- Chemoenzymatic synthesis, structural study and biological activity of novel indolizidine and quinolizidine iminocyclitols
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The synthesis, conformational study and inhibitory properties of diverse indolizidine and quinolizidine iminocyclitols are described. The compounds were chemo-enzymatically synthesized by two-step aldol addition and reductive amination reactions. The aldol addition of dihydroxyacetone phosphate (DHAP) to N-Cbz-piperidine carbaldehyde derivatives catalyzed by l-rhamnulose 1-phosphate aldolase from Escherichia coli provides the key intermediates. The stereochemical outcome of both aldol addition and reductive amination depended upon the structure of the starting material and intermediates. The combination of both reactions furnished five indolizidine and six quinolizidine type iminocyclitols. A structural analysis by NMR and in silico density functional theory (DFT) calculations allowed us to determine the population of stereoisomers with the trans or cis ring fusion, as a consequence of the inversion of configuration of the bridgehead nitrogen. The trans fusion was by far the most stable, but for certain stereochemical configurations of the 3-hydroxymethyl and hydroxyl substituents both trans and cis fusion stereoisomers coexisted in different proportions. Some of the polyhydroxylated indolizidines and quinolizidines were shown to be moderate to good inhibitors against α-l-rhamnosidase from Penicillium decumbens. Indolizidines were found to be moderate inhibitors of the rat intestinal sucrase and of the exoglucosidase amyloglucosidase from Aspergillus niger. In spite of their activity against α-l-rhamnosidase, all the compounds were ineffective to inhibit the growth of the Mycobacterium tuberculosis, the causative agent of tuberculosis. The Royal Society of Chemistry 2012.
- Gómez, Livia,Garrabou, Xavier,Joglar, Jesús,Bujons, Jordi,Parella, Teodor,Vilaplana, Cristina,Cardona, Pere Joan,Clapés, Pere
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experimental part
p. 6309 - 6321
(2012/09/05)
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- Electrochemical deallylation of α-allyl cyclic amines and synthesis of optically active quaternary cyclic amino acids
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Electrochemical oxidation of α-allylated and α-betizylated N-acylated cyclic amines by using a graphite anode easily affords the corresponding α-methoxylated products with up to 76% yield. Ease of oxidation was affected by the type of electrode, the size
- Kirira, Peter G.,Kuriyama, Masami,Onomura, Osamu
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experimental part
p. 3970 - 3982
(2010/07/04)
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- An efficient synthesis of sulfamides
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Here we report an efficient synthesis of sulfamides. 3,5-Lutidine was found to be an optimal solvent and catalyst for the reaction. The method was developed during our efforts to synthesize a series of novel FKBP-12 inhibitors in which the known ketoamide linker was replaced with sulfamide.
- Guo, Chuangxing,Dong, Liming,Kephart, Susan,Hou, Xinjun
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scheme or table
p. 2909 - 2913
(2010/06/14)
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- Effecient kinetic resolution of racemic amino aldehydes by oxidation with N-iodosuccinimide
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(Chemical Equation Presented) Selective recognition: The first efficient method for the kinetic resolution of racemic amino aldehydes (see scheme, PG=protecting group) is based on a copper(II)/(R,R)-Ph-BOX complex. The coordinated amino aldehydes were tra
- Minato, Daishirou,Nagasue, Yoko,Demizu, Yosuke,Onomura, Osamu
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supporting information; experimental part
p. 9458 - 9461
(2009/05/06)
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- Caspase inhibitors and uses thereof
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The present invention relates to novel classes of compounds of formula I which are caspase and TNF-alpha inhibitors. This invention also relates to pharmaceutical compositions comprising these compounds. The compounds and pharmaceutical compositions of th
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- Caspase inhibtors and uses thereof
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This invention provides caspase inhibitors having the formula wherein Ring A is an optionally substituted piperidine, tetrahydroquinoline or tetrahydroisoquinoline ring; R1 is hydrogen, CHN2, R, or —CH2Y; R is an optionall
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