150308-80-8Relevant articles and documents
Improved synthetic routes to the selenocysteine derivatives useful for Boc-based peptide synthesis with benzylic protection on the selenium atom
Shimodaira, Shingo,Iwaoka, Michio
, p. 260 - 271 (2017/03/09)
Selenocysteine (Sec) derivatives, i.e., Boc-Sec(MBn)-OH (1) and Boc-Sec(MPM)-OH (2), which are useful for chemical synthesis of selenopeptides, were obtained from L-serine in five steps with total yields of 73% and 74%, respectively. The enantiomeric excesses were confirmed to be >99% e.e. by optical resolution using a chiral column on HPLC. On the other hand, for the case of a Fmoc-protected Sec derivative, i.e., Fmoc-Sec(MPM)-OH, similar reactions resulted in low yields and partial racemization taking place. [PRESENTED EQUATION]
Investigation of peptide thioester formation via N→Se acyl transfer
Adams, Anna L.,Macmillan, Derek
, p. 65 - 73 (2013/04/10)
Native chemical ligation is widely used for the convergent synthesis of proteins. The peptide thioesters required for this process can be challenging to produce, particularly when using Fmoc-based solid-phase peptide synthesis. We have previously reported a route to peptide thioesters, following Fmoc solid-phase peptide synthesis, via an N→S acyl shift that is initiated by the presence of a C-terminal cysteine residue, under mildly acidic conditions. Under typical reaction conditions, we occasionally observed significant thioester hydrolysis as a consequence of long reaction times (~48h) and sought to accelerate the reaction. Here, we present a faster route to peptide thioesters, by replacing the C-terminal cysteine residue with selenocysteine and initiating thioester formation via an N→Se acyl shift. This modification allows thioester formation to take place at lower temperatures and on shorter time scales. We also demonstrate how application of this strategy also accelerates peptide cyclization, when a linear precursor is furnished with an N-terminal cysteine and C-terminal selenocysteine.
Preparation of the β3-homoselenocysteine derivatives Fmoc-β3hSec(PMB)-OH and Boc-β3hSec(PMB)-OH for solution and solid-phase-peptide synthesis and selenoligation
Floegel, Oliver,Casi, Giulio,Hilvert, Donald,Seebach, Dieter
, p. 1651 - 1666 (2008/02/13)
The title compounds, 4 and 7, have been prepared from the corresponding α-amino acid derivative selenocystine (1) by the following sequence of steps: cleavage of the Se-Se bond with NaBH4, p-methoxybenzyl (PMB) protection of the SeH group, Fmoc or Boc protection at the N-atom and Arndt-Eistert homologation (Schemes 1 and 2). A β3-heptapeptide 8 with an N-terminal β3-hSec(PMB) residue was synthesized on Rink amide AM resin and deprotected ('in air') to give the corresponding diselenide 9, which, in turn, was coupled with a β3-tetrapeptide thiol ester 10 by a seleno-ligation. The product β3- undecapeptide was identified as its diselenide and its mixed selenosulfide with thiophenol (Scheme 3). The differences between α- and β-Sec derivatives are discussed.