A homogeneous Pd(II) catalyst, utilizing a simple and inexpensive amine ligand (TMEDA), allows 2-alkynoates to be prepared in high yields by an oxidative carbonylation of terminal alkynes and alcohols. The catalyst system overcomes many of the limitations of previous palladium carbonylation catalysts. It has an increased substrate scope, avoids large excesses of alcohol substrate and uses a des...

Small optically active molecules, and more particularly short-chain chiral amines, are key compounds in the chemical industry precursors of various pharmaceuticals. Their chemo-biocatalytic production on a commercial scale is already established, mainly through lipase-catalyzed resolutions leading to ChiPros™ products among others. Nevertheless, their biocatalytic synthesis remains challenging ...

We have previously reported that substrates of monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO) exert short-term insulin-like effects in rat adipocytes, such as stimulation of glucose transport. In the present work, we studied whether these substrates could also mimic long-term actions of insulin. Adipose differentiation of 3T3 F442A cells, which is highly insulin-depend...

Active ester Cp-nitrophenyl ester) hydrolysis and transfer reactions catalyzed by transglutaminase have been studied at pH 7.5 and 0” in the presence of 50 mu Ca++. The initial velocities of appearance of two products of the reactions, $-nitrophenol and N-acylamines, were found to be consistent with a ping pong mechanism in which acyl-enzyme formed from active ester may react with water (hydrol...

Esters of pentavalent phosphorus acids are the most important class of organophosphorus (OP) compounds. They are derivatives of the following three parent acids, viz. phosphinic acid, phosphonic acid and phosphoric acid. Phosphorus compounds may be classified as anhydride, aliphatic, aromatic, and heterocyclic. The majority of OP insecticides are derivatives of phosphoric acid. Triesters of pho...

Copper amine oxidases are homodimeric enzymes containing one Cu(2+) ion and one 2,4,5-trihydroxyphenylalanine quinone (TPQ) per monomer. Previous studies with the copper amine oxidase from Escherichia coli (ECAO) have elucidated the structure of the active site and established the importance in catalysis of an active-site base, Asp-383. To explore the early interactions of substrate with enzyme...

Lehmphul et al. report the effect of 3-iodothyronamine in reducing insulin release in a model of immortalized pancreatic β-cells. Notwithstanding the simplified β-cell model used, this article offers an opportunity to reconsider, possibly under a new light, an old issue of research, which excited people working on amine oxidases (AOs) in the last 20 years. Toward this aim, we would like to prop...

Monoamine oxidase (MAO) enzymes regulate the level of neurotransmitters by catalyzing the oxidation of various amine neurotransmitters, such as serotonin, dopamine and norepinephrine. Therefore, they are the important targets for drugs used in the treatment of depression, Parkinson, Alzeimer and other neurodegenerative disorders. Elucidation of MAO-catalyzed amine oxidation will provide new ins...

Selective functionalization at the meta position of arenes remains a significant challenge. In this work, we demonstrate that a single anionic bipyridine ligand bearing a remote sulfonate group enables selective iridium-catalyzed borylation of a range of common amine-containing aromatic molecules at the arene meta position. We propose that this selectivity is the result of a key hydrogen bondin...