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A Nexus between Theory and Experiment: Non‐Empirical Quantum Mechanical Computational Methodology Applied to Cucurbit[n]uril⋅Guest Binding Interactions 下载免费PDF全文
Jiří Hostaš Dr. David Sigwalt Marina Šekutor Haresh Ajani Dr. Matúš Dubecký Prof. Jan Řezáč Dr. Peter Y. Zavalij Dr. Liping Cao Christian Wohlschlager Prof. Kata Mlinarić‐Majerski Prof. Lyle Isaacs Prof. Robert Glaser Prof. Pavel Hobza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17226-17238
A training set of eleven X‐ray structures determined for biomimetic complexes between cucurbit[n]uril (CB[7 or 8]) hosts and adamantane‐/diamantane ammonium/aminium guests were studied with DFT‐D3 quantum mechanical computational methods to afford ΔGcalcd binding energies. A novel feature of this work is that the fidelity of the BLYP‐D3/def2‐TZVPP choice of DFT functional was proven by comparison with more accurate methods. For the first time, the CB[n] ? guest complex binding energy subcomponents [for example, ΔEdispersion, ΔEelectrostatic, ΔGsolvation, binding entropy (?TΔS), and induced fit Edeformation(host), Edeformation(guest)] were calculated. Only a few weeks of computation time per complex were required by using this protocol. The deformation (stiffness) and solvation properties (with emphasis on cavity desolvation) of cucurbit[n]uril (n=5, 6, 7, 8) isolated host molecules were also explored by means of the DFT‐D3 method. A high ρ2=0.84 correlation coefficient between ΔGexptl and ΔGcalcd was achieved without any scaling of the calculated terms (at 298 K). This linear dependence was utilized for ΔGcalcd predictions of new complexes. The nature of binding, including the role of high energy water molecules, was also studied. The utility of introduction of tethered [‐(CH2)nNH3]+ amino loops attached to N,N‐dimethyl‐adamantane‐1‐amine and N,N,N′,N′‐tetramethyl diamantane‐4,9‐diamine skeletons (both from an experimental and a theoretical perspective) is presented here as a promising tool for the achievement of new ultra‐high binding guests to CB[7] hosts. Predictions of not yet measured equilibrium constants are presented herein. 相似文献
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Huong Le Thi Linh Le Duy Dai Do Ngoc Ogunwande Isiaka Ajani 《Chemistry of Natural Compounds》2022,58(5):939-942
Chemistry of Natural Compounds - 相似文献
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Olayinka O. Ajani Craig A. Obafemi Chinwe O. Ikpo Kehinde O. Ogunniran Obinna C. Nwinyi 《Chemistry of Heterocyclic Compounds》2009,45(11):1370-1378
3-Hydrazinoquinoxalin-2(1H)-one was prepared from quinoxaline-2,3-dione and subsequently used for the synthesis of some potentially
biologically active 3-(pyrazol-1-yl)quinoxalin-2(1H)-one derivatives. While 3-(3,5-dimethylpyrazol-1-yl)quinoxalin-2(1H)-one
showed a comparative effect with streptomycin, 3-(5-oxo-3-phenyl-4,5-di- hydropyrazol-1-yl)quinoxalin-2(1H)-one was found
to be the most active with an MIC value of 7.8 μg/ml. 相似文献
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Abdulazeez Olamilekan Elemosho Emmanuel Anyachukwu Irondi Emmanuel Oladeji Alamu Emmanuel Oladipo Ajani Abebe Menkir Busie Maziya-Dixon 《Molecules (Basel, Switzerland)》2021,26(22)
Most of the health benefits derived from cereals are attributed to their bioactive compounds. This study evaluated the levels of the bioactive compounds, and the antioxidant and starch-hydrolyzing enzymes inhibitory properties of six pipeline Striga-resistant yellow-orange maize hybrids (coded AS1828-1, 4, 6, 8, 9, 11) in vitro. The maize hybrids were grown at the International Institute of Tropical Agriculture (IITA), Nigeria. The bioactive compounds (total phenolics, tannins, flavonoids, and phytate) levels, antioxidant (DPPH• and ABTS•+ scavenging capacity and reducing power) and starch-hydrolyzing enzymes (α-amylase and α-glucosidase) inhibitory activities of the maize hybrids were determined by spectrophotometry. At the same time, carotenoids were quantified using a reverse-phase HPLC system. The ranges of the bioactive compounds were: 11.25–14.14 mg GAE/g (total phenolics), 3.62–4.67 mg QE/g (total flavonoids), 3.63–6.29 mg/g (tannins), 3.66–4.31% (phytate), 8.92–12.11 µg/g (total xanthophylls), 2.42–2.89 µg/g (total β-carotene), and 3.17–3.77 µg/g (total provitamin A carotenoids). Extracts of the maize hybrids scavenged DPPH• (SC50: 9.07–26.35 mg/mL) and ABTS•+ (2.65–7.68 TEAC mmol/g), reduced Fe3+ to Fe2+ (0.25 ± 0.64–0.43 ± 0.01 mg GAE/g), and inhibited α-amylase and α-glucosidase, with IC50 ranges of 26.28–52.55 mg/mL and 47.72–63.98 mg/mL, respectively. Among the six clones of the maize hybrids, AS1828-9 had the highest (p < 0.05) levels of tannins and phytate and the strongest antioxidant and starch-hydrolyzing enzymes inhibitory activities. Significant correlations were observed between total phenolics and the following: ABTS•+ (p < 0.01, r = 0.757), DPPH• SC50 (p < 0.01, r = −0.867), reducing power (p < 0.05, r = 0.633), α-amylase IC50 (p < 0.01, r = −0.836) and α-glucosidase IC50 (p < 0.05, r = −0.582). Hence, the Striga-resistant yellow-orange maize hybrids (especially AS1828-9) may be beneficial for alleviating oxidative stress and postprandial hyperglycemia. 相似文献
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Transport in Porous Media - Microstructures affect the properties of food products; accurate and relatively less complex microstructural representations are thus needed for modelling of transport... 相似文献
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Inside Back Cover: A Nexus between Theory and Experiment: Non‐Empirical Quantum Mechanical Computational Methodology Applied to Cucurbit[n]uril⋅Guest Binding Interactions (Chem. Eur. J. 48/2016) 下载免费PDF全文
Jiří Hostaš Dr. David Sigwalt Marina Šekutor Haresh Ajani Dr. Matúš Dubecký Prof. Jan Řezáč Dr. Peter Y. Zavalij Dr. Liping Cao Christian Wohlschlager Prof. Kata Mlinarić‐Majerski Prof. Lyle Isaacs Prof. Robert Glaser Prof. Pavel Hobza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(48):17487-17487
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Gohari AR Saeidnia S Malmir M Hadjiakhoondi A Ajani Y 《Natural product research》2010,24(20):1902-1906
The genus Salvia (Lamiaceae) contains more than 50 shrub species in Iran, and Salvia limbata C.A. Meyer grows widely in the north and central parts of the country. Six flavones and rosmarinic acid were isolated from the ethyl acetate and methanol extracts of the flowered aerial parts of S. limbata collected from Semnan province. The separation process was carried out using several chromatographic methods. Structural elucidation was based on NMR data, in comparison with those reported in the literature. The isolated compounds were identified as ladanein (1), salvigenin (2), luteolin 7-methyl ether (3), cirsiliol (4), eupatorin (5), luteolin 7-O-glucoside (6) and rosmarinic acid (7). Some of these flavonoids have been reported to show antibacterial and cytotoxic activities. 相似文献