25616-14-2

Upstream product

• 13734-41-3 t-Boc-L-valine 
• 75-77-4 chloro-trimethyl-silane 
• 108-95-2 phenol 
• 117049-08-8 (1R,2S,5R)-2-(1-methyl-1-phenylethyl)-5-methylcyclohexyl<(tert-butoxycarbonyl)amino>bromoacetate 
• 35590-87-5 (3S,6R)-3-(1-methylethyl)-6-(phenylmethyl)piperazine-2,5-dione 
• 946414-68-2 (3R,6S)-3-benzyl-3-methyl-6-isopropyl-piperazine-2,5-dione 
• 946414-69-3 (3S,6S)-3-benzyl-3-methyl-6-isopropyl-piperazine-2,5-dione 
• 852994-84-4 (3S)-N-1-(tert-butoxycarbonyl)-N-4-(4-methoxybenzyl)-3-isopropyl-piperazine-2,5-dione 
• 437768-95-1 (S)-N⁽¹⁾-(p-methoxybenzyl)-6-isopropylpiperazine-2,5-dione 
• 72-18-4 L-valine 
• 1143567-26-3 C₁₅H₂₃FN₄O₃ 
• 1383580-56-0 (2S,4S)-N-((6R,9R,12S,15S,16R,Z)-3-ethylidene-6-(4-hydroxybenzyl)-12-isobutyl-9-isopropyl-16-methyl-2,5,8,11,14-pentaoxo-1-oxa-4,7,10,13-tetraazacyclohexadecan-15-yl)-2,4-dimethylheptanamide 
• 219924-27-3 2,2-Dimethyl-propionic acid (2R,3R,4S,5S,6R)-2-({(R)-1-[2-(tert-butyl-dimethyl-silanyloxymethyl)-phenylcarbamoyl]-2-methyl-propyl}-formyl-amino)-4,5-bis-(2,2-dimethyl-propionyloxy)-6-(2,2-dimethyl-propionyloxymethyl)-tetrahydro-pyran-3-yl ester 
• 121441-03-0 (S)-2-[Benzyl-(2,2,2-trifluoro-acetyl)-amino]-3-methyl-butyric acid methyl ester 

Downstream Products

• 2901-80-6 (2R)-2-(benzoylamino)-3-methylbutyric acid 
• 186261-39-2 (R)-2-[(E)-3-(2,4-Dimethoxy-phenyl)-acryloylamino]-3-methyl-butyric acid ethyl ester 
• 24629-22-9 Bz-Gly-Val 
• 2754-02-1 N-(N-(1,1-dimethylethoxycarbonyl)-L-phenylalanyl)-L-valine methyl ester 
• 47507-41-5 (S)-2-((S)-2-((tert-butoxycarbonyl)amino)-3-phenylpropanamido)-3-methylbutanoic acid 
• 1149-26-4 (S)-N-(benzyloxycarbonyl)valine 
• 155225-25-5 N--(R)-serine methylester 
• 159858-07-8 N-Cbz-Val-Cit-4-aminobenzyl alcohol 

Relevant academic research and scientific papers

Isolation and structural determination of the antifouling diketopiperazines from marine-derived Streptomyces praecox 291-11

Marine derived actinomycetes constituting 185 strains were screened for their antifouling activity against the marine seaweed, Ulva pertusa, and fouling diatom, Navicula annexa. Strain 291-11 isolated from the seaweed, Undaria pinnatifida, rhizosphere showed the highest antifouling activity and was identified as Streptomyces praecox based on a 16S rDNA sequence analysis. Strain 291-11 was therefore named S. praecox 291-11. The antifouling compounds from S. praecox 291-11 were isolated, and their structures were analyzed. The chemical constituents representing the antifouling activity were identified as (6S,3S)-6-benzyl-3-methyl-2,5-diketopiperazine (bmDKP) and (6S,3S)-6-isobutyl-3- methyl-2,5-diketopiperazine (imDKP) by interpreting the nuclear magnetic resonance and high-resolution mass spectroscopy data. Approximately 4.8mg of bmDKP and 3.1 mg of imDKP were isolated from 1.2 g of the S. praecox 291-11 crude extract. Eight different compositions of culture media were investigated for culture, the TBFeC medium being best for bmDKP and TCGC being the optimum for imDKP production. Two compounds respectively showed a 17.7 and 21 therapeutic ratio (LC50/EC50) to inhibit zoospores, and two compounds respectively showed a 263 and 120.2 therapeutic ratio to inhibit diatoms.

Preparation of Constrained Unnatural Aromatic Amino Acids via Unsaturated Diketopiperazine Intermediate

Unnatural aromatic amino acids are useful tools in drug discovery, since their insertion in bioactive peptide sequences can change the side chains spatial orientation, the backbone conformation and above all, their bioactivity. In this communication, we propose a straightforward method to synthesize 2′,6′-dimethyl-tyrosine and 2′,6′-dimehylphenyl-alanine derivatives as handling building blocks for peptide synthesis via unsaturated diketopiperazine (DKP) intermediate.

Cycloforskamide, a cytotoxic macrocyclic peptide from the sea slug Pleurobranchus forskalii

A macrocylic dodecapeptide, cycloforskamide, was isolated from the sea slug Pleurobranchus forskalii, collected off Ishigaki Island, Japan. Its planar structure was deduced by extensive NMR analyses and was further confirmed by MS/MS fragmentation analyses. Finally, the absolute configuration was determined by total hydrolysis and chiral-phase gas chromatographic analysis. This novel dodecapeptide contains three d-amino acids and three thiazoline heterocycles and exhibits cytotoxicity against murine leukemia P388 cells, with an IC 50 of 5.8 μM.

Tumescenamide C, an antimicrobial cyclic lipodepsipeptide from Streptomyces sp.

Tumescenamide C, a new cyclic lipodepsipeptide, was isolated from a culture broth of an actinomycete Streptomyces sp. KUSC-F05. Tumescenamide C was a congener of tumescenamides A and B, representing a sixteen-membered ring system, consisting of two proteinogenic and three non-proteinogenic amino acids, to which a methyl-branched fatty acid was attached. The planar structure was determined by spectroscopic analysis, while its absolute stereochemistry was determined by chemical degradation and asymmetric synthesis. Tumescenamide C exhibited antimicrobial activity with high selectivity against Streptomyces species.

A phenylacetylated peptide, JBIR-96, isolated from Streptomyces sp. RI051-SDHV6

Searching for metabolites from Streptomyces sp. RI051-SDHV6 resulted in the discovery of a novel peptide, JBIR-96 (1). The structure of 1 was established as an N-phenylacetylated pentapeptide involving a cysteic acid and a peptide lactone structure by extensive NMR and MS analyses. In addition, the absolute configuration of 1 was established by Marfey's and modified Mosher's methods. (Chemical Equation Presented).

Biocatalytic synthesis of valaciclovir using commercial enzymes

Proof-of-concept has been demonstrated for the biocatalytic transformation of aciclovir into valaciclovir, attaining high conversions from a solid-to-solid biotransformation in l-valine methyl ester using various formulations of Subtilisin Carlsberg activated for use in organic solvent.

L-valine and L-proline - solid-state IR-LD spectroscopic study

Spectral investigation including IR-characteristic bands assignment of the amino acids zwitterions L-Valine (L-Val) and L-Proline (L-Pro) was carried out by linear-dichroic infrared (IR-LD) spectroscopy of oriented solid sample as a nematic liquid crystal suspension. The obtained experimental IR-LD results (transition moment directions) were compared with known crystal X-ray data for molecules orientation in the unit cells of the studied compounds, confirming the applicability of the used spectral method for structural determination. The influence of the protonation on the IR-spectroscopic patterns of the both amino acids is discussed.

Hydration of amino acids from ultrasonic measurements

In this paper the results of compressibility of aqueous solutions of amino acids in water and in aqueous HCl and NaOH solutions at 25 °C are presented. The effect of the charged protonated amino groups and deprotonated carboxylic groups on the hydration number was tested. The idea of additivity of the hydration number with the constituents of the solute molecule was successfully applied and discussed.

An enantioselective synthesis of (S)-4-fluorohistidine

We report a new synthesis of enantiomerically pure (S)-4-fluorohisitidine based on diastereoselective alkylation of MOM-protected 4-fluoro-5-bromomethyl imidazole using the Sch?llkopf bis-lactim amino acid synthesis. Improvements in procedures for preparation of key intermediates are also described. (S)-4-Fluorohisitidine prepared by this new method was identical in all respects to material prepared by previous procedures.

Diastereoselective synthesis of quaternary α-amino acids from diketopiperazine templates

Sequential enolate alkylations of (S)-N(1)-methyl-5-methoxy-6-isopropyl-3, 6-dihydropyrazin-2-one and (S)-N(1)-p-methoxybenzyl-5-methoxy-6-isopropyl-3,6- dihydropyrazin-2-one proceed with excellent levels of diastereoselectivity (>90% de) affording quaternary α-amino acids in high enantiomeric excess (>98% ee) after deprotection and hydrolysis. This journal is The Royal Society of Chemistry.