Search results for "Azolium"
showing 10 items of 148 documents
Oleanonic acid, a 3-oxotriterpene from Pistacia, inhibits leukotriene synthesis and has anti-inflammatory activity.
2001
One of the best known bioactive triterpenoids is oleanolic acid, a widespread 3-hydroxy-17-carboxy oleanane-type compound. In order to determine whether further oxidation of carbon 3 affects anti-inflammatory activity in mice, different tests were carried out on oleanolic acid and its 3-oxo-analogue oleanonic acid, which was obtained from Pistacia terebinthus galls. The last one showed activity on the ear oedema induced by 12-deoxyphorbol-13-phenylacetate (DPP), the dermatitis induced by multiple applications of 12-O-tetradecanoyl-13-acetate (TPA) and the paw oedemas induced by bradykinin and phospholipase A2. The production of leukotriene B4 from rat peritoneal leukocytes was reduced by ol…
Bovine seminal ribonuclease is cytotoxic for both malignant and normal telomerase-positive cells
2005
Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating nor…
An approach to As(III) and As(V) bioavailability studies with Caco-2 cells
2005
Foods and drinking water are the main sources of human exposure to inorganic arsenic [As(III) and As(V)]. After oral ingestion, the intestinal epithelium is the first barrier to absorption of these species. A human intestinal cell line (Caco-2) was used to evaluate cell retention and transport of As(III) (15.6-156.0 microM) and/or As(V) (15.4-170.6 microM). Cell monolayer integrity, cell viability, membrane damage and effects on cell metabolism were evaluated. Only the highest concentrations assayed [As(III): 156.0 microM; As(V): 170.6 microM] produced a cytotoxic effect with different cellular targets: As(III) altered the permeability of tight junctions, and As(V) caused uncoupling of the …
Toxicity evaluation of individual and mixed enniatins using an in vitro method with CHO-K1 cells
2013
Enniatins (ENs) A, A1, B and B1 are produced by Fusarium species. They are known as emerging fusario- toxins, and can cause outbreaks in both humans and animals. ENs elicits a wide range of different biolog- ical properties and toxicological effects, and their co-occurrence may enhance the extent of these hazards. As the potential toxins reach in vitro cells in the same way as they would in vivo, cytotoxicity was studied with CHO-K1, which is considered one of the most sensitive cell lines for preliminary screen- ing of cytotoxicity studies. In this study, individual cytotoxic effects of ENs were evaluated by MTT assay after exposing ENs to CHO-K1 cells for 24, 48, and 72 h. The IC50 values…
Studies on the mechanism of PMN activation. I. By dextran sulfates.
1982
Evidence is presented that enhanced reduction of the dye nitroblue-tetrazolium (NBT) by polymorphonuclear leukocytes (PMN) which are stimulated by dextran sulfates (DS) is not exclusively due to the phagocytosis of particles formed by NBT and DS. Not only the size of phagocytizable particles but the degree of substitution determines the acceleration of NBT-reduction. A likely cause of this acceleration is the triggering of the alternative pathway of the complement activation.
Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State
2006
Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chlori…
Azolium and acetate ions in DMF: Formation of free N-heterocyclic carbene. A voltammetric analysis
2016
In order to reveal the possible formation of free N-heterocyclic carbene (NHC) in DMF-azolium and acetate solutions, the proton exchange equilibrium between azolium cations and CH3COO− was investigated (by cyclic voltammetry) by adding CH3COOH or tetrabutylammonium acetate to DMF solutions of imidazolium or thiazolium salts of different acidity.The voltammetric analysis confirms that the deprotonation of the azolium cation by CH3COO− (with the formation of free NHC) is significant in the case of the more acidic thiazolium cations, while it is not effective with the less acidic imidazolium ones.Accordingly, the NHC-catalyzed benzoin condensation was carried out in DMF solutions of azolium sa…
DICATIONIC IMIDAZOLIUM SALTS: TUNABLE ANTIMICROBIAL AND ANTITUMORAL CHEMIOTHERAPEUTIC LEADS
2015
The chemical synthesis of novel chemotherapeutical leads is evolving thanks to possibility to design molecules with desired physical-chemical and, thus, biological properties. The imidazolium salts, recently proven effective to inhibit bacterial and/or cancer cell growth, posses an amphiphilic nature that is conferred by the imidazolium cation having a polar head generally coupled with aliphatic side chains. Thus, biological properties of imidazolium salts can be tuned through modifications involving the cation structure and/or the anion nature. By covalently linking two imidazolium rings, di-imidazolium salts were obtainedobtain differing in: i) kind of anions; ii) geometric isomerization …
Experimental conditions affect the site of tetrazolium violet reduction in the electron transport chain of Lactococcus lactis
2009
The reduction of tetrazolium salts to coloured formazans is often used as an indicator of cell metabolism during microbiology studies, although the reduction mechanisms have never clearly been established in bacteria. The objective of the present study was to identify the reduction mechanisms of tetrazolium violet (TV) in Lactococcus lactis using a mutagenesis approach, under two experimental conditions generally applied in microbiology: a plate test with growing cells, and a liquid test with non-growing (resting) cells. The results showed that in both tests, TV reduction resulted from electron transfer from an intracellular donor (mainly NADH) to TV via the electron transport chain (ETC), …
CCDC 127933: Experimental Crystal Structure Determination
2001
Related Article: S.Kiviniemi, M.Nissinen, M.T.Lamsa, J.Jalonen, K.Rissanen, J.Pursiainen|2000|New J.Chem.|24|47|doi:10.1039/a907608e