- Convergent synthesis of novel muramyl dipeptide analogues: Inhibition of porphyromonas gingivalis-induced pro-inflammatory effects by high doses of muramyl dipeptide
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Porphyromonas gingivalis (P.g.)-induced TNF-α can be affected by muramyl dipeptide (MDP) in a biphasic concentration-dependent manner. We found that in P.g.-exposed macrophages, treatment with 10 μg/mL of MDP (MDP-low) up-regulated TNF-α by 29%, while 100
- Cai, Bin,Panek, James S.,Amar, Salomon
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p. 6878 - 6890
(2016/08/05)
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- Total synthesis of (-)-platensimycin by advancing oxocarbenium- and iminium-mediated catalytic methods
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(-)-Platensimycin is a potent inhibitor of fatty acid synthase that holds promise in the treatment of metabolic disorders (e.g., diabetes and "fatty liver") and pathogenic infections (e.g., those caused by drug-resistant bacteria). Herein, we describe its total synthesis through a four-step preparation of the aromatic amine fragment and an improved stereocontrolled assembly of the ketolide fragment, (-)-platensic acid. Key synthetic advances include 1) a modified Lieben haloform reaction to directly convert an aryl methyl ketone into its methyl ester within 30 seconds, 2) an experimentally improved dialkylation protocol to form platensic acid, 3) a sterically controlled chemo- and diastereoselective organocatalytic conjugate reduction of a spiro-cyclized cyclohexadienone by using the trifluoroacetic acid salt of α-amino di-tert-butyl malonate, 4) a tetrabutylammonium fluoride promoted spiro-alkylative para dearomatization of a free phenol to assemble the cagelike ketolide core with the moderate leaving-group ability of an early tosylate intermediate, and 5) a bismuth(III)-catalyzed Friedel-Crafts cyclization of a free lactol, with LiClO4 as an additive to liberate a more active oxocarbenium perchlorate species and suppress the Lewis basicity of the sulfonyloxy group. The longest linear sequence is 21 steps with an overall yield of 3.8% from commercially available eugenol. Relay tactics: The stereocontrolled assembly of the potent antibiotic (-)-platensimycin in 21 steps and 3.8% yield from eugenol is described (see scheme; TBAF: tetrabutylammonium fluoride; Ts: toluene-4-sulfonyl). Highlights are 1) a rapid oxidative esterification of an acyl aromatic, 2) a reliable dialkylation protocol to form platensic acid, 3) a π-facial conjugate reduction of a dienone, 4) a TBAF-promoted alkylative dearomatization of a free phenol, and 5) a Friedel-Crafts closure of a free lactol.
- Eey, Stanley T.-C.,Lear, Martin J.
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p. 11556 - 11573
(2015/01/16)
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- Synthesis and anticonvulsant activity of (R)- and (S)-3-(Carbobenzyloxy- amino-1-glutarimidooxy)esters
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A series of (R)- and (S)-3-carbobenzyloxy-amino-1-glutarimidooxy-esters (5a-e) ((R)-and (S)-methyl-1-(3-carbobenzyloxy-amino-I glutarimidooxy)acetate (5a), (R)-and (S)-ethyl-1-(3-carbobenzyloxy-amino-glutarimidooxy)acetate (5b), (R)- and (S)-ethyl-1-(3-carbo-benzyloxy-amino-glutarimidooxy)propionate (5c), (R)- and (S)-methyl-2-(3-carbobenzyloxy-amino-glutarimidooxy)butyrate (5d), (R)- and (S)-ethyl-2-(3-carbobenzyloxy-amino-glutarimidooxy)butyrate (5e) were synthesized and investigated their anticonvulsant activities.
- Lee, Do-Hun
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p. 8125 - 8127
(2013/09/23)
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- Constrained peptidomimetics reveal detailed geometric requirements of covalent prolyl oligopeptidase inhibitors
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Prolyl oligopeptidases cleave peptides on the carboxy side of internal proline residues and their inhibition has potential in the treatment of human brain disorders. Using our docking program FITTED, we have designed a series of constrained covalent inhibitors, built from a series of bicyclic scaffolds, to study the optimal shape required for these small molecules. These structures bear nitrile functional groups that we predicted to covalently bind to the catalytic serine of the enzyme. Synthesis and biological assays using human brain-derived astrocytic cells and endothelial cells and human fibroblasts revealed that these compounds act as selective inhibitors of prolyl oligopeptidase activity compared to prolyl-dipeptidyl-aminopeptidase activity, are able to penetrate the cells and inhibit intracellular activities in intact living cells. This integrated computational and experimental study shed light on the binding mode of inhibitors in the enzyme active site and will guide the design of future drug-like molecules.
- Lawandi, Janice,Toumieux, Sylvestre,Seyer, Valentine,Campbell, Philip,Thielges, Sabine,Juillerat-Jeanneret, Lucienne,Moitessier, Nicolas
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experimental part
p. 6672 - 6684
(2010/04/28)
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- Aqueous phosphoric acid as a mild reagent for deprotection of tert-butyl carbamates, esters, and ethers
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(Chemical Equation Presented) Aqueous phosphoric acid (85 wt %) is an effective, environmentally benign reagent for the deprotection of tert-butyl carbamates, tert-butyl esters, and tert-butyl ethers. The reaction conditions are mild and offer good selectivity in the presence of other acid-sensitive groups, including CBZ carbamates, azetidine, benzyl and methyl esters, TBDMS, and methyl phenyl ethers. The mildness of the reaction is further demonstrated in the synthesis of clarithromycin derivative 4, in which a tert-butyl ester is removed in the presence of cyclic carbamate, lactone, ketal, acetate ester, and epimerizable methyl ketone functionalities. The reaction preserves the stereochemical integrity of the substrates. The reactions are high yielding, and the workup is convenient.
- Li, Bryan,Berliner, Martin,Buzon, Richard,Chiu, Charles K.-F.,Colgan, Stephen T.,Kaneko, Takushi,Keene, Nandell,Kissel, William,Le, Tung,Leeman, Kyle R.,Marquez, Brian,Morris, Ronald,Newell, Lisa,Wunderwald, Silke,Witt, Michael,Weaver, John,Zhang, Zhijun,Zhang, Zhongli
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p. 9045 - 9050
(2007/10/03)
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- A novel immunostimulator, N2-[α-O-Benzyl-N-(acetylmuramyl) -L-alanyl-D-isoglutaminyl]-N6-trans-(m-nitrocinnamoyl)-L-lysine, and its adjuvancy on the hepatitis B surface antigen
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N2-[α-O-Benzyl-N-(acetylmuramyl)-L-alanyl-D-isoglutaminyl] -N6-trans-(m-nitrocinnamoyl)-L-lysine (muramyl dipeptide C, or MDP-C) has been synthesized as a novel, nonspecific immunomodulator. The present study shows that MDP-C induces
- Yang, Hong-Zhen,Xu, Song,Liao, Xue-Yan,Zhang, Suo-De,Liang, Zheng-Lun,Liu, Bai-He,Bai, Jin-Ye,Jiang, Chao,Ding, Jian,Cheng, Gui-Fang,Liu, Gang
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p. 5112 - 5122
(2007/10/03)
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- (2S,5R/2R,5S)-Aminoethylpipecolyl aepip-aegPNA chimera: Synthesis and duplex/triplex stability
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This article reports the design and facile synthesis of novel chiral six-membered PNA analogues (2S,5R/2R,5S)-1-(N-Boc-aminoethyl)-5-(thymin-1-yl) pipecolic acid, aepipPNA IV that upon incorporation into standard aegPNA sequences effected stabilization of
- Shirude, Pravin S.,Kumar, Vaijayanti A.,Ganesh, Krishna N.
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p. 9485 - 9491
(2007/10/03)
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- Beta-strand mimetics and method relating thereto
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Conformationally constrained compounds which mimic the secondary structure of β-strand regions of biologically active peptides and proteins are disclosed. Such β-strand mimetic structures have utility over a wide range of fields, including use as diagnostic and therapeutic agents. Libraries containing the β-strand mimetic structures of this invention are also disclosed as well as methods for screening the same to identify biologically active members.
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- THIAZOLIDINE DERIVATIVES
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An object of the present invention is to provide novel thiazolidine derivatives which are useful as drugs. The thiazolidine derivatives according to the present invention are compounds represented by the following general formula [I] and salts thereof, wherein R 1is alkyl, hydroxy, alkoxy, alkoxyalkyl, phenyl, phenylalkyl, phenylalkoxy, phenoxy, phenoxyalkyl, amino, alkylamino or a nonaromatic heterocycle; R 2is H or alkyl; R 3is H, alkyl or phenyl; R 4is H or alkyl; R 5is alkyl, halogenoalkyl, hydroxy, alkoxy, phenyl, phenylalkoxy, phenoxy, carboxyl, alkoxycarbonyl, phenylalkoxycarbonyl or an aromatic heterocycle; A 1is alkylene; and A 2is alkylene.
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- Geometrical optimisation of 1,1′-binaphthalene receptors for enantioselective molecular recognition of excitatory amino acid derivatives
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A series of optically active 1,1′-binaphthalene-derived receptors with N-(pyridine-2,6-diyl)acetamide [CONH(py)] H-bonding sites in the 6,6′-positions has been prepared for the enantioselective complexation of the N-carbobenzyloxy (Cbz)-protected excitatory amino acids aspartic (Asp) and glutamic (Glu) acid via two COOH ... CONH(py) H-bonding arrays and additional secondary bonding interactions. The conformational homogeneity of the receptors is enhanced by locking the dihedral angle θ about the chirality axis through the C(1)-C(1′) bond of the 1,1′-binaphthalene moiety either by bridging the 2,2′-positions or by attaching bulky substituents to these centres. Computer modelling has shown that bridging is more efficient in locking this dihedral angle than the introduction of bulky substituents, and these predictions have been confirmed by 1H NMR binding studies in CDCl3 and in CDCl3-CD3OD 99.8:0.2. Plots of the enantioselectivity Δ(ΔG°) (difference in stability between diastereoisomeric complexes) in the recognition by the bridged receptors as a function of the enforced dihedral angle θ are peak-shaped, and the highest values have been measured in CDCl3 (300 K) for the complexation of the enantiomers of N-Cbz-Asp [Δ(ΔG°) = 6.9 kJ mol-1] and N-Cbz-Glu [Δ(ΔG°) = 5.2 kJ mol-1] by (R)-21 (θ = 86 ± 4°). The more stable diastereoisomeric complexes are highly structured, and tight host-guest bonding has been confirmed by the observation of up to five intermolecular NOEs. Enforcing the conformational homogeneity by bridging represents a new general principle for improving the chiral recognition potential of 1,1′-binaphthalene receptors.
- Lustenberger, Philipp,Martinborough, Esther,Mordasini Denti, Tiziana,Diederich, Francois
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p. 747 - 761
(2007/10/03)
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- New synthetic routes to α-amino acids and γ-oxygenated α-amino acids. Reductive denitration and oxidative transformations of γ-nitro-α-amino acids
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Transformation of γ-nitro-α-amino acid derivatives into α-amino acids by reductive denitration, into the γ-oxo-α-amino acids by ozonolysis of the corresponding amino acid ester nitronate derivatives, and into γ-hydroxy-α-amino acid derivatives by subsequent reduction of the oxo functionality, can be achieved in good yields. As the γ-nitro-α-amino acid derivatives are prepared from N,O-protected dehydroalanines derivable from the corresponding alanine, serine and cysteine derivatives by specific routes, the overall procedures provide a means for selective conversion of these simple α-amino acids into more complex ones.
- Crossley, Maxwell J.,Fung, Yik M.,Kyriakopoulos, Efstathia,Potter, Jeffrey J.
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p. 1123 - 1130
(2007/10/03)
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- Syntheses of Polypeptides by Hidrogenolysis of N-Benzyloxycarbonyl-Amino Acid Anhydrides
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When anhydrides of N-benzyloxycarbonyl-DL-aspartic acid (Z-DL-Asp), Z-L-Asp, N-Z-DL-glutamic acid (Z-DL-Glu), Z-L-Glu and N-Z-3-aminoglutaric acid (Z-β-Agl) were hydrogenolyzed in N,N-dimethylformamide (DMF), polypeptides were obtained in high yields.Hydrogenolyses of Z-DL-Glu and Z-L-Glu in dioxane gave pyroglutamic acid.
- Munegumi, Toratane,Meng, Yan-Quing,Harada, Kaoru
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p. 2748 - 2750
(2007/10/02)
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- Composition containing a penem or carbapenem antibiotic
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Administration of an N-acylated amino acid in association with a penem or carbapenem antibiotic relieves or eliminates the renal problems associated with administration of the antibiotic alone. The amino acid derivative and antibiotic may be formulated together as a composition or administered separately, either simultaneously or sequentially. The composition may be prepared by simple mixing.
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