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排序方式: 共有112条查询结果,搜索用时 15 毫秒
1.
Hamid Beyzaei Mohammadreza Moghaddam-Manesh Reza Aryan Behzad Ghasemi Alireza Samzadeh-Kermani 《Chemical Papers》2017,71(9):1685-1691
Pyrazolo[3,4-d]pyrimidines are one of the most important classes of fused heterocyclic compounds which exhibit a broad range of biological and medicinal properties. They are known as anticancer, antifungal, antibacterial, antiviral and anti-inflammatory agents. In this study, some new 6-substituted 4-amino-pyrazolo[3,4-d]pyrimidine derivatives were prepared via reaction of 5-amino-3-methyl-1-phenyl-1H-pyrazole-4-carbonitrile with various nitriles in the presence of sodium ethoxide as catalyst. The inhibitory properties of synthesized compounds were studied according to CLSI guidelines against some pathogenic bacteria including four gram-positive strains (Streptococcus pyogenes, Staphylococcus aureus, Bacillus cereus and Bacillus subtilis subsp. spizizenii) and three gram-negative strains (Pseudomonas aeruginosa, Shigella flexneri and Salmonella enterica subsp. enterica). The antibacterial effects of all derivatives were compared with those of antibiotics belonging to different classes. The values were reported as inhibition zone diameter (IZD), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The effect of substituents on the biological activity of derivatives was discussed as well. The inhibitory effect of compound 6a, was shown to be the most, with MIC values in the range of 32–4096 μg/mL. Since most of the synthesized compounds were effective against Streptococcus pyogenes and Pseudomonas aeruginosa, they can be considered as inhibitors of these two bacteria. 相似文献
2.
Hanna Talacua Serge H. M. Sntjens Shraddha H. Thakkar Aurelie M. A. Brizard Lex A. van Herwerden Aryan Vink Geert C. van Almen Patricia Y. W. Dankers Carlijn V. C. Bouten Ricardo P. J. Budde Henk M. Janssen Jolanda Kluin 《Macromolecular bioscience》2020,20(7)
For in situ tissue engineering (TE) applications it is important that implant degradation proceeds in concord with neo‐tissue formation to avoid graft failure. It will therefore be valuable to have an imaging contrast agent (CA) available that can report on the degrading implant. For this purpose, a biodegradable radiopaque biomaterial is presented, modularly composed of a bisurea chain‐extended polycaprolactone (PCL2000‐U4U) elastomer and a novel iodinated bisurea‐modified CA additive (I‐U4U). Supramolecular hydrogen bonding interactions between the components ensure their intimate mixing. Porous implant TE‐grafts are prepared by simply electrospinning a solution containing PCL2000‐U4U and I‐U4U. Rats receive an aortic interposition graft, either composed of only PCL2000‐U4U (control) or of PCL2000‐U4U and I‐U4U (test). The grafts are explanted for analysis at three time points over a 1‐month period. Computed tomography imaging of the test group implants prior to explantation shows a decrease in iodide volume and density over time. Explant analysis also indicates scaffold degradation. (Immuno)histochemistry shows comparable cellular contents and a similar neo‐tissue formation process for test and control group, demonstrating that the CA does not have apparent adverse effects. A supramolecular approach to create solid radiopaque biomaterials can therefore be used to noninvasively monitor the biodegradation of synthetic implants. 相似文献
3.
Shahnaz Rostamizadeh Ali Mohammad Amani Reza Aryan Hamid Reza Ghaieni Nasrin Shadjou 《合成通讯》2013,43(20):3567-3576
A simple, inexpensive, and efficient one-pot synthesis of 2,3-dihydroquinazoline-4(1H)-one derivatives under solvent-free conditions using a catalytic amount of iodine with excellent product yields is reported. This methodology provides easy, quantitative access to various 2,3-dihydroquinazoline-4(1H)-one derivatives, using commercially available iodine as a catalyst. 相似文献
4.
A one-pot synthesis of 3,5-disubstituted 1,2,4-oxadiazoles with two identical substituents directly from the reaction of nitriles and hydroxylamine hydrochloride in the presence of potassium fluoride as catalyst and solid support under solvent-free condition is described. Moreover, the formation of products has been discussed, and a plausible mechanism has been presented. Simplicity of the process, workup in aqueous media, and excellent yields are some advantages of this method. 相似文献
5.
Aryan Reza Beyzaei Hamid Nojavan Masoomeh Pirani Fatemeh Samareh Delarami Hojat Sanchooli Mahmood 《Molecular diversity》2019,23(1):93-105
Molecular Diversity - A facile and efficient catalyst- and oxidant-free multicomponent synthesis of a small library of highly substituted pyrido[2,3-d]pyrimidine derivatives is reported. The... 相似文献
6.
Chandra Sekhar Pedamallu Linet Özdamar Tibor Csendes Tamás Vinkó 《Journal of Global Optimization》2008,42(3):369-384
A new efficient interval partitioning approach to solve constrained global optimization problems is proposed. This involves
a new parallel subdivision direction selection method as well as an adaptive tree search. The latter explores nodes (intervals
in variable domains) using a restricted hybrid depth-first and best-first branching strategy. This hybrid approach is also
used for activating local search to identify feasible stationary points. The new tree search management technique results
in improved performance across standard solution and computational indicators when compared to previously proposed techniques.
On the other hand, the new parallel subdivision direction selection rule detects infeasible and suboptimal boxes earlier than
existing rules, and this contributes to performance by enabling earlier reliable deletion of such subintervals from the search
space. 相似文献
7.
In this paper a new multidimensional extension of the recently developed one-dimensional enclosure method called kite is given for interval global optimization. A more sophisticated version of the pruning technique based on the kite method is introduced. By the new componentwise approach all the one-dimensional theoretical results and procedures can be used in the higher-dimensional case. The possibilities in the implementation of the new algorithm together with numerical results on 40 standard test problems are presented. 相似文献
8.
The minority carrier lifetime at low and high excitation densities was determined in VPE layers of GaP and GaAs?0.2 P?0.8. The lifetime at high excitation densities, having a value up to ∽350 ns, is one to two orders of magnitude larger than the lifetime at low excitation densities. It is shown that impurities are involved in some saturable killer centres dominating at low excitation densities. In the case of the largest values of the minority carrier lifetime and at a dislocation density of > 105 cm?2, the non-radiative recombination at high excitation densities is shown to occur at dislocations; at lower values of the minority carrier lifetime the killer action may be due to microprecipitates. These findings also hold for LPE layers of GaP. It is shown that by measuring the minority carrier lifetime as a function of temperature a discrimination is possible between killer action due to diffusion of minorities towards sinks like dislocations or microprecipitates and due to capture by a normal point-defect type recombination centre. 相似文献
9.
Rationally Designed Semisynthetic Natural Product Analogues for Stabilization of 14‐3‐3 Protein–Protein Interactions 下载免费PDF全文
Sebastian A. Andrei Pim de Vink Eline Sijbesma Ling Han Prof. Luc Brunsveld Prof. Nobuo Kato Prof. Christian Ottmann Dr. Yusuke Higuchi 《Angewandte Chemie (International ed. in English)》2018,57(41):13470-13474
The natural product family of fusicoccanes are stabilizers of 14‐3‐3 mediated protein–protein interactions (PPIs), some of which possess antitumor activity. In this study, the first use of molecular dynamics (MD) to rationally design PPI stabilizers with increased potency is presented. Synthesis of a focused library, with subsequent characterization by fluorescence polarization, mutational studies, and X‐ray crystallography confirmed the power of the MD‐based design approach, revealing the potential for an additional hydrogen bond with the 14‐3‐3 protein to lead to significantly increased potency. Additionally, these compounds exert their action in a cellular environment with increased potency. The newly found polar interaction could provide an anchoring point for new small‐molecule PPI stabilizers. These results facilitate the development of fusicoccanes towards drugs or tool compounds, as well as allowing the study of the fundamental principles behind PPI stabilization. 相似文献
10.
Facile Synthesis of Some Novel Tetrasubstituted 2,4‐Diaminopyrimidine Derivatives in Aqueous Glucose Solution as a Fully Green Medium and Promoter 下载免费PDF全文
A novel environmentally benign method toward the synthesis of some novel tetrasubstituted 2,4‐diaminopyrimidine derivatives using an aqueous glucose‐mediated one‐pot three‐component reaction of malononitrile with various benzaldehyde and amidine derivatives is reported. Some pyrimidine derivatives possessing α‐amino acid moiety were synthesized by the present protocol for the first time. This protocol offers advantages including facile reaction conditions, using naturally occurring glucose as promoter and water as solvent, simple work‐up, relatively short reaction times, and high yields of the products. 相似文献