- Helices with additional H-bonds: crystallographic conformations of α,γ-hybrid peptides helices composed of β-hydroxy γ-amino acids (statines)
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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.
- Malik, Ankita,Kumar, Mothukuri Ganesh,Bandyopadhyay, Anupam,Gopi, Hosahudya N.
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- Stereodivergent approach to both syn- and anti-isomers of γ-amino-β-hydroxy acids: (3S,4S)- and (3R,4S)-AHPPA derivatives
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A stereodivergent approach employing an N-hydroxymethyl group has been utilized to produce both diastereomeric derivatives of (3S,4S)-AHPPA 3 and (3R,4S)-AHPPA 4, via an intramolecular conjugate addition and an intramolecular epoxidation, respectively. Th
- Yoo, Dongwon,Song, Jeeyun,Kang, Moon Sung,Kang, Eun-Sil,Kim, Young Gyu
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experimental part
p. 1700 - 1704
(2012/01/30)
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- Solid-Phase Synthesis of β-Lactams via the Miller Hydroxamate Approach
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(Matrix Presented) β-Lactams were prepared on solid phase starting from serine, threonine, or other β-hydroxyacids derived from naturally occurring amino acids and a resin bound hydroxylamine. The ring closure was carried out under Mitsunobu conditions. The amino group present on the β-lactam was used to assemble a short peptide. After a reductive cleavage with Sml2, β-lactam-containing peptides were obtained.
- Meloni, Marco Massimiliano,Taddei, Maurizio
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p. 337 - 340
(2007/10/03)
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- Stereoselective synthesis of (-)-N-Boc-AHPPA
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An efficient method has been developed for the stereoselective synthesis of N-Boc-AHPPA (7), a biologically important amino acid of non-proteinogenic origin.
- Veeresa
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p. 1479 - 1487
(2007/10/03)
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- A synthetic approach to 3-hydroxy 4-substituted carboxylic acids based on the stereoselective reduction of 1-trimethylsilyl-1-alkyn-3-ones
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The oxazaborolidine-mediated reduction of chiral, 4-substituted 1-trimethylsilyl-1-alkyn-3-ones followed by hydroboration affords syn or anti 3-hydroxy 4-substituted carboxylic acids, common substructures of a number of biologically active macrolides, peptides and depsipeptides, with high control on the new C(3) stereocenter. This strategy has been applied to the synthesis of (3S,4S)-3-hydroxy-4-methylheptanoic acid and of N-Boc-statine, constituents of permentin A and pepstatin, respectively. (C) 2000 Elsevier Science Ltd.
- Alemany, Carme,Bach, Jordi,Garcia, Jordi,López, Marta,Rodríguez, Ana B.
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p. 9305 - 9312
(2007/10/03)
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- A novel Wittig reaction of oxazolidinones: Stereospecific synthesis of N-BOC-(3S,4S)-statine and N-BOC-(3S,4S)-AHPPA
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Stereospecific synthesis of N-BOC-(3S,4S)-Statine and N-BOC-(3S,4S)- AHPPA is achieved via a novel Wittig reaction of oxazolidinones in an efficient manner.
- Vidyasagar Reddy,Venkat Rao,Iyengar
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p. 775 - 776
(2007/10/03)
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- Ring opening of optically active cis-disubstituted aziridino alcohols: An enantiodivergent synthesis of functionalized amino alcohol derivatives
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Ring-opening reactions of optically active cis-disubstituted aziridino alcohols have been investigated. Regio- and stereo-selective ring opening took place with internal and external nucleophiles. Unusual amino acids derivatives (14) and (15), the key synthetic intermediates for bestatin and related peptides, have been prepared. n.
- Fuji, Kaoru,Kawabata, Takeo,Kiryu, Yoshimitsu,Sugiura, Yukio
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p. 701 - 722
(2007/10/03)
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- Synthesis and anti-human immunodeficiency virus type 1 activities of new peptido-nucleoside analogues
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In order to investigate whether antiproteasic peptides coupled to anti-reverse transcriptase nucleosides can act as inhibitors at the different stages of the HIV life cycle, various peptido-nucleosides were synthesized using methodologies involving (benzotriazol-1-yloxy)-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) as a coupling reagent between the N4-cytosinyl moiety and the peptide carboxy terminus. The anti-HIV-1 activity in MT4 cells of this new class of compounds and their anti-HIV protease activities were determined. Fourteen peptido-nucleosides have been synthesized and six act against both the HIV-protease and viral replication in vitro. Although the activity of the most potent compounds against HIV was found to be one order of magnitude lower than that of the parent nucleoside drug 2',3'-dideoxy-3'-thiacytidine, this new class of compound could be of biological interest. Indeed, since the in vitro half-lives (t( 1/2 )) of the hydrolysis of the most potent compounds in human plasma were found to be longer than 2.5 h, these analogues could reach the infected cells in their structural integrity. This observation does not exclude that these compounds may exert their antiviral effects as combined prodrugs through extracellular or intracellular hydrolysis.
- Camplo,Niddam,Barthelemy,Faury,Mourier,Simon,Charvet,Trabaud,Graciet,Chermann,Kraus
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p. 789 - 800
(2007/10/03)
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- A Facile Synthesis of N-Protected Statine and Analogues via a Lipase-Catalyzed Kinetic Resolution
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A new synthesis of N-protected statine 4a and its analogue 4b is presented. cis-(+/-)-Butyric acid 2-isobutyl-5-oxopyrrolidin-3-yl ester (10a) and cis-(+/-)-butyric acid 2-benzyl-5-oxopyrrolidin-3-yl ester (10b) were prepared from methyl (E)-4-chloro-3-me
- Baenziger, Markus,McGarrity, John F.,Meul, Thomas
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p. 4010 - 4012
(2007/10/02)
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- An enantiodivergent synthesis of three β-amino alcohols: Preparation of key intermediates for bestatin and the related peptides
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An enantiodivergent method for preparation of three β-amino alcohols and three 1,2-diamines has been developed starting with a chiral aziridine 1. Unusual amino acid derivatives 3 and 5, which are key synthetic intermediates for bestatin and the related peptides, have been prepared.
- Kawabata,Kiryu,Sugiura,Fuji
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p. 5127 - 5130
(2007/10/02)
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- Syntheses and reactions of silyl carbamates. 2. A new mode of cyclic carbamate formation from tert-butyldimethylsilyl carbamate
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Stereoselective construction of 1,2 and 1,3 amino hydroxyl systems was achieved by the intramolecular trapping of the N-tert-butyldimethylsilyloxycarbonyl species (silyl carbamate) activated by fluoride ion. The reaction of the silyl carbamate with 1,2-sy
- Sakaitani, Masahiro,Ohfune, Yasufumi
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p. 1150 - 1158
(2007/10/02)
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- PROCESS FOR PRODUCING STATIN AND RELATED COMPOUNDS
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This invention relates to a process for producing statin having the general formula (I): STR1 and related compounds thereof; (wherein R is a C1 to C6 alkyl group, a phenyl group or a C7 to C8 phenylalkyl group and B is a protective group for an amino group). Recently, the anti-hyproperties of statin, namely the renin inhibitive properties, are attracting general attention.
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- Stereospecific Synthesis of N-Protected Statine and Its Analogues via Chiral Tetramic Acid
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The condensation of a chiral N-protected amino acid with Meldrum's acid in the presence of isopropenyl chloroformate (IPCF) and of 4-N,N-dimethylaminopyridine (DMAP) has been examined.The cyclisation of the reaction product, by heating in an organic solve
- Jouin, Patrick,Castro, Bertrand,Nisato, Dino
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p. 1177 - 1182
(2007/10/02)
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- A NEW MODE OF CYCLIC CARBAMATE FORMATION VIA tert.-BUTYLDIMETHYLSILYL CARBAMATE. STEREOSELECTIVE SYNTHESES OF STATINE AND ITS ANALOGUE
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Stereoselective construction of 1,2- and 1,3-amino hydroxyl systems was carried out using SN2' (initiated by AgF or AgF-Pd(II)) cyclic carbamate formations from tert.-butyldimethyl silyl carbamates.This method was applied to the syntheses of st
- Sakaitani, Masahiro,Ohfune, Yasufumi
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p. 3987 - 3990
(2007/10/02)
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