From DMSO

Solvent for Electrolytic Reactions. Dimethyl sulfoxide has been widely used as a solvent for polarographic studies and a more negative cathode potential can be used in it than in water. In DMSO, cations can be successfully reduced to metals that react with water. Thus, the following metals have been electrodeposited from their salts in DMSO cerium, actinides, iron, nickel, cobalt, and manganese as amorphous deposits zinc, cadmium, tin, and bismuth as crystalline deposits and chromium, silver, lead, copper, and titanium (96—103). Generally, no metal less noble than zinc can be deposited from DMSO. 

On-line changing of solvent from DMSO to H2O for a starch glucan establishing an absolute calibration function characteristics of mass and molar degree of polymerization distribution for a broad distributed starch sample... 

In Fig. 16.32, application of a TSK PW SEC system consisting of a combination of precolumn + PWM + 6000 + 5000 + 4000 + 3000 demonstrates a possibility for analytical purposes to change from DMSO-dissolved glucans to an aqueous solution. An initially DMSO-dissolved potato starch sample was applied to the TSK PW system and because separated with an aqueous... 

Phenoxaphosphine ring-containing poly (1,3,4-oxa-diazoles) were synthesized by cyclodehydration of poly-hydrazides obtained from (BCPO) and aliphatic and aromatic dihydrazines [152]. All these polymers are soluble in formic acid, w-cresol and concentrated H2SO4. The polyhydrazides yield transparent and flexible films when cast from DMSO solution under reduced pressure at 80-100°C. The polyhydrazides exhibit reduced viscosities of 0.24-0.40 dl/g in DMAC. Phenoxaphosphine ring-containing oxadiazole polymers showed little degradation below 400°C. 

The biological activity of the polymers was evaluated in vitro by the ability to stimulate the release of superoxide from DMSO-differentiated HL-60 cells [18-20]. The released superoxide was monitored by the cytochrome C method [21,22]. As shown in Figure 7, when the differen-... 

Since it might be possible that the perturbation of membrane directly stimulated the NADPH-oxidase located on the cell membrane, which is the enzyme for the production of superoxide [24], the possibility was examined by the assay using detergent (Triton X-100) instead of polymers. At 0.001% of Triton X-100, no stimulation of superoxide release from DMSO-differentiated HL-60 cells was observed. At 0.01% of Triton X-100, a... 

Apart from DMSO complexes, others including those with tetramethylene sulphoxide have been increasingly examined, but the account here focuses on DMSO. 

SET from DMSO carbanion to inert free radicals.1057... 

The solution of Agranat s cation [1 ] instantly gave black precipitates of mixed KCIO4 and [l 2 ]. The crude hydrocarbon salt was isolated by recrystallization from DMSO as greenish black needles. 

CH3S(0)CH2)2 is observed indicating that H atoms abstract hydrogen from DMSO to form CH3S(0)CH2 which dimerizes to (CH3S(0)CH2)2- The radical CH3S(0)CH2 is not found in the reaction of OH" with DMSO. ... 

Precipitation of compound from a DMSO stock is an issue of compound solubility in DMSO [14]. However, operationally, most organizations dissolving compounds in DMSO do not encounter problems in the solubilization process. This apparent paradox is explained by the issue of amorphous compounds. The vast majority of compounds solubilized into DMSO stocks are amorphous and inherently more soluble in DMSO (as previously discussed). The vast majority of the same compounds precipitating from DMSO are crystalline and much less soluble in DMSO (as previously discussed). The problem of compounds precipitating from DMSO occurs because so many compounds entering into screening libraries are amorphous. The precipitation of compounds from DMSO would be far less of a problem if screening compounds were entirely crystalline as they were 20 years ago. Quite simply DMSO insoluble crystalline compounds would never have been successfully dissolved in DMSO in the first place. 

If we add a known amount of a compound to our solution, we can use it to quantify the material of interest. This is great except that we may not want to contaminate our material with some other compound. A number of people have looked at using standards that are volatile so that they can be got rid of later (TMS is an example that we have seen published). The problem with this approach is that if the sample is volatile then you need to run it quickly before it disappears. TMS disappears really quickly from DMSO so it is probably not a good idea in this case. TMS also suffers from the fact that it has a long relaxation time so you have to be very careful with your experiment to ensure that you do not saturate the signal. The last major problem with TMS is that it comes at the same part of the spectrum as silicon grease which can be present in samples. Choosing a standard so that it has a short relaxation time, is volatile and comes in a part of the spectrum free of interference is really tricky. In fact, we wouldn t recommend it at all. 

Table X. Amino Acid Compositions of Acid Hydrolyzed Protein Fractions from DMSO and Aqueous Extracts of Pondweed and Water Spinach3...

HA and three different HA esters, supplied by Fidia Advanced Biomaterials SpA (Padua, Italy), were examined. HA esters were prepared by treating a quaternary ammonium salt of HA with an esterifying agent in a suitable aprotic solvent at a controlled temperature as described in detail elsewhere [2]. In this study we analyzed the following esters ethyl ester (HYAFF7), benzyl ester (HYAFFl 1), and dodecyl ester (HYAFF73 Figure 1). The materials used were both films and powders. Films were obtained by a phase inversion process from DMSO solutions as previously described [2,4]. 

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