Sharif Digital Repository

Salicylaldehyde-amino acid Schiff base complexes are used as non-enzymatic models for the metal-pyridoxal (Vitamin B6) amino acid Schiff base systems which are key intermediates in many metabolic reactions of amino acids catalyzed by enzymes which require pyridoxal as a cofactor (transamination, decarboxylation, α and β elimination, racemization, etc.). In addition, complexes of amino acid Schiff bases are considered to constitute new kinds of potential anticancer, antitumor, antiradical and antibacterial reagents. On the other hand nuclear magnetic resonance imaging (MRI), has become a powerful tool for clinical diagnostics thanks to the development of a new class of pharmaceuticals... 

In this study new magnetic solid phase extraction (MSPE) methods based on Fe3O4 magnetic nanoparticles (NPs) for extraction and preconcentration of oxadiargyl and fuoxetine from aqueous and biological samples were developed. In the first work, Fe3O4 NPs was successfully used as a magnetic nano-sorbent in magnetic micro-solid phase extraction (M-µ-SPE) of oxadiargyl, a newly used pesticide, from environmental water samples prior to gas chromatography-mass spectrometry determination. Oxadiargyl in mild acidic condition has tendency to be adsorbed on Fe3O4 NPs surfaces. Most important parameters that affect the extraction efficiency were also studied. Under optimized condition, the proposed... 

A novel Fe3O4/poly (aniline-naphthylamine) (ANI-NA)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for magnetic solid phase extraction. The extraction efficiency of this sorbent was examined by isolation of rhodamine B (RhB), a mutagenic and carcinogenic dye from aquatic media in dispersion mode. The efficiency of the synthesized Fe3O4/copolymer composite was examined and compared with Fe3O4/polyaniline (PANI) and Fe3O4/polynaphthylamine (PNA) by quantification of RhB using spectrofluorimetry. Among them, Fe3O4/poly (ANI-NA) nanocomposite showed a prominent efficiency. The scaning electron microscopy (SEM) image of the synthesized... 

By considering previous works undertaken in our laboratory on the interaction between O2N2 azacrown and [60]fullerene using UV-vis spectroscopy. It was found that the significant interaction occurs in less than one hour. Extending this time in this research, the reaction between [60]fullerene with 15 to 19 membered N2O2-azacrown macrocyclic ligands was investigated during ten days. The new compounds L1, L2 were synthesized and characterized applying HPLC, ESI-Mass, TG, DSC, IR as well as elemental analysis. The interaction of new compounds with Cu(II) and Ni(II) and Co(II) using UV-vis spectroscopy showed that L2 gave the highest Kb value of cations/(L1, L2). Besides, it was found that the... 

In the present research, a series of bimacrocyclic tweezer anchored through azobenzene moiety were synthesized and characterized by applying IR spectroscopy, 1H and 13C{1H} NMR, fluorescence spectroscopy, UV-visible spectroscopy, mass spectrometry and elemental analysis and in some cases by X-ray crystallography. Firstly, UV-visible spectroscopy established that the irradiation of the tweezers with UV light promoted the trans to cis isomerization. On the other hand, thermal cis-trans isomerization behavior of the azobenzene moiety in tweezers was surveyed in which the cis isomers were formed of the heating at 50 oC for 5 minutes. Where the -OH group was replaced with 4-toluenesulfonyl... 

In recent years, indirect methods of cancer detection that utilize changes in trace element levels in various parts of the body, such as hair and nails, have garnered significant attention from researchers.The primary objective of these methods is to identify alterations in trace element levels that serve as biological markers in the presence of disease. While direct examination of affected organs remains the gold standard for cancer diagnosis, it is often expensive, time-consuming, inconvenient, and associated with potential side effects. Therefore, if the effectiveness of this approach is validated, it could serve as a cost-effective, non-invasive, safe, and early diagnostic method in... 

Bisulfite is a food additive with preservative and antioxidant properties; however, excessive use can severely damage nutritional compounds in food, reducing nutritional value. Moreover, it can lead to the development of sensitivities, asthma, localized heart anemia, and lung cancer. Therefore, it is essential to establish a simple, innovative, fast, and reliable method for bisulfite identification in foodstuffs. In this research, a novel fluorescence sensor based on manganese oxide nanosheets and carbon dots was designed for bisulfite detection in food samples. Initially, manganese oxide nanosheets were synthesized via a bottom-up approach, and carbon dots were produced using a hydrothermal...