- The interaction of heteroaryl-acrylates and alanines with phenylalanine ammonia-lyase from parsley
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Acrylic acids and alanines substituted with heteroaryl groups at the β-position were synthesized and spectroscopically characterized (UV, HRMS, 1H NMR, and 13C NMR spectroscopy). The heteroaryl groups were furanyl, thiophenyl, benzofuranyl, and benzothiophenyl and contained the alanyl side chains either at the 2- or 3-positions. While the former are good substrates for phenylalanine ammonia lyase (PAL), the latter compounds are inhibitors. Exceptions are thiophen-3-yl-alanine, a moderate substrate and furan-3-yl-alanine, which is inert. Possible reasons for these exceptions are discussed. Starting from racemic het eroaryl-2-alanines their D-enantiomers were prepared by using a stereodestructive procedure. From the heteroaryl-2- acrylates, the L-enantiomers of the heteroaryl-2-alanines were prepared at high ammonia concentration. These results can be best explained by a Friedel - Crafts-type electrophilic attack at the aromatic part of the substrates as the initial step of the PAL reaction.
- Paizs, Csaba,Katona, Adrian,Retey, Janos
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p. 2739 - 2744
(2008/02/03)
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- Improved preparation of racemic 2-amino-3-(heteroaryl)propanoic acids and related compounds containing a furan or thiophene nucleus
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Racemic 2-amino-3-(heteroaryl)propanoic acids (1), mostly with a furan or thiophene nucleus as a heteroaryl group, were synthesized in 48-94% yield by the reduction of 3-(heteroaryl)-2-(hydroxyimino)propanoic acids (5) with zinc dust and formic acid in the presence of a catalytic amount of iron dust at 60°C for 2 h. Under these conditions, unfavorable hydrogenolysis of bromine on the thiophene nucleus does not occur. Traditional Nformylation of the prepared 3-(heteroaryl)alanine (1) with a mixture of formic acid and acetic anhydride afforded 2-(formylamino)-3-(heteroaryl)propanoic acids (6) in 51-95% yield.
- Kitagawa, Tokujiro,Khandmaa, Dashrenchin,Fukumoto, Ayumi,Asada, Makoto
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p. 1137 - 1139
(2007/10/03)
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- Process for the biotechnological preparation of L-thienylalanines in enantiomerically pure form from 2-hydroxy-3-thienylacrylic acids and their use
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Process for the biotechnological preparation of L-thienylalanines in enantiomerically pure form from 2-hydroxy-3-thienylacrylic acids, and their use. L-Thienylalanines are prepared via the hydantoin or the azlactone route. The starting substances used for the biotransformation are 2-hydroxy-3-thienylacrylic acids. The innovative step consists in the transamination of the enol form of the 2-hydroxy-3-thienylacrylic acids to give L-thienylalanines with the aid of biotransformation. The transaminiation is carried out in the presence of L-aspartic acid or L-glutamic acid as amino donor.
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- Inhibitors of interleukin-1β converting enzyme
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The present invention relates to novel classes of compounds which are inhibitors of interleukin-1β converting enzyme. The ICE inhibitors of this invention are characterized by specific structural and physicochemical features. This invention also relates to pharmaceutical compositions comprising these compounds. The compounds and pharmaceutical compositions of this invention are particularly well suited for inhibiting ICE activity and consequently, may be advantageously used as agents against interleukin-1 mediated diseases, including inflammatory diseases, autoimmune diseases and neurodegenerative diseases. This invention also relates to methods for inhibiting ICE activity and methods for treating interleukin-1 mediated diseases using the compounds and compositions of this invention.
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- Asymmetric synthesis of L-thienylalanines
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L-Thienylalanines were prepared via the hydantoin and azlactone routes with the key step consisting of the microbial transamination of 2-hydroxy-3-thienylacrylic with L-aspartic acid as amino donor.The transamination reaction was performed by a genetically engineered E. coli strain on scales up to 100 g of L-3-(2-thienyl)alanine 1a and is also applicable to the preparation of the isomeric amino acid 1b and some ring-substituted derivatives.
- Meiwes, Johannes,Schudok, Manfred,Kretzschmar, Gerhard
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p. 527 - 536
(2007/10/03)
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- Studies on Cyclic Dipeptides, I: Aryl Modifications of cyclo-[Phe-His]
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Seven new cyclic dipeptides have been synthesized and tested for their applicability as tools to elucidate the mechanism of formation of mandelonitrile with (SS)-cyclo-[Phe-His] type catalysts. Conformational analyses based on 1H NMR spectra are presented for all prepared cyclic dipeptides.
- Noe,Weigand,Pirker
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p. 1081 - 1097
(2007/10/03)
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- UNUSUAL AMINO ACIDS. IV. ASYMMETRIC SYNTHESIS OF THIENYLALANINES
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(Z)-2-N-Acylamino-3-thienyl-acrylic acids and thei esters were prepared by known procedures and hydrogenated to the corresponding optically active 2-N-acetyl(or benzoyl)-3-(2- or 3-thienyl)-alanines with optically yields up to 90percent using the rhodium complexes of 'PROPRAPHOS" 6a,b and O,N-bis(diphenylphosphino)-2-exo-hydroxy,3-endo-methylamino-norbornane 6c as chiral catalysts.Recrystallization and deacylation of the obtained amino acid derivatives yields the optically pure hydrochlorides of the thienylalanines as the free amino acids.
- Doebler, Christian,Kreuzfeld, H.-J.,Krause, H. W.,Michalik, M.
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p. 1833 - 1842
(2007/10/02)
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