Search results for " inorganic"

Synthesis, characterization of diorganotin(IV) complexes of N-(2-hydroxyarylidene)aminoacetic acid and antitumour screening in vivo in ehrlich ascite…

2001

Some new diorganotin(IV) complexes have been prepared by reacting potassium N-(2-hydroxyarylidene)aminoacetate with R2SnCl2(R = Me,nBu,Ph). The complexes have been characterized by 1H,13C,119Sn NMR, IR and 119mSn Mössbauer spectroscopic techniques in combination with elemental analysis. In the solid state, the complexes possess penta- and hexa-coordinated tin centres. The hexa-coordinated tin complexes were found to dissociate in solution, giving rise to penta-coordinated species as revealed by 119Sn NMR spectroscopy. Antitumour screening in vivo of the complexes L4snPh2,L4SnPh2· Ph3SnCl and L4SntBU2·t Bu2SnCl2 (L4 = N-(2-hydroxyacetophenone)aminoacetate) is also reported. Copyright © 2001 …

Amycolatopsis balhimycina gene expression under inorganic phosphate limitation

2009

Graphene and ionic liquids new gel paste electrodes for caffeic acid quantification

2015

Abstract Graphene/ionic liquids nanocomposite gels were synthesized by an electrochemical etching approach and fully characterized under a morphological and structural point of view. For this purpose, several analytical techniques were applied, as HR-TEM/EDX (High Resolution-Transmission Electron Microscopy/Energy Dispersive X-Ray Analysis); FE-SEM/EDX (Field Emission-Scanning Electron Microscopy/Energy Dispersive X-Ray Analysis); XPS (X-Ray Photoelectron Spectroscopy); FT-IR (Fourier Transform-Infrared Spectroscopy) and electrochemical techniques. After the characterization study, nanocomposite-gel paste electrodes were assembled, exhibiting a selective and specific detection toward the ca…

Highly Selective Detection of Nerve‐Agent Simulants with BODIPY Dyes

2014

Two chromo-fluorogenic probes, each based on the boron dipyrromethene core, have been developed for the detection of nerve-agent mimics. These chemosensors display both a color change and a significant enhancement of fluorescence in the presence of diethylcyanophosphonate (DCNP) and diisopropylfluorophosphate (DFP). No interference from other organophosphorus compounds or acids has been observed. Two portable chemosensor kits have been developed and tested to demonstrate its practical application in real-time monitoring.

Highly selective fluorescence detection of hydrogen sulfide by using an anthracene-functionalized cyclam-CuII complex

2013

An anthracene-functionalised cyclam-copper(II) complex for the detection of HS- in aqueous environments has been prepared. This probe displays poor fluorescence but can selectively and sensitively detect HS- anions in water over other anions, biothiols and common oxidants such as H2O2 through remarkably enhanced emission. This turn-on response in the presence of the HS- anion is ascribed to a demetallation reaction that inhibits emission quenching observed in the initial complex as a result of the presence of the paramagnetic Cu2+ centre. Moreover, real-time fluorescence imaging measurements confirm that probe [Cu(1)](2+) can be easily used to detect intracellular HS- at micromolar concentr…

Anti-cancer activity of di- and tri-organotin(IV) compounds with D-(+)-Galacturonic acid on human tumor cells

2018

Abstract We have compared the anti-proliferative activity in vitro, of R2SnGala (1-3) [R = Me, n-Bu, Ph] and novel R3SnGala (4, 5) [R = Me, n-Bu] with D-(+)-Galacturonic acid [HGala; Galaq-, q = (2) and (1) for R2SnGala and R3SnGala, respectively] compounds, towards human tumor cell lines of intestinal carcinoma (HCT-116) and breast adenocarcinoma (MCF-7). The new synthesized 4 and 5 compounds were characterized, in solution, by 1H, 13C and 119Sn NMR, that showed that HGala acts as monoanionic moiety and evidenced the dynamic behavior of the compounds, due to inter-conversions involving the anomeric carbon atom of the ligand. Cell viability, apoptosis induction and cell cycle distribution w…

Ag5 nanoclusters with dual catalytic antiradical activities

2022

Silver nanoclusters of five atoms (Ag5) display outstanding catalytic activities for the deactivation of radicals. Using 2,2-diphenyl-1‑picrylhydrazyl (DPPH) radical as a model system, we observed a fast radical reduction to DPPH anions using only [Ag5] 3 to 4 orders of magnitude less than [DPPH]. Moreover, nanoclusters remain stable at the end of the reaction, and can deactivate again DPPH radicals at the same rate, indicating that they act as anti-radical catalysts. The radical scavenger catalytic activity of Ag5 proceeds selectively through the oxidation of methanol (used to dissolve the radical) to formaldehyde, which is supported by DFT calculations. The obtained catalytic rate constan…

DHFR Inhibitors: Reading the Past for Discovering Novel Anticancer Agents.

2019

Dihydrofolate reductase inhibitors are an important class of drugs, as evidenced by their use as antibacterial, antimalarial, antifungal, and anticancer agents. Progress in understanding the biochemical basis of mechanisms responsible for enzyme selectivity and antiproliferative effects has renewed the interest in antifolates for cancer chemotherapy and prompted the medicinal chemistry community to develop novel and selective human DHFR inhibitors, thus leading to a new generation of DHFR inhibitors. This work summarizes the mechanism of action, chemical, and anticancer profile of the DHFR inhibitors discovered in the last six years. New strategies in DHFR drug discovery are also provided, …

Revisiting the thiosemicarbazonecopper(II) reaction with glutathione. Activity against colorectal carcinoma cell lines.

2018

Thiosemicarbazones (TSCs), and their copper derivatives, have been extensively studied mainly due to the potential applications as antitumor compounds. A part of the biological activity of the TSC-CuII complexes rests on their reactivity against cell reductants, as glutathione (GSH). The present paper describes the structure of the [Cu(PTSC)(ONO2)]n compound (1) (HPTSC =pyridine-2-carbaldehyde thiosemicarbazone) and its spectroscopic and magnetic properties. ESI studies performed on the reaction of GSH with 1 and the analogous [{Cu (PTSC*)(ONO2)}2] derivative (2, HPTSC* =pyridine-2-carbaldehyde 4N-methylthiosemicarbazone) show the absence of peaks related with TSC-Cu-GSH species. However GS…

A novel compound of triphenyltin(IV) with N-tert-butoxycarbonyl-L-ornithine causes cancer cell death by inducing a p53-dependent activation of the mi…

2017

The triphenyltin(IV) compound with N-tert-butoxycarbonyl-L-ornithine (Boc-Orn-OH), [Ph3Sn(Boc-Orn-O)], was synthesized and characterized by elemental analysis, FT-IR, solution1H,13C and119Sn NMR and ESI mass spectrometry. The organotin(IV) compound inhibited at very low micromolar concentrations the growth of human tumor cell lines HepG2 (hepatocarcinoma cells), MCF-7 (mammary cancer) and HCT116 (colorectal carcinoma) while it did not affect the viability of non-malignant human-derived hepatic cells Chang. The mechanism of the antiproliferative effect of Ph3Sn(Boc-Orn-O), investigated on human hepatoma HepG2 cells, was pro-apoptotic, being associated with externalization of plasma membrane …