163 research outputs found
The 'one-pot' preparation of substituted benzofurans
A simple one-pot procedure has been elaborated for the preparation of substituted benzofurans starting from halogenated phenols, and this method has been applied successfully to the total synthesis of dehydrotremetone, a natural product of White Snakeroot
Preparation of Pyridine N-oxide Derivatives in Microreactor
N-oxidations of different nitrogen-containing heterocyclic molecules are often applied for synthetic transformations in chemistry. The industrial implementation of classical batch oxidation processes are limited due to safety concerns derived from metal ion catalyzed decompositions. These restrictions and other safety concern issues can be minimized or even avoided by applying glass made microreactor setups for this transformation. The N-oxidation of different pyridine derivative, quinoline and isoquinoline is studied using two popular oxidizing reagents. The further transformation of pyridine derivatives is studied through the Polonovski rearrangement in microreactor
Probing pattern and dynamics of disulfide bridges using synthesis and NMR of an ion channel blocker peptide toxin with multiple diselenide bonds
Anuroctoxin (AnTx), a 35-amino-acid scorpion toxin containing four disulfide bridges, is a high affinity blocker of the voltage-gated potassium channel Kv1.3, but also blocks Kv1.2. To improve potential therapeutic use of the toxin, we have designed a double substituted analog, [N17A/F32T]-AnTx, which showed comparable Kv1.3 affinity to the wild-type peptide, but also a 2500-fold increase in the selectivity for Kv1.3 over Kv1.2. In the present study we have achieved the chemical synthesis of a Sec-analog in which all cysteine (Cys) residues have been replaced by selenocysteine (Sec) forming four diselenide bonds. To the best of our knowledge this is the first time to replace, by chemical synthesis, all disulfide bonds with isosteric diselenides in a peptide/protein. Gratifyingly, the key pharmacological properties of the Sec-[N17A/F32T]-AnTx are retained since the peptide is functionally active. We also propose here a combined experimental and theoretical approach including NOE- and Se-77-based NMR supplemented by MD simulations for conformational and dynamic characterization of the Sec-[N17A/F32T]-AnTx. Using this combined approach allowed us to attain unequivocal assignment of all four diselenide bonds and supplemental MD simulations allowed characterization of the conformational dynamics around each disulfide/diselenide bridge
Zinc(II) and cadmium(II) complexes of N-terminally free peptides containing two separate cysteinyl binding sites
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Rapid synthesis of self-assembling 1,2-thiomannobioside glycoconjugates as potential multivalent ligands of mannose-binding lectins
A study on the optical resolution of 1-isopropyl-3-methyl-3-phospholene 1-oxide and its use the synthesis of borane and platinum complexes
[(η6-p-cymene)Ru(H2O)3]2+ binding capability of aminohydroxamates - A solution and solid state study
Exploring the Syntheses of Novel Glycomimetics: Carbohydrate Derivatives with Se-S- or Se-Se- Glycosidic Linkages
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[(?6 -p-cymene)Ru(H2O)3] 2+ Binding Capability of Aminohydroxamates - A Solution and Solid State Study
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"Perfecting" pure shift HSQC: full homodecoupling for accurate and precise determination of heteronuclear couplings
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