bioproducts. Their carbohydrate components are also promising candidates for bioenergy production and bioremediation, but the structural characterization of these heterogeneous polymers in cells remains a formidable problem. Here we present a widely applicable protocol for identifying and quantifying the glycan content using magic-angle-spinning (MAS) solid-state NMR (ssNMR) spectroscopy, with validation from glycosyl linkage and composition analysis deduced from mass-spectrometry (MS). Two-dimensional 13C–13C correlation ssNMR spectra of a uniformly 13C-labeled green microalga Parachlorella beijerinckii reveal that starch is the most abundant polysaccharide in a naturally cellulose-deficient strain, and this polymer adopts a well-organized and highly rigid structure in the cell. Some xyloses are present in both the mobile and rigid domains of the cell wall, with their chemical shifts partially aligned with the flat-ribbon 2-fold xylan identified in plants. Surprisingly, most other carbohydrates are largely mobile, regardless of their distribution in glycolipids or cell walls. These structural insights correlate with the high digestibility of this cellulose-deficient strain, and the in-cell ssNMR methods will facilitate the investigations of other economically important algae species.

show abstract

MA’AT Analysis: Probability Distributions of Molecular Torsion Angles in Solution from NMR Spectroscopy

et al. 2023

Self Cite

View full text Add to dashboard Cite

Metrics & MoreArticle Recommendations CONSPECTUS: Monosaccharides adopt multiple conformations in solution, and this structural complexity increases significantly when they are assembled into oligosaccharides and polysaccharides. Characterization of the conformational properties of saccharides in solution by NMR spectroscopy has been hampered by several complicating factors, including difficulty interpreting spectra because of significant signal overlap, population averaging of NMR parameters, and unique properties of the spectra that make accurate measurements of NMR parameters prone to error (e.g., non-first-order effects on J-couplings). Current conformational assignments rely heavily on theoretical calculations, especially molecular dynamics (MD) simulations, to interpret the experimental NMR parameters. While these studies assert that the available experimental data fit the calculated models well, a lack of independent experimental validation of the force fields from which MD models are derived and an inability to test all possible models that might be compatible with the experimental data in an unbiased manner make the approach less than ideal. NMR spin couplings or J-couplings have been used as structure constraints in organic and other types of molecules for more than six decades. The dihedral angle dependence of vicinal (three-bond) 1 H− 1 H spin couplings ( 3 J HH ) first described by Karplus led to an explosion of applications for a wide range of conformational problems. Other vicinal J-couplings (e.g., 3J CCOP , 3 J HCOP , and 3 J COCH ) have been found to exhibit similar dihedral angle dependencies. 3 J values have been used to assign the preferred conformation in molecules that are conformationally homogeneous. However, many molecules, particularly those in biological systems, are conformationally flexible, which complicates structural interpretations of J values in solution. Three-state staggered models are often assumed in order to deconvolute the conformationally averaged J values into conformer populations. While widely applied, this approach assumes highly idealized models of molecular torsion angles that are likely to be poor representations of those found in solution. In addition, this treatment often gives negative populations and neglects the presence of librational averaging of molecular torsion angles. Recent work in this research group has focused on the development of a hybrid experimental−computational method, MA'AT analysis, that provides probability distributions of molecular torsion angles in solution that can be superimposed on those obtained by MD. Ensembles of redundant NMR spin couplings, including 3 J (vicinal), 2 J (geminal), and sometimes 1 J (direct) values, are used in conjunction with circular statistics to provide single-and multistate models of these angles. MA'AT analysis provides accurate mean torsion angles and circular standard deviations (CSDs) of each mean angle that describe the librational motion about the angle. Both conformational equilibria and dynamics are re...

show abstract

¹³C–¹³C spin-coupling constants in crystalline ¹³C-labeled saccharides: conformational effects interrogated by solid-state ¹³C NMR spectroscopy

Abstract: Solid-state 13C NMR reveals differences in O-glycosidic linkage conformation in solution and in crystalline disaccharides. Experimental JCC values in crystalline samples provide a means of validating JCC calculated from density functional theory.

Cited by 12 publications

References 63 publications

Computational¹H and¹³C NMR in structural and stereochemical studies

Computational¹H and¹³C NMR in structural and stereochemical studies

Identification and Quantification of Glycans in Whole Cells: Architecture of Microalgal Polysaccharides Described by Solid-State Nuclear Magnetic Resonance

MA’AT Analysis: Probability Distributions of Molecular Torsion Angles in Solution from NMR Spectroscopy

Contact Info

Product

Resources

About

13C–13C spin-coupling constants in crystalline 13C-labeled saccharides: conformational effects interrogated by solid-state 13C NMR spectroscopy

Abstract: Solid-state 13C NMR reveals differences in O-glycosidic linkage conformation in solution and in crystalline disaccharides. Experimental JCC values in crystalline samples provide a means of validating JCC calculated from density functional theory.

Cited by 12 publications

References 63 publications

Computational1H and13C NMR in structural and stereochemical studies

Computational1H and13C NMR in structural and stereochemical studies

Identification and Quantification of Glycans in Whole Cells: Architecture of Microalgal Polysaccharides Described by Solid-State Nuclear Magnetic Resonance

MA’AT Analysis: Probability Distributions of Molecular Torsion Angles in Solution from NMR Spectroscopy

Contact Info

Product

Resources

About

¹³C–¹³C spin-coupling constants in crystalline ¹³C-labeled saccharides: conformational effects interrogated by solid-state ¹³C NMR spectroscopy

Computational¹H and¹³C NMR in structural and stereochemical studies

Computational¹H and¹³C NMR in structural and stereochemical studies