36272-22-7Relevant academic research and scientific papers
Hepatoprotective amide constituents from the fruit of Piper chaba: Structural requirements, mode of action, and new amides
Matsuda, Hisashi,Ninomiya, Kiyofumi,Morikawa, Toshio,Yasuda, Daisuke,Yamaguchi, Itadaki,Yoshikawa, Masayuki
, p. 7313 - 7323 (2009)
The 80% aqueous acetone extract from the fruit of Piper chaba (Piperaceae) was found to have hepatoprotective effects on d-galactosamine (d-GalN)/lipopolysaccharide-induced liver injury in mice. From the ethyl acetate-soluble fraction, three new amides, p
Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
, (2021/12/23)
Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.
Rational Design of Thermodynamic and Kinetic Binding Profiles by Optimizing Surface Water Networks Coating Protein-Bound Ligands
Krimmer, Stefan G.,Cramer, Jonathan,Betz, Michael,Fridh, Veronica,Karlsson, Robert,Heine, Andreas,Klebe, Gerhard
, p. 10530 - 10548 (2016/12/16)
A previously studied congeneric series of thermolysin inhibitors addressing the solvent-accessible S2′ pocket with different hydrophobic substituents showed modulations of the surface water layers coating the protein-bound inhibitors. Increasing stabilization of water molecules resulted in an enthalpically more favorable binding signature, overall enhancing affinity. Based on this observation, we optimized the series by designing tailored P2′ substituents to improve and further stabilize the surface water network. MD simulations were applied to predict the putative water pattern around the bound ligands. Subsequently, the inhibitors were synthesized and characterized by high-resolution crystallography, microcalorimetry, and surface plasmon resonance. One of the designed inhibitors established the most pronounced water network of all inhibitors tested so far, composed of several fused water polygons, and showed 50-fold affinity enhancement with respect to the original methylated parent ligand. Notably, the inhibitor forming the most perfect water network also showed significantly prolonged residence time compared to the other tested inhibitors.
A new amide, piperchabamide F, and two new phenylpropanoid glycosides, piperchabaosides A and B, from the fruit of Piper chaba
Morikawa, Toshio,Yamaguchi, Itadaki,Matsuda, Hisashi,Yoshikawa, Masayuki
experimental part, p. 1292 - 1295 (2010/05/02)
A new amide, piperchabamide F (1), and two new phenylpropanoid glycosides, piperchabaosides A (2) and B (3), were isolated from 80% aqueous acetone extract from fruit of Piper chaba. Their stereostructures were elucidated on the basis of chemical and phys
Synthesis and odor evaluation of stereoisomers of imine derivatives in roasted spotted shrimp
Tachihara, Toru,Ishizaki, Susumu,Kurohayashi, Yoshiko,Tamura, Hiroshi,Ikemoto, Youichi,Onuma, Atsushi,Yoshikawa, Keisuke,Yanai, Tetsuya,Kitahara, Takeshi
, p. 274 - 279 (2007/10/03)
All possible stereoisomers of imine derivatives 1-4. which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood.
Spectroscopy of Hydrothermal Reactions, Part 26: Kinetics of Decarboxylation of Aliphatic Amino Acids and Comparison with the Rates of Racemization
Li, Jun,Brill, Thomas B.
, p. 602 - 610 (2007/10/03)
The kinetics of decarboxylation of six α-amino acids (glycine, alanine, aminobutyric acid, valine, leucine, and isoleucine) and β-aminobutyric acid were studied in aqueous solution at 310-330 deg C and 275 bar over the pH25 range 1.5-8.5 by using an in situ FT-IR spectroscopy flow reactor. Based on the rate of formation of CO2, the first-order or pseudo-first-order rate constants were obtained along with the Arrhenius parameters. The decarboxylation rates of amino acids follow the order Gly > Leu ca. Ile ca. Val > Ala > α-Aib > β-Aib. Differences in the concentration between 0.05 and 0.5 m had only a minor effect on the decarboxylation rate. The effect of the position of the amino group on the decarboxylation rate was investigated for α-, β-, and γ-aminobutyric acid and the order was found to be α > β >> γ. Although the pH dependence is complex, the decarboxylation rates of α-amino acids qualitatively have the inverse trend of the racemization rates.
Synthesis of the four possible stereoisomers of N-2′-methylbutyl-2-Methylbutylamide, the sex pheromone of the longhorn beetle Migdolus fryanus westwood
Santangelo,Zarbin,Cass,Ferreira,Correa
, p. 3685 - 3698 (2007/10/03)
The four stereoisomers of N-2′-methylbutyl-2-methylbutylamide, the sex pheromone of the longhorn beetle Migdolus fryanus, an economically important pest of sugarcane in South America, were synthesized. The key intermediate 2-methylbutan-1-ol is commercially available only in its (S)-(-)-form. The (R)-(+)-enantiomer was obtained optically pure from methyl (S)-(+)-3-hydroxy-2-methylpropionate in five steps.
CD OF PRIMARY AMINES AND 1- OR 3-SUBSTITUTED TETRAHYDROISOQUINOLINES IN PRESENCE OF
Diener, Wolfgang,Frelek, Jadwiga,Snatzke, Guenther
, p. 954 - 965 (2007/10/02)
The syntheses of (S)-(-)-1,2-dimethyl-1,2,3,4-tetrahydroisoquinoline (IX) and S-(+)-2,3-dimethyl-1,2,3,4-tetrahydroisoquinoline (XVI) in optically pure form and with known absolute configuration is described.The CD and NMR spectra of these compounds and of most of their intermediates are given, and from these data could be deduced, that the N-methyl groups of the two bases IX and XVI adopt different conformations in solution, but the same (viz. axial) in their complexes with .
