Muller adducts

In view of all these arguments we tend to believe that not position 10a, but only position 9a in l/2a-blocked flavins can be the site of nucleophilic attack in the Muller-adducts l/2a RF1-7-OR 133). As for electrophilic attack by O2 in flavohydroquinone, however, position 10a might be worth some consideration, if the following conditions can be met ... 

Only some Lewis acid-base adducts of group 13 trialkyls R3M or trihalides CI3M and transition metal complexes of the type LnFe—E=CR2, (E = P, As) Weber L, Scheffer MH, Stammler HG, Stammler A (1999) Eur J Inorg Chem 1607 (LnW=P) Scheer M, Muller J, Baum G, Haser M (1998) J Chem Soc Chem Commun 1051, have been synthesized and structurally characterized... 

Gamier, R., Rambourg-Schepens, M.O., Muller, A. Hallier, E. (1996) Glutathione transferase activity and formation of macromolecular adducts in two cases of acute methyl bromide poisoning. Occup. environ. Med., 53, 211-215... 

Wurtz coupling catalyst. Muller and Roscheisen1 noted that low yields in the Wurtz coupling of two molecules of a benzyl halide may be because the reaction proceeds in part at least in heterogeneous phase on the surface of the metal. They found that tetraphenyl ethylene forms a disodium adduct which is sufficiently soluble in THF or glyme for the efficient coupling of 2 moles of benzyl chloride ... 

Muller, M., Belas, F.J., Blair, I.A., and Guengerich, F.P. (1997) Analysis of l,]V2-ethenoguanine and 5,6,7,9-tetrahydro-7-hydroxy-9-oxoimidazo[l,2-a]purine in DNA treated with 2-chlorooxirane by high performance liquid chromatography/electro-spray mass spectrometry and comparison of amounts to other DNA adducts. Chem. Res. Toxicol, 10, 242-247. 

A direct comparison of the rates and equilibria associated with O and C attack by phenoxide on TNB is not currently available. However, in the case of 2,4,6-trinitroanisole (TNA), rate data for O attack by phenoxide can be compared with that by methoxide (32). Using fast reaction techniques (stopped flow and T jump), Bernasconi and Muller (32) found that the reaction of TNA with C6H50 in (CH3)2SO-water media gives rise in a rapid process to the O-bonded 1,1 phenoxide adduct as a transient species, which is then converted to the 1,3 hydroxide adduct of TNA in a slower process. The data showed that C6H50 attack (H20) is faster than CH30 attack (CH3OH) by a factor of 2.9, but C6H50 expulsion is faster by 4.5 X 106, with the result that the equilibrium constant for 1,1 phenoxide adduct formation is smaller than for 1,1 methoxide adduct formation by 1.5 X 106. 

More important for the application of nonionics in practice is knowledge of the relationship between the stabilising effect and the average ethylene oxide number in the molecule. The surfactant concentration c, necessary to increase the shelf-life of a standard emulsion is taken as a measure of the stabilising effect. Fig. 1.16 shows such a relationship for ethoxylated dodecanol (Muller Kretzschmar 1982). The ratio of the hydrophilic and hydrophobic parts in the molecule has a direct bearing on the concentration needed to stabilise the toluene-in-water system. The ethylene oxide adducts possesses particularly high variability and are readily available. 

A similar phenomenon was observed by Muller Kretzschmar (1982) with ethylene oxide adducts at significantly increased concentration of the background electrolytes connected with clouding of the emulsion. 

Eisenbrand G, Muller, N, Denkel E, et al. DNA adducts and DNA damage by antineoplastic and carcinogenic N-nitrosocompounds. J Cancer Res Clin Oncol 1986 112 196-204. 

R 645 L. Zeng, C. H. Chen, M. Muller and M. -M. Zhou, Structure-Based Rational Design of Chemical Ligands for AMPA-Subtype Glutamate Receptors , J. Mol. Neurosci., 2003,20, 345 R 646 S. Zhou, Separation and Detection Methods for Covalent Drug-Protein Adducts , J. Chromatogr., B, 2003,797, 63 R 647 I. Zhukov and A. Ejchart, NMR Spectroscopy in Structural Proteomics. NMR-Based Protein Structure Determination , Polimery (Warsaw, Poland), 2003, 48, 28... 

Kurelec B,Britvid S, Krca S, Muller WEG, Zahn RK( 1987) Metabolism of some carcinogenic aromatic amines in four species of marine sponges. Comp Biochem Physiol 86C 17-22 Kurelec B, Chacko M, Gupta RC (1988) Postlabelling analysis of carcinogen-DNA adducts in mussel, Mytilus galloprovincialis. Mar Env Res 24 317-320... 

Electron spin resonance spin trapping analysis of the signals obtained from the perfused rabbit retina showed that hydroxyl radical adducts were generated during the ischaemic period with no further increase at reperfusion (Muller et al. 1997). Electron spin resonance detection of the ascorbyl free radical/dimethyl sulfoxide complex in the retina confirmed that an oxidative stress occurred under ischaemia and was not increased under reperfusion. 

A soln. of p-tolu-syn-aldoxime and methylketene diethyl acetal in dry ether refluxed 4 hrs. ->adduct (Y 95%) refluxed 3 hrs. in dry ether in the presence of 2 drops of 40% BF3-etherate and a little HgO p-toluisonitrile (Y 73%).— Ar. anfi-aldoximes and aliphatic aldoximes give nitriles under the same conditions. F. e., also nitriles, s. T. Mukaiyama, K. Tonooka, and K. Inoue, J. Org. Ghem. 26, 2202 (1961) isonitriles from aldoximes s. a. E. Muller and B. Narr, Z. Naturf. 16b, 845 (1961). 

The F3 cyclic species is obtained through hydrolysis of the corresponding silane, methyl(3,3,3-trifluoropropyl)dichlorosilane. This silane is the hydrosilylation adduct of 3,3,3-trifluoropropene and methyldichlorosilane, CH3HSiCl2, a minor product of the Rochow-Muller direct process for manufacturing methylchlorosilanes. The hydrosilylation reaction is catalyzed with transition metal complexes of platinum or rhodium such as Speier s catalyst and hexachloroplatinic acid in isopropanol. The reaction conditions are very similar to those employed with unfluorinated reagents, complicated only by the fact that 3,3,3-trifluoropropene is a gas. 

Cd(II) can bind to both the bases and the phosphate groups of DNA, and tends to destabilize the DNA helix (Jacobson and Turner 1980). However, these effects do not constitute DNA damage in the usual sense of the term (i.e., strand breaks, cross-links, adducts). Incubation of DNA with Cd(II) alone or with H2O2 did not result in strand breaks (Roy and Rossman, unpublished data). Cadmium-metallothionein complex is able to induce DNA strand breaks (Muller et al. 1991). However, the production of DNA strand breaks in cells by a cadmium-metallothionein complex is unlikely. Pretreatment of cells with Zn(II) to induce metallothionein resulted in decreased toxicity and DNA strand breaks by Cd(II) (Coogan et al. 1992). Transfection of a metallothionein overproducing plasmid into G12 cells abolished the mutagenicity of Cd(II) (Goncharova and Rossman, in preparation). 

Arp H, Baumgartner J, Marschner C, Muller T (2011) A cyclic disilylated staimylene synthesis, dimerization, and adduct formation. J Am Chem Soc 133 5632... 

Furthermore, the l-H-Fl-9a-OOH chromophore is, in our opinion, known from l-R-Fl-9a-OR, which is the structure we assign to the alcohol adducts obtained first by F. Muller (ISS). This author preferred originally and rather intuitively, like many other colleagues (772, 727), the isomeric 1-R-Fl-lOa-OR structure. The following arguments oppose this assignment ... 

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