Copper-catalysed selective hydroamination reactions of alkynes

The development of selective reactions that utilize easily available and abundant precursors for the efficient synthesis of amines is a long-standing goal of chemical research. Despite the centrality of amines in a number of important research areas, including medicinal chemistry, total synthesis and materials science, a general, selective and step-efficient synthesis of amines is still needed. Here, we describe a set of mild catalytic conditions utilizing a single copper-based catalyst that enables the direct preparation of three distinct and important amine classes (enamines, α-chiral branched alkylamines and linear alkylamines) from readily available alkyne starting materials with high levels of chemo-, regio- and stereoselectivity. This methodology was applied to the asymmetric synthesis of ​rivastigmine and the formal synthesis of several other pharmaceutical agents, including ​duloxetine, ​atomoxetine, ​fluoxetine and ​tolterodine.National Institutes of Health (U.S.) (GM58160

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Metformin decreases angiogenesis via NF-kappa B and Erk1/2/Erk5 pathways by increasing the antiangiogenic thrombospondin-1

Polycystic ovary syndrome (PCOS) is associated with insulin resistance (IR), obesity, and cardiovascular complications. Thrombospondin-1 (TSP-1) is a novel antiangiogenic adipokine highly expressed in obese insulin-resistant subjects. We sought to assess TSP-1 levels in adipose tissue (AT) from PCOS women and matched controls. The effects of metformin treatment on circulating TSP-1 levels in PCOS subjects, the effects of serum from normal and PCOS women on in vitro migration and angiogenesis before and after metformin treatment, and ex vivo regulation of AT TSP-1 by D-glucose were also studied. Serum TSP-1 (ELISA), subcutaneous and omental AT TSP-1 mRNA (reverse transcriptase-polymerase chain reaction), and protein (western blotting) were significantly lower in PCOS women (P < 0.05). Corresponding plasminogen activator inhibitor-1 (PAI-1) and PAI-1 activity were significantly higher (P < 0.01). After 6 months of metformin treatment, there was a significant increase in serum TSP-1 (P < 0.05) and a corresponding decrease in PAI-1 and PAI-1 activity (P < 0.01). In vitro migration and angiogenesis were significantly increased in serum from PCOS women (P < 0.01); these effects were significantly attenuated by metformin treatment (P < 0.01) through the regulation of TSP-1 levels via nuclear factor-kappa B (NF-kappa B), extracellular regulated-signal kinase 1/2 (Erk1/2) and Erk5 pathways. Importantly, changes in the intima media thickness were predictive of changes in serum TSP-1 (P = 0.049). In AT explants, glucose significantly decreased TSP-1 protein production and secretion into conditioned media (ELISA) (P < 0.05, P < 0.001). TSP-1 levels are lower in PCOS women. Metformin treatment increases serum TSP-1 in these women. Our findings provide novel insights into the relationship between obesity, IR, and angiogenesis

Symmetric dimethylarginine (SDMA) is raised in women with polycystic ovary syndrome: a pilot study

Polycystic ovary syndrome (PCOS) is associated with endothelial dysfunction, which may be caused by elevated levels of asymmetric dimethylarginine (ADMA). ADMA reduces nitric oxide production in diabetes mellitus, hypertension and renal failure. Symmetric dimethylarginine (SDMA) is a stereoisomer produced alongside ADMA, and has recently been described as a risk factor for cardiovascular events. In this cross-sectional study based in a teaching hospital, 16 women with PCOS were recruited alongside 15 healthy controls, and fasting venous blood samples were obtained. Renal function was measured, and ADMA and SDMA were analysed using a high-performance liquid chromatography method. After controlling for BMI, mean ADMA and SDMA levels in women with PCOS were higher than in controls (p = 0.036 and p = 0.030, respectively). Renal function was not different between the two groups (p = 0.152). Women with PCOS have raised levels of SDMA, a molecule implicated in endothelial dysfunction and long-term cardiovascular risk