Relative stability of alternative chair forms and hydroxymethyl conformations of β-d-glucopyranose

Barrows, Susan E.; Dulles, Frederic J.; Cramer, Christopher J.; French, Alfred D.; Truhlar, Donald G.

doi:10.1016/0008-6215(95)00175-s

Cited by 184 publications

(214 citation statements)

References 111 publications

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“…As one of the most important monosaccharides in nature, ␣-Dglucose plays vital roles in the life processes of both plants and animals. The gas-phase and solution-phase properties of ␣-D-glucose have been active areas for experimental [41][42][43] as well as theoretical studies [42][43][44][45][46][47][48][49][50] for many years. Unambiguous nomenclature has been developed to describe the various conformers of neutral and deprotonated ␣-D-glucose [45,50]; this nomenclature is elaborated upon in the Appendix of this report.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of the role of multiple hydrogen bonding in offering stability to negative ion adducts in electrospray mass spectrometry

Cai

Concha

Murray

et al. 2002

J. Am. Soc. Mass Spectrom.

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An experimental approach, electrospray mass spectrometry (ES-MS), and a theoretical approach employing computer modeling, have been used to characterize the interaction between small inorganic anions and neutral analyte molecules that form anionic adduct species in negative mode ES mass spectrometry. Certain anionic adducts of small saccharides (e.g., ␣-D-glucose, sucrose) have shown exceptional stability in ES mass spectra even when internal energies are raised at high "cone" voltages. Computer modeling studies reveal that multiple hydrogen bonding strengthens the interaction between these neutral molecules and the attaching anion. The equilibrium structures and stabilization energies of these anionic adducts have been evaluated by semi-empirical, ab initio, and density functional theory (DFT) methods. Chloride anion is found to be capable of forming "bridging" hydrogen bonds between monosaccharide rings of polysaccharides resulting in the stabilization of chloride adducts, thus reducing the tendency for the glycosidic bond to decompose. Moreover, the tendency for various hydroxyl hydrogens on saccharide molecules to dissociate in the form of HA ( [5][6][7][8], have been used to generate anionic adducts for ES-MS studies. The formation and decomposition of chloride adducts have been further investigated from a thermodynamic standpoint [9 -12]. However, the conditions that favor the formation and survival of anionic adducts have not been extensively defined and are not fully understood. Moreover, the interactions between neutral analyte molecules and the attaching small inorganic anions have not been fully characterized.Various mass spectrometry methods have been applied to probe the interactions between ions and neutral analyte molecules [13][14][15]. These methods typically evaluate enthalpies of ion-molecule reactions or unimolecular dissociations of ionic adducts to derive gasphase thermodynamic properties such as bond energies and ion affinities. In some cases, the nature of the ion-molecule interaction could be further elucidated by determining the difference in the entropy changes for competing decomposition pathways [16,17]. To date, the vast majority of ion-molecule interaction studies performed by mass spectrometry focus on positive ion studies of cationic adduct species, especially protonated molecules [14] and alkali metal adducts [18 -21]. Dication adduct species, such as alkaline earth metal [22] and transition metal [23] adducts of oligosaccharides have also been explored. Small inorganic anions attaching to neutral analyte molecules, on the other hand, have received far less research attention. However, a few studies employing anion attachment in negative ion ES-MS have appeared, such as reports on iodide attachment to acetone [24], chloride attachment to saccharides [1, 10 -12], and cyanide attachment (including covalent) to fullerenes [6,8]. In order to gain insight into the exact nature of the interactions between neutral analyte molecules and attaching small inorganic anions that are responsi...

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Section: Resultsmentioning

confidence: 99%

Evaluation of the role of multiple hydrogen bonding in offering stability to negative ion adducts in electrospray mass spectrometry

Cai

Concha

Murray

et al. 2002

J. Am. Soc. Mass Spectrom.

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“…On the other hand, Barrows et al [17] have shown that due to fortuitous error compensation the HF/6-31G* relative energies of some saccharides conformers agree well with those calculated at very extensive correlated energy level. Thus HF/6-31G* can be a useful method for a quick first screening of a large number of conformers.…”

Section: Figmentioning

confidence: 70%

“…However, because these dihedral angles are quite sensitive to mutual interaction of OH groups as well as to their interactions with endocyclic oxygen atoms (O1, O5), they can deviate from these ideal values. In search for stable conformers of LG in vacuo their geometries were first optimized, in accordance to [17], at HF/6-31G* level to identify possible improper conformations. The optimized structures were re-optimized using B3LYP potential [16] with 6-31+G** basis [18,19] and Dunning's cc-pVDZ basis [20].…”

Section: Figmentioning

confidence: 99%

DFT and neutron diffraction study of 1,6-anhydro-β-D-glucopyranose (levoglucosan)

et al. 2007

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Geometries of 27 generated conformers of levoglucosan were optimized in vacuo at DFT level of theory combining several functionals with high quality basis sets. For the sake of comparison a reference molecular and crystal geometry obtained from 30 K single crystal neutron diffraction data was used. Analysis of the conformers' geometries revealed that in all stable conformers intramolecular twoor three centre hydrogen bonds were formed. Relative energy of the conformer, which approximated the molecule in the crystal structure the most, was only ∼3 kcal/mol higher, than the energy of the most stable conformer in vacuo. The largest discrepancies between the geometries calculated in vacuo and experimental geometry concentrated in the vicinity of anomeric C1. These differences were reduced by involving O1 to intermolecular hydrogen bond using a simple model of the respective hydrogen bond in the crystal.

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“…In two cases, preliminary work was reported for solutes containing C, H, and O atoms. However, those cases were not general parameterizations, but were instead restricted to certain classes of compounds for use in modeling aqueous solvation effects on the Claisen rearrangement [14] and sugar conformational analysis [96]. Careful analysis of work accomplished up to that point indicated that the dependence of surface tensions and Coulomb radii on bond orders and partial atomic charges led to instabilities associated with the difficulty of properly including these terms in Fock matrix updates as part of the SCRF equations.…”

Section: Smx Models For Semiempirical Hamiltoniansmentioning

confidence: 99%

SMx Continuum Models for Condensed Phases

Cramer

Truhlar

2006

Trends and Perspectives in Modern Computational Science

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Abstract:The SMx continuum models are designed to include condensed-phase effects in classical and quantum mechanical electronic structure calculations and can also be used for calculating geometries and vibrational frequencies in condensed phases. Originally developed for homogeneous liquid solutions, the SMx models have seen substantial application to more complicated condensed phases as well, e.g., the airwater interface, soil, phospholipid membranes, and vapor pressures of crystals as well as liquids. Bulk electrostatics are accounted for via a generalized Born formalism, and other physical contributions to free energies of interaction between a solute and the surrounding condensed phase are modeled by environmentally sensitive atomic surface tensions associated with solute atoms having surface area exposed to the surrounding medium. The underlying framework of the models, including the charge models used for the electrostatics, and some of the models' most recent extensions are summarized in this report. In addition, selected applications to environmental chemistry problems are presented.

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Relative stability of alternative chair forms and hydroxymethyl conformations of β-d-glucopyranose

Cited by 184 publications

References 111 publications

Evaluation of the role of multiple hydrogen bonding in offering stability to negative ion adducts in electrospray mass spectrometry

Evaluation of the role of multiple hydrogen bonding in offering stability to negative ion adducts in electrospray mass spectrometry

DFT and neutron diffraction study of 1,6-anhydro-β-D-glucopyranose (levoglucosan)

SMx Continuum Models for Condensed Phases

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