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Structural peculiarities and supramolecular organization of medicinally promising nanocomposites, synthesized from humic substances, which essentially differ depending on decomposition degree, have been studied using electron spin resonance, transmission electron, and confocal laser scanning microscopy techniques and some other modern physical–chemical methods. It is shown that stable zero-valent gold nanoparticle of about 10–17?nm in size are formed in a natural macromolecular matrix. The nanocomposites obtained turn out to be stable in aggregative state for a long time and preserve their properties that are extremely important for prospective medicinal substances.  相似文献   
44.
Two new heteroleptic palladium(II) complexes have been synthesized by reacting equimolar quantities of palladium(II) chloride, sodium 4‐(2‐methoxyphenyl)piperazine‐1‐carbodithioate and diphenyl‐p‐tolylphosphine ( 1 ) or tri‐p‐tolylphosphine ( 2 ). Complexes 1 and 2 have been characterized using elemental analysis, Fourier transform infrared spectroscopy, multinuclear NMR (1H, 13C and 31P) spectroscopy and single‐crystal X‐ray analysis. The latter technique confirms a pseudo square‐planar geometry in which two adjacent positions are occupied by bidentate dithiocarbamate while chloro and substituted triphenylphosphine are present at the remaining two positions. The anticancer activity of both complexes against five different cancer cell lines (LU – human lung carcinoma, established at UIC, Department of Surgical Oncology; MCF7 – human breast adenocarcinoma, ATCC number HTB‐22?; MDA‐MB‐231 – human breast adenocarcinoma, ATCC number HTB‐26?; Hepa‐1c1c7 – mouse liver hepatoma, ATCC number CRL‐2026?; PC‐3 – human prostate adenocarcinoma, ATCC number CRL‐1435?) was determined by MTT assay, revealing 2 has higher activity than 1 . A drug–calf thymus DNA binding study with UV–visible spectroscopy reveals a higher DNA binding affinity of 2 (3.511 × 104 M?1) than 1 (4.213 × 103 M?1). Density functional theory studies confirm the relatively more stable nature of 2 than 1 . Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
45.
We suggest a convenient method to obtain N-methyiphthalimide with a high yield in the reaction of phthalic anhydride with aqueous methylamine.  相似文献   
46.
In this study, single walled carbon nanotubes (SWCNTs) were covalently functionalized by terminal ethynyl bearing subphthalocyanine (SubPc) to obtain a new hybrid material, viz. SWCNT‐SubPc (CS), via “click” reaction for the first time. The structural characterization and study of the electrochemical sensor properties of the CS hybrid material to catechin were carried out. A convenient and fast analytical method was offered for the determination of catechin. It was shown that the deposition of CS on the surface of a glassy carbon electrode (GCE) led to a 2.2 and 8‐fold increase in the differential pulse voltammetry (DPV) responses to catechin in Britton‐Robinson (BR) buffer solution (a pH of 3) in comparison with SWCNT‐modified and bare GCE, respectively. The dynamic range, detection and quantification limits of catechin were determined to be 0.1–1.5 μM, 13 nM and 43 nM, respectively. Selectivity of the suggested CS/GCE sensor was investigated on addition of a number of interfering metal ions, antioxidants and biomolecules. The applicability of the modified electrode for the detection of catechin in real tea samples such as green, rosehip fruit, Turkish and Indian black tea was demonstrated with the standard addition method. Along with the ease in fabrication and low prices, the proposed CS/GCE sensor was reproducible, selective, stable and sensitive to catechin in major types of tea samples.  相似文献   
47.
The first highly asymmetric catalytic synthesis of densely functionalized dihydrobenzofurans is reported, which starts from ortho-hydroxy-containing para-quinone methides. The reaction relies on an unprecedented formal [4+1]-annulation of these quinone methides with allenoates in the presence of a commercially available chiral phosphine catalyst. The chiral dihydrobenzofurans were obtained as single diastereomers in yields up to 90 % and with enantiomeric ratios up to 95:5.  相似文献   
48.
We herein describe a facile and versatile synthetic route to the tetracyclic system of 6‐substituted 5,6‐dihydro‐11H‐pyrido[3,2‐i]‐1‐azacarbazoles with promising anticancer properties. These derivatives are built up by an elegant one‐step base‐catalyzed synthetic procedure from commercially available building blocks. One additional step provides the corresponding skeleton hitherto unknown in the literature. The possibility to synthesize a large library of compounds with various substitution patterns utilizing this method underlines the importance of this synthetic procedure.  相似文献   
49.
We previously reported the synthesis and characterization of new organometallic chalcones derived from ferrocene, cyrhetrene and cymantrene functionalized with a benzo‐15‐crown‐5 fragment. The ferrocene and cyrhetrene chalcones have been investigated as chemosensors for metal ions with optical response in acetonitrile. Several metal ions were selected considering the diameter of the cavity and the charge‐to‐radius ratio of the cation. The stoichiometry of the complexes was determined using Job's method. It was found that Na+ and Ca2+ complexes have a 1:1 stoichiometry while a 2:1 (metaloligand‐to‐cation) stoichiometry was determined for Ba2+ and Pb2+ complexes. The association constants were calculated according to the stoichiometry of the complex and the results showed that they are directly affected by the electron‐withdrawing nature of the organometallic fragment. Moreover, complexes of ferrocenyl chalcone have larger association constants than those of the cyrhetrenyl analogue. This experimental observation is consistent with the electronic properties of the ferrocenyl fragment.  相似文献   
50.
Abstract

Isocyanatophosphoric acid dichlondes was used for introduction of phosphorus-containing groups at electron-excess heterocycles. Hetaryl containing dichlorophosphates, convenient starting material for synthesis for wide set of derivatives, were prepared by C-acylation with this reagent.  相似文献   
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