68869-58-9Relevant academic research and scientific papers
Synthesis and electrochemical studies of disubstituted ferrocene/dipeptide conjugates with sulfur-containing side chains
Scully, Conor C.G.,Rutledge, Peter J.
scheme or table, p. 5653 - 5659 (2010/10/02)
A series of 1 1'-disubstituted ferrocenoyl peptides incorporating dipeptide sidearms has been synthesized and studied electrochemically. The target peptides include ferrocene as an electrochemical reporter, sulfur-containing amino acids (L-methionine, S-methyl-L-cysteine, S-trityl-L-cysteine, S-benzhydryl-L- cysteine) as metal binding agents, and amino acids with non-polar side chains (L-alanine, L-valine, L-phenylalanine) as spacers between reporter and metal binding groups. Ferrocene/dipeptide conjugates were prepared using solution phase peptide synthesis methods employing a BOC-protecting group strategy and HBTU- (O-(benzotriazol-1-yl)-N, N, N', N'-tetramethyluronium hexafluorophosphate) mediated peptide coupling. The electrochemical properties of these 1, 1'-substituted ferrocenoyl peptides have been characterized using cyclic voltammetry. All exhibit fully reversible one electron oxidation steps; forward sweep half wave peaks (EF), reverse sweep half wave peaks (ER), peak separations (DEP) and half wave potentials (E1/2) are reported. Finally, towards the goal of utilizing ferrocenoyl peptides to detect heavy metals in solution, the response of these ferrocene/dipeptide conjugates to metal cations (zinc(II), mercury(II), cadmium(II), lead(II), silver(I)) has been examined. Monitoring changes in the potential of the Fe(II)/Fe(III) redox couple to follow peptide/metal interactions, we have probed the influence of the spacer unit between the redox reporter and the metal-binding amino acid, and shown that these systems respond to mercury(II) more strongly than to other heavy metal ions.
Oxidative Deblocking of the 4-Methoxybenzyl Thioether Protecting Group: Application to the Directed Synthesis of Poly-cystinyl Peptides
Platen, Martin,Steckhan, Eberhard
, p. 1563 - 1576 (2007/10/02)
The 4-methoxybenzyl thioether protecting group is deblocked efficiently by oxidation with the homogeneous electron transfer agent tris(4-bromophenyl)ammoniumyl (2.+) leading to the disulfide in high yields.S-(4-methoxybenzyl)cysteine derivatives like 9 in this way can be transformed into the corresponding cystine derivatives like 10 in 90percent yield.Many N and carboxy protecting groups like the Boc and Z group and tert-butyl or benzyl ester functions are stable under the cleavage conditions.On the other hand the 4-methoxybenzyl thioether protecting group is totally unaffected by the conditions for oxidative deblocking of the S-trityl functions by either iodine or rhodanolysis.This opens up new opportunities for the directed synthesis of cystinyl peptides with more than one intra- or interchain disulfide bridge.Application of the new method to the synthesis of a cystine peptide with one intrachain S-S-bridge and a double-chain biscystinyl peptide is reported.
