- Fluorovinylsulfones and -Sulfonates as Potent Covalent Reversible Inhibitors of the Trypanosomal Cysteine Protease Rhodesain: Structure-Activity Relationship, Inhibition Mechanism, Metabolism, and in Vivo Studies
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Rhodesain is a major cysteine protease of Trypanosoma brucei rhodesiense, a pathogen causing Human African Trypanosomiasis, and a validated drug target. Recently, we reported the development of α-halovinylsulfones as a new class of covalent reversible cysteine protease inhibitors. Here, α-fluorovinylsulfones/-sulfonates were optimized for rhodesain based on molecular modeling approaches. 2d, the most potent and selective inhibitor in the series, shows a single-digit nanomolar affinity and high selectivity toward mammalian cathepsins B and L. Enzymatic dilution assays and MS experiments indicate that 2d is a slow-tight binder (Ki = 3 nM). Furthermore, the nonfluorinated 2d-(H) shows favorable metabolism and biodistribution by accumulation in mice brain tissue after intraperitoneal and oral administration. The highest antitrypanosomal activity was observed for inhibitors with an N-terminal 2,3-dihydrobenzo[b][1,4]dioxine group and a 4-Me-Phe residue in P2 (2e/4e) with nanomolar EC50 values (0.14/0.80 μM). The different mechanisms of reversible and irreversible inhibitors were explained using QM/MM calculations and MD simulations.
- Jung, Sascha,Fuchs, Natalie,Johe, Patrick,Wagner, Annika,Diehl, Erika,Yuliani, Tri,Zimmer, Collin,Barthels, Fabian,Zimmermann, Robert A.,Klein, Philipp,Waigel, Waldemar,Meyr, Jessica,Opatz, Till,Tenzer, Stefan,Distler, Ute,R?der, Hans-Joachim,Kersten, Christian,Engels, Bernd,Hellmich, Ute A.,Klein, Jochen,Schirmeister, Tanja
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p. 12322 - 12358
(2021/09/02)
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- A comprehensive one-pot synthesis of protected cysteine and selenocysteine SPPS derivatives
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A proof-of-principle methodology is presented in which all commercially-available cysteine (Cys) and selenocysteine (Sec) solid phase peptide synthesis (SPPS) derivatives are synthesized in high yield from easily prepared protected dichalcogenide precursors. A Zn-mediated biphasic reduction process applied to a series of four bis-Nα-protected dichalcogenide compounds allows facile conversion to their corresponding thiol and selenol intermediates followed by insitu S- or Se-alkylation with various electrophiles to directly access twenty one known Cys and Sec SPPS derivatives. Most of these derivatives were able to be precipitated in crude form out of petroleum ether in sufficient purity for direct use as peptide building blocks. Subsequent incorporation of these derivatives into peptide models nicely illustrates their viability and applicability toward SPPS.
- Flemer, Stevenson
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p. 1257 - 1264
(2015/04/14)
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- Efficient and practical procedure for the esterification of the free α-carboxylic acid of amino acid residues with β-(trimethylsilyl)ethoxymethyl chloride and triisopropylsilyl chloride
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An efficient and practical procedure for the free α-carboxylic acid esterification of amino acid residues with β-(trimethylsilyl)ethoxymethyl chloride and triisopropylsilyl chloride is described. The reaction takes place under mild conditions and the expected protected amino acids are obtained in good to excellent yields. Our method provides a useful alternative for the C-terminal carboxylic acid protection of amino acids and peptides. Moreover, the removal of such protection was also achieved under mild conditions, without affecting either the other protecting groups at the α-amino moiety and side chains or the optical integrity at the α-position of the amino acid residues. Examples of their use in peptide synthesis are also illustrated.
- Suppo, Jean-Simon,De Sant'Ana, Danilo Pereira,Dias, Luiz Carlos,De Figueiredo, Renata Marcia,Campagne, Jean-Marc
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supporting information
p. 3075 - 3084
(2015/01/08)
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- Catalytic hydrolysis of α-amino esters in the presence of chiral palladacycles
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The rate of hydrolysis of esters derived from optically active α-amino acids, catalyzed by chiral cyclopalladated benzylamines, depends on the configuration of chiral centers in the substrate and catalyst. The catalytic hydrolysis of sulfur-containing amino esters follows an intramolecular mechanism, and the difference in the reaction rates for the stereoisomers increases in going from ortho-palladated primary benzylamines (k S/k R = 1.1) to tertiary amines (k S/k R = 1.5); the strongest catalytic effect is observed for an ester and a complex with the same absolute configuration of the chiral centers. The efficiency of intermolecular catalysis is greater for a complex and ester with opposite absolute configurations of the chiral centers, and the rate constants of catalytic hydrolysis for two pairs of stereoisomers coincide within experimental error. The maximal difference in the reaction rates is observed for cyclopalladated secondary benzylamines; it reaches 2.3 for the phenylalanine ester. Nauka/Interperiodica 2007.
- Ageeva,Kurzeev,Kazankov
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p. 548 - 552
(2008/02/02)
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- Total synthesis and biological evaluation of (+)-kalkitoxin, a cytotoxic metabolite of the cyanobacterium Lyngbya majuscula
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(+)-Kalkitoxin, a metabolite of the marine cyanobacterium Lyngbya majuscula, was synthesized from (R)-2-methylbutyric acid, (R)-cysteine, and (3S, 4S, 6S)-3,4,6-trimethyl-8-(methylamino)octanoic acid. A key step in the synthesis was installation of the anti,anti methyl stereotriad by means of a tandem asymmetric conjugate addition of an organocopper species to an α,β-unsaturated N-acyl oxazolidin-2-one followed in situ by α-methylation of the resultant enolate. The thiazoline portion of kalkitoxin was assembled by titanium tetrachloride catalyzed cyclization of a vinyl substituted amido thiol.
- White, James D.,Xu, Qing,Lee, Chang-Sun,Valeriote, Frederick A.
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p. 2092 - 2102
(2007/10/03)
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- Exploration of the P1 SAR of aldehyde cathepsin K inhibitors.
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The synthesis and biological activity of a series of aldehyde inhibitors of cathepsin K are reported. Exploration of the properties of the S(1) subsite with a series of alpha-amino aldehyde derivatives substituted at the P(1) position afforded compounds with cathepsin K IC(50)s between 52 microM and 15 nM.
- Catalano, John G,Deaton, David N,Furfine, Eric S,Hassell, Annie M,McFadyen, Robert B,Miller, Aaron B,Miller, Larry R,Shewchuk, Lisa M,Willard Jr., Derril H,Wright, Lois L
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p. 275 - 278
(2007/10/03)
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- Total synthesis of (+)-kalkitoxin
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The neurotoxic lipopeptide (+)-kalkitoxin was synthesized by a route which employed asymmetric organocopper conjugate addition followed by in situ enolate alkylation to install the anti,anti-1,2,4-trimethyl relationship of the toxin; the synthesis of kalkitoxin required sixteen steps and proceeded in 3% overall yield.
- White, James D.,Lee, Chang-Sun,Xu, Qing
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p. 2012 - 2013
(2007/10/03)
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- PEPTIDIC COMPOUNDS AS CYSTEINE PROTEASE INHIBITORS
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The present invention is directed to compounds that are inhibitors of cysteine proteases, in particular, cathepsins B, K, L, F, and S and are therefore useful in treating diseases mediated by these proteases. The present invention is directed to pharmaceutical compositions comprising these compounds and processes for preparing them.
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- Peptidyl inhibitors of viral proteases
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The invention provides amino acid derivatives of the formula STR1 wherein E represents CHO or B(OH)2 ; R1 represents lower alkyl (optionally substituted by halo, cyano, lower alkylthio, aryl-lower alkylthio, aryl or heteroaryl), lower alkenyl or lower alkynyl; R2 represents lower alkyl optionally substituted by hydroxy, carboxy, aryl, aminocarbonyl or lower cycloalkyl; and R3 represents hydrogen or lower alkyl; or R2 and R3 together represent di- or trimethylene optionally substituted by hydroxy; R4 represents lower alkyl (optionally substituted by hydroxy, lower cycloalkyl, carboxy, aryl, lower alkylthio, cyano-lower alkylthio or aryl-lower alkylthio), lower alkenyl, aryl or lower cycloalkyl; R5 represents lower alkyl (optionally substituted by hydroxy, lower alkylthio, aryl, aryl-lower alkylthio or cyano-lower alkylthio) or lower cycloalkyl; R6 represents hydrogen or lower alkyl; R7 represent lower alkyl (optionally substituted by hydroxy, carboxy, aryl or lower cycloalkyl) or lower cycloalkyl; R8 represents lower alkyl optionally substituted by hydroxy, carboxy or aryl; and R9 represents lower alkylcarbonyl, carboxy-lower alkylcarbonyl, arylcarbonyl, lower alkylsulphonyl, arylsulphonyl, lower alkoxycarbonyl or aryl-lower al koxycarbonyl, and salts of acidic compounds of formula I with bases, which are viral proteinase inhibitors useful as antiviral agents, especially for the treatment or prophylaxis of infections caused by Hepatitis C, Hepatitis G and human GB viruses.
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- Total synthesis of nosiheptide. Synthesis of thiazole fragments
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The preparation of three new thiazole derivatives from natural products is described, as well as improvements in the synthesis of ethyl 2-aminomethyl-4-thiazolecarboxylate.
- Koerber-Ple,Massiot
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p. 1309 - 1315
(2007/10/03)
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- Two new procedures for the introduction of benzyl-type protecting groups for thiols
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Two new methods for the benzylation of thiols are described: a) direct-S- alkylation with para-substituted benzylic cations; and b) reductive S- alkylations of 2-aminothiols. Both methods provide efficient routes for the introduction of benzyl-type protecting groups in high yields.
- Richter, Lutz S.,Marsters Jr., James C.,Gadek, Thomas R.
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p. 1631 - 1634
(2007/10/02)
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