76387-70-7Relevant articles and documents
Solid-phase synthesis and CD spectroscopic investigations of novel β-peptides from L-aspartic acid and β-amino-L-alanine
Ahmed, Sahar,Beleid, Reem,Sprules, Tara,Kaur, Kamaljit
, p. 25 - 28 (2007)
(Chemical Equation Presented) A solid-phase synthesis method for the preparation of novel β3 and β2-peptides derived from L-aspartic acid and β-amino-L-alanine, respectively, is described. The methodology allows independent buildup of the β-peptide backbone and the introduction of sequential side chain substitutions. Representative peptides from the two classes, an amino-substituted β3-hexapeptide and an acyl-substituted β2-hexapeptide, have been prepared, and their solution conformation is studied by circular dichroism (CD) spectroscopy.
The microenvironment and pKaperturbation of aminoacyl-tRNA guided the selection of cationic amino acids
Hazra, Bibhas,Prasad, Mahesh,Roy, Rajat,Tarafdar, Pradip K.
supporting information, p. 8049 - 8056 (2021/10/04)
The proteinogenic lysine (Lys) and arginine (Arg) have multiple methylene groups between α-carbon and the terminal charged centre. Why nature did not select ornithine (Orn), 2,4-diamino butyric acid (Dab) and 2,3-diamino propionic acid (Dpr) with fewer methylene groups in the side chain remains an important question! The propensity of aminoacyl-tRNA (aa-tRNA) model substrates towards self-degradationviaintramolecular lactamization was studied using UV spectroscopy and1H-NMR titration, which showed that Lys and Arg remain stable, and Orn and Dab cyclize to lactam. Hydrophobicity-assisted surface mediated model peptide formation highlighted that the microenvironment and pKaperturbation led to poor regioselectivity (α-aminevs.terminal amine) in Dpr and other non-proteinogenic analogues. The α-selectivity became even poorer in the presence of phosphate, making them ill-suited for peptide synthesis. Superior regioselectivity of the Lys aa-tRNA model substrate suggests that the extra methylene bridge helped nature to separate the microenvironments of the α-amine and ε-amine to synthesize the peptide backbone.
2,3-Diaminopropanols obtained from D-serine as intermediates in the synthesis of protected 2,3-L-diaminopropanoic acid (L-DAP) methyl esters
Aiello, Donatella,Athanassopoulos, Constantinos M.,Mazzotti, Fabio,Siciliano, Carlo,Temperini, Andrea,de Luca, Pierantonio
, (2020/03/23)
A synthetic strategy for the preparation of two orthogonally protected methyl esters of the non-proteinogenic amino acid 2,3-l-diaminopropanoic acid (l-Dap) was developed. In these structures, the base-labile protecting group 9-fluorenylmethyloxycarbonyl (Fmoc) was paired to the p-toluensulfonyl (tosyl, Ts) or acid-labile tert-butyloxycarbonyl (Boc) moieties. The synthetic approach to protected l-Dap methyl esters uses appropriately masked 2,3-diaminopropanols, which are obtained via reductive amination of an aldehyde prepared from the commercial amino acid Nα-Fmoc-O-tert-butyl-d-serine, used as the starting material. Reductive amination is carried out with primary amines and sulfonamides, and the process is assisted by the Lewis acid Ti(OiPr)4. The required carboxyl group is installed by oxidizing the alcoholic function of 2,3-diaminopropanols bearing the tosyl or benzyl protecting group on the 3-NH2 site. The procedure can easily be applied using the crude product obtained after each step, minimizing the need for chromatographic purifications. Chirality of the carbon atom of the starting d-serine template is preserved throughout all synthetic steps.
High-efficiency preparation method of D-dencichine
-
, (2019/01/21)
The invention relates to a high-efficiency synthesis method of a hemostasis compound D-dencichine, comprising the following steps: firstly enabling D-serine to react with di-tert-butyl dicarbonate ester to generate Boc-D-serine, then generating Gabriel reaction with hydroxy of methylsulfonyl chloride activated Boc-D--serine to obtain N-alpha-Boc-D-alpha, beta-diaminopro, finally condensing with oxalate mono-methyl ester sylvite then performing hydrolytic acidification to obtain a dencichine crude product, and purifying to obtain a dencichine competitive product, with the product content reaching more than 99.8%. Compared with existing D-dencichine synthesis methods, the reaction condition is more mild, the operation is simple and convenient, the material cost is relatively low, and the hemostasis compound D-dencichine is environment-friendly, is suitable for industrial production, and solves the problem of resource for later development of clinical trial of D-dencichine.
