158804-50-3

Upstream product

• 16937-99-8 N-Boc-D-Leu 
• 100-39-0 benzyl bromide 
• 100-51-6 benzyl alcohol 

Downstream Products

• 68838-94-8 (R)-benzyl 2-amino-4-methylpentanoate hydrochloride 
• 129919-89-7 N-(tert-butoxycarbonyl)-N-methyl-D-leucine benzyl ester 
• 1332482-23-1 C₂₃H₃₆N₂O₅ 
• 1309055-92-2 D-valyl-D-leucine benzyl ester TFA salt 
• 205874-89-1 N^α-t-butoxycarbonyl-N^g-tosylarginyl-D-leucine benzyl ester 
• 333363-53-4 (R)-4-Methyl-2-{methyl-[(S)-1-(2-oxo-propionyl)-pyrrolidin-2-ylmethyl]-amino}-pentanoic acid benzyl ester 
• 333363-51-2 L-lactyl-Pro-ψ(NHCH2)-N-methyl-D-leucine benzyl ester 
• 333363-48-7 N-Boc-Pro-ψ(NHCH2)-N-methyl-leucine benzyl ester 
• 89536-86-7 H-N-Me-D-Leu-OBzl 
• 849833-84-7 N-(2-Boc-aminoethyl)-N-(thymin-1-ylacetyl)-D-leucine benzyl ester 
• 849833-82-5 N-(2-Boc-aminoethyl)-D-leucine benzyl ester 
• 46741-65-5 D-leucine benzyl ester 

Relevant academic research and scientific papers

Effect of PNA backbone modifications on cyanine dye binding to PNA-DNA duplexes investigated by optical spectroscopy and molecular dynamics simulations

Optical spectroscopy and molecular dynamics simulations have been used to study the interaction between a cationic cyanine dye and peptide nucleic acid (PNA)-DNA duplexes. This recognition event is important because it leads to a visible color change, signaling successful hybridization of PNA with a complementary DNA strand. We previously proposed that the dye recognized the minor groove of the duplex, using it as a template for the assembly of a helical aggregate. Consistent with this, we now report that addition of isobutyl groups to the PNA backbone hinders aggregation of the dye when the substituents project into the minor groove but have a weaker effect if directed out of the groove. UV-Visible and circular dichroic spectroscopy were used to compare aggregation on the different PNA-DNA duplexes, while molecular dynamics simulations were used to confirm that the substituents block the minor groove to varying degrees, depending on the configuration of the starting amino acid. In addition to a simple steric blockage effect of the substituent, the simulations suggest that directing the isobutyl group into the minor groove causes the groove to narrow and the duplex to become more rigid, structural perturbations that are relevant to the growing interest in backbone-modified PNA for applications in the biological and materials sciences.

N-linked peptidoresorc[4]arene-based receptors as noncompetitive inhibitors for α-chymotrypsin

This paper deals with the design, synthesis, and evaluation of a new series of receptors for protein surface recognition. The design of these agents is based around the attachment of four constrained dipeptide chains onto a central resorc[4]arene scaffold. By varying the sequence, nature, and stereochemistry of the chains we prepared anionically functionalized N-linked peptidoresorc[4] arenes 12, 13, and 17 by Pd/C-catalyzed hydrogenation of the corresponding benzyl esters 10, 11, and 16. From this family of receptors we have identified noncompetitive inhibitors of α-chymotrypsin (ChT), which function by binding to the surface of the enzyme in the neighborhood of the active site cleft (Ki values ranging from 12.4 ± 5.1 μM for free carboxylic acid (+)-12b to 0.76 ± 0.14 μM for benzyl ester (-)-16a). For anionically functionalized receptors 12, 13, and 17 the ChT inhibition is based essentially on electrostatic interaction, and the bound enzyme can be released from the resorcarene surface by increasing the ionic strength, with its activity almost completely restored. For receptors with terminal benzyl ester groups (10 and 16) a hydrophobic network can be suggested.

Synthetic Studies of Tamandarin B Side Chain Analogues

The syntheses of three tamandarin B analogues are described. The goal of these studies was to prepare material to determine their relative therapeutic index and to gain an oversight as to their potential for clinical applications.

From peptides to their alternating ester-urea analogues: Synthesis and influence of hydrogen bonding motif and stereochemistry on aggregation

(Chemical Equation Presented) Peptide-mimicking scaffolds with an incorporated ester-urea motif, replacing two adjacent amide residues, were synthesized and their aggregation behavior was studied in dependence of hydrogen bonding sites as well as backbone stereochemistry. Two oligomer series containing either 50% or 100% ester-urea units and either all-(L) or (D)-alt-(L) backbone configuration were prepared via ester and amide couplings, using a divergent/convergent exponential growth strategy. Their aggregation behavior in organic solution was investigated by means of concentration-dependent NMR spectroscopy and compared to the parent peptide series. Interestingly, the naturally occurring peptide scaffold exhibits the largest tendency to associate in combination with the strongest difference in aggregation behavior between all-(L) and (D)-alt-(L) backbone stereochemistry. With increasing incorporation of the ester-urea motif the aggregation strength decreases and become much less dependent on the backbone configuration. The obtained structure-aggregation relationships reveal the importance of the commensurability and multivalency of hydrogen bonding sites as well as conformational restriction for peptide association and should hence aid the design of peptide mimics, such as β -sheet breakers or gelators. 2009 American Chemical Society.

Peptide nucleic acids (PNAs) with a functional backbone

The synthesis of 10 new T-PNA monomers derived from L-amino acids is presented. The monomers were incorporated into decameric PNA oligomers, and the hybridisation with RNA, DNA and PNA complements studied by thermal stability measurements.

Design and synthesis of peptides passing through the blood-brain barrier

The blood-brain barrier (BBB) is a highly selective membranous barrier regulating the transport of substances in blood into the brain parenchyma. At present, delivery of biologically active peptides or peptide drugs into the brain is quite an important subject from the standpoint of chemotherapy for brain diseases H-MeTyr-Arg-MeArg-D-Leu-NH(CH2)8NH2 termed 001-C8 was first synthesized to elucidate the structural specificity of peptides for passing through the BBB. The Na-methylamino acid and D-amino acid residues were appropriately situated in this peptide to protect against the digestion by peptidase. Furthermore, a number of basic peptides were prepared as 001-C8 analogs for studying the relationship between structure and BBB permeability of peptides.