Dimethyl Sulfoxide Water Research Articles

Screening of medicinal plants for antibacterial principles against β-lactam resistant strains

Sir, In the present work, screening of different plants used in Indian folk medicine was carried out for the detection of antibacterial principles against β-lactam resistant bacterial strains, which may be useful as new drugs to combat deadly infections. [1,2] Twenty-nine plants were tested for their antibacterial activities. The collected plants were washed and shade dried. Twenty grams of the plant material was macerated and extracted with hexane, diethyl ether, methanol and water using a Soxhlet apparatus, based on their polarity. The dry fractions were made into a suspension using 10% dimethylsulfoxide (DMSO) in distilled water. The concentration of the extracts was adjusted to 1 mg/mL in each case. The antibacterial properties of the plant extracts were evaluated by employing the disc diffusion method. Evaluation of the synergistic effect of the plant extracts with β-lactam antibiotics was done according to the method of Muroi and Kubo. [3] The diethyl ether extracts of Holoptelea integrifolia, Pongamea pinnata, Spondias dulci and methanol extract of Syzygium samarengense showed good synergistic effects with amoxicillin and ampicillin against Staphylococcus aureus in disc diffusion method. They were further fractionated by silica gel chromatography to identify the antibacterial compound. The structure of the compounds in the active fractions was elucidated by spectroscopic analysis methods such as gas chromatography–mass spectrometry (GC–MS), Fourier Transform Infrared Spectroscopy (FTIR) and 1H nuclear magnetic resonance (NMR) analysis [Table 1]. The diethyl ether extracts exhibited a higher degree of antimicrobial activity compared to methanol extract. The extracts of H. integrifolia, P. pinnata, S. dulci and S. samarengense showed an increase in the growth inhibition zone in the presence of amoxicillin. This indicates that the plants contain compounds which can enhance the effect of amoxicillin. Other plant extracts did not show any noticeable synergistic effect. The synergistic effect of plant extracts against resistant bacterial strains may lead to a new choice for the treatment of infectious diseases. [4] The active principle can be used along with commonly used antibiotics. Data from the literature as well as from our studies reveal a great potential of plants in this direction.

The Influence of Casting Machine Speed in Cellulose Acetate Membrane Preparation

Membranes are being increasingly used as a valuable separation tool in laboratory as well as in industrial processes. Continual development of new membrane materials is crucial to sustain and expand the growing interest in this technology and modern polymer chemistry is highly proficient in tailoring polymers with desired properties such as increased mechanical, thermal and chemical stability. Cellulose acetate (CA) is one of the membrane polymers that has been used for aqueous based separation and used as both reverses osmosis (RO) and ultrafiltration (UF) membranes. This paper presents investigation of influence of casting machine speed in membrane preparation. CA is used in this study. That was CA-398-30 with average acetyl content 39.8 wt %. Non solvent used is water and the solvent is 99.7 % organic Dimethyl Sulfoxide (DMSO). The homogenous CA/DMSO solutions were prepared by dissolving CA in DMSO solvent. The CA concentration were varied 13 and 16 % while casting solution speed were varied from 20 to 80 mm/sec with distance cutting machine were fixed at 14 cm. In addition, non solvent in coagulation bath also were varied by 100 % water and 10 % DMSO in water. The results of this experiment describe effect of casting machine speed to water permeability. The effect of CA concentration to water permeability shows the adversative result between 13 and 16 % CA in 100 non solvent water. The similar result also observed in 10 % DMSO in water.

Behavior of lignin in a dimethylsulfoxide—water mixture

The hydrodynamic behavior of lignin in a dimethylsulfoxide-water mixture have been studied at the temperature range of 20–60°C and at a water content from 0 to 30%. The rise of temperature was shown to deteriorate the quality of the solvent; i.e., the system under investigation belongs to systems with a lower critical solution temperature. The dimension of lignin particles in the mixed solvent decreases with an increasing proportion of water in the system.

Structures and Intermolecular Interactions in Dimethyl Sulfoxide-Water System Studied by All-atom Molecular Simulations

An all-atom dimethyl sulfoxide (DMSO) and water model have been used for molecular dynamics simulation. The NMR and IR spectra are also performed to study the structures and interactions in the DMSO-water system. And there are traditional strong hydrogen bonds and weak C-H ··· O contacts existing in the mixtures according to the analysis of the radial distribution functions. The insight structures in the DMSO-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Interestingly, the molar fraction of DMSO 0.35 is found to be a special concentration by the network. It is the transitional region which is from the water rich region to the DMSO rich region. The stable aggregates of (DMSO)m·S=O···HW-OW·(H2O)n might play a key role in this region. Moreover, the simulation is compared with the chemical shifts in NMR and wavenumbers in IR with concentration dependence. And the statistical results of the average number hydrogen bonds in the MD simulations are in agreement with the experiment data in NMR and IR spectra.

Synthesis and structural characterization of a new polymeric zinc(II) complex with thiophene-2-carboxylic acid

A new polymeric zinc(II) complex with thiophene-2-carboxylic acid (α-tpc) of composition [Zn2(C20H12O8S4)] n was obtained and structurally characterized by X-ray diffraction, thermal analysis, nuclear magnetic resonance (NMR), and infrared spectroscopies. Upfield shift in the 1H-NMR spectrum is explained by the crystalline structure, which shows the thiophene rings overlapping each other in parallel pairs. The compound crystallizes in the monoclinic system, space group P21/c, with a = 9.7074(4) Å, b = 13.5227(3) Å, c = 18.9735(7) Å, β = 95.797(10)°, and Z = 4. Three α-tpc groups bridge between two Zn(II) ions through oxygens and the fourth one bridges between one of these ions and the third one, symmetry related by a twofold screw axis. This arrangement gives rise to infinite chains along the crystallographic a direction. The metal atoms display an approximate tetrahedral configuration. The complex is insoluble in water, ethanol, and acetone, but soluble in dimethyl sulfoxide.

Multicomponent Interdiffusion and Self-Diffusion of the Cationic Poly{[9,9-bis(6′-N,N,N-trimethylammonium)hexyl]fluorene-phenylene} Dibromide in a Dimethyl Sulfoxide + Water Solution

The diffusion behavior of the conjugated polyelectrolyte poly{[9,9-bis(6′-N,N,N-trimethylammonium)hexyl]fluorene-phenylene} bromide (HTMA-PFP) with different molecular weights has been studied in dimethyl sulfoxide (DMSO) + water solutions. Samples of HTMA-PFP with various molecular weights were obtained by synthesis of poly[9,9-bis(6′-bromohexyl)fluorene-phenylene] via a Suzuki coupling reaction, characterized by size exclusion chromatography (SEC), and quaternized with trimethylamine. Multicomponent chemical interdiffusion coefficients (mutual diffusion coefficients) were determined for solutions of HTMA-PFP and DMSO in water using the Taylor dispersion method. The results suggest specific interactions between the DMSO and the polymer. In addition, these systems were studied by pulse-field gradient nuclear magnetic resonance spectroscopy (PFG-NMR), and the corresponding self-diffusion coefficients were obtained. These were modeled using the Kirkwood−Riseman model, and a good fit to the observed behavior was obtained using literature data for molecular dimensions.

The gibbs energies of transfer of glycine and glycinate ion from water into water-dimethyl sulfoxide mixtures

The Gibbs energies of transfer of glycine from water into water-dimethyl sulfoxide mixtures were determined at 298 K by measurements of substance distribution between immiscible phases. The enthalpy and entropy contributions to ΔG° of glycinate ion resolvation in water-dimethyl sulfoxide solvents were analyzed. The destabilization of glycinate ion was found to be largely determined by the energy component mainly. There was a correlation between the enthalpies of transfer of glycinate ion and the autoprotolysis constants of water-dimethyl sulfoxide solvents. The suggestion was made that changes in the Gibbs energies of glycinate ion resolvation in water-dimethyl sulfoxide and water-alcohol mixtures were largely determined by changes in the acid-base properties of the solvents.

General Toxicity and Genotoxicity of Nodularia Moravica (Cyanoprokaryota, Nostocales)

ABSTRACTGeneral toxicity and genotoxicity of cyanoprokaryote Nodularia moravica was investigated on the base of Allium root meristem in vivo test system. Seeds sprouted in dechlorinated tap water were analyzed as a control sample. Seeds sprouted in the water-Dimethyl sulfoxide (9:1, v:v) extract, diluted 50 and 100 times (D1–797 and D2-797, respectively) were used as test samples. It was found that different concentrations of dilutions of the initial extract of cyanoprokaryote Nodularia moravica induced damages such as micronuclei (MNi), fragments, anaphasic and telophasic bridges and laggards with higher total frequency than in the control. Germination percentage and root length were found to be in positive correlation with percentage of chromosome aberrations and depend on the extract concentration. It was concluded that Nodularia moravica extract in water-DMSO solution induces general and genotoxycity in Allium cepa root meristem cells. There were not found data about cytotoxicity.

Influence of confinement by smooth and rough walls on particle dynamics in dense hard-sphere suspensions

We used video microscopy and particle tracking to study the dynamics of confined hard-sphere suspensions. Our fluids consisted of 1.1-microm-diameter silica spheres suspended at volume fractions of 0.33-0.42 in water-dimethyl sulfoxide. Suspensions were confined in a quasiparallel geometry between two glass surfaces: a millimeter-sized rough sphere and a smooth flat wall. First, as the separation distance (H) is decreased from 18 to 1 particle diameter, a transition takes place from a subdiffusive behavior (as in bulk) at large H, to completely caged particle dynamics at small H. These changes are accompanied by a strong decrease in the amplitude of the mean-square displacement (MSD) in the horizontal plane parallel to the confining surfaces. In contrast, the global volume fraction essentially remains constant when H is decreased. Second, measuring the MSD as a function of distance from the confining walls, we found that the MSD is not spatially uniform but smaller close to the walls. This effect is the strongest near the smooth wall where layering takes place. Although confinement also induces local variations in volume fraction, the spatial variations in MSD can be attributed only partially to this effect. The changes in MSD are predominantly a direct effect of the confining surfaces. Hence, both the wall roughness and the separation distance (H) influence the dynamics in confined geometries.

A simple and efficient anionic chromogenic chemosensor based on 2,4-dinitrodiphenylamine in dimethyl sulfoxide and in dimethyl sulfoxide–water mixtures

Solutions of 2,4-dinitrodiphenylamine ( 1) in dimethylsulfoxide (DMSO) are colorless but upon deprotonation they become red. Addition of various anionic species (HSO 4 −, H 2PO 4 −, NO 3 −, CN −, CH 3COO −, F −, Cl −, Br −, and I −) to solutions of 1 revealed that only CN −, F −, CH 3COO −, and H 2PO 4 − led to the appearance of the red color in solution. The presence of increasing amounts of water in solutions containing 1 made it progressively selective toward CN − and the system with the addition of 4.3% (v/v) of water was highly selective for CN − among all anions studied. The experimental data collected indicated that proton transfer from 1 to the anion occurs, and a model was used to explain the experimental results, which considers two 1:anion stoichiometries, 1:1 and 1:2. For the latter, the data suggest that the anion forms firstly a hydrogen-bonded complex with a second anion equivalent necessary for the abstraction of the proton, with the formation of a [HA 2] − complex. The study performed here demonstrates the important role of the environment of the anion and 1 for the efficiency of the chromogenic chemosensor. Besides the different affinities of each anion for water, the solvation of both the anion and 1 is responsible for reducing the interaction between these species. In small amounts, water or hydrogen-bonded DMSO–water complexes are able to stabilize the conjugated base of 1 through hydrogen bonding, making 1 more acidic, which explains the change from 1:1 and 1:2 toward 1:1 1:anion stoichiometry upon addition of water. In addition, water is able to solvate the anion and also 1, which hinders the formation of 1:1 hydrogen-bonded 1:anion complexes prior to the abstraction of the proton.

Phenol sorption on cellulose from binary aqueous–organic mixtures

Phenol–water–dimethylsulfoxide–cellulose and phenol–water–acetonitrile–cellulose systems are studied. The sorption isotherms of the components on cellulose from water–organic mixtures are obtained, and immersion heats of cellulose in water–dimethylsulfoxide and water–acetonitril mixtures and heats of phenol dissolution in the above-mentioned mixtures are measured. It is shown that sorption of the components of binary water–organic mixtures and phenol sorption from these mixtures on cellulose are due to the intermolecular interactions in the water–dimethylsulfoxide and water–acetonitril solutions.

The effect of carbonyl carbon atom replacement in acetone molecule (ACN) by sulfur atom (DMSO): Part II. Thermodynamic functions of complex formation of crown ethers with Na+ in mixed solvents

The thermodynamic functions of complex formation of benzo-15-crown-5 ether (B15C5) and sodium cation (Na+) in acetone–water mixtures at 298.15 K have been calculated. The equilibrium constants of B15C5/Na+ complex formation have been determined by conductivity measurements. The enthalpic effect of complex formation has been measured by the calorimetric method. The complexes are enthalpy-stabilized but entropy-destabilized in acetone–water mixtures. The effects of hydrophobic hydration, preferential solvation of B15C5 by a molecule of water and acetone, respectively and the solvation of Na+ on the complex formation processes have been discussed. The calculated thermodynamic functions of B15C5/Na+ complex formation and the effect of benzene ring on the complex formation have been compared with analogous data obtained in dimethylsulfoxide–water mixtures. The effect of carbonyl atom replacement in acetone molecule by sulphur atom (DMSO molecule) on the thermodynamic functions of complex formation has been analysed.

Polarizable force field for water-dimethyl sulfoxide systems: II properties of mixtures by molecular dynamics simulations

A consistent polarizable force field for dimethyl sulfoxide (DMSO) with the TIP4P-FQ (fluctuating charge) water model was developed to explore the properties of pure DMSO liquid and the DMSO–water mixtures in this work. The DMSO–water mixtures at a range of concentrations of DMSO were selected to explore the unusual properties of them at 298 K and 1 atm. The radial distribution functions of neat DMSO liquid from the simulations with the current model are more excellently consistent with data from a neutron diffraction experiment than the additive models. More reasonable results for the static (radial distribution function, density, excess volume, heat of vaporization and mixing heat) and dynamic properties (lifetime of hydrogen bond, reorientational relaxation time and self-diffusion coefficient) of the mixtures over a range of composition were obtained by the current model and parameters than the previous additive models. The interaction between methyl hydrogen and water oxygen is mainly characteristic of weak hydrogen bond interactions and weaker than that between methyl hydrogen and DMSO oxygen. The hydrated methyl is more preferred than the methyl–methyl association. The enhanced structure of water and DMSO within the first shell is due to decrease of the water number in the hydrogen bond chain of DMSO– nwater–DMSO. The distributions and fluctuations of dipole moment can well reflect the polarization effect and the microscopic configures in the mixtures. The static dielectric permittivities of the DMSO–water mixtures are in well agreement with the corresponding experimental values.

Investigation of the Soret effect in aqueous and non-aqueous mixtures by the thermal lens technique

In the present work we investigate the thermal diffusion behavior of three different binary mixtures with a thermal lens (TL) setup. In the setup used in this study we avoid the addition of a dye for systems, such as aqueous mixtures, with a weak absorption band at a wavelength of 980 nm. In some aqueous systems with a complex phase behavior the addition of dye significantly affects the apparent measured thermal diffusion properties. The studied systems are dimethylsulfoxide (DMSO) in water, the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate (EMIES) in butanol and a non-ionic surfactant hexaethylene glycol monododecyl ether (C(12)E(6)) in water. The Soret coefficients of the selected systems cover a range of two orders of magnitude. For DMSO in water with a very low Soret coefficient of the order of S(T) approximately 10(-3) K(-1) we find for a low DMSO content (c = 0.33) a reasonable agreement with previous measurements, while the weak thermal lens signal for the DMSO-rich mixture (c = 0.87) leads to 20% too large Soret coefficients with an uncertainty of more than 30%. Secondly we studied a liquid salt 1-ethyl-3-methylimidazolium ethylsulfate (EMIES) in butanol with a roughly ten times higher Soret coefficient of S(T) approximately 10(-2) K(-1). For this system we performed additional measurements with another experimental technique, the classical thermal diffusion forced Rayleigh scattering (TDFRS), which requires the addition of a small amount of dye to increase the absorption. In the entire investigated concentration range the results obtained with the TL and classical TDFRS technique agree within the error bars. As a third system we studied a non-ionic surfactant hexaethylene glycol monododecyl ether (C(12)E(6)) in water with a Soret coefficient of the order of S(T) approximately 10(-1) K(-1). For this system we find good agreement with previous measurements. We conclude that the TL technique is a reliable method for systems with a strong optical contrast and fairly large Soret coefficient of the order of S(T) approximately 10(-2) K(-1).

The compressibility of water-dimethyl sulfoxide mixtures over the temperature and pressure ranges 278–323.15 K and 1–1000 bar

The compressibility coefficients of water-dimethyl sulfoxide (DMSO) binary liquid mixtures were measured over the temperature range 278–323.15 K at pressures from atmospheric to 1000 bar. At these state parameters, the partial molar volumes and partial molar compressibility coefficients \( \bar k_1 \) and \( \bar k_2 \) of water and DMSO were calculated. The dependences of the compressibility coefficients of mixtures on mixture composition passed a minimum. The minimum shifted to lower DMSO concentrations as the temperature increased. The dependences contained the inversion region where the k value was independent of pressure. The limiting molar partial compressibility coefficient of DMSO \( \bar k_2 \) was negative at 278.15 K and increased as the temperature grew.

Protein–polysaccharide viscoelastic matrices: synergic effects of amylose on lysozyme physical gelation in aqueous dimethylsulfoxide

A synergic effect of amylose on rheological characteristics of lysozyme physical gels evolved out of dimethylsulfoxide–water was verified and analyzed. The dynamics of the gels were experimentally approached by oscillatory rheology. The synergic effect was characterized by a decrease in the threshold DMSO volume fraction required for lysozyme gelation, and by a significant strengthening of the gel structure at over-critical solvent and protein concentrations. Drastic changes in the relaxation and creep curve patterns for systems in the presence of amylose were verified. Complex viscosity dependence on temperature was found to conform to an Arrhenius-like equation, allowing the determination of an activation energy term (Ea, apparent) for discrimination of gel rigidity. A dilatant effect was found to be induced by temperature on the flow behavior of lysozyme dispersions in DMSO–H2O in sub-critical conditions for gelation, which was greatly intensified by the presence of amylose in the samples. That transition was interpreted as reflecting a change from a predominant colloidal flow regime, where globular components are the prevailing structural elements, to a mainly fibrillar, polymeric flow behavior.

Polarizable force field for water–dimethyl sulfoxide systems: I Parameterization and gas phase test

A new polarizable, flexible force field for dimethyl sulfoxide (DMSO) was developed to study the properties of DMSO–Water systems. The charge-related parameters of DMSO molecule (atomic valence-state hardness and negativity) were well derived from ab initio (B3LYP/6-311++G (2 d, p)) charge responses. The perturbed external field were generated by the “massless TIP4P-FQ water” in order to be consistent with TIP4P-FQ water force field. The polarized behaviors of DMSO molecule under the external fields in gas phase can be well described by the current model and parameters. The DMSO-FQ model can provide a reasonable representation of the induced dipole for DMSO molecule in DMSO–water clusters. The energetic and structural properties of DMSO–water clusters in gas-phase have been studied by DFT and the polarizable force field developed here. The hydrogen bond lengths, binding energies and many-body energies of a series of DMSO–Water clusters calculated by the high level ab initio methods are well reproduced by the current model.

Evaluation of activity of the crude ethanolic extract of Magonia pubescens St. Hil (Sapindaceae) against larvae of the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae)

The acaricidal potential of the crude ethanolic extract (c.e.e.) of the stem peel of Magonia pubescens was evaluated against larvae of Rhipicephalus (Boophilus) microplus. The larvae were placed in filter paper envelopes impregnated with different concentrations of c.e.e., dissolved in dimethylsulfoxide (DMSO) and distilled water for determination of lethal concentrations (LC). The following treatments were used: 1. Envelopes of dry filter paper; 2. Envelopes of filter paper moistened with distilled water; 3. Envelopes of filter paper moistened with a solution of DMSO in distilled water; and 4. Envelopes moistened with 2 mL of each concentration of the c.e.e. to be tested. The bioassays were carried out in quadruplicate at 27°±1° C and RH e"80% and 12h light. Mortality was observed after 48 h, LC50 and LC99 values of 365 and 4,000 ppm being obtained. There was no significant mortality in larvae exposed to the first three treatments (p < 0.05).

Development of a liquid chromatographic assay for an anti-HIV tablet containing lamivudine, zidovudine and TMC278.HCL

A liquid chromatographic method was developed to analyse a tablet containing three anti-human immunodeficiency virus (HIV) compounds: lamivudine, zidovudine and a compound with the code name TMC278.HCl. Due to the presence of UV absorbing chromophores in the three active components, a single LC method with UV detection was developed. A Hypersil BDS C 18 column was used as stationary phase and the assay was performed with gradient elution using mobile phases containing acetonitrile, 0.2 M potassium dihydrogen phosphate and water. The sample pretreatment is performed by treating the formulation with dimethyl sulfoxide–water (1:1) followed by filtration. After method development, the influence of the different chromatographic parameters on the separation, the interference of other active compounds and excipients, the repeatability and the linearity were investigated. The method was shown to be robust, selective, linear and repeatable. Finally, the content of the compounds in the tablet was determined.

Sorption of phenol on cellulose from binary aqueous-organic mixtures

Sorption of phenol on cellulose from water-dimethyl sulfoxide and water-acetonitrile mixtures was studied. Different shape of the isotherms of phenol sorption form these mixtures is due to different character of phenol solvation in different concentration regions of water-dimethyl sulfoxide and water-acetonitrile mixtures.