Trans-activation systems

Trans-activator system pm Tissue-specific activation... 

Recently, this latter viral trans-activation system has been modified to a tetracycline-responsive system (Gossen and Bujard, 1992). In vitro, the trans-activation of a luciferase responder gene could be regulated over up to... 

Me0>2P(0)0CMe = CHC02Me. A trade name for a highly active systemic insecticide both CIS and trans isomers are active. 

In each case the sulfated metabolite undergoes active tubular. secretion by the OATS in proximal tubular cells and. hence, attains high levels in luminal fluid. The negatively charged sulfate moiety pruhably hinds to the Cr-binding. site on (he luminal membrane-bound INa /IK /2CI co-tran-sport. system of (hick ascending limb and macula densa cells. 

The encouraging result of the trans-epoxy acylates with the chiral spiro compounds was appUed to the optically active system (Scheme 15). Asymmetric reduction of the enone 31 by Corey s method [72] afforded the allyl alcohol (-)-34 (90% ee). Epoxidation of (-)-34 by the stereoselective Sharpless epoxidation [73] afforded the cts-epoxy alcohol, cfs-(-)-35, as the sole product. The Mitsunobu reaction [74] of czs-(-)-35 with benzoic acid gave the trans-epoxy benzoate, trans- -)-36, (90% ee) in 89% yield. Treatment of trans-(-)-36 with BF3-Et20 afforded the optically active spiro compound (+)-37 in 89% yield with retention of the optical purity (90% ee). This means that the rearrangement occurs stereospecifically. The optically pure epoxy camphanate (-)-38 could be obtained after one recrystallization of the crude (-)-38 (90% de), which was obtained by the Mitsimobu reaction of cfs-(-)-35 with D-camphanic acid. The optically pure spiro compoimd (+)-39 (100% de) was obtained from the optically pure (-)-38 in 89% yield. 

Commercial hexythiazox is a racemic mixture of the two trans enantiomers Scheme 26.2.2 shows the main synthetic pathways [11, 17, 19]. Starting from 4-chloro propiophenone the key intermediate erythro amino alcohol may be obtained by stereoselective catalytic reduction of the corresponding hydroxy imi-noketone or by sodium borohydride reduction of the aminoketones obtained via Gabriel synthesis. Different routes lead from this aminoalcohol to the trans-thiazolidinone system the basis of all routes is activation of the hydroxy group, e.g., in form of the sulfonate and a ring forming reaction with carbon disulfide or carbonyl sulfide. The final acylation of the NH group with cyclohexyl isocyanate leads to hexythiazox. 

Recently it has been shown that Cu(I), as well as its analog Ag(I), can activate metallothionein gene transcription in yeast by binding directly the ACEI trans-activator protein [8 Our experiments with the Ag(I) ion show that it does not appear to mimic the effect of Cu on the accumulation of qrt c-552 mRNA. This could indicate either that the active metalloregulator of the cyt c-552 gene is Cu(II) rather than Cu(I) or that the sensory molecule that responds to Cu is exquisitely specific for Cu (ys. other metals) as the regulator. This level of specificity combined with the extreme sensitivity of the response, < 100 nM total (chelated + free) Cu, suggest that the ( t c-552/Cu-response system could find practical application as a metal ion biosensor. 

Tran-Thang C, Kruithof E, Lahm H, Schuster WA, Tada M, Sordat B (1996) Modulation of the plasminogen activation system by inflammatory cytokines in human colon carcinoma cells. Br J Cancer 74 846-852 Trikha M, Corringham R, Klein B, Rossi JF (2003) Targeted antiinterleukin-6 monoclonal antibody therapy for cancer a review of the rationale and clinical evidence. Clin Cancer Res 9 4653-4665... 

For all catalysts, the cw-1,4 structure units of the polybutadiene range between a content of 74 and 85.8%, the trans-, A between 0.5 and 4.2%, and the 1,2-units between 13.7 and 22.6% (Table 7). The most active systems generate the polymer with the highest content of cis-, A and the lowest content of trans-, A and 1,2-units. The fluorinated compounds show a similar behavior. A mechanism for the formation of these microstructures is published by Porri [192]. 

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