Despite the ubiquity of carbohydrates, assessment of their conformations is challenging for experimental approaches alone. This is especially true for cyclic sugars with five-membered rings (known as furanosides) due to their high degree of flexibility.\(^{1,2}\) To understand their structure, furanosides are studied with nuclear magnetic resonance (NMR) spectroscopy.\(^{3,4}\) The structural information contained in vicinal proton-proton coupling constants (\(^{3}J_{H,H}\)) from NMR is deciphered through computational studies. Past theoretical work in this domain has relied on classical molecular dynamics to reconstruct detailed conformational distributions.\(^{3–5}\) Classical molecular dynamics methods omit nuclear quantum effects, which are known to have a delocalizing effect on the positions and momenta of low-mass atoms like protons. Here, we investigate the impact of nuclear quantum effects on the conformational distributions of arabinofuranosides, along with the impact had on calculated \(^{3}J_{H,H}\) values.

To quantify the impact of nuclear quantum effects on arabinofuranosides, this work uses path integral molecular dynamics simulations of arabinofuranoside monomers. The results from the path integral approach show the broadening of dihedral angle distributions within the monomers, with slight differences in the final \(^{3}J_{H,H}\) values compared to classical simulation results. This work informs future analyses of flexible chemical structures that rely on proton positions as a primary source of conformational information. Additionally, it indicates whether the addition of nuclear quantum effects has broader consequences on structural properties. This can be considered in other biochemical simulations that are sensitive to conformational changes, such as in binding studies.\(^{6}\)

References
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