Stark degradation

An analogous Stark degradation releases the C-terminal residues successively as thiohydratoin (TH) amino acids (Bailey and Shively, 1990). 

Braeutigam P, Wu Z-L, Stark A, Ondruschka B (2009) Degradation of BTEX in Aqueous Solution by Hydrodynamic Cavitation. Chem Eng Tech 32 745-753... 

Recent Developments in Chemical Modification and Sequential Degradation of Proteins George R. Stark... 

Despite the progress, the stark fact remains that the major solid tumors of people—lung, breast, colorectal, ovarian, and prostate—claim a great many lives and degrade the quality of life in the process. The drugs that we employ to battle these malignancies leave a lot to be desired. 

G.R. Stark, Recent developments in chemical modification and sequential degradation of proteins, Adv. Protein Chem. 24 (1970) 261-308. 

Figure 10-5 Diagrammatic Representation of Amylopectin Structure. Lines represent a-D-glucan chains linked by 1,4-bonds. The branch points are 1,6-a glucosidic bonds. Source From J.J. Marshall, Starch Degrading Enzymes, Old and New, Starke, Vol. 27, pp. 377-383, 1975.

Finally, two recent studies by Vancurova et al. [91] added new insights to our current understanding of the NF-kB system in neutrophils. In one instance, they found that TNF induces NF-kB more potently in neutrophils from newborn individuals, relative to neutrophils from adult donors this correlates well with the elevated production of IL-8 and IL-ip reported in neonatal neutrophils [93, 94], These authors also showed that dexamethasone inhibits NF-kB induction by TNF in both newborn and adult neutrophils [91] we observed a similar effect of dexamethasone in neutrophils from adult donors (our unpubl. data). In a later study, the same group demonstrated that IkB-o is distributed in approximately equal amounts between the cytoplasm and the nucleus of neutrophils [76] - in stark contrast to most other cell types. Moreover, TNF stimulation led to the degradation of iKB-a in both cellular compartments, in addition to its known ability to promote the nuclear recruitment of NF-KB/Rel proteins [76]. This effect of TNF could be partially blocked by MG-132, aproteasome inhibitor that is known to inhibit NF-kB [95], as well as by the PKC8 inhibitor, rottlerin [76]. 

Hi) Homocitrulline. This derivative is formed from reaction of lysine with cyanate (Stark, 1965). It may be employed for the same reasons as described for homoarginine (although the charge conservation is lost) and is also encountered as a by-product of the cyanate end-group procedure of Stark and Smyth (1963). It is only partially stable to acid hydrolysis, some 25% being degraded to lysine in 24 hr under the normal conditions of acid hydrolysis. 

U. Seeliger, G. Skupin, and D. Starke, Biologically-degradable polyester mixture, US Patent 8 003 731, assigned to BASF SE (Ludwigshafen, DE), August 23, 2011. 

L.M. Matuana, S. Jin, and N.M. Stark, Ultraviolet weathering of HDPE/wood-flour composites coextruded with a clear HDPE cap layer. Polym. Degrad. Stabil. 96, 97-106 (2011). 

N.M. Stark and L.M. Matuana, Influence of photostabilizers on wood flour-HDPE composites exposed to xenon-arc radiation with and without water spray. Polym. Degrad. Stabil. 91, 3048-3056 (2006). 

Just as steel msts and wood rots, plastics degrade in the environment. This is in stark contrast to the picture of the 1960s, which presented plastic as both... 

Asym. synthesis. D(-)-Ephedrine hydrate and p-chlorobenzaldehyde refluxed 1 hr. in benzene, then the calculated amount of water removed using a Dean-Stark column (2R 4S 5R)-2-chlorophenyl-3,4-dimethyl-5-phenyloxazolidine. Y ca. 100%. - The induced asym. center in position 2 has the R conflguration. On degradation, the oxazolidines yield optically pure a-arylethylamines or a-aryl-ethyl halides. F. e. s. L. Neelakantan, J. Org. Chem. 36, 2256, 2253 (1971) carbohydrate derivs. s. H. Dorn and D. Arndt, Z. Chem. 77, 306 (1971). 

The peptide bound to the solid support is then degraded from the COOH-terminus by the Stark procedure (1968), which involves reaction with acetic anhydride and ammonium thiocyanate. In presence of an acid, the COOH-terminal amino acid is cleaved as a thiohydantoin or iminohy-dantoin, leaving the remaining peptide attached to the solid support. Successive degradation steps are then carried out on the bound peptide. 

H+) (Collins, 1957) (Scheme 13-1). The same resin has been used for selective cleavage of the thiohydantoin formed from a peptide in preparation for COOH-terminal identification (Yamashita, 1971). Earlier, cold 6 N HCl was used for this cleavage reaction (Cromwell and Stark, 1969), but these conditions were considered too drastic since cleavage of the peptide bond also took place. Thus, the method using aqueous HCl was not suitable for sequential degradation from the COOH-terminus of the peptide. 

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