scholarly journals Reactions of Ozone with 1-(m-Substituted phenylazo)-2-naphthol-6-sulfonic Acids in Aqueous Solutions

1985 ◽  
Vol 58 (9) ◽  
pp. 2526-2530 ◽  
Author(s):  
Yasuo Onari
1969 ◽  
Vol 47 (6) ◽  
pp. 1037-1043 ◽  
Author(s):  
J. W. Purdie

L-Cysteine-D-penicillamine mixed disulfide (CySSPen) was irradiated in aerated and deaerated aqueous solutions with 60Co γ-rays. G values were determined for all products identified after exposure to 10 000 rads. The major products were the sulfinic and sulfonic acids (CySO2H, CySO3H, and PenSO2H), the sulfhydryl derivatives (CySH and PenSH), symmetrical disulfides (CySSCy and PenSSPen), three trisulfides (CySSSCy, CySSSPen, and PenSSSPen), and ammonia. Each half of the disulfide behaved in exactly the same way as the corresponding symmetrical disulfide. Products from the CyS— part of the disulfide were dose rate dependent while products from the PenS— part were independent of dose rate. The reactions proposed for the symmetrical disulfides were adequate to explain radiolysis of the unsymmetrical disulfide.Radiolysis of a mixture of cystine and penicillamine disulfide was examined for comparison with the unsymmetrical disulfide and was found to give very similar results. It was concluded that the free radicals produced from the water attack each half at approximately equal rates.


2010 ◽  
Vol 52 (7) ◽  
pp. 709-714
Author(s):  
N. G. Strokova ◽  
G. A. Vikhoreva ◽  
A. I. Chernukhina ◽  
L. V. Vladimirov ◽  
I. Yu. Shishkina ◽  
...  

2021 ◽  
Vol 20 (2) ◽  
pp. 103-118
Author(s):  
Panayiotis V. Ioannou ◽  
Gerasimos M. Tsivgoulis

Aiming at the preparation of the novel unnatural, non-isosteric sulfonolipids bearing one, two and three acyl groups 8, 9 and 10, their precursors hydroxyl-containing sulfonates have been prepared from a variety of hydroxyl-containing halogenides and epoxides using the Strecker reaction. Thus, the sulfonates 16 and 22 were prepared pure, while the sulfonate 27 could only be prepared as a by-product using 1,4-dibromo-2,3-butanediol 26 and in low yields. For these reactions, probable pathways leading to the isolated or spectroscopically identified products are proposed. Conclusions about the relative nucleophilicity of SO32- compared to AsO33 - (as well as HO- which is present in their aqueous solutions) were drawn based on the yields of the corresponding arsonic acids and sodium sulfonates. The IR (KBr) and 1H NMR (D2O) spectra of sulfonates (and in some cases of their sulfonic acids) are analyzed and discussed.


Author(s):  
K. J. Böhm ◽  
a. E. Unger

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:


Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.


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