排序方式: 共有128条查询结果,搜索用时 31 毫秒
51.
Glycodendrimers have attracted considerable interest in the field of dendrimer sciences owing to their plethora of implications in biomedical applications. This is primarily due to the fact that cell surfaces expose a wide range of highly diversified glycan architectures varying by the nature of the sugars, their number, and their natural multiantennary structures. This particular situation has led to cancer cell metastasis, pathogen recognition and adhesion, and immune cell communications that are implicated in vaccine development. The diverse nature and complexity of multivalent carbohydrate–protein interactions have been the impetus toward the syntheses of glycodendrimers. Since their inception in 1993, chemical strategies toward glycodendrimers have constantly evolved into highly sophisticated methodologies. This review constitutes the first part of a series of papers dedicated to the design, synthesis, and biological applications of heterofunctional glycodendrimers. Herein, we highlight the most common synthetic approaches toward these complex molecular architectures and present modern applications in nanomolecular therapeutics and synthetic vaccines. 相似文献
52.
53.
Leyla Yurttaş Aslıhan Kubilay Asaf Evrim Evren İpek Kısacık Hülya Karaca Gençer 《Phosphorus, sulfur, and silicon and the related elements》2020,195(9):767-773
AbstractSome new 3,4,5-trisubstituted 1,2,4-triazole derivatives were synthesized and studied for their antimicrobial activity. The lead compounds were obtained starting from 8-hydroxyquinoline and ethyl 2-chloroacetate. The obtained ester compound (1) first reacted with hydrazine hydrate (2) then with phenyl isothiocyanate (3). Ring closure by KOH led to 3-mercapto-1,2,4-triazole derivative (4). Lastly, it reacted with 2-chloro-N-(substituted (benzo)/thiazole)acetamide derivatives to obtain the final compounds (5a–j). The structural elucidation of the compounds was performed by 1H NMR and 13C NMR spectroscopy and high resolution mass spectrometry techniques and elemental analysis. The synthesized compounds were investigated for their antimicrobial activities against seven bacteria and four fungi. As a result of the activity studies, it was observed that compounds N-(6-nitrobenzothiazol-2-yl)-2-[[4-phenyl-5-((quinolin-8-yloxy)methyl)-4H-1,2,4-triazol-3-yl]thio]acetamide (5a) and N-(6-fluorobenzothiazol-2-yl)-2-[[4-phenyl-5-((quinolin-8-yloxy)methyl)-4H-1,2,4-triazol-3-yl]thio]acetamide (5d) were the most active molecules. Also, the antifungal activity of the compounds was found to be higher than their antibacterial activity although lower than the standard drug’s potential. Additionally, the physicochemical properties of the compounds were calculated which were evaluated to be at a suitable range for oral administration. 相似文献
54.
AliH. Merili Sevda Prldar Sevda Süzge Leyla Biti Filiz Merili Hasan
zelik Josef Zapp Hans Becker 《Helvetica chimica acta》2006,89(2):210-217
From the aerial parts of Aconitum cochleare Woroschin, two new norditerpenoid alkaloids named aconitilearine ( 1 ) and N‐deethylmethyllycaconitine ( 2 ) were isolated along with the eight known norditerpenoid alkaloids 3 – 10 . The structures for the new compounds were established on the basis of 1H, 13C, DEPT, homonuclear 1H,1H‐COSY, NOESY, HSQC, and HMBC NMR studies. 相似文献
55.
56.
Self‐Assembled Functional DNA Superstructures as High‐Density and Versatile Recognition Elements for Printed Paper Sensors 下载免费PDF全文
Prof. Dr. Meng Liu Dr. Qiang Zhang Dr. Balamurali Kannan Prof. Dr. Gianluigi A. Botton Jie Yang Prof. Leyla Soleymani Prof. Dr. John D. Brennan Prof. Dr. Yingfu Li 《Angewandte Chemie (International ed. in English)》2018,57(38):12440-12443
Micrometer‐sized functional nucleic acid (FNA) superstructures (denoted as 3D DNA) were examined as a unique class of biorecognition elements to produce highly functional bioactive paper surfaces. 3D DNA containing repeating sequences of either a DNA aptamer or DNAzyme was created from long‐chain products of rolling circle amplification followed by salt aging. The resulting 3D DNA retained its original spherical shape upon inkjet printing and adhered strongly to the paper surface via physisorption. 3D DNA paper sensors showed resistance to degradation by nucleases, suppressed nonspecific protein adsorption, and provided a much higher surface density of functional DNA relative to monomeric FNAs, making such species ideally suited for development of paper‐based biosensors. 相似文献
57.
Akın Baysal Feyyaz Durap Bahattin Gümgüm Leyla T. Yıldırım Dinçer Ülkü Ayse Dilek Boğa Saim Özkar 《Helvetica chimica acta》2007,90(6):1211-1217
The reaction of 1,5‐dihydro‐2H‐cyclopenta[1,2‐b:5,4‐b′]dipyridin‐2‐one ( 3 ) with an alkylamine (butylamine, hexylamine or ethylenediamine) yields, quite unexpectedly and in the absence of catalyst, the novel compound 1,5‐dihydro‐2H‐cyclopenta[1,2‐b:5,4‐b′]dipyridin‐2‐imine ( 4 ) as the sole, analytically pure, solid product, which was fully characterized. The structure of 4 was unequivocally solved by single‐crystal X‐ray‐diffraction analysis. The compound crystallizes in a monoclinic cell (space group P 21/c), with two molecules in the asymmetric unit, held together by intermolecular H‐bonds. Compound 4 could be interesting as a bi‐ or even tridentate ligand, and exhibits a strong fluorescence upon excitation at 310 nm. A mechanism, based on the observed C? N bond cleavage, is proposed. 相似文献
58.
We have calculated the transition energies (ionization potential, excitation energies, electron affinity) of neutral lanthanum
(La I) and singly ionized lanthanum (La II). The calculations are based upon the multiconfiguration Hartree-Fock (MCHF) method
within the framework of Breit-Pauli relativistic corrections. These energies are important for determination of physical and
chemical properties for La I and La II. Results obtained have been compared with other works. 相似文献
59.
Leyla Pehlivan Estelle Métay Dominique Delbrayelle Gérard Mignani Marc Lemaire 《Tetrahedron》2012,68(15):3151-3155
An efficient method for the reduction of phosphine oxide derivatives into their corresponding phosphines is described. The system InBr3/TMDS allows the reduction of different secondary and tertiary phosphine oxides as well as aliphatic and aromatic phosphine oxides. 相似文献
60.
We have conducted molecular dynamics simulations to study the frictional properties of alkanethiols CH(3)(CH(2))(n-1)SH (Cn, 12 ≤ n ≤ 15) self-assembled monolayers (SAMs) on Au(111) surfaces, under various loading and shearing conditions. For the examined alkanethiols, we found some evidence of the friction coefficient being dependent on the number of carbon atoms in the molecule being odd or even. Alkanethiols with n = odd show consistently higher friction coefficients than those with n = even. Such odd-even effect seems to be independent of the sliding velocity. However, the effect is significant only at lower loads (<700 MPa). The structural origin of this odd-even effect has been discussed. The effect of loading on the structure is also studied. For dodecanethiol (n = 12) we find the film responds to increased loading initially by increasing the tilt and then by deformation of individual molecules. SAM-Au contacts under shear show periodic storage and release of energy and a clear stick-slip pattern in the shear stress, film thickness, and the tilt and tilt orientation angles. 相似文献