The use of DCC, triethylamine and 4-dimethylaminopyridine in dichloromethane provides a general and standard one-pot procedure for the O-acylation of cyclic β-dicarbonyl compound derivatives (1) with palmitic and stearic acids which have long hydrocarbon tails, to synthesis of new type of fatty acid derivative in good to excellent yields. Structure elucidation was carried out by FT-IR, 1H NMR and 13C NMR spectroscopy techniques. The acyl migration was also found in results and the corresponding structure was characterized by X-ray crystallography. A proposed mechanism was discussed for the formation of products. 相似文献
We report the synthesis of iron oxide magnetic nanoparticles (IONPs) coated with various natural amino acids (AAs) using a one‐pot reaction in an aqueous medium. Several AAs, which contained hydrophilic and hydrophobic groups, were selected to study their effects on size, morphology and toxicity of IONPs. Functionalized IONPs were characterized using X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning and transmission electron microscopies. Furthermore, vibrating sample magnetometry analysis shows these nanoparticles have excellent magnetic properties. Cellular toxicity of IONPs was also investigated on HFF2 cell lines. The AA‐coated IONPs are non‐toxic and biocompatible. Natural AA‐coated IONPs show a potential for their development in in vitro and in vivo biomedical fields due to their non‐toxicity, good ζ‐potential and related small size and narrow size distribution. 相似文献
The complex anatomy of teeth limits the accessibility and efficacy of regenerative treatments. Therefore, the application of well-known inducers as injectable hydrogels for the regeneration of the dentin-pulp complex is considered a promising approach. In this regard, this study aimed to develop an injectable hydrogel containing mineral trioxide aggregate (MTA). The injectable chitosan/oxidized-nanocrystalline cellulose/MTA (CS/OCNC/MTA) hydrogels were prepared, and the physicochemical properties of these hydrogels were evaluated by TGA, FTIR, Rheological analysis, and SEM. Moreover, the effect of MTA on the swelling and degradability of scaffolds was assessed. The proliferative effects of synthesized hydrogels were also determined on human dental pulp stem cells (hDPSCs) by MTT assay. For induction of differentiation and biomineralization in these cells, the alkaline phosphatase activity and Alizarin Red S staining tests were performed in the presence of fabricated scaffolds. The proliferation of hDPSCs was significantly increased in the presence of these hydrogels. Moreover, the addition of MTA to hydrogel structure dramatically improved the differentiation of hDPSCs. These results suggested that this novel injectable hydrogel provides appropriate physiochemical properties and can be considered a promising scaffold for regenerative endodontic procedures.
A series of polysubstituted cyclopentadienephosphonate derivatives were synthesized via one-pot multicomponent reactions of primary amines and phosphites with activated acetylenic compounds in water as the solvent at room temperature.Particularly valuable features of this method include high yields of products, broad substrate scope, short reaction time and a straightforward procedure. 相似文献
Theoretical investigation of linear and nonlinear optical (NLO) properties in simple complexes consist of alkali metals and π-conjugated systems have been studied at MP2/6-311++G(2d,2p) computational level. Lithium, sodium, and potassium as alkali metals were chosen for interaction with some non-aromatic, aromatic and anti-aromatic systems. For better comparison of results, the π-systems were chosen with the same carbon number: butadiene as a non-aromatic in comparison with cyclobutadiene as an anti-aromatic and hexatriene as a non-aromatic in comparison with benzene as an aromatic system. Results revealed that gap energy of studied π-systems was decreased under the interacting with alkali metals. Furthermore all designed complexes were shown very good results in average polarizability (α) and first hyperpolarizability (β0) parameters. So these very simple dimer complexes could be introduced as promising innovative nonlinear optical materials. 相似文献
The present research employs density functional theory(DFT) computations to analyze the structure and energy of complexes formed by psoralen drug with alkali(Li+, Na+, K+) and alkaline earth(Be2+, Mg2+, Ca2+) metal cations. The computations are conducted on M06-2X/aug-cc-pVTZ level of theory in the gas phase and solution. The Atoms in Molecules(AIM) and natural bond orbital(NBO) analyses are applied to evaluating the characterization of bonds and the atomic charge distribution, respectively. The results show that the absolute values of binding energies decrease with going from the gas phase to the solution. Furthermore, the considered complexes in the water(as a polar solvent) are more stable than the CCl4(as a non-polar solvent). The DFT based chemical reactivity indices, such as molecular orbital energies, chemical potential, hardness and softness are also investigated. The outcomes show that the considered complexes have high chemical stability and low reactivity from the gas phase to the solution. Finally, charge density distributions and chemical reactive sites of a typical complex explored in this study are obtained by molecular electrostatic potential surface. 相似文献
In the present work, the influence of substituents on cooperativity between CH···π and N···H hydrogen bonds is theoretically investigated in the T-shaped configuration of X-benzene⊥(FH···pyrazine···HF) complexes. The calculations are performed at MP2(FC)/6-311++G(d,p) level of theory. The results indicate that the absolute value of binding energy increases as the substituent changes from strong electron acceptor to strong electron donor. Moreover, cooperative and synergistic energies are computed in the complexes. The energetic data reveal a direct correlation between the electron-donating power of substituents and favorable influences of CH···π and N···H hydrogen bonds on each other. The results of AIM and NBO analyses show that the N···H hydrogen bond is strengthened by going from electron acceptor substituents to electron donor ones. It is also found that Hammett constants can be used to predict cooperative and synergistic effects between CH···π and N···H hydrogen bonds. 相似文献
New Schiff base (SB) functionalized graphene oxide (GO) nanosheets containing phosphomolybdic counter‐anion H2PMo12O40¯ (H2PMo) were successfully prepared by grafting of 3‐aminopropyltriethoxysilane (APTS) on GO nanosheets followed by condensation with benzil and finally reaction with phosphomolybdic acid (H3PMo12O40, denoted as H3PMo) and characterized using Fourier transform infrared (FT‐IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), particle size distribution, energy‐dispersive X‐ray (EDX) analysis, EDX elemental mapping, and inductively coupled plasma optical emission spectrometry (ICP‐OES). The prepared new nanomaterial, denoted as GO‐SB‐H2PMo, was shown to be an efficient heterogeneous catalyst in one‐pot, three‐component reaction of β‐naphthol, aldehydes, and dimedone, giving high yields of tetrahydrobenzo[a]xanthene‐11‐ones within short reaction times. The catalyst is readily recovered by simple filtration and can be recycled and reused several times with no significant loss of catalytic activity. 相似文献