Fmoc-Trp

Sequential acylation reactions were carried out at ambient temperature for 1.5 h using a DMF solution (1.3 mL) of the appropriate A-Fmoc-protected amino acids [Fmoc-Arg/D-Arg(Pmc)-OH, 265 mg Fmoc-Trp/D-Trp(Boc)-OH, 211 mg 0.4 mmol) and then carboxyl activated using TBTU (154 mg, 0.4mmol), HOBt (54mg, 0.4mmol), and DIEA (140pL, 0.8 mmol). Repetitive A"-Fmoc deprotection was achieved using 20% v/v piperidine in DMF (6 min, 2.5 mL min - ). 

Figure 3 Conjugation chemistry of PLGA to Fmoc-Trp(Boc) (adapted with permission from the publisher [24]).

Fmoc-amino acids used as building blocks of testing compounds are as follows Fmoc-Asp(OtBu)-OH, Fmoc-Cys(Trt)-OH, Fmoc-Asn(Trt)-OH, Fmoc-Gln(Trt)-OH, Fmoc-Met-OH, Fmoc-Glu(OtBu)-OH, Fmoc-Lys (Boc)-OH, Fmoc-Ile-OH, Fmoc-His(Trt)-OH, Fmoc-Tyr(tBu)-OH, Fmoc-Arg(Pmc)-OH, Fmoc-Phe-OH, Fmoc-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Val-OH, Fmoc-Pro-OH, Fmoc-Trp(Boc)-OH, Fmoc-D-Ala-OH, Fmoc-D-Arg(Pmc)-OH, Fmoc-D-Trp(Boc)-OH, Fmoc-D-Cys(Trt)-OH, Fmoc-D-Asp(OtBu)-OH, Fmoc-D-Glu(OtBu)-OH, Fmoc-D-His(Trt)-OH, Fmoc-D-Gln(Trt)-OH, Fmoc-D-Leu-OH, Fmoc-D-Met-OH, Fmoc-D-Pro-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-D-Lys(Boc)-OH, Fmoc-D-Tyr(tBu)-OH, Fmoc-D-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-D-Asn(Trt)-OH, Fmoc-3-(4-pyridyl)alanine, Fmoc-D-3-(3-pyridyl)alanine, Fmoc-4-tert-butoxyproline, Fmoc-3-chlorophenylalanine, Fmoc-norleucine, Fmoc-2-cyclohexylglycine, Fmoc-2-aminoisobutyric acid, Fmoc-tranexamic acid, Fmoc-(i ,S)-3-amino-3-(2-furyl)propionic acid, Fmoc-(i ,S)-(6,7-di-methoxy)-l,2,3,4-tetrahydroquinoline-3-carboxylic acid, Fmoc- (R, S)-3-amino-3-(4-hydroxyphenyl)propionic acid, Fmoc-(i ,S)-3-aminovaleric acid, Fmoc-(i ,5 )-3-amino-3-(3,4-dichlorophenyl)propionic acid, Fmoc-isonipecotic acid, Fmoc-(i ,S)-3-amino-3-(3,4-methylenedioxyphenyl)... 

Diethyl amine Fmoc-Ser-OH Boc-Leu-OH Fmoc-Trp-OH Flydrazine Piperidine Triflouroacetic acid Potassium cyanate... 

N,N-Diisopropylethylamine Diisopropylcarbodiimide Hydroxybenzotriazole Boc-D-Phe Fmoc-Cys(Trt) Fmoc-Trp Fmoc-Lys(Boc) Fmoc-Thr(tBu)... 

Peptide synthesis reagents and materials Use NovaSyn TGR resin (Novabiochem) for C-terminal amide synthesis and Fmoc amino acid monomers (Novabiochem) including Fmoc-Arg(Pbf)-OH, Fmoc-Asn(Trt)-OH, Fmoc-Cys(Trt)-OH, Fmoc-Gln(Trt)-OH, Finoc-Glu(OfBu)-OH, Fmoc-His(Trt)-OH, Fmoc-Lys(Boc)-OH, and Fmoc-Trp(Boc)-OH. Other peptide synthesis reagents are as for PNA (above) with the addition of 1,2-ethanedithiol (EDT, >98%, Fluka). A Phenomenex Jupiter C-18 column (analytical and semi-preparative) may be used for reversed-phase HPLC. 

This unwanted side reaction can be eliminated by the use of Fmoc-OSu, which was proposed by several groups and is now the long preferred option for the introduction of the group. A typical reaction protocol for the synthesis of Fmoc-Trp-OH on a five-mole scale is given. 

White P. Fmoc-Trp(Boc)-OH a new derivative for the synthesis of peptides containing tryptophan. In Smith JA, Rivier JE, eds. Peptides Chemistry and Biology (Proceedings of the 12th American Peptide Symposium). Leiden ESCOM, 1992,537-538. 

Increase EOT content of cleavage cocktail. Resynthesize peptide using Trt-protected derivatives for introduction of Ser, Thr, and Tyr, and Fmoc-Trp(Boc) for addition of Trp... 

Repeat cleavage, monitoring reaction by HPLCto ensure minimum reaction time. Repeat cleavage using TMSBr in TFA. Resynthesize peptide using Fmoc-Trp(Boc)... 

Repeat cleavage using TMSBr in TFA. Resynthesize peptide using Fmoc Trp(Boc). 

Reduction of indole double bond of Trp Use Fmoc-Trp(Boc)-OH, and avoid use of triethyl silane (TES)... 

AP-Fmoc amino acid Weigh each of the amino acids in the WFTTLISTIM sequence (Fmoc-Phe-OH, Fmoc-lle-OH, Fmoc-Leu-OH, Fmoc-Met-OH, Fmoc-Ser(tBu)-OH, Fmoc-Thr(fBu)-OH, Fmoc-Trp(Boc)-OH). All the W -Fmoc amino acids (5.2 equiv., 0.5 M) were dissolved in a freshly made 4 1 mixture of HOBt/HOAt in NMP. 

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