New metallocenic phenylalanine analogs

Solid‐Phase Synthesis, Characterization, and Antibacterial Activities of Metallocene–Peptide Bioconjugates

“…In the 1980 s some ferrocenyl peptides and half-sandwich peptide complexes were isolated in low yields because of problems with decomposition. [29][30][31][32][33][34][35][36] More recently, labeling of DNA with ferrocene has been reported. [37][38][39][40][41] The solid-phase synthesis of Mo carbonyl complexes have also been reported; without biomolecules [42][43][44] and with [Leu 5 ]-enkephalin.…”

Synthesis, characterization, X-ray crystallography, and cytotoxicity of a cymantrene keto carboxylic acid for IR labelling of bioactive peptides on a solid support

“…Especially metallocenes have been at the focus of intense research efforts, since, for example, the Fe II/III redox couple as in ferrocene allows for an easy electrochemical quantification of the labelled peptide [1][2][3][4][5][6][7][8][9]. Substantially less work has however been carried out based on other properties of organometallic compounds [10][11][12][13][14][15][16][17][18][19][20][21][22]. We are particularly interested in the attachment of IR spectroscopic labels to peptides for biological imaging applications with scanning near-field IR microscopy (SNIM) [23].…”

Incorporation of the Unnatural Organometallic Amino Acid 1′‐Aminoferrocene‐1‐carboxylic Acid (Fca) into Oligopeptides by a Combination of Fmoc and Boc Solid‐Phase Synthetic Methods

“…Twenty years ago, a few papers were published dealing with the application of SPPS to metallocenes. Ferrocenylalanine (Fer) and cymantrenylalanine (Cym) were incorporated [ [18][19][20][21] It is worth to mention SPPS of a "ferrocenophanic" conformationally constrained analogue of substance P. [22] Very recently, SPPS of N-terminated cobaltocenium-NLS peptides [23] and metallocenoyl (M = Fe, Co) tripeptides [24] with antibacterial activity were described by one of us. In all peptides described up to the present day, the organometallic group is part of the side chain or linked to the N-terminus.…”

“…The total decomposition of Fmoc-Fca-Ala-Gly-Val-Leu-resin upon removal of the protecting group led us to terminate this peptide with BocFca which is a convenient intermediate either for further elongation of the peptide chain by Fmoc-protected amino acids to yield 3 or for its successfully cleavage from the resin (for 2). The target molecules of previously reported SPPS with metallocenes were: (i) bioconjugates obtained by replacement of one or two Phe "internal" subunits by metallocenylalanine or (metallocene-1,1Ј-diyl)bis(alanine), [18][19][20][21][22] (ii) N-metallocenoyl terminated peptide sequences. [23,24] In this paper, we show that it is possible to incorporate the unnatural ferrocene amino acid Fca into the peptide backbone by SPPS.…”