Methodology Fmoc solid phase

Peptide-resin assembly was performed by Fmoc solid-phase methodology. All peptide-amphiphiles were synthesized as C-terminal amides to prevent piperazine-2,5-dione formation. 62 Peptide-resins were characterized by Edman degradation sequence analysis as described previously for embedded (non-covalent) sequencing. 67 Peptide-resins were then lipidated with the appropriate (Cn)2-Glu-C2-OH tail to give the dialkyl peptide-amphiphile-resin. 

Mullen, D.G., et al. (2011). Synthesis of a-factor peptide from Saccharomyces cerevisiae and photoactive analogues via Fmoc solid phase methodology. Bioorg Med Chem 19 490-497. 

Fmoc chemistry has been the preferred methodology for solid-phase gly-copeptide synthesis because mild acidic conditions can be used for the final deprotection and cleavage. After some initial controversy about the use of... 

Fmoc-protected peptide esters or glycopeptide esters is another efficient methodology in solid-phase synthesis (Witte et al., 1998)... 

Cudic, P. Stawikowski, M. (2007) Pseudopeptide synthesis via Fmoc solid-phase synthetic methodology Mini-Rev. Org. Chem., Vol. 4, No. 4, pp. 268-280. 

Mellor SL, McGuire C, Chan WC. lV-Fmoc-aminooxy-2-chlorotrityl polystyrene resin A facile solid-phase methodology for the synthesis of hydroxamic acids. Tetrahedron Lett 1997 38 3311-3314. 

Otvos et al. (27) adopted the Fmoc-pentafluorophenyl ester methodology and have applied O-deacetylated glycopeptide intermediates (170 and 171) for solid-phase synthesis of glycopeptides. In this way, the A-glycopep-tide (26) H-Gly-L-Lys-L-Ala-L-Tyr-L-Thr-L-Ile-L-Phe-L-... 

Mellor, S. L. McGuire, C. Chan, W. C. M-Fmoc-Aminooxy-2-Chlorotrityl Polystyrene Resin A Facile Solid-Phase Methodology for the Synthesis of Hydroxamic Acids, Tetrahedron Lett. 1997, 38, 3311. 

Solid-phase synthesis of Abz-containing peptides has been reported using standard Boc or Fmoc methodology, without any particular difficulty. 22-25 26 29 341 32 43 ... 

The two most commonly used types of allyl alcohol linker are 4-hydroxycrotonic acid derivatives (Entry 1, Table 3.7) and (Z)- or ( )-2-butene-l, 4-diol derivatives (Entries 2 and 3, Table 3.7). The former are well suited for solid-phase peptide synthesis using Boc methodology, but give poor results when using the Fmoc technique, probably because of Michael addition of piperidine to the a, 3-unsaturated carbonyl compound [167]. Butene-l,4-diol derivatives, however, are tolerant to acids, bases, and weak nucleophiles, and are therefore suitable linkers for a broad range of solid-phase chemistry. 

Support-bound triacylmethanes (e.g. 2-acetyldimedone) readily react with primary aliphatic amines to yield enamines. These are stable towards weak acids and bases, and can be used as linkers for solid-phase peptide synthesis using either the Boc or Fmoc methodologies, as well as for the solid-phase synthesis of oligosaccharides [456]. Cleavage of these enamines can be achieved by treatment with primary amines or hydrazine (Entries 2 and 3, Table 3.23 see also Section 10.1.10.4). 

A wide choice of peptide synthesizers is currently available, ranging from manual to fully automated. They are all based on solid-phase peptide synthesis methodologies in which either f-butoxy carbonyl (t-boc) (11), or 9-fluor-enylmethoxycarbonyl (Fmoc) (12) is the major protecting group during synthesis. A detailed description of peptide synthesis is clearly beyond the scope of this chapter, and further information on practical and theoretical approaches to this chemistry may be found elsewhere (13-15). However, a brief outline of solid-phase synthesis may prove useful. 

The peptide chains al, a2, and al are constructed by solid-phase methodology using Fmoc chemistry on the HMP resin. The peptides are then cleaved from the resin and assembled into the heterotrimer by stepwise regioselective cross-linking (Scheme 12). 

The following peptide chains were constructed by solid-phase methodology al, which contained either 3 or 5 Gly-Pro-Hyp repeats on the N-terminus of H-Gly-Pro-Gln-Gly-Ile-Ala-Gly-Gln-Arg-Gly-Val-Val-Gly-Cys(Acm)-Gly-Gly-OH a2, which contained 3 or 5 Gly-Pro-Hyp repeats on the N-terminus of H-Gly-Pro-Gln-Gly-Leu-Leu-Gly-Ala-Hyp-Gly-Ile-Leu-Gly-Cys(Acm)-Cys(StBu)-Gly-Gly-OH and al, which contained either 3 or 5 Gly-Pro-Hyp repeats on the N-terminus of H-Gly-Pro-Gln-Gly-Ile-Ala-Gly-Gln-Arg-Gly-Val-Val-Gly-Leu-Cys(StBu)-Gly-Gly-OH. All three peptides were synthesized using Fmoc chemistry on HMP resin. Couplings were performed with HBTU/HOBt except for Cys residues, which were coupled as pentafluorophenyl esters to minimize racemization. Peptides were cleaved from the resin with H20/TFA (1 19) containing 1% Et3SiH. 

The synthesis of a linear precursor peptide of the HSV-a-[Tyr ]-conotoxin chimera (see Note 8) was performed by solid phase methodology on an Applied Biosystems Mod. 431A peptide synthesizer (Applied Biosystems Paris, France). Fmoc-based chemistry was used for the preparation of peptide using Rink-amide resin with 0.43 mmol/g loading. Four equivalents of Fmoc amino acid derivatives and HBTU/HOBt were used for coupling. The following amino acid derivatives were used in the synthesis Fmoc-Cys(Trt)-OH, Fmoc-Gly-OH, Fmoc-Val-OH, Fmoc-Pro-OH, Fmoc-Cys(Acm)-OH, Fmoc-Asn(Trt)-OH, Fmoc-Tyr( Bu)-OH. The synthetic protocol for Fmoc chemistry was as follows ... 

A wide choice of peptide-synthesizers is currently available, ranging from manual to fully automated. They are all based on solid-phase peptide syn thesis methodologies in which either fboc (fbutoxy carbonyl) or Fmoc... 

There are numerous side reactions that can occur during solid-phase peptide synthesis, some of which are specific to the chemistries employed using Fmoc-based methodology. This section describes some of the prevalent reactions that will lead to heterogeneity in the resultant peptide. 

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