- N -boc deprotection and isolation method for water-soluble zwitterionic compounds
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A highly efficient TMSI-mediated deprotection and direct isolation method to obtain zwitterionic compounds from the corresponding N-Boc derivatives has been developed. This method has been demonstrated in the final deprotection/isolation of the β-lactamase inhibitor MK-7655 as a part of its manufacturing process. Further application of this process toward other zwitterionic compounds, such as dipeptides and tripeptides, has been successfully developed. Furthermore, a catalytic version of this transformation has been demonstrated in the presence of BSA or BSTFA.
- Liu, Zhijian,Yasuda, Nobuyoshi,Simeone, Michael,Reamer, Robert A.
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p. 11792 - 11796
(2015/02/19)
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- A genetically encodable ligand for transfer hydrogenation
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Simple tripeptides are shown here to be versatile ligands for iridium-catalyzed transfer hydrogenations affording large acceleration effects. A water-soluble iridium complex with Gly-Gly-Phe, for example, catalyzes the reduction of diverse ketones, aldehydes, and imines by formate with turnover frequencies rivaling or outperforming those of established ligand systems. Regioselective reduction of coenzyme NAD+ to NADH illustrates the potential utility of this system for biotechnological applications. Because peptides are genetically encodable, they represent an attractive class of foldamer ligands for creating artificial metalloenzymes.
- Mayer, Clemens,Hilvert, Donald
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supporting information
p. 3427 - 3431
(2013/07/19)
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- ATRIOPEPTINS. II. SYNTHESIS OF N-TERMINAL FRAGMENTS
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Peptides, corresponding to the N-terminal sequence in atriopeptins, were synthesized by classical methods of peptide chemistry in solutions.The obtained peptides were characterized by various physicochemical methods.The scheme and methods of the synthesis are discussed.
- Ovchinnikov, Mikhail V.,Bespalova, Zhanna D.,Molokoedov, Aleksandr S.,Revenko, Inna V.,Sepetov, Nikolai F.,et al
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p. 784 - 795
(2007/10/02)
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- SYNTHESIS, PROPERTIES, AND REACTIONS OF α- AND β-D-GLUCOPYRANOSYL ESTERS OF SOME TRIPEPTIDES
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The 2,3,4,6-tetra-O-benzyl-1-O-(N-benzyloxycarbonyltripeptidyl)-D-glucopyranoses 1, 8, and 13 were synthesised from 2,3,4,6-tetra-O-benzyl-α-D-glucopyranose and the active esters of the appropriate N-protected tripeptides (Gly-Gly-Gly-, L-Phe-Gly-Gly-, and Gly-Gly-L-Phe-) in the presence of imidazole; the anomeric mixtures were resolved and the α and β anomers characterised.The β anomer of 13, containing the L and D enantiomers (ratio ca. 3:1) of Gly-Gly-Phe- as the aglycon, could be resolved by column chromatography into the pure isomeric forms.Catalytic hydrogenolysis of the β anomers, in the presence and absence of a strong acid, yielded the free 1-esters 2β, 9β, and 14β, which were characterised as the mono-oxalate or trifluoroacetate salts and as free bases.Similarly, the α anomers afforded 2α, 9α, and 14α, whereas omission of the strong acid led to accompanying 1 --> 2 acyl migration, to give the 2-O-acyl derivatives.All of the compounds prepared were converted into the N-acetyl and/or peracetylated derivatives.The 1-esters 2β and 9β, both in the charged and uncharged form, and the trifluoroacetate salt of 14β, are susceptible to cleavage by β-D-glucosidase; the enzyme had no effect on the uncharged form of 14β.This difference between 14β and its salt is discussed in conformational terms.
- Valentekovic, Stefica,Keglevic, Dina
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