74568-07-3Relevant articles and documents
Joining a host-guest platform and a light-emission motif: Pyrazinamide-calixarene hybrids
Alvarenga, Meiry Edivirges,Alves, Rosemeire Brondi,Guimar?es, Freddy Fernandes,Lara, Thiago Vinicius Costa,Maia, Lauro June Queiroz,Martins, Felipe Terra,da Silva, Cleiton Moreira,de Santana, Ricardo Costa
, (2022/03/07)
Calixarenes are macrocyclic polyphenols widely used as hosts in supramolecular chemistry approaches. Recently, aminopyrazine has emerged as a high-efficiency blue light emitting moiety. Inspired by this knowledge, here we prepared two pyrazinamide-calixarene hybrids, in order to join in a single molecular platform both host-guest and light-emission properties. Both compounds were decorated with pyrazinamide at the upper rim, on two phenyl rings alternated into the four-units of the calixarene macrocycle. Their difference was the t?butyl substitution on the other two alternate phenyl rings. The t?butyl substituted derivative crystallized in two crystal forms, a non-solvated and a DMF mono-solvate phase, both with just one crystallographically independent hybrid molecule, while the compound without t?butyl moieties crystallized with three hybrid conformers and four DMF molecules. The molecular substitution pattern has also impacted on the crown conformation, being related to more inclined pyrazinamide-phenyl average planes in the absence of the t?butyl substituents. The coplanarity pattern between pyrazinamide and its bonded phenyl ring and the conformational profile of this substituent changed among the three conformers of derivative without the t?butyl group and between those assembling the two crystals forms of the other compound, which was also found in our DFT calculations. Under an excitation wavelength of 388 nm, a broad band emission between 400 nm and 550 nm was found for the three crystal forms, with maxima at ca. 500 nm, with low quantum yields of up to 0.4%. TD-DFT absorption spectra were overlaid to the experimental excitation spectra, while the low efficiency was rationalized both as an effect of the DMF guest and the tail-to-tail π…π stacking interactions between coplanar pyrazinamide-phenyl moieties of the centrosymmetric related molecules.
Synthesis of new calix[4]arene derivatives and evaluation of their cytotoxic activity
Oguz, Mehmet,Yildirim, Ayse,Durmus, Irem Mukaddes,Karakurt, Serdar,Yilmaz, Mustafa
, p. 52 - 59 (2021/11/03)
Since calixarenes are more easily synthesized and functionalized than other supramolecules, they are compounds of interest in organic chemistry. In this study, the dihydrazide (3a and 3b) and diamino propyl (6a and 6b) derivatives of p-tert-butylcalix[4]arene and calix[4]arene were synthesized. Then the L-proline methyl ester substituted chlorocyclopropenium was reacted with the calix[4]arene derivatives (3a, 3b, 6a, and 6b) at room temperature in CH2Cl2 to obtain calix[4]arene superbase derivatives (4a, 4b, 7a, and 7b) in 75%, 60%, 70%, and 55% yield, respectively. The synthesized compounds’ structure was elucidated using spectroscopic techniques (FTIR, 1H NMR, and 13C NMR). The cytotoxic properties of the calix[4]arene superbase derivatives were investigated against different human cancer cell, including A549, DLD-1, HEPG2, and PC-3 and human healthy epithelium cell line PNT1A. The cytotoxicity results showed that calix[4]arene superbase derivatives inhibited the proliferation of DLD-1, A549, HEPG2, and PC-3 cells in a dose-dependent manner. Compound 7a had the highest toxic effect on colorectal carcinoma (IC50: 4.7 μM), and the IC50 values were 18.5 μM and 74.4 μM against human prostate and lung cancer cells, respectively. Furthermore, compound 4b was found more effective on hepatocellular carcinoma cells (IC50: 210.2 μM). As a result, the synthesized calix[4]arene superbase derivatives can be developed to treat different human cancer cell. They can be considered as a preliminary result for molecular-level research. [Figure not available: see fulltext.]
Optimization of toxic metal adsorption on DEA-calix[4]arene appended silica resin using a central composite design
Gul, Samiha,Memon, Fakhar N.,Memon, Shahabuddin
, p. 3448 - 3463 (2022/02/21)
The present study is devoted to the application of Central Composite Design (CCD) to purify water contaminated with toxic metal ions (Pb2+, Cd2+ and Hg2+) using a p-tert-diethanolaminomethylcalix[4]arene (DEA-C4) based silica resin. The synthesized material was characterized using SEM, FTIR and EDX techniques. Three effective parameters (pH, adsorbent dosage and concentration of metal ion) were optimized by assessment with CCD. The data was analyzed using the quadratic model and the obtained results revealed the highest % adsorptions for Pb2+ (92.7), Cd2+ (93.7) and Hg2+ (88.2) at the optimum points for pH (5.4, 3.18 and 3.89), adsorbent dosage (23.8, 25.5 and 26.12 mg) and metal ion concentration (5.3, 7.62 and 7.18 ppm), respectively. Analysis of variance (ANOVA) results show a good fit for the regression model, showing R2 values of 0.99 for Pb2+, 0.99 for Cd2+ and 0.98 for Hg2+. Furthermore, the results from Freundlich adsorption isotherms suggest its favorability, as the values for n are >1 (i.e., 7.06, 8.85 and 13.2) and there are higher values for R2 = 0.97, 0.99 and 0.98 for Pb2+, Cd2+ and Hg2+, respectively. However, for the Langmuir isotherm, the value of the separation factor RL is >1 (1.01, 1.02 and 1.05 for Pb2+, Cd2+ and Hg2+, respectively), revealing its un-favorability. In kinetics, the pseudo-second-order kinetic model (Ho and McKay) shows R2 values of 0.998, 0.999 and 0.999 for Pb2+, Cd2+ and Hg2+, suggesting the chemical reaction seems significant in the rate controlling step. The thermodynamic results concluded that the reaction is spontaneous and exothermic in nature.
