ZnO nanostructures of diverse shape were grown via a solution process with different precursors and conditions. Morphological investigation of the nanostructures was carried out using field emission scanning electron microscopy and transmission microscopy observations and revealed that the nanostructures exhibit a wurtzite phase with an ideal lattice fringe distance of approximately 0.52 nm. The powder crystallinity was examined via X-ray diffraction spectroscopy. Screening results from anticancer studies of the effects on human brain tumor U87, cervical cancer HeLa, and normal HEK cells of ZnO nanostructures of diverse shape were obtained and indicate promising activity that varies with changes in the structure and the size of the particles. Treatment-induced cell death [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and survival assay], growth inhibition, cytogenetic damage (formation of micronuclei), and apoptosis were studied as parameters for the cellular response. Treatment with nanostructures enhanced growth inhibition and cell death in a concentration-dependent manner in both U87 and HeLa cell lines. At higher concentrations (above 15.6 μg/ml) the cytotoxic effects of the nanoparticles were highly synergistic and mainly mediated through apoptosis, implying the possible interactions of lesions caused by the agents. The enhanced cell death due to nanoparticles was accompanied by a significant increase (2-3 fold at 31.25 μg/ml) in the formation of micronuclei in U87 cells. The increase in the formation of micronuclei observed after treatment indicates that these structures may interfere with the rejoining of DNA strand breaks. Among all the nanostructures, nanoparticles and sheets exhibited potent activity against both HeLa and U87 cells. However, despite potent in vitro activity, all nanostructures exhibited diminished cytotoxicity against normal human HEK cells at all effective concentrations.
The fusion of fluorine in drug molecules through different fluorinating reagents remains a cornerstone in pharmaceutical chemistry. Progress in the field of deoxyfluorination through the development of novel reagents has...
Copper-catalyzed
[3 + 2] cycloadditions
of N-tosylcyclopropylamine with alkynes and alkenes
have been accomplished under visible light irradiation. The developed
approach is compatible with a range of functionalities and allows
the synthesis of diversified aminated cyclopentene and cyclopentane
derivatives being relevant for drug synthesis. The protocol is operationally
simple and economically affordable as it does not require any ligand,
base, or additives. As the key step, the one-electron oxidation of
the N-tosyl moiety by visible light-induced homolysis
of a transient Cu(II)-tosylamide complex is proposed, providing a
facile entry for N-centered radicals.
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