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1.
Employing a cleavable carbohydrate–peptide linker, a new strategy for single-bead analysis of multivalent cyclic neoglycopeptides based on Edman degradation is described. Edman degradation of glycopeptides is hampered by the acid lability of the glycosidic bond and potential incompatibilities of phenylthiohydantoin (PTH) derivatives of glycosylated amino acids with PTH derivatives of the proteinogenic amino acids. To overcome this problem, carbohydrates are detached from the cyclopeptide templates before single-bead analysis, allowing for micro sequencing under routine conditions. With this strategy, application of multivalent cyclic neoglycopeptides in split-mix libraries with a subsequent screening process becomes possible for the first time. 相似文献
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Polyethers, which are produced by alcoholysis of oxiranes, are often used as solvents in chemical plants. The spectra of the products can be influenced by the choice of the catalyst (acid or base). The results of the base-catalyzed ethanolysis of 1,2-epoxybutane are displayed. The reaction was investigated calorimetrically by varying the molar ratio between ethanol and 1,2-epoxybutane, the starting temperature and the concentration of the catalyst sodium hydroxide. Additionally, the influence of the used alcohol will be shown in one example. To determine the activation parameters, the experiments were evaluated by the nonlinear software package TA-kin v3.3. 相似文献
5.
Dunahay Terri G. Jarvis Eric E. Dais Sonja S. Roessler Paul G. 《Applied biochemistry and biotechnology》1996,57(1):223-231
Applied Biochemistry and Biotechnology - Genetic transformation of two species of diatoms has been accomplished by introducing chimeric plasmid vectors containing a bacterial antibiotic resistance... 相似文献
6.
M. Schneider A. Hinz A. Groh K. M. Evenson W. Urban 《Applied physics. B, Lasers and optics》1987,44(4):241-245
Frequency stabilization of the CO laser using a CO lamb-dip is achieved in the range from 5.0–6.3 m. The CO saturation signal is obtained from a low-pressure discharge in absorption and is detected using optogalvanic, detection. The frequency stability and reproducibility has been verified to be better than 100 kHz; this is an improvement of more than one order of magnitude compared with locking techniques using CO laser gain profiles.Alexander von Humboldt Awardee from National Bureau of Standards, Boulder, Colorado, USA 相似文献
7.
Bühl M Grigoleit S Kabrede H Mauschick FT 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,12(2):477-488
59Co chemical shifts were computed at the GIAO-B3LYP level for [Co(CN)6]3-, [Co(H2O)6]3+, [Co(NH3)6]3+, and [Co(CO)4]- in water. The aqueous solutions were modeled by Car-Parrinello molecular dynamics (CPMD) simulations, or by propagation on a hybrid quantum-mechanical/molecular-mechanical Born-Oppenheimer surface (QM/MM-BOMD). Mean absolute deviations from experiment obtained with these methods are on the order of 400 and 600 ppm, respectively, over a total delta(59Co) range of about 18,000 ppm. The effect of the solvent on delta(59Co) is mostly indirect, resulting primarily from substantial metal-ligand bond contractions on going from the gas phase to the bulk. The simulated solvent effects on geometries and delta(59Co) values are well reproduced by using a polarizable continuum model (PCM), based on optimization and perturbational evaluation of quantum-mechanical zero-point corrections. 相似文献
8.
[RhH(CO)(PPh3)2] (1) reacts with Et3N·3HF to give the fluoro compound [RhF(CO)(PPh3)2] (2). In a comparable reaction [RhF(PEt3)3] (5) has been obtained from [RhH(PEt3)3] (3) or [RhH(PEt3)4] (4) with substoichiometric amounts of Et3N·3HF in THF. If the latter reaction is carried out in benzene, the complexes 5, cis-mer-[Rh(H)2F(PEt3)3] (6) and cis-fac-[Rh(H)2F(PEt3)3] (7) are obtained. Treatment of 5 with HCl in ether effects the generation of [RhCl(PEt3)3] (8) and the bifluoride compound [Rh(FHF)(PEt3)3] (9), which can be converted into 5 in the presence of Et3N and Cs2CO3. Treatment of 5 with HSiR2Ph (R=Ph, Me) leads to the formation of 3 and the rhodium(III) silyl complexes fac-[Rh(H)2(SiR2Ph)(PEt3)3] (10: R=Ph, 11: R=Me). 相似文献
9.
Novel representatives of the important group of biologically active dibenzosuberone derivatives were prepared: 3,7-dibromo-5-(dimethylaminoethyl- oxyimino)-10,11-dihydro-5H-dibenzo[a,d]cyclohepta-1,4-diene (1), 3,7-dibromo-5-(3- dimethylaminopropylidene)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene (2) and 1,7- dibromo-5-(3-dimethylaminopropylidene)-10,11-dihydro-5H-dibenzo-[a,d]-cycloheptene (3). These compounds are potential tricyclic antidepressants (TCAs), which are still the most frequently prescribed antidepressants in many countries. 相似文献
10.
Boris Pejin Kristina Tešanović Dragica Jakovljević Sonja Kaišarević Filip Šibul Milena Rašeta 《Natural product research》2019,33(5):750-754
The polysaccharide (PSH) extracts from the edible mushroom species Coprinus comatus and Coprinellus truncorum were screened in liquid for their acetylcholinesterase inhibitory (AChE) activity. Both extracts were found to display inhibition of the aforementioned enzyme reaching similar IC50 values of 0.62 ± 0.07 and 0.61 ± 0.03 mg/mL, respectively. According to the means of FTIR spectroscopy, these PSH extracts mostly contained β-glucans. However, the presence of some proteins and polyphenolics as minor ingredients were also detected. Compared with existing literature data for anti-AChE activity of the sugar samples, the findings within this study may be treated as a profound bioactivity. Consequently, this study puts some light on the possible use of the screened macrofungi in the palliative treatment of Alzheimer’s disease. 相似文献