排序方式: 共有157条查询结果,搜索用时 15 毫秒
151.
Nikolay A. Bumagin Alexey V. Kletskov Sergey K. Petkevich Iryna A. Kolesnik Alexander S. Lyakhov Ludmila S. Ivashkevich Alexander V. Baranovsky Peter V. Kurman Vladimir I. Potkin 《Tetrahedron》2018,74(27):3578-3588
New substituted 3-((1H-1,2,3-triazol-1-yl)methyl)-5-arylisoxazoles (aryl?=?Ph, p-Tol) and 2-(5-phenylisoxazol-3-yl)-5-(2-(1-((5-(p-tolyl)isoxazol-3-yl)methyl)-1H-1,2,3-triazol-4-yl)ethyl)-1,3,4-oxadiazole were synthesized by means of click-chemistry procedures. The obtained compounds were used as ligands in preparation of palladium(II) complexes, and the latter proved to be high-turnover-number catalysts for CC cross-coupling reactions under Green Chemistry conditions. One of the ligands was structurally characterized by single crystal X-ray diffraction, and the structure of complexes was determined by 1H, 13C, 15N NMR spectroscopy and quantum-chemical modeling. 相似文献
152.
153.
Cai Z Riedel H Thaw Saw NM Kütük O Mewis I Jäger H Knorr D Smetanska I 《Applied biochemistry and biotechnology》2011,164(4):443-453
Plant cell cultures provide a large potential for the production of secondary metabolites. Through the application of different
physical and chemical cell stress factors, we investigated the production of the secondary metabolites in plant cell cultures.
The effects of pulsed electric field (PEF) and ethephon on growth and secondary metabolism, particularly anthocyanins and
phenolic acids synthesis, were investigated by using suspension culture of Vitis vinifera L. cv. Gamay Fréaux as a model system. Anthocyanins were measured by spectrophotometer and extracellular phenolic acids were
determined by high-performance liquid chromatography. The compounds were identified by liquid chromatography–mass spectrometry
and nuclear magnetic resonance. After the treatments with PEF and ethephon, the concentrations of anthocyanins and phenolic
acids in cell culture were higher than in the control, without loss of biomass. The combination of PEF treatment and ethephon
improved secondary metabolites formation. Production levels of extracellular phenolic acids, 3-O-glucosyl-resveratrol were increased by PEF and ethephon treatments. The results show that PEF induced a defense response
of plant cells and may have altered the cell/membrane’s dielectric properties. PEF, an external stimulus or stress, is proposed
as a promising new abiotic elicitor for stimulating secondary metabolites biosynthesis in plant cell cultures. 相似文献
154.
Iryna G. Davydenko Aleksei D. Kachkovsky Marina L. Dekhtyar Yurii L. Slominskii Aleksei I. Tolmachev 《Journal of Physical Organic Chemistry》2010,23(2):96-104
On the basis of the 7,8‐dihydrobenzo[c,d]furo[2,3‐f]indole nucleus, a number of unsymmetrical carbocyanines as well as styryl dyes have been synthesized and their absorption spectra have been measured. Starting from the deviations of long‐wavelength maxima, the value of electron‐donor ability D has been estimated for the heterocycle under study and a number of dye end groups have been ranked by their electron‐donor properties. Experimental inferences are supported by the quantum chemically calculated bond length alternations and energy levels for the dyes concerned. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
155.
Jakub Sawicki Iryna Omelchenko Anna Zakharova Eckehard Schöll 《The European physical journal. Special topics》2018,227(10-11):1161-1171
Complex networks consisting of several interacting layers allow for remote synchronization of distant layers via an intermediate relay layer. We extend the notion of relay synchronization to chimera states, and study the scenarios of relay synchronization in a three-layer network of FitzHugh–Nagumo (FHN) oscillators, where each layer has a nonlocal coupling topology. Varying the coupling strength and time delay in the inter-layer connections, we observe relay synchronization between chimera states, i.e., complex spatio-temporal patterns of coexisting coherent and incoherent domains, in the outer network layers. Special regimes where only the coherent domains of chimeras are synchronized, and the incoherent domains remain desynchronized, as well as transitions between different synchronization regimes are analyzed. 相似文献
156.
Dmitry Dibchak Mariya Snisarenko Artem Mishuk Oleh Shablykin Lina Bortnichuk Oleksii Klymenko-Ulianov Yurii Kheylik Iryna V. Sadkova Henry S. Rzepa Pavel K. Mykhailiuk 《Angewandte Chemie (International ed. in English)》2023,62(39):e202304246
A general approach to 3-azabicyclo[3.1.1]heptanes by reduction of spirocyclic oxetanyl nitriles was developed. The mechanism, scope, and scalability of this transformation were studied. The core was incorporated into the structure of the antihistamine drug Rupatidine instead of the pyridine ring, which led to a dramatic improvement in physicochemical properties. 相似文献
157.
Rajesh Guntupalli Iryna Sorokulova Robert Long Eric Olsen William Neely Vitaly Vodyanoy 《Colloids and surfaces. B, Biointerfaces》2011,82(1):182-189
Stable, insoluble Langmuir monolayer films composed of Staphylococcus aureus-specific lytic bacteriophage were formed at an air–water interface and characterized. The phage monolayer was very strong, withstanding a surface pressure of ~40 mN/m at 20 °C. The surface pressure–area (Π–A) isotherm possessed a shoulder at ~7 × 104 nm2/phage particle, attributed to a change in phage orientation at the air–water interface from horizontal to vertical capsid-down/tail-up orientation as surface pressure was increased. The Π–A-dependence was accurately described using the Volmer equation of state, assuming horizontal orientation to an air–water interface at low surface pressures with an excluded area per phage particle of 4.6 × 104 nm2. At high pressures phage particles followed the space-filling densely packed disks model with a specific area of 8.5 × 103 nm2/phage particle. Lytic phage monolayers were transferred onto gold-coated silica substrates from the air–water interface at a constant surface pressure of 18 mN/m by Langmuir–Blodgett method, then dried and analyzed by scanning electron microscopy (SEM) and ellipsometry. Phage specific adsorption (Γ) in Langmuir–Blodgett (LB) films measured by SEM was consistent with that calculated independently from Π–A isotherms at the transfer surface pressure of 18 mN/m (Γ = 23 phage particles/μm2). The 50 nm-thickness of phage monolayer measured by ellipsometer agreed well with the horizontal phage average size estimated by SEM. Surface properties of phage Langmuir monolayer compare well with other monolayers formed from nano- and micro-particles at the air–water interface and similar to that of classic amphiphiles 1,2-diphytanoyl-sn-glycero-3-phosphocholine (phospholipid) and stearic acid. 相似文献