72155-47-6Relevant academic research and scientific papers
ISO - AHPPA derivative and its preparation method
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Paragraph 0016; 0017; 0018, (2017/04/29)
The invention discloses an ISO-AHPPA derivative and a preparation method thereof. According to the preparation method of the ISO-AHPPA derivative, a mixture of diethyl zinc and stannic chloride is used as the catalyst, wherein the mole ratio of the diethy
Helices with additional H-bonds: crystallographic conformations of α,γ-hybrid peptides helices composed of β-hydroxy γ-amino acids (statines)
Malik, Ankita,Kumar, Mothukuri Ganesh,Bandyopadhyay, Anupam,Gopi, Hosahudya N.
, (2017/02/05)
β-Hydroxy-γ-amino acids (Statines) are a class of naturally occurring non-ribosomal amino acids frequently found in many peptide natural products. Peptidomimetics constituted with statines have been used as inhibitors for various aspartic acid proteases. In contrast to the synthetic γ-amino acids, very little is known about the folding behavior of these naturally occurring β-hydroxy γ-amino acids. To understand the folding behavior of statines, three α,γ-hybrid peptides P1 (Ac-Aib-γPhe-Aib-(R, S)Phesta-Aib-γPhe-Aib-CONH2), P2 (Ac-Aib-γPhe-Aib-(S, S)Phesta-Aib-γPhe-Aib-CONH2), and P3 (Ac-Aib-γPhe-Aib-(S, S)Phesta-Aib-(S, S)Phesta-Aib-CONH2) were synthesized on solid phase and their helical conformations in single crystals were studied. Results suggest that both syn and anti diastereoisomers of statines can be accommodated into the helix without deviating overall helical conformation of α,γ-hybrid peptides. In comparison with syn diastereoisomer, the anti diastereoisomer was found to be directly involved in the intramolecular H-bonding with the backbone carbonyl groups (i to i + 3) similar to the backbone amide NHs in the helix.
Exploring β-hydroxy γ-amino acids (statines) in the design of hybrid peptide foldamers
Bandyopadhyay, Anupam,Malik, Ankita,Kumar, Mothukuri Ganesh,Gopi, Hosahudya N.
, p. 294 - 297 (2014/01/23)
The synthesis and characterization of syn and anti β-hydroxy γ-amino acid (statine) diastereoisomers, their utilization in the design of hybrid peptide foldamers, and their single crystal conformations are studied.
Stereoselective synthesis of four possible isomers of streptopyrrolidine
Mohapatra, Debendra K.,Thirupathi, Barla,Das, Pragna P.,Yadav, Jhillu S.
experimental part, p. 34 - 39 (2011/03/22)
The synthesis of (4R,5R)-streptopyrrolidine (1), (4S,5R)-streptopyrrolidine (2) (4R, 5S)-streptopyrrolidine (3) and (4S,5S)-strepto- pyrrolidine (4) have been achieved in a concise and highly efficient manner via a highly stereoselective aldol type reacti
Mechanism-based inhibitors of the aspartyl protease plasmepsin II as potential antimalarial agents
Gupta, Deepak,Yedidi, Ravikiran S.,Varghese, Sheeba,Kovari, Ladislau C.,Woster, Patrick M.
experimental part, p. 4234 - 4247 (2010/08/22)
Four aspartyl proteases known as plasmepsins are involved in the degradation of hemoglobin by Plasmodium falciparum, which causes a large percentage of malaria deaths. The enzyme plasmepsin II (Plm-II) is the most extensively studied of these aspartyl proteases and catalyzes the initial step in the breakdown of hemoglobin by the parasite. Several groups have reported the design, synthesis, and evaluation of reversible peptidomimetic inhibitors of Plm II as potential antimalarial agents. We now report four peptidomimetic analogues, compounds 6-9, which are rationally designed to act as mechanism-based inhibitors of Plm II. Three of these analogues produce potent irreversible inactivation of the enzyme with IC50 values in the low nanomolar range. Of these three compounds, two retain the low micromolar IC 50 values of the parent compound in Plasmodium falciparum (clone 3D7) infected erythrocytes. These analogues are the first examples of fully characterized mechanism-based inactivators for an aspartyl protease and show promise as novel antimalarial agents.
A Novel, Facile and Diastereoselective Synthesis of (3S,4S) and (3R,4S)-N-Me-AHPPA
Reddy, G. Vidyasagar,Rao, G. Venkat,Iyengar, D. S.
, p. 703 - 704 (2007/10/03)
Diastereoselective syntheses of (3S,4S) and (3R,4S)-N-methyl-AHPPA are achieved via a novel Wittig reaction of an oxazolidinone followed by reduction.
Total synthesis and conformational studies of hapalosin, N-desmethylhapalosin and 8-Deoxyhapalosin
Wagner, Bjoern,Gonzalez, Gabriel Islas,Tran Hun Dau, Marie Elise,Zhu, Jieping
, p. 737 - 747 (2007/10/03)
Hapalosin (2), a 12-membered cyclic depsipeptide possessing MDR-reversing activity, and analogues (3) and (4) have been synthesized using macrolactamization as an important ring-forming step. Three building blocks: (2S, 3R)-3-(tert-butyldimethylsilyloxy)-2-methyl-decanoic acid (13), benzyl (S)-2-hydroxy-3-methylbutanate (14), and (4S,3R)-4-(benzyloxycarbonyl-methylamino)-3-methoxymethoxy-5-phenyl-pentanoic acid (28) were prepared from Evans's chiral imide (9), l-valine, and l-N-Boc phenylalanine (17), respectively, and were assembled together by applying twice Yamaguchi's coupling methodology. A new and efficient selective N-methylation of γ-hydroxy-β-amino ester taking advantage of the vicinal amino alcohol function was uncovered in the course of this study. Thus, treatment of compound 19 with HCHO in the presence of catalytic amount of pTsOH followed by reduction (NaBH3CN, TFA, CH2Cl2) of the so-formed oxazolidine 24 gave the N-methylated product 25. Furthermore, a dual role of oxazolidine as protecting group of vicinal amino alcohol and latent N-methyl function was established which allowed synthesizing both hapalosin (2) and N-desmethylhapalosin (3) from the same linear precursor 32 in a step-efficient and atom economic way. In contrast to hapalosin (2) and N-desmethyl analogue (3), the amide bond of 8-deoxy hapalosin (4) exists at room temperature (CDCl3) exclusively in s-cis conformation as evidenced by NOE studies. This observation has been explained on the basis of computational studies. No significant MDR reversing activity of 8-deoxy hapalosin (4) was observed in K562 R and S/Adriblastine against human erythroleucemic cell lines indicating thus the important contribution of hydroxy group to the bioactivity of hapalosin. Copyright (C) 1999 Elsevier Science Ltd.
Synthesis of N-protected γ-amino-β-keto-esters from urethane N-carboxyanhydrides (UNCAs)
Paris, Marielle,Fehrentz, Jean-Alain,Heitz, Annie,Loffet, Albert,Martinez, Jean
, p. 8489 - 8492 (2007/10/03)
N-protected γ-amino-β-keto-esters were synthesized from the corresponding N-protected N-carboxyanhydride (UNCAs) by reaction with the lithium enolate of ethyl acetate in good yields. These compounds are precursors of statine derivatives.
Synthesis of hapalosin and 8-deoxy-hapalosin
Wagner, Bjoern,Beugelmans, Rene,Zhu, Jieping
, p. 6557 - 6560 (2007/10/03)
Hapalosin, a new MDR reversing agent, and its congener 8-deoxyhapalosin have been synthesized via macrolactamization. A new procedure for selective N-methylation of a vicinal amino alcohol is uncovered in the course of this study.
