- Characterization of FabG and FabI of the Streptomyces coelicolor dissociated fatty acid synthase
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Streptomyces coelicolor produces fatty acids for both primary metabolism and for biosynthesis of the secondary metabolite undecylprodiginine. The first and last reductive steps during the chain elongation cycle of fatty acid biosynthesis are catalyzed by FabG and FabI. The S. coelicolor genome sequence has one fabI gene (SCO1814) and three likely fabG genes (SCO1815, SCO1345, and SCO1846). We report the expression, purification, and characterization of the corresponding gene products. Kinetic analyses revealed that all three FabGs and FabI are capable of utilizing both straight and branched-chain β-ketoacyl-NAC and enoyl-NAC substrates, respectively. Furthermore, only SCO1345 differentiates between ACPs from both biosynthetic pathways. The data presented provide the first experimental evidence that SCO1815, SCO1346, and SCO1814 have the catalytic capability to process intermediates in both fatty acid and undecylprodiginine biosynthesis.
- Singh, Renu,Reynolds, Kevin A.
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p. 631 - 640
(2015/03/31)
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- Highly atom-efficient oxidation of electron-deficient internal olefins to ketones using a palladium catalyst
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A 100 % atom-efficient synthesis of ketones from electron-deficient internal olefins was achieved using O2 as a "green" oxidant (see scheme, DMA=N,N-dimethylacetamide, EWG=electron-withdrawing group). Various electron-deficient olefins were oxidized to the corresponding ketones with over 99 % selectivity and without the formation of olefin isomers or their oxidized products. Copyright
- Mitsudome, Takato,Yoshida, Syuhei,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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p. 5961 - 5964
(2013/06/27)
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- Chemoenzymatic asymmetric synthesis of pregabalin precursors via asymmetric bioreduction of β-cyanoacrylate esters using ene-reductases
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The asymmetric bioreduction of a library of β-cyanoacrylate esters using ene-reductases was studied with the aim to provide a biocatalytic route to precursors for GABA analogues, such as pregabalin. The stereochemical outcome could be controlled by substrate-engineering through size-variation of the ester moiety and by employing stereochemically pure (E)- or (Z)-isomers, which allowed to access both enantiomers of each product in up to quantitative conversion in enantiomerically pure form. In addition, stereoselectivities and conversions could be improved by mutant variants of OPR1, and the utility of the system was demonstrated by preparative-scale applications.
- Winkler, Christoph K.,Clay, Dorina,Davies, Simon,O'Neill, Pat,McDaid, Paul,Debarge, Sebastien,Steflik, Jeremy,Karmilowicz, Mike,Wong, John W.,Faber, Kurt
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p. 1525 - 1533
(2013/04/10)
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- Biomimetic synthesis of a new class of bacterial signaling molecules
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The first synthesis of a newly discovered class of bacterial signaling molecules from Streptomyces coelicolor has been developed. These molecules, known as the methylenomycin furans (MMFs), trigger production of the antibiotic methylenomycin. The synthesis features a scandium triflatecatalyzed domino reaction of β-ketoesters and dihydroxyacetone yielding 2,3,4-substituted furans. The proposed reaction sequence (aldol reaction, cyclization, and dehydrative aromatization) may be reminiscent of the biosynthetic reaction in which dihydroxyacetone phosphate and a β-ketothioester are condensed by an enzyme.
- Davis, Jesse B.,Bailey, J. Daniel,Sello, Jason K.
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supporting information; experimental part
p. 2984 - 2987
(2009/12/05)
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- KINESIN INHIBITORS
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This invention relates to the compounds of formula (I) shown below. Each variable in formula (I) is defined in the specification. These compounds can be used to treat a kinesin Eg5 protein-mediated disorder.
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Page/Page column 58
(2009/01/20)
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- PYRIDYL ACETIC ACID COMPOUNDS
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The present invention provides a compound represented by the formula (I): wherein R1 is a C?1-6#191 alkyl group optionally substituted by a C?3-10#191 cycloalkyl group, R2 is a C?2-6#191 alkyl group, R3 is a hydrogen atom, a C?1-6#191 alkyl group or a halogen atom, and X is -OR6 or -NR4R5 wherein R4 and R6 are each independently a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, R5 is an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group or an optionally substituted hydroxy group, or R4 and R5 optionally form, together with the adjacent nitrogen atom, an optionally substituted nitrogen-containing heterocycle, or a salt thereof. The compound of the present invention has a superior peptidase inhibitory action and is useful as an agent for the prophylaxis or treatment of diabetes and the like.
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Page/Page column 60-61
(2008/06/13)
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- Synthesis and NMR analysis in solution of oligo(3-hydroxyalkanoic acid) derivatives with the side chains of alanine, valine, and leucine (β-depsides): Coming full circle from PHB to β-peptides to PHB
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Oligomers of 3-hydroxyalkanoic acids that contain two, three, and six residues with and without O-terminal (tBu)Ph2Si and C-terminal PhCH2 protection have been synthesized in such a way that the side chains on the oligoester backbone were those of the proteinogenic amino acids Ala (Me), Val (CHMe2), and Leu (CH2CHMe2). The enantiomerically pure 3-hydroxyalkanoates were obtained by Noyori hydrogenation of the corresponding 3-oxo-alkanoates with [Ru((R)-binap)Cl2](binap=2,2′bis(diphenylphosphanyl)-1, 1′-binaphthalene)/H2 (Scheme 1), and the coupling was achieved under the conditions (pyridine/(COCl)2, CH2Cl2, -78°) previously employed for the synthesis of various oligo(3-hydroxybutanoic acids) (Schemes 2 and 3). The Cotton effects in the CD spectra of the new oligoesters provided no hints about chiral conformation (cf. a helix) in MeOH, MeCN, octan-1-ol, or CF3CH2OH solutions (Figs. 1 and 2). Detailed NMR investigations in CDCl3 solution (Figs. 3-6, and Tables 1-5) of the hexa(3-hydroxyalkanoic acid) with the side chains of Val (HC), Ala (HB), Leu (HH), Val, Ala, Leu (from O- to C-terminus; 3) gave, on the NMR time-scale, no evidence for the presence of any significant amount of a 21- or a 31-helical conformation, comparable to those identified in stretched fibers of poly[(R)-3-hydroxybutanoic acid], or in lamellar crystallites and in single crystals of linear and cyclic oligo[(R)-3-hydroxybutanoic acids], or in the corresponding β-peptide(s) (the oligo(3-aminoalkanoic acid) analogs; 1-3). Thus, the extremely high flexibility (averaged or 'random-coil' conformation) of the polyester chain (CO - O rotational barrier ca. 13 kcal/mol; no hydrogen bonding), as compared to polyamide chains (CO - NH barrier ca. 18 kcal/mol; hydrogen bonding) has been demonstrated once again. The possible importance of this structural flexibility, which goes along with amphiphilic properties, for the role of PHB in biology, in evolution, and in prebiotic chemistry is discussed. Structural similarities of natural potassium-channeling proteins and complexes of oligo(3-hydroxybutanoates) with Na+, K+, or Ba2+ are alluded to (Figs. 7-9).
- Albert, Matthias,Seebach, Dieter,Duchardt, Elke,Schwalbe, Harald
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p. 633 - 658
(2007/10/03)
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- Pheromone synthesis, CXCIII. - Simple synthesis of (±)-stigmolone (8- hydroxy-2,5,8-trimethyl-4-nonanone), the pheromone of Stigmatella aurantiaca
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The racemic myxobacterial pheromone (±)-1 (stigmolone), which induces the formation of the fruiting body of Stigmatella aurantiaca, was synthesized from methyl isobutyl ketone (2) in 48% overall yield in four steps.
- Domon, Kenji,Mori, Kenji
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p. 979 - 980
(2007/10/03)
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- Enantioselective synthesis of β-amino acids based on BINAP-ruthenium(II) catalyzed hydrogenation
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BINAP-Ru(II) catalyzed hydrogenation of β-substituted (E)-β-(acylamino)acrylic acids allows efficient enantioselective synthesis of β-amino acids. The Z double bond isomers which possess an intramolecular hydrogen bond between amide and ester groups are more reactive but are hydrogenated with poor enantioselectivity. BINAP-Rh(I) complexes afford only moderate stereoselectivity with the opposite sense of enantioselection.
- Lubell,Kitamura,Noyori
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p. 543 - 554
(2007/10/02)
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- SYNTHESIS OF 5-SUBSTITUTED 4-O-METHYL TETRAMATES
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4-Methoxy-Δ3-pyrrolin-2-ones (4-O-methyl tetramates) are alkylated at C-5 via a lithio-derivative; an N-substituent may be introduced either during or after heterocycle formation.
- Jones, Raymond C.F,Bates, Andrew D.
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p. 5285 - 5288
(2007/10/02)
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- Studies of intramolecular Diels-Alder reactions: preparation of methyl spirohepta-4,6-dien-1-yl esters and their internal cycloaddition reactivity
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Different routes to the spirohepta-4,6-dien-1-yl esters 5,6,7,26, and 28 are described and their intramolecular Diels-Alder reactivity examined.A sidechain oxygen substituent is essential for cyclization although its exact role in the cycloaddition remains obscure.The trienes 5,6, and 28 cyclize to the tetracyclo1.7.04.6.06.10>undecenes 9, 10, and 30 which are useful synthetic intermediates for the preparation of sesquiterpenes.
- Gallacher, Gerard,Ng, Ang Ser,Attah-Poku, Samuel K.,Antczak, Kazimierz,Alward, Sandra J.,et al.
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p. 1709 - 1716
(2007/10/02)
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- A NEW PREPARATIVE METHOD FOR 1,3-DICARBONYL COMPOUNDS BY THE REGIOSELECTIVE OXIDATION OF α,β-UNSATURATED CARBONYL COMPOUNDS, CATALYZED BY PdCl2 USING HYDROGENPEROXIDES AS THE REOXIDANT OF Pd0
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α,β-Unsaturated esters and ketones are oxidized regioselectively to give β-keto esters and 1,3-diketones in good yields in aqueous acetic acid using Na2PdCl4 as the catalyst and t-butyl hydroperoxide or hydrogen peroxide as the reoxidant of Pd0.
- Tsuji, Jiro,Nagashima, Hideo,Hori, Kimihiko
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p. 257 - 260
(2007/10/02)
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- α-Carboxylation reaction of carbonyl compounds with bromomagnesium ureide-carbon dioxide adducts
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Bromomagnesium ureide-carbon dioxide adducts, models of the carboxylated biotin complex, undergo caboxylation of a variety of carbonyl compounds in good yield.
- Sakurai, Hideki,Shirahata, Akihiko,Hosomi, Akira
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p. 1967 - 1970
(2007/10/02)
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