71731-66-3

Upstream product

• 4457-32-3 4-nitrobenzyl chloroformate 

Downstream Products

• 53793-17-2 (S)-2-((((4-nitrobenzyl)oxy)carbonyl)amino)propanoic acid 
• 122411-88-5 N-(4-nitro-benzyloxycarbonyl)-L-leucine 
• 161855-97-6 N-(4-nitro-benzyloxycarbonyl)-L-isoleucine 
• 82251-86-3 pNBC-Phe-OH 
• 864531-85-1 3-tert-butoxy-2-(4-nitro-benzyloxycarbonylamino)-propionic acid 
• 864531-90-8 3-(4-tert-butoxy-phenyl)-2-(4-nitro-benzyloxycarbonylamino)-propionic acid 
• 864531-92-0 5-tert-butoxycarbonylamino-2-(4-nitro-benzyloxycarbonylamino)-pentanoic acid 
• 4596-53-6 N-[[(4-Nitrophenyl)methoxy]carbonyl]glycine 
• 174653-61-3 N_α-(9-fluorenylmethoxycarbonyl)-N_ε-(2-nitrobenzyloxycarbonyl)-lysine 

Relevant academic research and scientific papers

Solid-phase synthesis of peptide conjugates derived from the antimicrobial cyclic decapeptide BPC194

The solid-phase conjugation of the antimicrobial peptide c(KKLKKFKKLQ) (BPC194) to a linear or cyclic sequence through a 1,2,3-triazole ring is described. Cyclic alkynylpeptidyl resins derived from BPC194 were treated with azidopeptides derived from the antimicrobial peptide BP100 or from the bacteriocin iturin A. The cyclic alkynyl-peptidyl resins incorporated at the 3-position a propargylglycine, a glutamic acid residue derivatized with propargylamine or a lysine bearing a propioloyl group. The reactions of the cyclic alkynyl resins with the BP100-derived azidopeptides depended on the length and the sequence of the azidopeptides. The reactions were performed by treatment of the alkynyl resin with CuI and ascorbic acid, and required the presence of piperidine/DMF or DIEA in 2,6-lutidine/DMF. The latter conditions also allowed the conjugation of the alkynyl-peptidyl resin bearing a propioloyl lysine to a linear or cyclic azidopeptide derived from the cyclic moiety of iturin A.

Total Solid-Phase Synthesis of Dehydroxy Fengycin Derivatives

A rapid and efficient solid-phase strategy for the synthesis of dehydroxy fengycins derivatives is described. This synthetic approach involved the linkage of a Tyr to a Wang resin via a Mitsunobu reaction and the elongation of the peptide sequence followed by subsequent acylation of the N-terminus of the resulting linear peptidyl resin, esterification of the phenol group of a Tyr with an Ile, and final macrolactamization. The amino acid composition as well as the presence of the N-terminal acyl group significantly influenced the stability of the macrolactone. Cyclic lipodepsipeptides with a l-Tyr3/d-Tyr9 configuration were more stable than those containing the Tyr residues with an opposite configuration. This work constitutes the first approach on the total solid-phase synthesis of dehydroxy fengycin derivatives.

Solid-phase synthesis of cyclic lipopeptidotriazoles

The solid-phase synthesis of cyclic lipopeptidotriazoles derived from the cyclic decapeptide c(Lys-Lys2-Leu-Lys-Lys5-Phe-Lys-Lys- Leu-Gln) (BPC194), incorporating a triazolyl ring at Lys2 and a hexanoyl group at Lys5, was studied. Four different strategies that required the use of five orthogonal protecting groups (Fmoc, tBu, All, pNZ, ivDde) were explored. The influence of the side-chain protection of Lys 2 and Lys5 with the ivDde and pNZ groups was evaluated by incorporating Lys2(ivDde)/Lys5(pNZ) or Lys 2(pNZ)/Lys5(ivDde). The order of removal of these protecting groups and of the introduction of the hexanoyl and triazolyl moieties was also studied. The best strategy included: (i) synthesis of a cyclic peptidyl resin bearing Lys2(ivDde) and Lys5(pNZ); (ii) pNZ group removal; (iii) acylation with hexanoic acid; (iv) ivDde group removal; and (v) acylation with propiolic acid followed by an azide-alkyne 1,3-dipolar cycloaddition. By using this protocol, a set of cyclic lipopeptidotriazoles was prepared in high purities.

p-Nitrobenzyloxycarbonyl (pNZ) as a temporary Na-protecting group in orthogonal solid-phase peptide synthesis - Avoiding diketopiperazine and aspartimide formation

p-Nitrobenzyloxycarbonyl (pNZ) was used as a temporary protecting group for α-amino functionalities in solid-phase peptide synthesis. The corresponding derivatives are readily synthesized solids that perform well on solid phase. The pNZ moiety is orthogonal with the most common protecting groups used in peptide chemistry, and is removed under neutral conditions in the presence of catalytic amounts of acid. The use of pNZ derivatives in conjunction with Fmoc chemistry circumvents typical side reactions associated with the use of piperidine, such as DKP and aspartimide formation. The flexibility of pNZ can be exploited for the preparation of libraries of small organic molecules. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.