Pure Dimethyl Sulphoxide Research Articles

Histological evaluation of the repair process of replanted rat teeth after storage in resveratrol dissolved in dimethyl sulphoxide.

The storage media is directly related to the prognosis of avulsed teeth, with resveratrol drawing attention due to its antioxidant and anti-inflammatory proprieties. The aim of this study was to evaluate the repair process in rat teeth following delayed replantation after storage in resveratrol (R) dissolved in dimethyl sulphoxide (DMSO). The upper right central incisors of 36 rats were divided into 4 groups. In group I, the teeth were extracted and immediately replanted. Group II teeth were stored in 50mL R+DMSO (0.0512g/mL), whereas group III teeth were stored in 50mL pure DMSO, both for a period of 60minutes. The teeth of group IV were stored dry for 60minutes. The teeth of groups II, III and IV were then replanted, and the animals were euthanized after 60days. Longitudinal histological cuts were HE stained for histomorphometric analysis of the periodontal ligament, alveolar bone, cementum and dentin. The analysis of HE stained histological sections showed the following statistical differences: the acute inflammatory process in the epithelial insertion was less prominent in group II than in group III; the organization of the periodontal ligament was better in group I, while the intensity and extension of acute inflammation in the periodontal ligament were better in group I, and worse in group III; the chronic inflammatory infiltrate was less in groups I and IV, and the depth and extent of resorption, as well as the repair of root resorption, were better in group I. Storage in R+DMSO solution did not inhibit root resorption after delayed replantation in rat teeth. It is concluded that pure DMSO is not a suitable transport medium for avulsed teeth.

Numerical analysis of the characteristic times controlling supercritical antisolvent micronization

In this work jet break-up time and of dynamic surface tension vanishing are considered as mechanisms in competition during supercritical antisolvent precipitation and a mathematical model, based on these two characteristic phenomena, is presented.Jet break-up time has been evaluated solving continuity and conservation of momentum equations; on the other hand, dynamic surface tension vanishing time has been evaluated according to the time-evolution model proposed by Cahn and Hilliard. Phase equilibria have also been taken into account, considering the Peng and Robinson equation of state and the related mixing rules.Calculations have been applied to yttrium acetate (YAc) as model solute, dimethylsulphoxide (DMSO) as liquid solvent and carbon dioxide (CO2) as antisolvent.The cross-over times, between jet break-up dominated and dynamic surface tension vanishing dominated regions, have been calculated at different pressures for pure DMSO and at different YAc concentrations in the liquid solution; a good agreement with previous experimental results has been obtained. The numerical results also correctly describe the influence of solute concentration on the pressure at which cross-over between the two regions is obtained.The characteristic times for acetone (AC) have also been evaluated, to perform a comparison with DMSO; in this case, cross-over has been observed in proximity of the mixture critical point pressure of the binary system.

Evaluation of the Acute Effects of Organic Solvents on Adults of Sitophilus zeamais Motschulsky, 1855 (Coleoptera, Curculionidae)

The continuous use of synthetic insecticides has created problems for the environment and human health. With the objective of reducing such problems, ecofriendly measures have been taken and, in this case, plants have representing an important resource for pest control. Due to the increase of studies using organic extracts in bioassays and the difficulty of finding solubilizant agents that do not interfere in the results, the aim of this work was to evaluated the acute effect of different solvents on Sitophilus zeamais by contact and ingestion assays. The results suggest that pure dimethyl sulphoxide (DMSO) and Tween- 20 solvents have toxic acute effects on adults of S. zeamais, but they can be used diluted at 1 or 5% with no toxic acute effect. On contrary, pure dichloromethane (DCM) and methanol (MeOH) did not cause any acute effect on target organism. Thus, DCM and MeOH solvents even in the pure form and the Tween-20 and DMSO diluted at 1 or 5% can be used as solubilizant agents for apolar to medium polarity plant extracts, involving contact or ingestion assay on adults of S. zeamais.

Dimethyl sulphoxide addition or withdrawal causes biphasic volume changes and its withdrawal causes t‐system vacuolation in skeletal muscle

Dimethyl sulphoxide addition or withdrawal causes biphasic volume changes and its withdrawal causes t‐system vacuolation in skeletal muscle

Hydrogen‐bonded nucleophile effects in ANS: the reactions of 1‐chloro and 1‐fluoro‐2,4‐dinitrobenzene with 2‐guanidinobenzimidazole, 1‐(2‐aminoethyl)piperidine andN‐(3‐aminopropyl)morpholine in aprotic solvents

AbstractThe kinetics of the reactions of 2,4‐dinitrofluorobenzene (DNFB) and 2,4‐dinitrochlorobenzene (DNClB) with 2‐guanidinobenzimidazole (2‐GB) at 40 ± 0.2 °C in dimethylsulphoxide (DMSO), toluene, and in toluene–DMSO mixtures, and with 1‐(2‐aminoethyl)piperidine (2‐AEPip) andN‐(3‐aminopropyl)morpholine (3‐APMo) in toluene at 25 ± 0.2 °C were studied under pseudo first‐order conditions. For the reactions of 2‐GB carried out in pure DMSO, the second‐order rate coefficients were independent of the amine concentration. In contrast, the reactions of 2‐GB with DNFB in toluene, showed a kinetic behaviour consistent with a base‐catalysed decomposition of the zwitterionic intermediate. These results suggest an intramolecular H‐bonding of 2‐GB in toluene, which is not present in DMSO. To confirm this interpretation the reactions were studied in DMSO–toluene mixtures. Small amounts of DMSO produce significant increase in rate that is not expected on the basis of the classical effect of a dipolar aprotic medium; the effect is consistent with the formation of a nucleophile/co‐solventmixed aggregate. For the reactions of 3‐APMo with both substrates in toluene, the second‐order rate coefficients,kA, show a linear dependence on the [amine]. 3‐APMo is able to form a six‐membered ring by an intramolecular H‐bond which prevents the formation of self‐aggregates. In contrast, a third order was observed in the reactions with 2‐AEPip: these results can be interpreted as a H‐bonded homo‐aggregate of the amine acting as a better nucleophile than the monomer. Most of these results can be well explained within the frame of the ‘dimer nucleophile’ mechanism. Copyright © 2010 John Wiley & Sons, Ltd.

Evaluation of the toxicity of onyx compared with n-butyl 2-cyanoacrylate in the subarachnoid space of a rabbit model: an experimental research

The toxic effects of onyx, its solvent dimethyl sulphoxide (DMSO), and n-butyl 2-cyanoacrylate (NBCA) were evaluated after infusion into the subaracnoid space of a rabbit model. Each of the two various concentrations of onyx, pure DMSO, NBCA, and normal saline solution were percutaneously infused into the pontocerebellar cisternae of 39 domestic male albino rabbits, after which, the brain stems and medial cerebellar tissues were harvested for biochemical and histopathological studies. The specimens infused in various concentration of onyx, DMSO, and NBCA showed neural tissue necrosis and edema with inflammatory cell infitration in the acute stage. Although the mean values of the lipid peroxidase in the control, saline, and NBCA groups were found to be almost similar, they were found to be low in the onyx and DMSO groups. This experimental study suggests that NBCA, and various concentrations of onyx and DMSO have toxic effects on the neural tissues of rabbits when infused into the subarachnoid space.

Viscosities and Refractive Indices of Binary Mixtures of Dimethylsulphoxide with Some Aromatic Hydrocarbons at Different Temperatures: An Experimental and Theoretical Study

The viscosities, η, and refractive indices, n, of pure dimethylsulphoxide (DMSO), benzene, toluene, o-xylene, m-xylene, p-xylene and mesitylene, and those of their 54 binary mixtures, with DMSO as common component, covering the whole composition range have been measured at 298.15, 303.15, 308.15, 313.15, and 318.15 K. From the experimental data, the deviations in viscosity, Δη and deviations in molar refraction, ΔRm have been calculated. The variation of these parameters with composition and temperature of the mixtures have been discussed in terms of molecular interaction in these mixtures. The effect of the number and position of the methyl groups in these aromatic hydrocarbons on molecular interactions in these mixtures has also been discussed. The free energies, ΔG*, enthalpies, ΔH* and entropies, ΔS* of activation of viscous flow have also been obtained by using Eyring viscosity equation. The ΔH* values were found independent of temperature. The dependence of these thermodynamic parameters on composition of the mixtures has been discussed. Further, the viscosities and refractive indices of these binary mixtures were calculated theoretically from pure component data by using various empirical and semi-empirical relations and the results were compared with the experimental findings.

Measurements of the Properties of Binary Mixtures of Dimethylsulphoxide (DMSO) with 1-Alkanols (C4, C6, C7) at 303.15 K

This paper presents experimental data for densities, ρ, ultrasonic velocities, u, and refractive indices, n, of pure dimethylsulphoxide (DMSO), 1-butanol, 1-hexanol, 1-heptanol, and their binary mixtures, with DMSO as a common component, over the whole composition range at 303.15 K. The molar refraction, Rm, molecular association, MA, excess molar volume, VE, and deviation in isentropic compressibility, ΔKs, were calculated from the experimental data. The apparent molar volume, Vϕ,2, and apparent molar isentropic compressibility, Kϕ,2, of alkanols in DMSO were also calculated. The values of Vϕ,2 and Kϕ,2 were used to estimate the partial molar volume, \(\bar{V}^{0}_{\phi,2}\), and partial molar isentropic compressibility, \(\bar{K}^{0}_{\phi,2}\), of alkanols in DMSO at infinite dilution. The changes in these parameters with composition and the size of the alkyl chain length in the alkanol molecule are discussed with reference to the nature of interactions between component molecules. Excess molar volumes have also been estimated from measurements of refractive indices

Microscopic structure of liquid dimethyl sulphoxide and its electrolyte solutions: molecular dynamics simulations

Molecular dynamics (MD) simulations of pure dimethyl sulphoxide (DMSO) and solutions of Na+, Ca2+, Cl−, NaCl and CaCl2 in DMSO have been performed at 298.15 K and 398.15 K in NVT ensembles by using a four-interaction-site model of DMSO and reaction field method for Coulombic interactions. The structure of solvent, ion-solvation shells and ion-pairs have been analysed by employing a concept of coordination centres and characteristic vectors of the solvent molecule. Results are given for atom-atom (corresponding to DMSO), ion-atom and ion-ion radial distribution functions (RDFs), orientation of the DMSO molecules and their geometrical arrangements in the first solvation shells of the ions (Na+, Ca2+, Cl−). A preferential formation of cyclic dimers with antiparallel alignment between dipole moments of nearest-neighbour molecules in the pure solvent is found. Geometrical models of the first coordination shells of the ions in ‘infinitely dilute solutions’ are proposed. Ion-ion RDFs in NaCl-DMSO and CaCl2-DMSO solutions reveal the presence of both solvent separated (SSIP) and contact (CIP) ion pairs. The structures of the solvation shells of such ion pairs are also discussed.

Evidence of interaction between agarose and guar gum from changes in network response to solvent pertubation

Comparative investigation has been carried out on the gel setting temperatures and mechanical properties of agarose gels of several concentrations and of 1:1 agarose-guar gum gels of 1% total polymer concentration. In order to investigate the origin of the synergistic interactions observed, the 1% gels were submitted to immersion tests in ethyl alcohol and in dimethyl sulphoxide-water solutions. Weight changes were observed and the mechanical properties of the resulting gels revealed distinguishing characteristics between the two systems. The solid state 13C NMR spectrum of 1:1 agarose-guar gum gel after immersion in pure dimethyl sulphoxide corroborates the role of guar gum in retaining the network, despite dissolution of a large quantity of agarose. Transmission electron microscopy (TEM) was used to image the supramolecular structure of agarose, guar gum and agarose-guar gum systems. Artefacts were observed for pure agarose and guar gum as a result of the procedure used for sample preparation. Nevertheless, the connectivity expected for a tridimensional network was observed in the agarose domains of the mixed gel and attributed to the stabilizing effect of guar gum.

Nereis virens (Annelida: Polychaeta) is not an adequate sentinel species to assess the genotoxic risk (comet assay) of PAH exposure to the environment.

Polychaetes, because of their bioturbation capacity, play an important role in the distribution of anthropogenic contaminants (including polycyclic aromatic hydrocarbons [PAHs]) throughout the sediments. In this work the use of Nereis virens (Annelida: Polychaeta) as a bioindicator to assess the genotoxic risk of PAH exposure for the environment was evaluated. For this purpose the alkaline single cell gel electrophoresis [comet] assay was applied on the coelomocytes of in vivo exposed Nereis virens. Benzo[a]pyrene (B[a]P) was chosen because it is classified by the IARC (International Agency for Research on Cancer) as "probably carcinogenic to humans" and because its mechanisms of action are well-known. Nereis virens was exposed to B[a]P in concentrations of 0.3, 0.6, 10, 20, 35 and 45 mg/ml by an intracoelomic injection of B[a]P (20 microliters) dissolved in dimethyl sulphoxide (DMSO). A solvent control with DMSO, a positive control with ethyl methane sulphonate (EMS) (12.1 mg/ml) and a negative control were included in each experiment. For each treatment four animals were analysed. After 1 hr treatment coelomocytes were harvested by puncturing the coelomic cavity with a sharpened Pasteur pipette, mixed with 0.5% low melting point agarose and sandwiched between two other gel layers. Ethidium bromide stained nuclei were analysed for tail length and tail moment. 12.1 mg/ml EMS, pure DMSO (98.9%) and B[a]P in all tested concentrations induced a statistically significant increase of DNA single strand breaks in the comet assay. The effect of B[a]P, however, was only at the highest concentration (45 mg/ml) significantly stronger than the effect of DMSO alone. Although a relatively large heterogeneity in the results could be observed, these experiments clearly showed that Nereis virens is not suited as a sentinel species for the assessment of the genotoxic risk of PAH exposure because this species seems to be very resistant to benzo[a]pyrene.

Nereis virens (Annelida: Polychaeta) is not an adequate sentinel species to assess the genotoxic risk (comet assay) of PAH exposure to the environment

Polychaetes, because of their bioturbation capacity, play an important role in the distribution of anthropogenic contaminants (including polycyclic aromatic hydrocarbons [PAHs]) throughout the sediments. In this work the use of Nereis virens (Annelida: Polychaeta) as a bioindicator to assess the genotoxic risk of PAH exposure for the environment was evaluated. For this purpose the alkaline single cell gel electrophoresis [comet] assay was applied on the coelomocytes of in vivo exposed Nereis virens. Benzo[a]pyrene (B[a]P) was chosen because it is classified by the IARC (International Agency for Research on Cancer) as "probably carcinogenic to humans" and because its mechanisms of action are well-known. Nereis virens was exposed to B[a]P in concentrations of 0.3, 0.6, 10, 20, 35 and 45 mg/ml by an intracoelomic injection of B[a]P (20 microliters) dissolved in dimethyl sulphoxide (DMSO). A solvent control with DMSO, a positive control with ethyl methane sulphonate (EMS) (12.1 mg/ml) and a negative control were included in each experiment. For each treatment four animals were analysed. After 1 hr treatment coelomocytes were harvested by puncturing the coelomic cavity with a sharpened Pasteur pipette, mixed with 0.5% low melting point agarose and sandwiched between two other gel layers. Ethidium bromide stained nuclei were analysed for tail length and tail moment. 12.1 mg/ml EMS, pure DMSO (98.9%) and B[a]P in all tested concentrations induced a statistically significant increase of DNA single strand breaks in the comet assay. The effect of B[a]P, however, was only at the highest concentration (45 mg/ml) significantly stronger than the effect of DMSO alone. Although a relatively large heterogeneity in the results could be observed, these experiments clearly showed that Nereis virens is not suited as a sentinel species for the assessment of the genotoxic risk of PAH exposure because this species seems to be very resistant to benzo[a]pyrene.

Beware of proteins in DMSO

The effect on the secondary structure of representative α-helical, β-sheet and disordered proteins by varying concentrations of dimethyl sulphoxide (DMSO) in 2H 2O has been investigated by Fourier transform infrared spectroscopy. Significant perturbations of protein secondary structure are induced by DMSO and DMSO/ 2H 2O mixtures. For highly structured proteins, such as myoglobin and concanavalin A, the infrared spectra point to a progressive destabilisation of the secondary structure until at moderate DMSO concentrations (around 0.33 mol fraction) intermolecular β-sheet formation and aggregation are induced, as indicated by the appearance of a strong band at 1621 cm −1. This is a direct consequence of the disruption of intramolecular peptide group interactions by DMSO (partial unfolding). At higher DMSO concentrations (above 0.75 mol fraction), such aggregates are dissociated by disruption of the intermolecular CO… 2H-N deuterium bonds. The presence of a single amide I band at 1662 cm −1 corresponding to free amide CO groups indicates that at high concentrations and in pure DMSO the proteins are completely unfolded, lacking any secondary structure. While low concentrations of DMSO showed no detectable effect upon the gross secondary structure of myoglobin and concanavalin A, the thermal stability of both proteins was markedly reduced. In α-casein, a highly unstructured protein, the situation is one of direct competition. The amide I maximum in 2H 2O, at 1645 cm −1, is typical of unordered proteins with CO groups deuterium-bonded predominantly to 2H 2O. Addition of DMSO disrupts such interactions by competing with the peptide CO group for the deuterium bond donor capacity of the 2H 2O, and so progressively increases the amide I maximum until it stabilizes at 1663 cm −1, a position indicative of free CO groups.

Interaction of dimethyl sulphoxide with chloranil by ESR and optical methods

The molecular charge-transfer absorption bands have been observed in solution of dimethyl sulphoxide (DMSO) and tetrachloro-p-benzoquinone (chloranil) in chloroform and cyclohexanone. The stability constant, the thermodynamic parameter of the complex and the extinction co-efficient of CT bands at 350 nm in chloroform and 360 nm in cylohexanone have been estimated on the assumption of the 1:1 complex formation. Detection of ESR signal of the solution of chloranil in pure DMSO (g ≈ 2) indicates the formation of chloranil radical anion, the precursor being the charge-transfer complex, which dissociates partly in high dielectric constant DMSO.

Determination by ion exchange of the complexation of europium by a stibine, an arsine, and perchlorate in anhydrous aprotic organic solvents

It has been shown for the first time that a lanthanide (Eu3+) can be complexed by a stibine or a neutral arsine. In benzonitrile (PhCN) as the solvent the predominant complexes were (1)[Eu(Ph3Sb)z]3+ with triphenylstibine at a concentration of 0.003 mol dm–3, (2)[Eu(Ph3As)y(ClO4]2+ with triphenylarsine at 0.07 mol dm–3, and (3)[Eu(Ph3As)x(ClO4)2]+ with Ph3As at 0.003 mol dm–3. In pure PhCN, neutral and/or negative complexes of Eu3 + with ClO4– were found, but in pure dimethyl sulphoxide no complexation was detected. All complexes were determined by an ion-exchange technique employing the macroreticular resin Amberlyst 15.

Medium-range order in liquids: Interactions in supercooled electrolyte solutions system Zn(NO3)2 - DMSO)

X-ray analysis of supercooled electrolyte solutions in the system dimethylsulphoxide (DMSO) - Zn(NO3)2 was made for pure DMSO (chemical formula (CH3)2 S=O) and for compositions characterized by molar ratios R = DMSO/Zn(NO3)2 = 6, 3 and 2. The X-ray scattering picture in the whole composition interval is dominated by a massive peak which shifts with increasing Zn2+ content from 1.44 Å−1 (for pure DMSO) to 1.54 Å−1 (for R=2) and describes a decrease of intermolecular distances in this system from 5.4 to 5.0 Å. Clusters are identified as DMSO molecules which decrease their intermolecular distance as a result of a four-fold solvation of the Zn2+ ion in DMSO. This model is supported by the analysis of corresponding radial electron density distribution curves which exhibit with increasing Zn2+ content a development of a ZnO coordination sphere located at 2.3 Å. The proposed structural model helps also in the understanding of the anomalous behaviour of the viscosity vs composition dependence.

The Henry's law constant of dimethyl sulphoxide

Abstract The partial pressure of dimethylsulphoxide (DMSO) was measured above the pure liquid and aqueous DMSO solutions at various temperatures between 7 and 35°C. These measurements yielded an expression for the dimensioned Henry's law constant of DMSO as a function of temperature: KH = 136600–1570 T°C (mol kg‐1atm‐1. The Henry's Law constant at 15 °C was measured as 1.17 ±0.02 × 105 mol kg‐1 atm‐1. Despite the solubility of DMSO in water, this result suggests that the solubility is too low for atmospheric DMSO to partition predominantly into the aqueous aerosol.

Application of headspace gas chromatography for the investigation of kinetics of oxidation of thiols by dimethyl sulphoxide in aqueous medium

The kinetics of the oxidation of thiols by dimethyl sulphoxide in the presence of water were investigated using headspace gas chromatography (HSGC). The rate constants for this reaction were determined and found to be considerably larger than those for oxidation in pure dimethyl sulphoxide. The applicability of HSGC to studies of reaction kinetics was examined. It was established that HSGC can be employed for the determination of rate constants provided that the rate of the equilibration process is high compared with the reaction rate. The relative standard deviations indicate that the precision of the determination of rate constants by HSGC is good.

Electrochemical characteristics of the complex formed by TiCl 4 and dimethyl sulphoxide

Conductance and cryoscopic measurements were carried out on solutions of TiCl 4(DMSO) 2 in pure dimethyl sulphoxide (DMSO). The results obtained indicate that the complex dissociates according to the reaction TiCl 4(DMSO) 2 = TiCl(DMSO) 2 3+ + 3Cl − and that simultaneously chemical transformation takes place to a small extent. Electrochemical tests performed with platinum electrodes show that this solution allows electrochemical reduction of titanium to form compact coatings.

Thermodynamic properties for transfer of electrolytes from water to dimethylsulphoxide and to dimethylsulphoxide + water mixtures

The free energies, enthalpies and entropies of transfer of a variety of electrolytes, including alkali metal halides, silver halides, tetraphenylarsonium and tetraphenylboride salts, from water to dimethylsulphoxide and dimethylsulphoxide + water mixtures have been measured. The values show a simple monotonic variation with solvent composition, in marked contrast to those in the acetonitrile + water and dimethylsulphoxide + propylene carbonate systems. The results suggest that strong preferential solvation of the ions does not take place in the mixtures, in agreement with earlier n.m.r. studies, despite significant differences in the interactions of pure dimethylsulphoxide and pure water with the electrolytes. The lack of preferential solvation in the mixtures is discussed in terms of the effect of the strong interactions between water and dimethylsulphoxide on the ion–solvent interactions.