- New templates for syntheses of ring-fused, C10 β-turn peptidomimetics leading to the first reported small-molecule mimic of neurotrophin-3
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β-Turn peptidomimetics 1 were designed to mimic hot spots of neurotrophin-3 (NT-3) and others. Solid-phase syntheses of these were developed, though limitations were encountered with scale-up. Consequently, an alternative design with 2 was investigated. 1 and 2 favored distorted type I β-turn conformations in solution. It was found that peptidomimetic 2b has NT-3-like neurotrophic activity in cell survival assays, selectively binds the NT-3 receptor TrkC, and induces the tyrosine phosphorylation of the TrkC receptor.
- Pattarawarapan, Mookda,Zaccaro, Maria Clara,Saragovi, Uri H.,Burgess, Kevin
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Read Online
- Highly Enantioselective Synthesis of Indazoles with a C3-Quaternary Chiral Center Using CuH Catalysis
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C3-substituted 1H-indazoles are useful and important substructures in many pharmaceuticals. Methods for direct C3-functionalization of indazoles are relatively rare, compared to reactions developed for the more nucleophilic N1 and N2 positions. Herein, we report a highly C3-selective allylation reaction of 1H-N-(benzoyloxy)indazoles using CuH catalysis. A variety of C3-allyl 1H-indazoles with quaternary stereocenters were efficiently prepared with high levels of enantioselectivity. Density functional theory (DFT) calculations were performed to explain the reactivity differences between indazole and indole electrophiles, the latter of which was used in our previously reported method. The calculations suggest that the indazole allylation reaction proceeds through an enantioselectivity-determining six-membered Zimmerman-Traxler-type transition state, rather than an oxidative addition/reductive elimination sequence, as we proposed in the case of indole alkylation. The enantioselectivity of the reaction is governed by both ligand-substrate steric interactions and steric repulsions involving the pseudoaxial substituent in the six-membered allylation transition state.
- Ye, Yuxuan,Kevlishvili, Ilia,Feng, Sheng,Liu, Peng,Buchwald, Stephen L.
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supporting information
p. 10550 - 10556
(2020/07/27)
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- A New Caged-Glutamine Derivative as a Tool To Control the Assembly of Glutamine-Containing Amyloidogenic Peptides
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We present the design, synthesis, and characterization of a novel photocaged glutamine derivative (modified on the side chain of glutamine), and describe its use in enhancing peptide stability and solubility. Our results demonstrate that this approach can
- Awad, Loay,Jejelava, Nino,Burai, Ritwik,Lashuel, Hilal A.
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p. 2353 - 2360
(2016/12/23)
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- A Clickable and Photocleavable Lipid Analogue for Cell Membrane Delivery and Release
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For drug delivery purposes, the ability to conveniently attach a targeting moiety that will deliver drugs to cells and then enable controlled release of the active molecule after localization is desirable. Toward this end, we designed and synthesized clickable and photocleavable lipid analogue 1 to maximize the efficiency of bioconjugation and triggered release. This compound contains a dibenzocyclooctyne group for bioorthogonal derivatization linked via a photocleavable 2-nitrobenzyl moiety at the headgroup of a synthetic lipid backbone for targeting to cell membranes. To assess delivery and release using this system, we report fluorescence-based assays for liposomal modification and photocleavage in solution as well as through surface immobilization to demonstrate successful liposome functionalization and photoinduced release. In addition, fluorophore delivery to and release from live cells was confirmed and characterized using fluorescence microscopy and flow cytometry analysis in which 1 was delivered to cells, derivatized, and photocleaved. Finally, drug delivery studies were performed using an azide-tagged analogue of camptothecin, a potent anticancer drug that is challenging to deliver due to poor solubility. In this case, the ester attachment of the azide tag acted as a caging group for release by intracellular esterases rather than through photocleavage. This resulted in a dose-dependent response in the presence of liposomes containing delivery agent 1, confirming the ability of this compound to stimulate delivery to the cytoplasm of cells.
- Alam, Shahrina,Alves, Daiane S.,Whitehead, Stuart A.,Bayer, Andrew M.,McNitt, Christopher D.,Popik, Vladimir V.,Barrera, Francisco N.,Best, Michael D.
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p. 1021 - 1031
(2015/06/30)
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- Triggered liposomal release through a synthetic phosphatidylcholine analogue bearing a photocleavable moiety embedded within the sn-2 acyl chain
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Liposomes represent promising carriers for drug delivery applications. To maximize this potential, there has been significant interest in developing liposomal systems encapsulating molecular cargo that are highly stable until their contents are released r
- Bayer, Andrew M.,Alam, Shahrina,Mattern-Schain, Samuel I.,Best, Michael D.
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p. 3350 - 3357
(2014/04/03)
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- Solid-phase synthesis of 1,2,5-trisubstituted imidazolidin-4-ones
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A general solid-phase synthesis of 1,2,5-trisubstituted imidazolidin-4-ones is described. The key synthetic transformation incorporates a microwave-assisted condensation of an α-amino amide on solid support with an aldehyde in solution to give the corresp
- Qin, Lan-Ying,Cole, Andrew G.,Metzger, Axel,O'Brien, Linda,Sun, Xiling,Wu, Jin,Xu, Yan,Xu, Kai,Zhang, Ying,Henderson, Ian
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scheme or table
p. 419 - 422
(2009/05/11)
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- A versatile new synthetic route to 1 N-hydroxyindazoles
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A new and versatile cyclization reaction affording rare 1 JV-hydroxyindazoles Is presented. Treatment of 2-nitrobenzylamines with methanolic sodium hydroxide furnishes 1 N-hydroxylndazoles regloselectively and In high yield. The reaction tolerates a range
- Lehmann, Fredrik,Koolmeister, Tobias,Odell, Luke R.,Scobie, Martin
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supporting information; experimental part
p. 5078 - 5081
(2009/12/28)
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- Photocleavage of peptides and oligodeoxynucleotides carrying 2-nitrobenzyl groups
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Peptides and oligodeoxynucleotides containing photolabile 2-nitrobenzyl groups as mid-sequences were prepared. Photocleavage of aqueous solutions of these compounds neared completion within 30 min to a few hours depending on the photolabile group used. A
- Ramos, Roger,Manning, Brendan,Avino, Anna,Gargallo, Raimundo,Eritja, Ramon
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experimental part
p. 613 - 622
(2009/08/08)
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- Formulation of photocleavable liposomes and the mechanism of their content release
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In pursuit of designing photocleavable liposomes as drug delivery vehicles, we synthesized several amphiphilic lipids by connecting stearyl amine (as the non-polar tail) and charged amino acids (as polar heads) via the o-nitrobenzyl derivatives. The lipid
- Chandra, Binita,Subramaniam, Rajesh,Mallik, Sanku,Srivastava
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p. 1730 - 1740
(2008/02/04)
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- Controlled release liposomes and methods of use
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The present invention provides liposomes that include a trigger polypeptide, a lipid layer, and a compartment surrounded by the lipid layer and methods of using the liposomes.
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Page/Page column 12
(2008/06/13)
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- Design of photocleavable lipids and their application in liposomal "uncorking"
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The design of o-nitrobenzyl containing photocleavable lipid-amino acid conjugates, and their application in liposomal uncorking are described. The Royal Society of Chemistry 2005.
- Chandra, Binita,Mallik, Sanku,Srivastava
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p. 3021 - 3023
(2007/10/03)
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- Syntheses and Activities of New C10 β-Turn Peptidomimetics
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A program to identify small molecules that mimic or disrupt protein-protein interactions led us to design the peptidomimetics 1-3. Solid-phase syntheses of 1-3 were developed. The purities of the crude materials isolated from the resin tend to be highest for the S- and N-compounds 2 and 3 and better than in the corresponding syntheses of peptidomimetics A. The particular dipeptide units incorporated were chosen to correspond with the turn regions of the neurotrophins (e.g., nerve growth factor {NGF} and the neurotrophin factor-3 {NT-3}). Preliminary studies were performed to access the binding of these analogues to Trk receptors and their ability to induce cell survival (just as NGF and NT-3 do). Several active compounds were identified. However, poor water solubilities of some of the other compounds preclude reliable testing. Consequently, solid-phase modifications to the synthetic procedures were investigated to provide access to the derivatives 12-14 in which the aromatic nitro group is replaced by amine, guanidine, or sulfonamide functionalities. The latter are more acceptable pharmacophores than nitro groups and also tend to increase the water solubilities of the peptidomimetics.
- Lee, Hong Boon,Zaccaro, Maria Clara,Pattarawarapan, Mookda,Roy, Sudipta,Saragovi, H. Uri,Burgess, Kevin
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p. 701 - 713
(2007/10/03)
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- Gastrin releasing peptide compounds
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New and improved compounds for use in radiodiagnostic imaging or radiotherapy having the formula M-N—O—P-G, wherein M is the metal chelator (in the form complexed with a metal radionuclide or not), N—O—P is the linker, and G is the GRP receptor targeting
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- 3-Nitro-4-bromomethyl benzoic acid
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The invention is addressed to the preparation of 3-nitro-4-bromomethyl benzoic acid, as a new compound from which 3-nitro-4-bromomethyl benzoyl amide polystyrene resin can be prepared for solid synthesis of protected peptide acids and amides and separation thereof without cleavage of acid labile protecting groups or decomposition of aromatic acid groups and from which purified polypeptides can be formed.
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