Search results for " chimica"
showing 10 items of 3438 documents
Targeting Orthosteric and Allosteric Pockets of Aromatase via Dual-Mode Novel Azole Inhibitors
2020
[Image: see text] Breast cancer (BC) is the most diffused cancer type in women and the second leading cause of death among the female population. Effective strategies to fight estrogen responsive (ER+) BC, which represents 70% of all BC cases, rely on estrogen deprivation, via the inhibition of the aromatase enzyme, or the modulation of its cognate estrogen receptor. Current clinical therapies significantly increased patient survival time. Nevertheless, the onset of resistance in metastatic BC patients undergoing prolonged treatments is becoming a current clinical challenge, urgently demanding to devise innovative strategies. In this context, here we designed, synthesized, and performed in …
Mesoporous Silica-Based Materials with Bactericidal Properties
2019
[EN] Bacterial infections are the main cause of chronic infections and even mortality. In fact, due to extensive use of antibiotics and, then, emergence of antibiotic resistance, treatment of such infections by conventional antibiotics has become a major concern worldwide. One of the promising strategies to treat infection diseases is the use of nanomaterials. Among them, mesoporous silica materials (MSMs) have attracted burgeoning attention due to high surface area, tunable pore/particle size, and easy surface functionalization. This review discusses how one can exploit capacities of MSMs to design and fabricate multifunctional/controllable drug delivery systems (DDSs) to combat bacterial …
Essential Oil Composition of Alluaudia procera and in Vitro Biological Activity on Two Drug-Resistant Models
2019
Drug resistance is a major obstacle in antibiotic and antitumor chemotherapy. In response to the necessity to find new therapeutic strategies, plant secondary metabolites including essential oils (EOs) may represent one of the best sources. EOs in plants act as constitutive defenses against biotic and abiotic stress, and they play an important role in the pharmacology for their low toxicity, good pharmacokinetic and multitarget activity. In this context, natural products such as EOs are one of the most important sources of drugs used in pharmaceutical therapeutics. The aim of this paper was to identify the chemical composition of the essential oil of Alluaudia procera leaves, obtained by hy…
Quinoline anticancer agents active on DNA and DNA-interacting proteins: From classical to emerging therapeutic targets.
2021
Quinoline is one of the most important and versatile nitrogen heterocycles embodied in several biologically active molecules. Within the numerous quinolines developed as antiproliferative agents, this review is focused on compounds interfering with DNA structure or with proteins/enzymes involved in the regulation of double helix functional processes. In this light, a special focus is given to the quinoline compounds, acting with classical/well-known mechanisms of action (DNA intercalators or Topoisomerase inhibitors). In particular, the quinoline drugs amsacrine and camptothecin (CPT) have been studied as key lead compounds for the development of new agents with improved PK and tolerability…
Recent development in fluorinated antibiotics
2019
This chapter presents the most recent results in the development of fluorinated antibioticsby taking into consideration modern challenges of multidrug-resistant pathogens. After a brief introduction on the direct and indirect effects of fluorine and fluorinated moieties in regulating biological activity, the chapter is developed in three main subsections discussing the two major classes of fluorinated antibiotics, fluoroquinolones and oxazolidinones, plus an overview of recent research on the antibiotic activity of fluorinated analogs of tetracyclines, peptidomimetics, triazoles, and nucleosides. Discussed aspects include: (1) Synthesis and challenges posed by the introduction of fluorinate…
Targeting a Targeted Drug: An Approach Toward Hypoxia-Activatable Tyrosine Kinase Inhibitor Prodrugs
2016
Tyrosine kinase inhibitors (TKIs), which have revolutionized cancer therapy over the past 15 years, are limited in their clinical application due to serious side effects. Therefore, we converted two approved TKIs (sunitinib and erlotinib) into 2-nitroimidazole-based hypoxia-activatable prodrugs. Kinetics studies showed very different stabilities over 24 h; however, fast reductive activation via E. coli nitroreductase could be confirmed for both panels. The anticancer activity and signaling inhibition of the compounds against various human cancer cell lines were evaluated in cell culture. These data, together with molecular docking simulations, revealed distinct differences in the impact of …
Development and biological investigations of hypoxia-sensitive prodrugs of the tyrosine kinase inhibitor crizotinib
2019
Despite the huge success of tyrosine kinase inhibitors as anticancer agents, severe side effects are a major problem. In order to overcome this drawback, the first hypoxia-activatable 2-nitroimidazole-based prodrugs of the clinically approved ALK and c-MET inhibitor crizotinib were developed. The 2-aminopyridine functionality of crizotinib (essential for target kinase binding) was considered as ideal position for prodrug derivatization. Consequently, two different prodrugs were synthesized with the nitroimidazole unit attached to crizotinib either via carbamoylation (A) or alkylation (B) of the 2-aminopyridine moiety. The successful prodrug design could be proven by docking studies and a dr…
Gas-phase ion chemistry of protonated melatonin
2005
The gas-phase ion chemistry of protonated melatonin has been investigated by mass spectrometric (MS) techniques involving chemical ionisation, fast atom bombardment and electrospray ionisation. Either naturally- occurring or collision-induced decomposition e-D derivatives obtained by exchange with D(2)O. The analysis of experimental results allows definite pathways for the formation of the ion at m/z 174 to be assigned and sheds some more light on the overall fragmentation pathways. Experiments on labelled derivatives evidenced H-D scrambling processes during fragmentation
Cross-Linked Thiazolidine Network as Support for Palladium: A New Catalyst for Suzuki and Heck Reactions
2015
A thiazolidine-based material was used for the first time as support for palladium. The support was prepared by starting from a highly cross-linked thiazolium-based material, obtained by radical oligomerization of a bisvinylthiazolium dibromide salt in the presence of 3-mercaptopropyl-modified silica SBA-15. Palladium was immobilized by treatment with tetrachloropalladate salt. Reduction with sodium borohydride afforded a thiazolidine-based material that acted as ligands for the Pd species. The thiazolidine-based palladium catalyst was fully characterized and, working in only 0.1 mol% amount, displayed good activity in the Suzuki-Miyaura and in the Heck reactions. Several biphenyl and alken…
EFFECT OF IONIC STRENGTH AND MEDIUM COMPOSITION ON THE REMOVAL OF Pb2+ BY ALGINATE GEL BEADS. DPVASV AND ICP-OES MEASUREMENTS.
2012
The biosorption, i.e. a passive sequestering process by metabolically inactive biomass, shows a growing interest for toxic metal ions removal from contaminated aqueous solutions (1), such as municipal and industrial wastewaters. Since the sorption mechanism occurs mainly by ion exchange between the metal ion present in solution and the counter ion of the biopolymer (2), the efficiency of the sorption process largely depends on ionic strength and on the medium composition of solution containing the metal ion to be removed. In order to evaluate quantitatively the influence of ionic strength and medium on the metal removal process by the biomass, we report here results of a study on the sorpti…