The Impact of Polyols on Water Structure in Solution: A Computational Study

Abstract

Using molecular dynamics simulations, we study the effect of polyalcohols on water structuring in concentrated solutions, comparing six different polyols that vary in the number of hydroxyl groups and internal structure. For all polyols, we find that the hydrogen bond network order, as assessed by changes in the tetrahedral order parameter, is distorted in the binary solutions as compared with that of pure water and depends on the number of hydroxyl groups and the polyol conformation. While the total number of hydrogen bonds is only slightly reduced relative to that found in pure water, we find that hydrogen bonds that form with polyols tend to be less linear than hydrogen bonds formed between water molecules. We suggest that this reflects the competition between water and polyol molecules for hydrogen bonding with surrounding waters and offer a link between this competition and the resulting disorder that follows polyol solvation. The conclusions of this study should help shed light on the action that polyols can have as stabilizers to other macromolecules such as proteins in solution.

CHAPTER 7. Excess Volumes of Liquid Nonelectrolyte Mixtures

“…However, for the second water coordination shell the change of water structure is similar to that seen in water at high pressure and for dilute solutions of the cryoprotectants methanol 452 and trehalose. 453 In addition, their results indicate that the hydrogen bonded network is very effectively mixed between glycerol and water, which is consistent with molecular dynamics simulation results of Dashnau et al 454 and Politi et al 455 For neutron diffraction studies in a concentrated mixture of glycerol with water see Towey et al 456 Thermodynamic properties of mixtures of 2-n-alkoxyethanols, in particular molar heat capacities at constant pressure, have attracted attention because of the unusual composition dependence found with some mixtures, reminiscent of that associated with micellization. Molar heat capacities and molar volumes of several such systems have been determined by Roux et al: 457 461 Excess enthalpies, excess isobaric heat capacities, densities and speeds of ultrasound were measured covering the entire composition range.…”

Crowding Alone Cannot Account for Cosolute Effect on Amyloid Aggregation

“…We suggest that this flexible structure that lacks intrachain hydrogen bonds, and is fully hydrated in aqueous solution, can be significantly impacted in aqueous osmolyte solutions that are known to alter the hydrogen bonding network [49], [51], [52].…”

The Relationship Between Bound Water and Carbohydrate Reserves in Association with Cellular Integrity in Fragaria vesca Stored Under Different Conditions

“…So, while myoinositol was located in the positive part of PC1, joined to simple sugars, the third group composed of sorbitol was found in PC3 and there was no addition for mannitol. Regarding the effect of polyols on water, structuring differences between myo-inositol and sorbitol were reported (Politi et al 2009) despite them having the same number of hydroxyl groups. So, myo-inositol forms no internal hydrogen bonds and creates more interpolyol bonds than sorbitol.…”