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A study was conducted to characterize the solid-support synthesis of N-linked glycopeptides. The method supports the fashioning of the carbohydrate domain of choice while accommodating benefits associated with solid-phase synthesis in the carbohydrate-peptide coupling step. Azasulfonamidation reactions were carried out to determine polymer-bound 2-N-acetyl-1-beta-glucosylamine. Results indicated that the synthesis technique can be extended in the formation of a other glycopeptides.

A novel series of N-type calcium channel inhibitors have been discovered. Optimization of potency and HT-ADME properties provides 4-aminocyclopentapyrrolidines with analgesic efficacy after oral dosing., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A novel 4-aminocyclopentapyrrolidine series of N-type Ca(2+) channel blockers have been discovered. Enantioselective synthesis of the 4-aminocyclopentapyrrolidines was enabled using N-tert-butyl sulfinamide chemistry. SAR studies demonstrate selectivity over L-type Ca(2+) channels. N-type Ca(2+) channel blockade was confirmed using electrophysiological recording techniques. Compound 25 is an N-type Ca(2+) channel blocker that produces antinociception in inflammatory and nociceptive pain models without exhibiting cardiovascular or motor liabilities., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Potent small molecule antagonists for the PAC(1)-R have been discovered. Previously known antagonists for the PAC(1)-R were slightly truncated peptide ligands. The hydrazides reported here are the first small molecule antagonists ever reported for this class B GPCR.

A series of novel 6-O-arylpropargyl-9-oxime-ketolides was synthesized and evaluated against various pathogens. These new compounds show promising in vitro antibacterial potency and in vivo efficacy against macrolide resistant strains.

The parallel synthesis and antibacterial activity of 5-hydroxy[1,2,5] oxadiazolo[3,4-b]pyrazines is reported. The compounds were synthesized by condensing diaminofurazan with alpha-keto acids to give a variety of aryl-substituted analogues. Halogenated phenyl groups at C-6 give rise to the greatest Haemophilus influenzae antibacterial activity.

Improved strategies for synthesis make it possible to expand the range of glycopeptides available for detailed conformational studies. The glycopeptide 1 was synthesized using a new solid phase synthesis of carbohydrates and a convergent coupling to peptide followed by deprotection. Its conformational properties were subjected to NMR analysis and compared with a control peptide 2 prepared by conventional solid phase methods. Whereas peptide 2 fails to manifest any appreciable secondary structure, the glycopeptide 1 does show considerable conformational bias suggestive of an equilibrium between an ordered and a random state. The implications of this ordering effect for the larger issue of protein folding are considered.

The "core" pentasaccharide region of high mannose asparagine-linked glycoproteins was synthesized using thioethyl donors and methyl triflate to promote coupling. All monosaccharide units were prepared from glycals. The central mannose residue was installed by inversion of the C2 hydroxyl of a glucosyl precursor. The protecting group scheme employed allows for the extension of the pentasaccharide through the terminal mannose units and a peptide can be coupled through transformation of the glycal.

Oligosaccharides and glycopeptides are of considerable importance in molecular biology and pharmacology. However, their synthesis is complicated by the large number of different linking sites between each saccharide unit, the need for stereochemical control, the chemical sensitivity of the glycopeptide bonds, and the need to harmonize diverse protecting groups. Here, an efficient solid-phase synthesis of three N-linked glycopeptides based on glycal assembly is presented. The peptide domain can be extended while the ensemble remains bound to the polymer. The glycopeptides synthesized here are among the largest N-linked glycopeptides ever accessed by either solution- or solid-phase synthesis.