37910-65-9Relevant academic research and scientific papers
Identification of the Amipurimycin Gene Cluster Yields Insight into the Biosynthesis of C9 Sugar Nucleoside Antibiotics
Kang, Wen-Jia,Pan, Hai-Xue,Wang, Shengyang,Yu, Biao,Hua, Huiming,Tang, Gong-Li
supporting information, p. 3148 - 3152 (2019/05/10)
Feeding studies indicate a possible synthetic pattern for the N-terminal cis-aminocyclopentane carboxylic acid (ACPC) and suggest an unusual source of the high-carbon sugar skeleton of amipurimycin (APM). The biosynthetic gene cluster of APM was identified and confirmed by in vivo experiments. A C9 core intermediate was discovered from null mutants of ACPC pathway, and an ATP-grasp enzyme (ApmA8) was reconstituted in vitro for ACPC loading. Our observations allow a first proposal of the APM biosynthetic pathway.
The N-Hydroxymethyl Group as a Traceless Activating Group for the CAL-B-Catalysed Ring Cleavage of β-Lactams: A Type of Two-Step Cascade Reaction
Forró, Enik?,Galla, Zsolt,Fül?p, Ferenc
, p. 2647 - 2652 (2016/06/09)
An efficient enzymatic two-step cascade procedure has been devised for rapid access to diverse amino acids from N-hydroxymethyl-β-lactams; representative amino acids include the antifungal agent cispentacin, intermediates for the taxol side-chain, and assorted cathepsin inhibitors. When CAL-B-catalysed hydrolyses of racemic N-hydroxymethyl-β-lactams were performed with H2O (0.5 equiv.) in iPr2O at 60 °C, relatively quick (vs. non-activated counterparts) and enantioselective (E > 200) ring cleavage reactions took place. As the ring-opened amino acids formed, the hydroxymethyl group, as a traceless activating group, underwent spontaneous in situ degradation. Consequently, the desired β-amino acid and unreacted N-hydroxymethyl-β-lactam enantiomers (ee > 95 %) were formed. The formation of polymers, induced by liberation of formaldehyde, was successfully restricted by the addition of benzylamine as a capture agent, to the enzymatic reactions. An efficient enzymatic two-step cascade procedure was devised for CAL-B-catalysed hydrolysis of racemic N-hydroxymethyl-β-lactams. Conditions in which the hydroxymethyl group serves as a traceless activating group (E > 200), giving desired β-amino acid along with unreacted starting lactam enantiomers (ee > 95 %) were identified; polymerization was controlled by addition benzylamine addition.
High-Performance Liquid Chromatographic Enantioseparation of Cyclic β-Amino Acids on Zwitterionic Chiral Stationary Phases Based on Cinchona Alkaloids
Ilisz, István,Gecse, Zsanett,Lajk?, Gyula,Forr?, Enik?,Fül?p, Ferenc,Lindner, Wolfgang,Péter, Antal
, p. 563 - 570 (2015/08/25)
Stereoselective high-performance liquid chromatographic separations of eight sterically constrained cyclic β-amino acid enantiomer pairs were carried out using the newly developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+) and ZWIX(-). The effects of the mobile phase composition, the nature and concentrations of the acid and base additives, the counterions and temperature on the separations were investigated. The changes in standard enthalpy, Δ(ΔH°), entropy, Δ(ΔS°), and free energy, Δ(ΔG°), were calculated from the linear van't Hoff plots derived from the ln α vs. 1/T curves in the studied temperature range (10-50°C). The values of the thermodynamic parameters depended on the nature of the selectors and the structures of the analytes. Unusual temperature behavior was observed on the ZWIX(-) column: decreased retention times were accompanied by increased separation factors with increasing temperature. On the ZWIX(+) column only enthalpically, whereas on the ZWIX(-) column both enthalpically and entropically driven separations were observed. The elution sequence was determined in all cases and was observed to be the opposite on ZWIX(+) and on ZWIX(-). Chirality 27:563-570, 2015.
Stereoselective organocatalytic approach to α,β-disubstituted- β-amino acids: A short enantioselective synthesis of cispentacin
Pou, Ana,Moyano, Albert
, p. 3103 - 3111 (2013/06/26)
α-Branched α,β-unsaturated aldehydes have been tested in the organocatalytic tandem Michael addition/cyclization with N-(benzyloxycarbonyl)hydroxylamine, a reaction which until now has been restricted to α-unsubstituted enals. Starting from cyclopentene-2- carbaldehyde, and using diphenylprolinol trimethylsilyl ether as a chiral amine catalyst, this approach has led to the development of a practical, high yielding (93-98 % overall yield, three steps), and highly enantioselective (up to 98:2 er) route to the cyclic β-amino acid cispentacin, which compares favourably with previously described asymmetric syntheses of this biologically active natural product. When using acyclic α-branched α,β-unsaturated aldehydes as substrates, the reaction yields depend on the substitution pattern of the aldehydes, and mixtures of cis- and trans-isomers are obtained. Nevertheless, this strategy has proved to be successful in some instances, and (3R,4R)-benzyl 3-ethyl-4-methyl-5-oxoisoxazolidin-2-carboxylate could be obtained in 70 % overall yield (two steps) from the reaction of 2-ethylcrotonaldehyde and N-(benzyloxycarbonyl)hydroxylamine under catalysis with diphenylprolinol trimethylsilyl ether, and with high enantiomeric purity (99:1 er). The organocatalytic tandem Michael addition/cyclization of cyclopentene-2-carbaldehyde with N-Cbz-hydroxylamine, using diphenylprolinol TMS ether as a chiral amine catalyst, gives a practical, high yielding, and highly enantioselective route to the cyclic β-amino acid cispentacin. Acyclic α-branched enals give variable results in the same reaction, depending on the substitution pattern. Copyright
CYCLOALKYL-FUSED TETRAHYDROQUINOLINES AS CRTH2 RECEPTOR MODULATORS
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Page/Page column 53, (2013/02/28)
The invention provides certain cycloalkyl-fused tetrahydroquinolines of the Formula (I), and their pharmaceutically acceptable salts and esters, wherein R1, R2, R7, R8, R8a, E, Y, Z, n, u, and t are a
Hairpin folding behavior of mixed α/β-peptides in aqueous solution
Lengyel, George A.,Frank, Rebecca C.,Horne, W. Seth
supporting information; experimental part, p. 4246 - 4249 (2011/06/21)
The invention of new strategies for the design of protein-mimetic oligomers that manifest the folding encoded in natural amino acid sequences is a significant challenge. In contrast to the α-helix, mimicry of protein β-sheets is less understood. We report
PEPTIDES AND PEPTIDOMIMETIC COMPOUNDS, THE MANUFACTURING THEREOF AS WELL AS THEIR USE FOR PREPARING A THERAPEUTICALLY AND/OR PREVENTIVELY ACTIVE PHARMACEUTICAL COMPOSITION
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, (2010/04/25)
Peptides, peptidomimetics and derivatives thereof of the general formula I: H2N-GHRPX1-β-X4X5X6X7X8X9X10-X11 (I), in which X1-X10 denote one of the 20 genetically coded amino acids, wherein X8, X9 and X10 may also denote a single chemical bond;X11 denotes OR1 in which R1 equals hydrogen or (C1-C10) alkyl NR2R3 with R2 and R3 are equal or different and denote hydrogen, (C1-C10) alkyl, or a residue —W-PEG5-60K, in which the PEG residue is attached via a suitable spacer W to the N-atom, ora residue NH—Y-Z-PEG5-60K, in whichY denotes a chemical bond or a genetically coded amino acids from the group S, C, K or R andZ denotes a spacer, via which a polyethylene glycol (PEG)-residue can be attached, and their physiologically acceptable salts, andβ denotes an amino acid, or a peptidomimetic element, which induces a bend or turn in the peptide backbone.
Enantiomeric discrimination of cyclic β-amino acids using (18-crown-6)-2,3,11,12-tetracarboxylic acid as a chiral NMR solvating agent
Chisholm, Cora D.,Fueloep, Ferenc,Forro, Eniko,Wenzel, Thomas J.
experimental part, p. 2289 - 2294 (2010/11/05)
(18-Crown-6)-2,3,11,12-tetracarboxylic acid is an excellent chiral NMR solvating agent for cyclic β-amino acids with cyclopentane, cyclohexane, cycloheptane, cyclopentene, cyclohexene, bicyclo[2.2.1]heptane, and bicyclo[2.2.1]heptene rings. The crown ether was added to the neutral β-amino acids in methanol-d4. A neutralization reaction between the crown ether and β-amino acid forms the ammonium ion needed for favorable association. Enantiomeric discrimination of the two hydrogen atoms α to the amine and carboxylic acid moieties of the β-amino acid was observed with every substrate studied. Trends in the order of the enantiomeric discrimination of certain hydrogen atoms for substrates of similar structures correlate with the absolute configuration.
Vapour-assisted enzymatic hydrolysis of β-lactams in a solvent-free system
Forro, Eniko,Fueloep, Ferenc
, p. 1005 - 1009 (2008/09/21)
A new, solvent-free, vapour-assisted method, developed for the synthesis of carbocyclic cis β-amino acid enantiomers through the Candida antarctica lipase B-catalysed enantioselective (E >200) hydrolysis of β-lactams with 0.5 equiv of H2O at 70 °C, has been demonstrated to be applicable on a preparative scale to produce (±)-2 (the starting racemate for cispentacin), (±)-3 (the starting racemate for 4-tert-butylcispentacin, a new cispentacin analogue) and (±)-7 (the starting racemate for 1,4-ethylene-bridged cispentacin).
2,4-diamino-pyrimidines as aurora inhibitors
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Page/Page column 18, (2008/06/13)
The present invention encompasses compounds of general formula (1) wherein R1 to R3 are defined as in claim 1, which are suitable for the treatment of diseases characterised by excessive or abnormal cell proliferation, and the use thereof for preparing a pharmaceutical composition having the above-mentioned properties.
