Interaction Of Dimethyl Sulfoxide Research Articles

Weak Interactions in Dimethyl Sulfoxide (DMSO)–Tertiary Amide Solutions: The Versatility of DMSO as a Solvent

The structures of equimolar mixtures of the commonly used polar aprotic solvents dimethylformamide (DMF) and dimethylacetamide (DMAc) in dimethyl sulfoxide (DMSO) have been investigated via neutron diffraction augmented by extensive hydrogen/deuterium isotopic substitution. Detailed 3-dimensional structural models of these solutions have been derived from the neutron data via Empirical Potential Structure Refinement (EPSR). The intermolecular center-of-mass (CoM) distributions show that the first coordination shell of the amides comprises ∼13-14 neighbors, of which approximately half are DMSO. In spite of this near ideal coordination shell mixing, the changes to the amide-amide structure are found to be relatively subtle when compared to the pure liquids. Analysis of specific intermolecular atom-atom correlations allows quantitative interpretation of the competition between weak interactions in the solution. We find a hierarchy of formic and methyl C-H···O hydrogen bonds forms the dominant local motifs, with peak positions in the range of 2.5-3.0 Å. We also observe a rich variety of steric and dispersion interactions, including those involving the O═C-N amide π-backbones. This detailed insight into the structural landscape of these important liquids demonstrates the versatility of DMSO as a solvent and the remarkable sensitivity of neutron diffraction, which is critical for understanding weak intermolecular interactions at the nanoscale and thereby tailoring solvent properties to specific applications.

Different Effects of Salt Bridges near the Active Site of Cold-Adapted Proteus mirabilis Lipase on Thermal and Organic Solvent Stabilities

Organic solvent-tolerant (OST) enzymes have been discovered in psychrophiles. Cold-adapted OST enzymes exhibit increased conformational flexibility in polar organic solvents resulting from their intrinsically flexible structures. Proteus mirabilis lipase (PML), a cold-adapted OST lipase, was used to assess the contribution of salt bridges near the active site involving two arginine residues (R237 and R241) on the helix η1 and an aspartate residue (D248) on the connecting loop to the thermal and organic solvent stabilities of PML. Alanine substitutions for the ion pairs (R237A, R241A, D248A, and R237A/D248A) increased the conformational flexibility of PML mutants compared to that of the wild-type PML in an aqueous buffer. The PML mutants became more susceptible to denaturation after increasing the dimethyl sulfoxide or methanol concentration than after a temperature increase. Methanol was more detrimental to the structural stability of PML compared to dimethyl sulfoxide. These results suggest that direct interactions of dimethyl sulfoxide and methanol with the residues near the active site can have a destructive effect on the structure of PML compared with the global effect of heat on the protein structure. This study provides insight into the conformational changes within an OST enzyme with different effects on its thermal and organic solvent stabilities.

Non-covalent interactions in dimethylsulfoxide (DMSO) clusters and DFT benchmarking

Dimethylsulfoxide (DMSO) is one of the most used solvents in industries and in Chemistry. Understanding the dynamics of the solvent is subjected to the understanding of interactions in DMSO clusters. Despite its importance, a very few studies have been reported on DMSO clusters. In this work, we have explored thoroughly the potential energy surfaces (PESs) of the DMSO clusters from dimer to tetramer at the MP2/aug-cc-pVDZ level of theory. In order to understand the non-covalent interactions in DMSO clusters, we have performed a quantum theory of atoms in molecules (QTAIM) analysis. The QTAIM analysis showed that there are eight different types of non-covalent interactions stabilizing the DMSO clusters. The CH⋯O hydrogen bonding and H⋯H bonding are found to be the strongest and the weakest non-covalent interactions in DMSO clusters, respectively. In addition, we have reported the temperature-dependent isomer distribution of all the investigated clusters for temperatures ranging from 50 to 500 K. To allow affordable investigations of medium and large sized DMSO clusters in future investigations, we have assessed the performance of ten functionals of the density functional theory (DFT) in calculating the binding energies of the DMSO clusters. The ten DFT functionals (M05, M05-2X, M06, M06-2X, M08HX, PBE0, ωB97XD, PW6B95D3, APFD and MN15) have been benchmarked to MP2/CBS and DLPNO-CCSD(T)/CBS. The functionals PW6B95D3 and ωB97XD are recommended for further affordable investigations of the DMSO clusters.

Interactions of Dimethylsulfoxide with a Dipalmitoylphosphatidylcholine Monolayer Studied by Vibrational Sum Frequency Generation

The interactions between phospholipid monolayers and dimethylsulfoxide (DMSO) molecules were investigated by vibrational sum frequency generation (VSFG) spectroscopy in a Langmuir trough system. Both the head and the tail groups of dipalmitoylphosphatidylcholine (DPPC) as well as DMSO were probed to provide a comprehensive understanding of the interactions between DPPC and DMSO molecules. A condensing effect is observed for the DPPC monolayer on a concentrated DMSO subphase (>20 mol %). This effect results in a well-ordered conformation for the DPPC alkyl chains at very large mean molecular areas. Interactions between DMSO and DPPC headgroups were also studied. DMSO-induced dehydration of the DPPC phosphate group is revealed at DMSO concentration above 10 mol %. The average orientation of DMSO with DPPC versus dipalmitoylphosphate sodium salt (DPPA) monolayers was compared. The comparison revealed that DMSO molecules are perturbed and reorient because of the interfacial electric field created by the charged lipid headgroups. The orientation of the DPPC alkyl chains remains nearly unchanged in the liquid condensed phase with the addition of DMSO. This suggests that DMSO molecules are expelled from the condensed monolayer. In addition, implications for the DMSO-induced permeability enhancement of biological membranes from this work are discussed.

Dimethylsulfoxide oxidizes glutathione in vitro and in human erythrocytes: Kinetic analysis by 1H NMR

The interaction of dimethylsulfoxide (Me 2SO) with glutathione was investigated under non-equilibrium conditions in solution using 1H NMR and in intact erythrocytes using 1H spin–echo NMR. In solution the reaction was observed to follow second-order kinetics (Rate = k 1[glutathione][Me 2SO]) at 300 K pH 7.4, k sol = 4.7 × 10 −5 mol −1 L 1 s −1. In intact erythrocytes the rate constant for the cellular environment, k cell, was found to be slightly larger at 8.1 × 10 −5 mol −1 L 1 s −1. Furthermore, the reaction of Me 2SO with erythrocyte glutathione showed a biphasic dependence on the Me 2SO concentration, with little oxidation of glutathione occurring until the Me 2SO concentration exceeded 0.5 mol L −1. The results suggest that at lower concentrations, Me 2SO can be effectively removed, most probably by reaction with glutathione, which is regenerated by glutathione reductase, although preferential reaction with other cellular components (e.g., membrane or cellular thiols) cannot be ruled out. Thus the concentrations of Me 2SO that are commonly used in cryopreservation of mammalian cells (∼1.4 mol L −1) can cause oxidation of intracellular glutathione.

Helicity Induction on Poly(phenylacetylene)s Bearing Phosphonic Acid Pendants with Chiral Amines and Memory of the Macromolecular Helicity Assisted by Interaction with Achiral Amines in Dimethyl Sulfoxide

Two novel stereoregular poly(phenylacetylene)s bearing a phosphonic acid residue (poly-1) and its monoethyl ester (poly-2) as pendants were prepared by the polymerization of diethyl (4-ethynylphenyl)phosphonate followed by hydrolysis of the diethyl ester groups and polymerization of ethyl (4-ethynylphenyl)phosphonate, respectively. The polymers were found to form a predominantly one-handed helical conformation upon complexation with various chiral amines through noncovalent acid−base interactions in dimethyl sulfoxide (DMSO). The complexes exhibited an induced circular dichroism (ICD) in the UV−visible region of the polymer backbones. In particular, poly-2 is an induced helical polymer more sensitive to the chirality of amines than poly-1 and poly((4-carboxyphenyl)acetylene) and yields the same Cotton effect sign when complexed with chiral amines of the same absolute configuration. Moreover, the macromolecular helicity of poly-1 and poly-2 induced by chiral amines was “memorized” after the chiral amines w...

The interaction of dimethylsulfoxide with a gold surface

The interaction of dimethylsulfoxide (DMSO) with a Au(100) surface was studied by means of TDS, XPS and ΔΦ measurements. At monolayer coverages, DMSO desorbs from two states situated at the relatively high temperatures of 240 and 275 K. The adsorbed molecule, however, shows no chemical shifts in its core levels. This is rationalized by a bidentate bonding of DMSO to the surface through the electron lone-pairs on the O and S atoms. The adsorption geometry agrees also with the behavior of the work function (ΔΦDMSO = − 770 meV).

Interaction of dimethylsulfoxide and arachidonic acid with the teratogenic effects of caffeine in mice.

Dose-response of the teratogenic effect of caffeine (CA) and the potential role of facial hematomas in the pathogenesis of caffeine-induced cleft palate were investigated using CD1 mice treated with 150, 200, or 250 mg CA/kg i.p. on gestational day (GD) 12. Dimethylsulfoxide (DMSO; 20%) and arachidonic acid (AA, 200 mg/kg) were administered along with CA (200 mg/kg) to study their interaction with CA-induced teratogenesis and elevation in maternal glucocorticoids (MGC, measured by RIA) on GD 13 and 14. Dose-dependent increase in the incidence of cleft palate (CP) was noted in CA-exposed mice. High maternal deaths, an increased number of resorptions, gross facial hematomas (GFH), and club foot (CF) were produced only by the highest (250 mg/kg) dose of CA. Palates from all offspring with GFH were clefted at this dose level. None of the control or CA-treated nonclefted offspring had GFH or microscopic hematomas (MH). At 200 mg/kg of CA, DMSO in combination with CA actually increased CA-induced CP from 30% to 100% and also produced 100% GFH as compared to 0% by CA alone at this dose. Greater than 50% of clefted offspring without GFH, given either dose (200 or 250 mg/kg) of CA, had MH. Very high levels of MGC were present in CA-treated mice on GD 13 and 14. Although simultaneous administration of DMSO reduced the magnitude of CA-induced MGC elevations on GD 14, the MGC levels remained high for greater than 24 hours following CA exposure. Increase in maternal mortality and fetal resorptions, a decrease in the number of live pups and their body weights, and no change in the incidence of CP were seen when CA-treated mice were simultaneously exposed to AA. These results suggest a correlation between caffeine-induced FH and CP; a role for increased hematomagenic effects of DMSO in its potentiation of the cleft-palatogenic effect of caffeine; and absence of a role for AA-mediated effects of MGC in the causation of CA-induced CP and other malformations.

Interactions of dimethyl sulfoxide and granulocyte‐macrophage colony‐stimulating factor on the cell cycle kinetics and phosphoproteins of G1‐enriched HL‐60 cells: Evidence of early effects on lamin B phosphorylation

We have found that GM-CSF and DMSO have antagonistic effects on the proliferation but not maturation of asynchronously growing HL-60 cells such that growth in the presence of both more closely resembles normal hematopoiesis (Brennan et al., J. Cell Physiol. 132:246, 1987). Studies were undertaken to determine whether or not the agents affected the same mitogenic pathway and locus in the cell cycle. HL-60 populations containing at least 90% G1 cells were obtained by centrifugal elutriation, exposed to 100 u/ml recombinant human GM-CSF and/or 0-1.25% DMSO, and phosphoprotein changes quantified on autoradiograms of [32P]-orthophosphate-labeled cell proteins separated by giant 2-D gel electrophoresis. Results were correlated with 1) intracellular pH, determined by measurement of BCECF fluorescence; 2) [32P]-orthophosphate uptake; 3) cell cycle progression, determined by flow quantitation of DNA content in mithramycin or propidium iodide-stained cells; and 4) growth, determined by cell volume and concentration. GM-CSF stimulated and DMSO inhibited the GM-CSF-stimulated phosphorylation of 1 protein (approximately 65 kDa, p.i. 5.6) within 2 min of exposure. These effects were sustained through G1, not associated with changes in intracellular pH, and preceded similar antagonistic effects on phosphate uptake (15-30 minutes), cell volume change (16-24 hr), and cell concentration increase (28-32 hr). GM-CSF accelerated and DMSO inhibited G1 to S transit with the most marked antagonism observed in the second cycle following synchronization (28 to 40 hrs). Cell maturation (morphology, NBT reduction) was dominated by DMSO and not antagonized by GM-CSF. We have identified p65 as the nuclear intermediate filament protein, lamin B, on the basis of its locus on gels and its binding of a monoclonal antibody to intermediate filaments and antiserum to human lamin B on immunoblots. These studies suggest that at least part of the GM-CSF-DMSO antagonism is exerted through the same mitogenic pathway, that a major locus of cytokinetic effect is on G1 to S transit, and that nuclear envelope protein phosphorylation is an important early event.

Electrochemical studies of vanadium-riboflavin interactions in dimethyl sulfoxide

The electrochemistry and complexation of VO(ClO4)2, VCl3, and VOF3 with singly-reduced riboflavin have been studied by cyclic voltammetry and controlled-potential coulometry in dimethyl sulfoxide at a platinum electrode. The UV, visible, and near-IR spectra of solutions of these species have also been examined. Vanadium(IV) forms the complex VO(Rib)2 (Rib− = singly reduced riboflavin) which is reduced to VO(Rib)2−2 at −0.74 V vs. SCE. VO(Rib)2 is oxidized at −0.15 V producing free VO2+ and neutral riboflavin. Reduced riboflavin forms a complex with VCl3 having an oxidation potential of −0.12 V, which is similar to that for the vanadium(IV) complex. A mixture of reduced riboflavin and VOF3 results in the spontaneous reduction of the metal and oxidation of the riboflavin anion to neutral riboflavin.

The interaction of dimethyl sulfoxide with N-benzoyl amino acids

The interaction of dimethyl sulfoxide with N-benzoyl amino acids in deuterochloroform has been investigated by 13C n.m.r. spectroscopy. Examination of the chemical shifts of the benzene ring reveals that intermolecular hydrogen bonding between dimethyl sulfoxide and the amido-hydrogen atom increase the effective steric size of the amino hydrogen, resulting in an increase in the torsional angle between the benzene ring and the C(O)NHCH(R)COOH side chain. Self-association of N- benzoyl amino acids in deuterochloroform occurs largely through two COOH...O=C hydrogen bonds and does not involve intermolecular hydrogen bonding to the N-H proton.

Interactions of Dimethyl Sulfoxide with Lipid and Protein Monolayers

Phospholipids, cholesterol, protein, and mixed phos-pholipid-protein monolayers were used as models to study interactions between dimethyl sulfoxide and cell membranes. Surface pressure measurements were used to study these dimethyl sulf-oxide-film interactions. While films of dipalmitoyl lecithin, egg lecithin, and cholesterol showed no interaction with dimethyl sulfoxide, films of bovine serum albumin exhibited a significant condensation effect. The degree of film condensation was found to be a function of pH and dimethyl sulfoxide concentration in the subphase. It was postulated that the observed effect of dimethyl sulfoxide on albumin films is due to the loss of protein from the surface. Lipid-protein films showed only small condensation effects in the presence of dimethyl sulfoxide, indicating that the phospholipids protect the protein from attack by dimethyl sulfoxide. These studies indicate that the remarkable penetration abilities of dimethyl sulfoxide may be due to some alteration of protein structure as a result of dehydration at the biomembrane.

Solvent-solute interactions in dimethylsulfoxide

The osmotic and activity coefficients of six non-electrolytes and ten electrolytes in dimethylsulfoxide have been measured by the depression of the freezing temperature. A cryoscopic constant of (4.40 ± 0.01) K kg mol −1 has been determined for the solvent. The behavior of non-electrolytes both as to solubility and osmotic coefficients is intermediate between that in water and in ethylene carbonate. Ethylene carbonate and dimethylsulfoxide are both polar aprotic solvents but the smaller size of the latter apparently allows it to solvate both electrolytes and non-electrolytes more effectively. Solvent size is apparently more important than dielectric constant or dipole moment in determining the properties of solutions. The osmotic and activity coefficient of salts decrease in the sequence: Li + > NA + > K + > Cs + > NH + 4 > (C 2 H 5 ) 4 N + . The ammonium ion is apparently not solvated by DMSO through hydrogen bonding.

A study of the intermolecular interaction of dimethyl sulfoxide in solution

A study of the intermolecular interaction of dimethyl sulfoxide in solution