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1.
Terada Y Misoi R Watanabe N Hornberger M Kreis W 《Chemical & pharmaceutical bulletin》2000,48(3):349-352
Cardenolide glucohydrolase II (CGH II) is a cardenolide-specific glucohydrolase obtained from Digitalis lanata leaves. We investigated the structure-specificity relationship of several cardenolide disaccharides as a substrate for CGH II. Conformation analysis of the substrates was performed using molecular mechanics calculations. The sugar chain conformation of two inert glycosides was significantly different from that of the other glycosides. The other two glycosides, which were weak substrates of CGH II, were suggested to have an intramolecular hydrogen bond between the sugar groups. It was deduced that this hydrogen bond restricts the conformational change of the sugar chain and prevents the glycosides from enzymatic recognition. 相似文献
2.
Simon Knig Philipp Kreis Leonie Reinders Ronald Beyer Andreas Wego Christian Herbert Mark Steinmann Erik Frank Michael R. Buchmeiser 《先进技术聚合物》2020,31(8):1827-1835
The primary use of poly(acrylonitrile) (PAN) fibers, commonly referred to as acrylic fibers, is in textile applications like clothing, furniture, carpets, and awnings. All commercially available PAN fibers are processed by solution spinning; however, alternative, more cost‐effective processes like melt spinning are still highly desired. Here, the melt spinning of PAN‐co‐poly(methyl acrylate) (PMA) plasticized with propylene carbonate (PC) at 175°C is reported. The use of methyl acrylate (MA) as comonomer and PC as an external plasticizer renders the approach a combination of internal and external plasticization. Various mixtures of PAN and PC used in this work were examined by rheology, subjected to melt spinning, followed by discontinuous and continuous washing, respectively. The best fibers were derived from a PAN‐co‐PMA copolymer containing 8.1 mol‐% of MA having a number‐average molecular weight M n of 34 000 g/mol, spun in the presence of 22.5 wt.‐% of PC. The resulting fibers were analyzed by scanning electron microscopy and wide‐angle X‐ray scattering (WAXS), and were subjected to mechanical testing. 相似文献
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Kreis R Slotboom J Pietz J Jung B Boesch C 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2001,149(2):245-250
There is a need for absolute quantitation methods in (31)P magnetic resonance spectroscopy, because none of the phosphorous-containing metabolites is necessarily constant in pathology. Here, a method for absolute quantitation of in vivo (31)P MR spectra that provides reproducible metabolite contents in institutional or standard units is described. It relies on the reciprocity principle, i.e., the proportionality between the B(1) field map and the map of reception strength for a coil with identical relative current distributions in receive and transmit mode. Cerebral tissue contents of (31)P metabolites were determined in a predominantly white matter-containing location in healthy subjects. The results are in good agreement with the literature and the interexamination coefficient of variance is better than that in most previous studies. A gender difference found for some of the (31)P metabolites may be explained by different voxel composition. 相似文献
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Ohne Zusammenfassung 相似文献
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Juliana S Luz Celso RR Ramos Márcia CT Santos Patricia P Coltri Fernando L Palhano Debora Foguel Nilson IT Zanchin Carla C Oliveira 《BMC biochemistry》2010,11(1):22
Background
The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors. 相似文献8.
The conversion of 23-nor-5,20(22)E-choladienic acid-3β-ol and other intermediates of the putative norcholanic acid pathway of cardenolide biosynthesis by recombinant 3β-hydroxysteroid dehydrogenase from Digitalis lanata in dehydrogenation and reduction reactions was investigated. 23-nor-4,20(22)E-choladienic acid-3-one was found to be a substrate of recombinant progesterone 5β-reductases from D. lanata and Arabidopsis thaliana. The role of various substrates in cardenolide biosynthesis is discussed. 相似文献
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Fr. Gisiger H. Kreis W. Normann und H. Herbst 《Fresenius' Journal of Analytical Chemistry》1928,73(5-6):238
Ohne Zusammenfassung 相似文献