2667-02-9

Upstream product

• 35661-40-6 N-Fmoc L-Phe 
• 69700-83-0 Boc-L-Phe-L-Phe-L-Phe-OBzl 
• 16879-80-4 tert-butyl ((S)-1-oxo-1-(((S)-3-oxo-1,4-diphenylbutan-2-yl)amino)-3-phenylpropan-2-yl)carbamate 
• 66617-58-1 N-(tert-butoxycarbonyl)-L-phenylalanine benzyl ester 
• 70669-39-5 Phe-Phe-OBzl 
• 962-39-0 L-Phenylalanine benzyl ester 
• 13734-34-4 N-tert-butoxycarbonyl-L-phenylalanine 
• 302-72-7 rac-Ala-OH 
• 5241-58-7 L-Phenylalanine amide 

Relevant academic research and scientific papers

Bioconjugates of Co(III) complexes with Schiff base ligands and cell penetrating peptides: Solid phase synthesis, characterization and antiproliferative activity

In this work we synthesized a chelating Schiff base by a single condensation of salicylaldehyde with 3,4-diamino benzoic acid (1). This ligand was used further for complexation to CoCl2·6H2O under nitrogen. In the next step, three six-coordinate Co(III) complexes were synthesized by coordinating this complex with imidazole (2), 2-methyimidazole (3) and N-Boc-L-histidine methyl ester (4) (Boc: tert.-butoxycarbonyl) in axial positions with simultaneous oxidation of Co(II) to Co(III) under ambient environment. All Co(III) complexes were characterized by multinuclear NMR spectroscopy (1H, 13C and 59Co NMR), FT-IR, mass spectrometry and HPLC. The Co(III) complexes were conjugated to three different cell penetrating peptides: FFFF (P1), RRRRRRRRRGAL (P2) and FFFFRRRRRRRRRGAL (P3). Standard solid-phase peptide chemistry was used for the synthesis of cell penetrating peptides. Coupling of N-terminal peptides with the cobalt complexes, possessing a carboxylic group on the tetradentate Schiff base ligand, afforded Co(III)-peptide bioconjugates, which were purified by semi-preparative HPLC and characterized by analytical HPLC and mass spectrometry. The antiproliferative activity of the synthesized compounds was studied against different human tumour cell lines: lung cancer A549, liver cancer HepG2 and normal human fibroblasts GM5657T, in comparison with the activity of cisplatin as a reference drug. The bioconjugate 21 containing the Co complex 4 and the combined phenylalanine and polyarginine cell penetrating sequence P3 shows better activity against the liver cancer line HepG2 than the parent Co(III) complex 4.

Self-Assembly of Tetraphenylalanine Peptides

Three different tetraphenylalanine (FFFF) based peptides that differ at the N- and C-termini have been synthesized by using standard procedures to study their ability to form different nanoassemblies under a variety of conditions. The FFFF peptide assembles into nanotubes that show more structural imperfections at the surface than those formed by the diphenylalanine (FF) peptide under the same conditions. Periodic DFT calculations (M06L functional) were used to propose a model that consists of three FFFF molecules defining a ring through head-to-tail NH3+?-OOC interactions, which in turn stack to produce deformed channels with internal diameters between 12 and 16 ?. Depending on the experimental conditions used for the peptide incubation, N-fluorenylmethoxycarbonyl (Fmoc) protected FFFF self-assembles into a variety of polymorphs: ultra-thin nanoplates, fibrils, and star-like submicrometric aggregates. DFT calculations indicate that Fmoc-FFFF prefers a parallel rather than an antiparallel β-sheet assembly. Finally, coexisting multiple assemblies (up to three) were observed for Fmoc-FFFF-OBzl (OBzl = benzyl ester), which incorporates aromatic protecting groups at the two peptide terminals. This unusual and noticeable feature is attributed to the fact that the assemblies obtained by combining the Fmoc and OBzl groups contained in the peptide are isoenergetic. Variety show! Three different tetraphenylalanine-based peptides that differ at the N- and C-termini have been synthesized by using standard procedures to study their ability to form different nanoassemblies (e.g., nanotubes, see figure) under a variety of conditions.

Biomimetic peptide bond formation in water with aminoacyl phosphate esters

Aminoacyl phosphates, biomimetic analogues of aminoacyl adenylates, react efficiently with amino acid esters to form dipeptides with retention of stereochemical integrity. The reactions are selective and occur readily in the presence of nucleophiles other than amino groups on their side chains. Aminoacyl phosphate esters that lack an amino-protecting group are also suitable for peptide bond formation, leading to a simplified overall process.

Biomimetic protecting-group-free 2′, 3′-selective aminoacylation of nucleosides and nucleotides

Aminoacyl phosphate monoesters can be prepared free of an amino-protecting group and used directly in lanthanum-promoted selective monoacylation of either the 2′ or 3′-hydroxyl of nucleosides and nucleotides. For example, phenylalanyl ethyl phosphate rapi

Peptide bond formation by aminolysin-A catalysis: A simple approach to enzymatic synthesis of diverse short oligopeptides and biologically active puromycins

A new S9 family aminopeptidase derived from the actinobacterial thermophile Acidothermus cellulolyticus was cloned and engineered into a transaminopeptidase by site-directed mutagenesis of catalytic Ser491 into Cys. The engineered biocatalyst, designated aminolysin-A, can catalyze the formation of peptide bonds to give linear homo-oligopeptides, hetero-dipeptides, and cyclic dipeptides using cost-effective substrates in a one-pot reaction. Aminolysin-A can recognize several C-terminal-modified amino acids, including the l- and d-forms, as acyl donors as well as free amines, including amino acids and puromycin aminonucleoside, as acyl acceptors. The absence of amino acid esters prevents the formation of peptides; therefore, the reaction mechanism involves aminolysis and not a reverse reaction of hydrolysis. The aminolysin system will be a beneficial tool for the preparation of structurally diverse peptide mimetics by a simple approach.