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111.
Yongho Park Yumi Koga Cindy Su Amanda L. Waterbury Christopher L. Johnny Brian B. Liau 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(16):5441-5445
Cycloheximide (CHX) is an inhibitor of eukaryotic translation elongation that has played an essential role in the study of protein synthesis. Despite its ubiquity, few studies have been directed towards accessing synthetic CHX derivatives, even though such efforts may lead to protein synthesis inhibitors with improved or alternate properties. Described here is the total synthesis of CHX and analogues, and the establishment of structure–activity relationships (SAR) responsible for translation inhibition. The SAR studies aided the design of more potent compounds, one of which irreversibly blocks ribosomal elongation, preserves polysome profiles, and may be a broadly useful tool for investigating protein synthesis. 相似文献
112.
113.
For the nth order nonlinear differential equation y
(n)(t)=f(y(t)), t [0,1], satisfying the multipoint conjugate boundary conditions, y
(j)(ai) = 0,1 i k, 0 j n
i
- 1, 0 =a
1 < a
2 < < a
k
= 1, and
i=1
k
n
i
=n, where f: [0, ) is continuous, growth condtions are imposed on f which yield the existence of at least three solutions that belong to a cone. 相似文献
114.
Hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine is a widely used biocide in metalworking fluids that resists direct quantification in many analytical methods due to instability. It can be detected in electrospray-mass spectrometry (ES-MS) due to the formation of a charged and relatively stable adduct with the sodium ion. This adduct produces a distinct ion spectrum via collision-induced fragmentation, which should promote specific detection of the analyte in complex matrices. ES-MS detection of the analyte added to, or already present in, metalworking fluid samples at microg mL(-1) levels is demonstrated. Parameters affecting the formation and detection of the sodium adduct, including choice of solvent, alkalinity, and sodium ion level are explored. Linearity of response in flow injection mode is demonstrated. 相似文献
115.
116.
117.
Vedran Hasimbegovic Johnny Slätt Jan Bergman Tomasz Janosik 《Journal of heterocyclic chemistry》2007,44(5):1213-1217
A study probing the scope of acylation of indoles with dicarboxylic acids in acetic anhydride has been performed, resulting in products incorporating 3‐acylindole‐ or 1‐acylindole motifs depending on the choice of the acid reactant. Synthetically useful results were only obtained from reactions involving malonic acid or Meldrum's acid. Correlations to previous studies have also been made and discussed. 相似文献
118.
Nicolas Bréfuel Isabelle Vang Sergiu Shova Françoise Dahan Jean-Pierre Costes Jean-Pierre Tuchagues 《Polyhedron》2007
The synthesis and characterization of new symmetrical FeII complexes, [FeLA(NCS)2] (1), and [FeLBx(NCS)2] (2–4), are reported (LA is the tetradentate Schiff base N,N′-bis(1-pyridin-2-ylethylidene)-2,2-dimethylpropane-1,3-diamine, and LBx stands for the family of tetradentate Schiff bases N,N′-bis[(2-R-1H-imidazol-4-yl)methylene]-2,2-dimethylpropane-1,3-diamine, with: R = H for LB1 in 2, R = Me for LB2 in 3, and R = Ph for LB3 in 4). Single-crystal X-ray structures have been determined for 1 (low-spin state at 293 K), 2 (high-spin (HS) state at 200 K), and 3 (HS state at 180 K). These complexes remain in the same spin-state over the whole temperature range [80–400 K]. The dissymmetrical tetradentate Schiff base ligands LCx, N-[(2-R2-1H-imidazol-4-yl)methylene]-N′-(1-pyridin-2-ylethylidene)-2,2-R1-propane-1,3-diamine (R1 = H, Me; R2 = H, Me, Ph), containing both pyridine and imidazole rings were obtained as their [FeLCx(NCS)2] complexes, 5–10, through reaction of the isolated aminal type ligands 2-methyl-2-pyridin-2-ylhexahydropyrimidine (R1 = H, 5–7) or 2,5,5-trimethyl-2-pyridin-2-ylhexahydropyrimidine (R1 = Me, 8–10) with imidazole-4-carboxaldehyde (R2 = H: 5, 8), 2-methylimidazole-4-carboxaldehyde (R2 = Me: 6, 9), and 2-phenyl-imidazole-4-carboxaldehyde (R2 = Ph: 7, 10) in the presence of iron(II) thiocyanate. Together with the single-crystal X-ray structures of 7 and 9, variable-temperature magnetic susceptibility and Mössbauer studies of 5–10 showed that it is possible to tune the spin crossover properties in the [FeLCx(NCS)2] series by changing the 2-imidazole and/or C2-propylene susbtituent of LCx. 相似文献
119.
Johnny Henderson Basant Karna Christopher C. Tisdell 《Proceedings of the American Mathematical Society》2005,133(5):1365-1369
Shooting methods are employed to obtain solutions of the three-point boundary value problem for the second order equation, where is continuous, and and conditions are imposed implying that solutions of such problems are unique, when they exist.
120.