Search results for "synthesis"
showing 10 items of 2844 documents
Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superf…
2006
Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C222(1) and diffract to 2.0 A, with unit-…
Human Enterovirus Group B Viruses Rely on Vimentin Dynamics for Efficient Processing of Viral Nonstructural Proteins.
2019
A virus needs the host cell in order to replicate and produce new progeny viruses. For this, the virus takes over the host cell and modifies it to become a factory for viral proteins. Irrespective of the specific virus family, these proteins can be divided into structural and nonstructural proteins. Structural proteins are the building blocks for the new progeny virions, whereas the nonstructural proteins orchestrate the takeover of the host cell and its functions. Here, we have shown a mechanism that viruses exploit in order to regulate the host cell. We show that viral protein synthesis induces vimentin cages, which promote production of specific viral proteins that eventually control apo…
Influence of Oral Contraceptive Use on Adaptations to Resistance Training
2019
Introduction: The majority of young women use oral contraceptives (OCs). Use of OCs has been associated with lower myofibrillar protein and tendon collagen synthesis rates, but it is unknown whether OCs will limit the adaptive response of myotendinous tissue to resistance training. Design and Methods: Fourteen healthy untrained young regular OC users (24 +/- 1 years, fat% 32 +/- 1, 35 +/- 2 ml.min(-1).kg(-1)) and 14 NOC users (non-OC, controls) (24 +/- 1 years, fat% 32 +/- 2, 34 +/- 2 ml.min(-1).kg(-1)) performed a 10-week supervised lower extremity progressive resistance training program. Before and after the intervention biopsies from the vastus lateralis muscle and the patellar tendon we…
Synthesis and characterization of perfluoroalkyl-pyrenes embedded in a polymethylmethacrylate matrix
2012
Synthesis of novel fluorinated building blocks and α-helix peptidomimetics
2018
At its heart, the present PhD thesis is based on the premise of two important areas in modern organic chemistry: firstly, the development of new methodologies to incorporate fluorine into organic molecules; and secondly, the design and synthesis of small molecules with high therapeutic potential. The work presented in the first three chapters will therefore focus on the incorporation of fluorine into organic molecules and the synthesis of fluorinated building blocks. In each chapter, we aim to obtain biologically relevant small molecules containing fluorine atoms or fluorinated groupings. The introduction of fluorine is a commonly used method in drug discovery to fine-tune the properties of…
Synthesis, structure and photophysical properties of a highly luminescent terpyridine-diphenylacetylene hybrid fluorophore and its metal complexes
2014
A new fluorescent terpyridyl-diphenylacetylene hybrid fluorophore 4'-[4-{(4-methoxyphenyl)ethynyl}phenyl]-2,2':6',2''-terpyridine, L, was synthesized via Sonogashira cross-coupling of 4'-(4-bromophenyl)-2,2':6',2''-terpyridine and 4-ethynylanisole in the presence of Pd(PPh3)4/CuI as a catalyst. The solid state structure of L shows a trans arrangement of pyridine nitrogen atoms along the interannular bond in the terpyridine domain. Five transition metal complexes of L, {[FeL2](CF3SO3)2 (1), [ZnL2](ClO4)2 (2), [CdL2](ClO4)2 (3), [RuL2](PF6)2 (4), and PtMe3IL (5)}, have also been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. The X-ray crystal structu…
One-pot synthesis of fluorinated 2-amino-pyrimidine-N-oxides. Competing pathways in the four-atom side-chain rearrangements of 1,2,4-oxadiazoles
2006
Abstract Trifluoromethylated 2-amino-pyrimidine N-oxides have been synthesized by reaction of the 3-amino-5-methyl-1,2,4-oxadiazole with trifluoromethyl-β-diketones in the presence of perchloric acid, followed by hydrolysis. In this ring-to-ring transformation an initial formation of (unisolated) 1,2,4-oxadiazole-pyrimidinium salts, and subsequent ring-opening at the oxadiazole moiety occurs. Isolation of 2-(hydroxyamino)-pyrimidine from the reaction mixture evidenced the presence of a competing pathway where the N(4) nitrogen of the oxadiazole is involved in the formation of a regioisomeric pyrimidinium salt. The effect of the trifluoromethyl group on the product distribution is discussed.…
The Influence of Acetylcholine and Choline on the Incorporation of Phosphate into Phospholipids of Etiolated Bean Hypocotyl Hooks
1980
Summary Acetylcholine influenced the radiolabelling of phospholipids in vivo in etiolated hypocotyl tissue of dwarf beans in darkness. Under aerobic conditions the specific activity of the phospholipids was decreased and under anaerobic conditions increased. The biosynthesis of phospholipids was strongly increased by the bivalent cations calcium and manganese and decreased by 2,4-dinitrophenol, anaerobiosis, atropine and ascorbic acid. Magnesium stimulated the uptake of the radioactive phosphate but not the specific activity of the phospholipids. The results are discussed in comparison with the «phospholipid-effect» of acetylcholine in animal tissues.
Inorganic phosphate is a trigger factor for Microbispora sp. ATCC-PTA-5024 growth and NAI-107 production
2014
Background NAI-107, produced by the actinomycete Microbispora sp. ATCC-PTA-5024, is a promising lantibiotic active against Gram-positive bacteria and currently in late preclinical-phase. Lantibiotics (lanthionine-containing antibiotics) are ribosomally synthesized and post-translationally modified peptides (RiPPs), encoded by structural genes as precursor peptides. The biosynthesis of biologically active compounds is developmentally controlled and it depends upon a variety of environmental stimuli and conditions. Inorganic phosphate (Pi) usually negatively regulates biologically-active molecule production in Actinomycetes, while it has been reported to have a positive control on lantibiotic…
Comparing various concepts of function prediction. Part 1.
1974
Prediction: f(m+1) is guessed from given f(0), ..., f(m). Program synthesis: a program computing f is guessed from given f(0), ..., f(m). The hypotheses are required to be correct for all sufficiently large m, or with some positive frequency. These approaches yield a hierarchy of function prediction and program synthesis concepts. The comparison problem of the concepts is solved.