35590-65-9

Upstream product

• 5845-61-4 cyclo(L-Ala-L-Ala) 
• 7625-53-8 rac-Ala-OMe 
• 407-25-0 trifluoroacetic anhydride 
• 39825-33-7 isopropyl L-alanine 
• 2483-51-4 N-[(benzyloxy)carbonyl]-L-alanyl-L-alanine methyl ester 
• 39825-33-7 isopropyl ester of alanine 
• 3082-75-5 L-Alanine ethyl ester 
• 17344-99-9 AlaOEt 
• 10065-72-2 L-Alanine methyl ester 
• 15761-38-3 L-N-Boc-Ala 
• 3744-87-4 Boc-(R)-Ala 
• 124988-44-9 ethyl (R)-2-azidopropionate 
• 122748-83-8 Boc-Ala-Ala-O-pentachlorphenylester 
• 64532-72-5 Z-L-Ala-D-Ala-OEt 

Downstream Products

• 95-89-6 2,5-dimethyl-3-chloropyrazine 
• 27023-19-4 2,5-dichloro-3,6-dimethylpyrazine 

Relevant academic research and scientific papers

Anti-biofilm and anti-adherence properties of novel cyclic dipeptides against oral pathogens

Microorganisms embedded in a biofilm are significantly more resistant to antimicrobial agents and the defences of the human immune system, than their planktonic counterpart. Consequently, compounds that can inhibit biofilm formation are of great interest for novel therapeutics. In this study, a screening approach was used to identify novel cyclic dipeptides that have anti-biofilm activity against oral pathogens. Five new active compounds were identified that prevent biofilm formation by the cariogenic bacterium Streptococcus mutans and the pathogenic fungus Candida albicans. These compounds also inhibit the adherence of microorganisms to a hydroxylapatite surface. Further investigations were conducted on these compounds to establish the structure–activity relationship, and it was deduced that the common cleft pattern is required for these molecules to act effectively against biofilms.

Interfacial supramolecular biomimetic epoxidation catalysed by cyclic dipeptides

We synthesised a library of cis- and trans-cyclic dipeptides and evaluated their efficacy as catalysts in the asymmetric Weitz-Scheffer epoxidation of trans-chalcone. A thorough investigation relying on structure-activity studies and computational studies provided insights into the mechanism of the process. Our results revealed some structural features required for efficient conversion and for introduction of chirality into the product. The cyclic dipeptide acts as a catalyst by templating a supramolecular arrangement at the aqueous-organic interface required for efficient transformations to occur. Among all cyclic dipeptides investigated, cyclo(Leu-Leu) was the most efficient supramolecular catalyst.

Epimerization of cyclic alanyl-alanine in basic solutions

Alanine anhydrides (Cyclo-(Ala-Ala)) are the simplest dipeptides that have two chiral centers and three diastereomers: Cyclo-(L-Ala-L-Ala), Cyclo-(D-Ala-D-Ala), and Cyclo-(L-Ala-D-Ala). Analysis of the epimerization of these peptides may throw light on the development of homochirality in proteins. We show that the epimerization rate of Cyclo-(L-Ala-L-Ala) and Cyclo-(D-Ala-D-Ala) is higher than that of Cyclo-(L-Ala-D-Ala), while the ring-opening rates of Cyclo-(L-Ala-L-Ala) and Cyclo-(D-Ala-D-Ala) arelower than that of Cyclo-(L-Ala-D-Ala) in basic aqueous solutions. The total reaction resulted in the preferred stability of Cyclo-(L-Ala-L-Ala) and Cyclo-(D-Ala-D-Ala) to Cyclo-(D-Ala-L-Ala).

Efficient transformation of azides to primary amines using the mild and easily accessible CeCl3·;7H2O/NaI system

(Chemical Equation Presented) Because of the nitrogen functionality, the azido group plays an important role in the synthesis of amines, and numerous reduction methods of azides to primary amines are reported. Recent reports have highlighted the capability of NaI as a useful reagent for this transformation when it is used in combination with a Lewis acid promoter. However, these methods often suffer from harsh reaction conditions; for this reason, the development of a simple and efficient protocol using NaI in presence of inexpensive and readily available cerium salts Lewis acids would extend the scope of this organic transformation. In continuation of our interest on the use of the CeCl3·7H2O/NaI system, in this paper we report how azides undergo reduction by NaI in the presence of CeCl 3·7H2O in refluxing acetonitrile under neutral conditions to produce the corresponding primary amines. The rate and yield of the reaction are considerably improved by employing this microwave-assisted procedure, and this may be of value for the preparation of densely functionalized molecules having biological and pharmaceutical activities.

Stereochemistry of Piperazine-2,5-dione Formation by Self-condensation of DL-Amino Acid Esters

'Racemic' piperazine-2,5-diones (diketopiperazines, dkps) have been synthesized by the self-condensation of DL-amino acid esters without solvent.It was found that 'racemic' dkps consisted of cis- and trans-isomers, and that cis-dkp was preferentially formed in the early stage of the self-condensation, the cis:trans ratios gradually decreasing with increasing reaction time.These results may be attributed to the difference in the rates of cyclization of two kinds of diastereoisomeric dipeptide esters, intermediates in the formation of dkps from DL-amino acid esters.It was further confirmed that the pre-cis-dipeptide ester, which formed cis-dkp, cyclized faster than the pre-trans-dipeptide ester in methanol.Differences in steric hindrance in the cyclization reaction of pre-cis- and pre-trans-isomers may be an important factor in the stereochemistry of self-condensation.

Facile Synthesis of Cyclic Dipeptides and Detection of Racemization

Several cyclic dipeptides were synthesized by refluxing methanolic solution of dipeptide methyl esters in high yield and purity.Cyclic dipeptides prepared by the Fischer method, the Nitecki method, and the present methanol-reflux method were compared with

Asymmetric Syntheses via Heterocyclic Intermediates, V. - Asymmetric Synthesis of α-Methyl Amino Acids by Alkylation of the Lithiated Lactim Ether of cyclo-(L-Ala-L-Ala)

The (3S,6S)-2,5-dimethoxy-3,6-dimethyl-3,6-dihydropyrazine (7) is obtained from cyclo-(L-Ala-L-Ala) 5 (93-95percent optically pure) and trimethyloxonium tetrafluoroborate.With butyllithium the lithio derivative 8 is formed which reacts with alkyl halides in good chemical yields and with more than 90percent diastereoselectivity, whereby R-configuration is induced at C-3.A model concept is discussed, which explains the remarkably high asymmetric induction. - Hydrolysis (0.25 N HCl, room temp.) gives L-alanine methyl ester (4) and the (R)-α-methyl amino acid methyl esters 13.The two amino acid esters are separable by distillation or chromatography.

15N NMR Spectroscopy. 19 - Spectroscopic Characterization of Cyclodipeptides (2,5-Dioxopiperazines)

Various cyclodipeptides containing glycine, alanine, leucine, valine, phenylalanine, phenylglycine and sarcosine units were synthesized by cyclization of dipeptide pentachlorophenyl esters.The 13C and natural abundance 15N NMR spectra of these heterocycles were measured in trifluoroacetic acid and compared with the spectra of the corresponding amino acids and polypeptides.The 13C NMR carbonyl signals of all cyclodipeptides show a 1.5-4.0 ppm upfield shift relative to the corresponding polypeptides.The 15N NMR signals show no such consistent relationship.The substituent effects and the neighbouring residue effects observed in the 15NMR spectra of the cyclodipeptides are different from those of polypeptides, while the one bond N-H coupling constant of cis and trans amide groups was almost identical.The nitrogen and the carbonyl signal of the Gly units in cyclo-Gly-Phe show an extraordinary downfield shift, reflecting the interaction of the phenyl group with the 2,5-dioxopiperazine ring.

RhCl3-catalyzed Amide Bond Formation under Mild Conditions

The reaction of carboxylic acid esters with amines is accelerated in the presence of catalytic amounts of RhCl3*3H2O at a reasonably low temperature; optically active 2,5-dioxopiperazines can be synthesized in high yield from the corresponding amino-acid esters using this procedure.