Search results for "stereo"

Development and testing of a tool for learning stereometry at high school: Poster

2021

Development and application of (bio)analytical methodologies in capillary electrophoresis. Enantioselectivity considerations

2014

El desarrollo de nuevos fármacos es un proceso largo, complejo y costoso que incluye la evaluación en diferentes etapas de propiedades farmacocinéticas y farmacodinámicas de la nueva molécula. En las primeras etapas del desarrollo de un fármaco es habitual el uso de métodos in vitro para el cribado de alto rendimiento de las propiedades de nuevas moléculas, con el objetivo de obtener datos preliminares sobre la potencial actividad farmacológica de una molécula y sobre su farmacocinética. Cuando se emplean moléculas quirales, tanto sus propiedades farmacocinéticas como las farmacodinámicas pueden presentar un cierto grado de enantioselectividad debido a la interacción con biomacromoléculas ó…

Kultur i svenskundervisning : det nordiska inslaget i läroböckerna i svenska

2002

Pyrithione-based ruthenium complexes as inhibitors of aldo-keto reductase 1C enzymes and anticancer agents.

2016

Four ruthenium complexes of clinically used zinc ionophore pyrithione and its oxygen analog 2-hydroxypyridine N-oxide were prepared and evaluated as inhibitors of enzymes of the aldo–keto reductase subfamily 1C (AKR1C). A kinetic study assisted with docking simulations showed a mixed type of inhibition consisting of a fast reversible and a slow irreversible step in the case of both organometallic compounds 1A and 1B. Both compounds also showed a remarkable selectivity towards AKR1C1 and AKR1C3 which are targets for breast cancer drug design. The organoruthenium complex of ligand pyrithione as well as pyrithione itself also displayed toxicity on the hormone-dependent MCF-7 breast cancer cell…

Nitensidine A, a guanidine alkaloid from Pterogyne nitens, is a novel substrate for human ABC transporter ABCB1.

2014

The Pterogyne nitens (Fabaceae) tree, native to South America, has been found to produce guanidine alkaloids as well as bioactive flavonols such as kaempferol, quercetin, and rutin. In the present study, we examined the possibility of interaction between human ATP-binding cassette (ABC) transporter ABCB1 and four guanidine alkaloids isolated from P. nitens (i.e., galegine, nitensidine A, pterogynidine, and pterogynine) using human T cell lymphoblast-like leukemia cell line CCRF-CEM and its multi-drug resistant (MDR) counterpart CEM/ADR5000. In XTT assays, CEM/ADR5000 cells were resistant to the four guanidine alkaloids compared to CCRF-CEM cells, although the four guanidine alkaloids exhibi…

Partially competitive inhibition of intestinal baclofen absorption by beta-alanine, a nonessential dietary aminoacid.

1991

In situ intestinal absorption of baclofen in the rat in the presence of beta-alanine has been investigated. Through the perfusion of 0.50 mM baclofen solutions containing variable concentrations of the aminoacid (from 5 to 100 mM), a partially competitive inhibition of baclofen absorption was characterized: absorption rate pseudoconstants of the spasmolytic drug decrease as beta-alanine concentration increases, until a limiting value is obtained (36.8 per cent of that found for baclofen alone). A computer method was developed in order to calculate parameters governing baclofen absorption in the presence of beta-aminoacid, with the following results: Vm = 11.22 mM h-1; Km = 7.42 mM; Ki = 2.4…

Estimation of ADME Properties in Drug Discovery: Predicting Caco-2 Cell Permeability Using Atom-Based Stochastic and Non-stochastic Linear Indices

2007

The in vitro determination of the permeability through cultured Caco-2 cells is the most often-used in vitro model for drug absorption. In this report, we use the largest data set of measured P(Caco-2), consisting of 157 structurally diverse compounds. Linear discriminant analysis (LDA) was used to obtain quantitative models that discriminate higher absorption compounds from those with moderate-poorer absorption. The best LDA model has an accuracy of 90.58% and 84.21% for training and test set. The percentage of good correlation, in the virtual screening of 241 drugs with the reported values of the percentage of human intestinal absorption (HIA), was greater than 81%. In addition, multiple …

Synthesis, structural diversity, inter-conversion and reactivity of Cu(II) complexes of hydroxy-rich molecules

2002

Tetranuclear Cu(II) complexes having linear, cubane and pseudodouble-cubane cores were synthesized using hydroxy-rich molecules possessing amine and imine groups. The products were structurally characterized and were studied for their ability to oxidize catechol as well as for their inter-conversion between mono- and tetra-nuclear complexes.

Lanthanide–saccharide chemistry: synthesis and characterisation of Ce(III)–saccharide complexes

2000

A series of nine Ce(III) complexes has been synthesised with seven different monosaccharides (D-glucose, D-fructose, D-galactose, D-mannose, L-sorbose, D-ribose and D-xylose) and two different disaccharides (D-maltose and L-lactose), and these have been characterised with various analytical, spectral, magnetic and electrochemical techniques. The NMR studies have highlighted some interesting features about the metal-ion-binding pattern of the saccharides. Some additional coordination has been proposed along with the chelating groups in the saccharide molecules, based on the shifts in 13C NMR spectra. On the other hand, solution absorption studies and solid-state magnetic susceptibilities hav…

Recognition of oxovanadium(V) species and its separation from other metal species through selective complexation by some acyclic ligands

1998

Acyclic molecules possessing –OH (phenoxo and alkoxo type) groups and imine or amine moieties have been developed to sense the specific preference for VO3+ species. These molecules also showed a capability to quantitatively separate oxovanadium(V) species from a reaction mixture containing metal species of V, Mo, U, Fe, and Mn ions in solution. A cascade quantitative separation of VO3+ followed by cis–MoO2+2 followed by trans –UO2+2 species is demonstrated from their mixture. Synthesis and structural details of oxo-species of vanadium molybdenum and uranium are also discussed. Factors influencing the complexation of these molecules towards oxo metal species of V, Mo and U are also addressed.