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11.
The development of resistance and unwanted harmful interaction with other biomolecules instead of DNA are the major drawbacks for application of platinum (Pt) complexes in cancer chemotherapy. To conquer these problems, much works have been done so far to discover innovative Pt complexes. The objective of the current study was to evaluate the anti cancer activities of a series of four and five-coordinated Pt(II) complexes, having deprotonated 2-phenyl pyridine (abbreviated as C^N), biphosphine moieties, i.e., dppm?=?bis(diphenylphosphino) methane (Ph2PCH2PPh2) and dppa?=?bis(diphenylphosphino)amine (Ph2PNHPPh2), as the non-leaving carrier groups. The growth inhibitory effect of the Pt complexes [Pt(C^N)(dppm)]PF6: C 1 , [Pt(C^N)(dppa)]PF6: C 2 , and [Pt(C^N)I(dppa)]: C 3 , toward the cancer cell lines was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. In addition, the florescence quenching experiments of the interaction between human serum albumin (HSA) and the Pt complexes were performed in order to obtain the binding parameters and to evaluate the denaturing properties of these complexes upon binding to the general carrier protein of blood stream. The structure?Cactivity relationship studies reveal that four-coordinated Pt complexes C 1 and C 2 with both significant hydrophobic and charge characteristics, not only exhibit strong antiproliferation activity toward the cancer cell lines, but also they display lower denaturing effect against carrier protein HSA. On the other hand, five-coordinated C 3 complex with the unusual intermolecular NH??Pt hydrogen binding and the intrinsic ability for oligomerization, exhibits poor anticancer activity and strong denaturing property. The current study reveals that the balance between charge and hydrophobicity of the Pt complexes, also their hydrogen binding abilities and coordination mode are important for their anticancer activities. Moreover, this study may suggest C 1 and C 2 as the potential template structures for synthesis of new generation of four-coordinated Pt complexes with strong anticancer activities and weak denaturing effects against proteins.  相似文献   
12.
The interactions of two organoplatinum complexes, [Pt(C^N)Cl(dppa)], 1, and [Pt(C^N)Cl(dppm)], 2 (C^N = N(1), C(2')-chelated, deprotonated 2-phenylpyridine, dppa = bis(diphenylphosphino)amine, dppm = bis(diphenylphosphino)methane), as antitumor agents, with bovine serum albumin (BSA) and human serum albumin (HSA) have been studied by fluorescence and UV-vis absorption spectroscopic techniques at pH 7.40. The quenching constants and binding parameters (binding constants and number of binding sites) were determined by fluorescence quenching method. The obtained results revealed that there is a strong binding interaction between the ligands and proteins. The calculated thermodynamic parameters (ΔG, ΔH, and ΔS) confirmed that the binding reaction is mainly entropy-driven, and hydrophobic forces played a major role in the reaction. The displacement experiment shows that these Pt complexes can bind to the subdomain IIA (site I) of albumin. Moreover, synchronous fluorescence spectroscopy studies revealed some changes in the local polarity around the tryptophan residues. Finally, the distance, r, between donor (serum albumin) and acceptor (Pt complexes) was obtained according to F?rster theory of nonradiation energy transfer.  相似文献   
13.
The papers have a porous structure which can be a suitable medium for the growth of bacteria. Therefore, in the sanitary papers, creation of a suitable antibacterial property is necessary. In this way, the plant extracts were prepared using solid–liquid extraction method from the Rosmarinus officinalis, Olea europaea, Mentha spicata and Punica granatum. Relatively, the total phenol and flavonoid contents were determined according to colorimetric method. Their antioxidant activity was evaluated using DPPH method. The extracts were sprayed on the surface of the handsheets, and then their antibacterial activity was investigated. The results showed that extracts from the P. granatum has the highest phenol (5.82%) and antioxidant activity (71.13%), while the extract from the R. officinalis had the highest flavonoid (4.23%) and antibacterial activity (90.43%). Hence, it can be concluded that these two extracts could be the suitable combinations to create desirable antibacterial properties in the manufacture of papers with sanitary purposes.  相似文献   
14.
Three new complexes of group thirteen metals, gallium(III), indium(III), and thallium(III) with proton transfer compounds, obtained from 2,6‐pyridinedicarboxylic acid (dipicolinic acid), were synthesized and characterized using elemental analysis, IR, 1H and 13C NMR spectroscopy and single crystal X‐ray diffraction. The gallium(III) and indium(III) complexes were prepared using (pydaH2)(pydc) (pyda = 2,6‐pyridinediamine, pydcH2 = dipicolinic acid) and thallium(III) complex was obtained from (creatH)(pydcH) (creat = creatinine). The chemical formulae and space groups of the complexes are (pydaH)[Ga(pydc)2] · 3.25H2O · CH3OH, ( 1 ), [In(pydc)(pydcH)(H2O)2] · 5H2O, Pna21 ( 2 ) and [Tl2(pydcH)3(pydc)(H2O)2], ( 3 ). Non‐covalent interactions such as ion‐pairing, hydrogen bonding and π‐π stacking are discussed. The complexation reactions of pyda, pydc, and pyda + pydc with In3+ and Ga3+ ions in aqueous solution were investigated by potentiometric pH titrations, and the equilibrium constants for all major complexes formed are described.  相似文献   
15.
Advances in Data Analysis and Classification - In recent years dictionary learning has become a favorite sparse feature extraction technique. Dictionary learning represents each data as a sparse...  相似文献   
16.
The preparation and electrocatalytic behavior of glassy carbon electrodes modified with three different cobalt porphyrin complexes were investigated. The electrocatalytic ability of the modified electrodes for the reduction of dioxygen to hydrogen peroxide and water in air‐saturated aqueous solutions was examined by cyclic voltammetry and chronoamperometry techniques. The porphyrin‐adsorbed glassy carbon electrodes possess excellent electrocatalytic abilities for dioxygen reduction with overpotential about 0.5 V lower than that at a plain glassy carbon electrode. The experimental parameters were optimized and the mechanism of the catalytic process was discussed. The possible effects of the electron‐donating properties of groups in the meso‐position of the porphyrin ring were investigated.  相似文献   
17.
This research was to apply the combination of the particle swarm optimization method and artificial neural network training with the aim of building a quantitative model to forecast the size of copper nanoparticles (Cu-NPs) prepared in sodium alginate. Sodium alginate, sodium hydroxide, copper sulfate, hydrazinium hydroxide, and ascorbic acid were used as stabilizer, pH moderator, copper precursor, reducing agent, and antioxidant, respectively. The results showed that the different sizes of Cu-NPs were obtained by changing these functions. Meaning that by increasing the amount of sodium alginate and or increase the volume of hydrazine hydrate, particle sizes of Cu-NPs were reduced. Other variables had the opposite effects due to the increase of the size of the Cu-NPs. The prediction results were remarkably in agreement with the experimental data with a correlation coefficient of 0.99 and a mean square error of 0.0058.  相似文献   
18.
A facile and efficient method for the preparation of tetrahydropyranyl ethers from alcohols is improved in solvent-free media. These reactions are catalyzed by P2O5 and afford various tetrahydropyranyl ethers in shorter reaction time, with good to excellent yields (75–95%) at room temperature. This method is also compatible with substrates containing acid-sensitive functional groups.  相似文献   
19.
Light induced cis/trans isomerization in the family of merocyanine (MC) dyes offers a recyclable proton pumping ability which can potentially be used in hybrid bio‐electronic devices. In this article, a hexadecyl MC dye is embedded in lipid molecules to make a macromolecular configuration of a lipid/hexadecyl MC membrane. Lipid molecules play a critical role in stabilizing the dye in a membrane structure for practical use in energy devices. In this study, we first examined the proton pumping characteristic of the lipid/hexadecyl MC membrane in a conventional photoelectrochemical cell. Next, a major modification in the cell was introduced by eliminating I2/I‐electrolyte which resulted in a two‐fold increase in the open circuit voltage compared with that of the conventional cell. In addition, the charging time in the new cell was reduced approximately four orders of magnitude. This research demonstrated that the newly designed lipid‐ MC cell can act as a promising bioelectronic device based on the green energy of photoinduced MC dye proton pumping.  相似文献   
20.
Haddadi  M. R.  Parvaneh  V.  Mursaleen  M.  Rakočević  V. 《Mathematical Notes》2021,110(3-4):522-531
Mathematical Notes - In this paper, we introduce a new class of algebras satisfying certain conditions which has been named power algebras and we prove some fixed point theorems for a new class of...  相似文献   
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