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141.
In this article, we introduce a class of Markov processes whose transition probability densities are defined by multifractional pseudodifferential evolution equations on compact domains with variable local dimension. The infinitesimal generators of these Markov processes are given by the trace of strongly elliptic pseudodifferential operators of variable order on such domains. The results derived provide a pseudomultifractal version of some existing special classes of multifractional Markov processes. In particular, pseudostable processes are defined on domains with variable local dimension in this framework. In the case where the local dimension of the domain and the local Hölder exponents of the transition probability densities are constant, the existing results on fractal versions of Lévy processes are recovered. 相似文献
142.
Michael McKendall Tasha Smith Kien Anh Jamie Ellis Terri McGee Maryam Foroozesh Naijue Zhu Cheryl L. Klein Stevens 《Journal of chemical crystallography》2008,38(4):231-237
Abstract Cytochrome P450 enzymes are a superfamily of enzymes involved in the metabolism of endogenous compounds as well as xenobiotics.
Due to the large number of reactions catalyzed by these enzymes and their importance in drug metabolism and carcinogenesis,
they have been the focus of many studies over the years. Based on the knowledge that flavones are natural substrates of certain
P450 enzymes (such as P450 1A2) involved in carcinogenesis, we have synthesized and studied a number of flavonoids as potential
inhibitors of these enzymes. These compounds are structurally very similar to the natural flavone substrates of these enzymes
but have methoxy substituents at various positions. Here we are reporting the synthesis, structural analysis, X-ray crystal
structures, and preliminary inhibition studies of four methoxyflavones from this series. Crystallographic data: 2′-methoxyflavone,
P-1, a = 7.2994(8) ?, b = 8.3322(7) ?, c = 10.8240(10) ?, α = 97.905(8)°, β = 92.779(10)°, γ = 111.105(8)°, V = 604.9(1) ?3; 3′-methoxyflavone, P21/n, a = 15.1313(16) ?, b = 3.9699(4) ?, c = 19.9454(16) ?, β = 91.673(8)°, V = 1197.6(2) ?3; 4′-methoxyflavone, P21/n, a = 16.451(12) ?, b = 3.881(1) ?, c = 19.529(16) ?, β = 106.65(1)°, V = 1195.1(4) ?3; 3′,4′-dimethoxyflavone, C2/c, a = 30.819(5) ?, b = 4.0857(7) ?, c = 26.100(3) ?, β = 124.21(1)°, V = 2717.6(7) ?3.
Index Abstract Methoxyflavone Inhibitors of Cytochrome P450
Michael McKendall, Tasha Smith, Kien Anh, Jamie Ellis, Terri McGee, Maryam Foroozesh, Naijue Zhu and Cheryl L. Klein Stevens*
This paper is a report of the synthesis, structural analysis, X-ray crystal structures, and preliminary inhibition studies
of 2′-methoxyflavone, 3′-methoxyflavone, 4′-methoxyflavone, and 3′,4′-dimethoxyflavone.
相似文献
Cheryl L. Klein StevensEmail: |
143.
Nguyen Van Bon Wang San-Lang Nguyen Thi Hanh Doan Chien Thang Tran Thi Ngoc Kuo Yao-Haur Nguyen Quang Vinh Nguyen Anh Dzung 《Research on Chemical Intermediates》2019,45(12):6061-6071
Research on Chemical Intermediates - Natural α-glucosidase inhibitors (aGIs) have been considered effective agents for type 2 diabetes management. In this study, Syzygium zeylanicum (L.)... 相似文献
144.
Jana Anhäuser Dr. Rakesh Puttreddy Lukas Glanz Andreas Schneider Dr. Marianne Engeser Prof. Dr. Kari Rissanen Prof. Dr. Arne Lützen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(53):12294-12297
An enantiomerically pure diamine based on the 4,15-difunctionalized [2.2]paracyclophane scaffold and 2-formylpyridine self-assemble into an optically pure cyclic metallosupramolecular Fe4L6 helicate upon mixing with iron(II) ions in a diastereoselective subcomponent self-assembly process. The cyclic assembly results from steric strain that prevents the formation of a smaller linear dinuclear triple-stranded helicate, and hence, leads to the larger strain-free assembly that fulfils the maximum occupancy rule. Interestingly, use of the racemic diamine also leads to a racemic mixture of the homochiral cyclic helicates as the major product in a highly diastereoselective narcissistic chiral self-sorting manner given the fact that the assembly contains ten stereogenic elements, which can in principle give rise to 149 different diastereomers. The metallosupramolecular aggregates could be characterized by NMR, UV/Vis and CD spectroscopy, mass spectrometry, and X-ray crystallography. 相似文献
145.
Quantum transport in disordered ferromagnetic (III,Mn)V semiconductors is studied theoretically. Mesoscopic wires exhibit an Anderson disorder-induced metal-insulator transition that can be controlled by a weak external magnetic field. This metal-insulator transition should also occur in other materials with large anisotropic magnetoresistance effects. The transition can be useful for studies of zero-temperature quantum critical phase transitions and fundamental material properties. 相似文献
146.
Nikolai A. Poklonski Nguyen Ngoc Hieu Sergey A. Vyrko Andrei M. Popov 《Physics letters. A》2008,372(35):5706-5711
The dependence of the interwall conductance on distance between walls and relative positions of walls are calculated at the low voltage by Bardeen method for (n,n)@(2n,2n) double-walled carbon nanotubes (DWCNTs) with n=5,6,…,10. The calculations show that interwall conductance does not depend on temperature (for T?500 K) and current-voltage characteristic is linear. The conductance decreases by 6 orders of magnitude when the interwall distance is doubled. Thus, depending on the interwall distance, DWCNTs can be used as temperature stable nanoresistors or nanocapacitors. 相似文献
147.
148.
Thao Quyen Cao Nguyen Viet Phong Jang Hoon Kim Dan Gao Hoang Le Tuan Anh Viet-Duc Ngo Le Ba Vinh Young Sang Koh Seo Young Yang 《Molecules (Basel, Switzerland)》2021,26(15)
The bitter melon, Momordica charantia L., was once an important food and medicinal herb. Various studies have focused on the potential treatment of stomach disease with M. charantia and on its anti-diabetic properties. However, very little is known about the specific compounds responsible for its anti-inflammatory activities. In addition, the in vitro inhibitory effect of M. charantia on pro-inflammatory cytokine production by lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs) has not been reported. Phytochemical investigation of M. charantia fruit led to the isolation of 15 compounds (1−15). Their chemical structures were elucidated spectroscopically (one- and two-dimensional nuclear magnetic resonance) and with electrospray ionization mass spectrometry. The anti-inflammatory effects of the isolated compounds were evaluated by measuring the production of the pro-inflammatory cytokines interleukin IL-6, IL-12 p40, and tumor necrosis factor α (TNF-α) in LPS-stimulated BMDCs. The cucurbitanes were potent inhibitors of the cytokines TNF-α, IL-6, and IL-12 p40, indicating promising anti-inflammatory effects. Based on these studies and in silico simulations, we determined that the ligand likely docked in the receptors. These results suggest that cucurbitanes from M. charantia are potential candidates for treating inflammatory diseases. 相似文献
149.
150.
Anh Ha Lan Nhan Dang Duc Frew Russell Quynh Tran Minh 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(9):3613-3621
Journal of Radioanalytical and Nuclear Chemistry - This research aimed to authenticate the geographical origin of imported fresh apples using isotopic techniques. The results show that the... 相似文献