Search results for "TYR"
showing 10 items of 2017 documents
Asymmetric Michael Addition in Synthesis of β-Substituted GABA Derivatives
2022
γ-Aminobutyric acid (GABA) represents one of the most prolific structural units widely used in the design of modern pharmaceuticals. For example, β-substituted GABA derivatives are found in numerous neurological drugs, such as baclofen, phenibut, tolibut, pregabalin, phenylpiracetam, brivaracetam, and rolipram, to mention just a few. In this review, we critically discuss the literature data reported on the preparation of substituted GABA derivatives using the Michael addition reaction as a key synthetic transformation. Special attention is paid to asymmetric methods featuring synthetically useful stereochemical outcomes and operational simplicity. This research was funded by the National Na…
Dominus qui incepit ipse perficiat: exhortaciones de fray Josep Mercader a las monjas dominicas del monasterio de Montesión en Barcelona (1740-1745)
2016
Resumen: De entre la galeria de personajes interesantes que nos ofrece el convento dominicano de Santa Catalina virgen y martir de Barcelona en el siglo XVIII destaca fray Josep Mercader (profesion 1720-1779). Un apartado importante aunque «intimo» de su obra lo constituyen las once breves exhortaciones que entre los anos 1740-1745 dirigio a las monjas dominicas del monasterio barcelones de Montesion con ocasion de las ceremonias de recepcion y profesion. En estos 20 folios podemos encontrar el discurso que un dominico cualificado dirigio a las monjas de clausura de su orden en dos momentos tan significativos de su trayectoria religiosa. Palabras clave: Josep Mercader, Dominicos (frailes y …
Zur Autoxydation von Polystyrol
1971
Die mit Azoisobuttersauredinitril (AIBN) initiierte Autoxydation von Polystyrol (PS) in Chlorbenzol bei 60°C ist von der Ordnung 0,75, bezogen auf AIBN, und 0,34, bezogen auf PS. Der niedrige Exponent der Polystyrolkonzentration weist neben intermolekularen Wachstumsschritten auf intramolekulare Reaktionsschritte bei der Autoxydation hin. Die bei der Autoxydation am Polystyrol gebildeten Hydroperoxidgruppen zerfallen in Essigsathylester als Losungsmittel mit einer Aktivierungsenthalpie von 19,7 kcal/Mol und einer Aktivierungsentropie von −29 cal/Mol Grad. Das spricht fur einen monomolekularen bifunktionellen Zerfallsmechanismus. Als fluchtige Produkte bei diesem Hydroperoxidzerfall werden P…
Ectopic NGAL expression can alter sensitivity of breast cancer cells to EGFR, Bcl-2, CaM-K inhibitors and the plant natural product berberine
2012
Neutrophil gelatinase-associated lipocalin (NGAL, a.k.a Lnc2) is a member of the lipocalin family and has diverse roles. NGAL can stabilize matrix metalloproteinase-9 from autodegradation. NGAL is considered as a siderocalin that is important in the transport of iron. NGAL expression has also been associated with certain neoplasias and is implicated in the metastasis of breast cancer. In a previous study, we examined whether ectopic NGAL expression would alter the sensitivity of breast epithelial, breast and colorectal cancer cells to the effects of the chemotherapeutic drug doxorubicin. While abundant NGAL expression was detected in all the cells infected with a retrovirus encoding NGAL, t…
Biphasic Erk1/2 activation sequentially involving Gs and Gi signaling is required in beta3-adrenergic receptor-induced primary smooth muscle cell pro…
2013
Abstract The beta3 adrenergic receptor (B3-AR) reportedly induces cell proliferation, but the signaling pathways that were proposed, involving either Gs or Gi coupling, remain controversial. To further investigate the role of G protein coupling in B3-AR induced proliferation, we stimulated primary human myometrial smooth muscle cells with SAR150640 (B3-AR agonist) in the absence or presence of variable G-protein inhibitors. Specific B3-AR stimulation led to an Erk1/2 induced proliferation. We observed that the proliferative effects of B3-AR require two Erk1/2 activation peaks (the first after 3 min, the second at 8 h). Erk1/2 activation at 3 min was mimicked by forskolin (adenylyl-cyclase a…
De novo design of protein kinase inhibitors by in silico identification of hinge region-binding fragments.
2013
Protein kinases constitute an attractive family of enzyme targets with high relevance to cell and disease biology. Small molecule inhibitors are powerful tools to dissect and elucidate the function of kinases in chemical biology research and to serve as potential starting points for drug discovery. However, the discovery and development of novel inhibitors remains challenging. Here, we describe a structure-based de novo design approach that generates novel, hinge-binding fragments that are synthetically feasible and can be elaborated to small molecule libraries. Starting from commercially available compounds, core fragments were extracted, filtered for pharmacophoric properties compatible w…
Binge-like alcohol exposure in adolescence: behavioural, neuroendocrine and molecular evidence of abnormal neuroplasticity … and return
2021
Binge alcohol consumption among adolescents affects the developing neural networks underpinning reward and stress processing in the nucleus accumbens (NAc). This study explores in rats the long-lasting effects of early intermittent exposure to intoxicating alcohol levels at adolescence, on: (1) the response to natural positive stimuli and inescapable stress
Sedimentation of dissolved macromolecules in the vicinity of the consolute point 1. Strictly binary systems and kinetic considerations
1986
This paper analyzes the effect of gravity on polymer solutions near the consolute point. Calculations are carried out for monodisperse polystyrene in cyclohexane using the Flory-Huggins expression with a concentration-dependent interaction parameter for the free energy of mixing. Depending on molecular weight and distance to the demixing temperature, the influence of gravity leads to non-negligible gradients of the volume fraction in the one-phase region as well as in the two-phase region. In particular, the effect of gravity on the measurement of the coexistence curve in a finite sample is calculated explicitly.
Compatibility between polystyrene copolymers and polymers in solution via hydrogen bonding
2006
Abstract It has been applied the concept of improving miscibility, by introducing and optimizing the extent of intermolecular hydrogen-bonding interactions between two polymers. We select a commodity polymer such as polystyrene, to study the compatibility in chloroform with poly(vinyl pyridine) and poly(vinyl pyrrolidone), both considered as proton acceptors. In order to enhance polymer–polymer miscibility, polystyrene is slightly modified by copolymerization with methacrylic acid, in the first case, and with vinyl-phenol comonomer, in the second one. In this way, two series of polystyrene-based copolymers are synthesized and characterized bearing ca. 8% (w/w) of –OH groups. The miscibility…
Demixing of unsheared and sheared solutions of polystyrene in tert-butylacetate and the pressure influence on their flow behaviour
1979
For the system tert-butyl acetate/polystyrene (M= 670000) the phase separation behaviour (upper critical solution temperatures, upper critical solution pressures) is investigated by means of visual and turbidimetric cloud-point measurements and by viscometry. For near-critical concentrations the visually determined cloud-points are found at higher, for low concentrations at lower temperatures as compared with the turbidimetrically determined binodal temperature,Tbin Plots of the invers of the turbidity measured atTbin as a function of the polymer concentration,w2, yield a minimum from which the critical composition can be determined. The viscometrically obtained demixing points (break-down …