14009-94-0Relevant articles and documents
Effect of Cholesterol on the Stereoselective Hydrolysis in Artificial Membrane Systems
Ueoka, Ryuichi,Matsumoto, Yoko
, p. 3774 - 3778 (1984)
The catalytic efficiency and enantioselectivity for the hydrolysis of p-nitrophenyl N-dodecanoyl-D(L)-phenylalaninate (2b) in the catalytic system of N-tetradecanoyl-L-histidyl-L-leucine (1b) and didodecyldimethylammonium bromide (3a) were enhanced by addition of cholesterol at an optimum temperature (25 deg C).Furthermore, it is suggested that the hydrophobic interaction between reactants in the bilayer membrane system (3a) might be reduced by adding cholesterol on the basis of isokinetic temperature.It is concluded from these results that the fluidity of the artificial bilayer matrix (3a) varies upon addition of cholesterol.
Preparation of N-acetyl, tert-butyl amide derivatives of the 20 natural amino acids
Ekkati,Campanali,Abouelatta,Shamoun,Kalapugama,Kelley,Kodanko, Jeremy J.
scheme or table, p. 747 - 751 (2010/08/05)
N-Acetyl-AA(amino acid)-NHtBu derivatives of all 20 naturally occurring amino acids have been synthesized. Syntheses were performed via solution-phase methodology with yields that allow for access to gram quantities of substrates, in most cases. Syntheses include the coupling of a hindered amine, tert-butylamine, with each amino acid, either directly or in two steps using an activated ester isolated as an intermediate. The introduction of protecting groups was necessary in some cases. The development of synthetic sequences to access challenging substrates, such as the one derived from asparagine, are discussed.
Targeting peptides with an iron-based oxidant: Cleavage of the amino acid backbone and oxidation of side chains
Ekkati, Anil R.,Kodanko, Jeremy J.
, p. 12390 - 12391 (2008/03/30)
The oxidation of protected amino acids using an iron-based oxidant is described. Substrates of the general formula Ac-X-NHtBu, where X = Gly (1), Ala (2), Val (3), Phe (4), Tyr (5), Trp (6), and Met (7) were constructed to model individual amino acid residues within a polypeptide chain. Oxidation of 1 by the iron catalyst [FeII(N4Py)(MeCN)](ClO4)2 (8) and KHSO5 leads to scission of the amino acid backbone and produces N-acetylformamide as the major product. Decomposition of the iron-based oxidant [FeIV(O)(N4Py)]2+, derived from 8, is slower in the presence of 2,2-d2-1 (96% D) than with 1, giving a kinetic isotope effect of 4.8, which is consistent with [FeIV(O)(N4Py)]2+ cleaving an α-CH bond of 1. Aliphatic amino acid substrates 2 and 3 do not react with [FeIV(O)(N4Py)]2+ under the same conditions used with 1. With substrates 4-7 oxidation of the amino acid side chain is observed. Decomposition of [FeIV(O)(N4Py)]2+ upon treatment with 10 equiv of 1 and 4-7 revealed that 5 is the most reactive toward the FeIVO species. Pseudo-first-order rate constants of 17.0(5) × 10-3, 3.15(8) × 10-3 and 5.8(2) × 10-5 s-1 were obtained for decomposition of [FeIV(O)(N4Py)]2+ ([Fe] = 1 mM, 1:1 H2O/MeCN) by 6, 7, and 1, respectively. Copyright
NOVEL ARYLAMIDINE DERIVATIVE OR SALT THEREOF
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Page 117, (2010/02/09)
An arylamidine derivative represented by a general formula described below or a salt thereof has an excellent antifungal action and high safety, and it is useful as an antifungal agent with good pharmacokinetics and pharmacodynamic properties: wherein X represents an unsubstituted or substituted lower alkylene or alkenylene group; G1 represents an oxygen atom, a sulfur atom, or an imino group; G2 represents a carbon atom or a nitrogen atom; Ra represents at least one group selected from the group consisting of a hydrogen atom, a halogen atom, and unsubstituted or substituted alkyl, cycloalkyl and alkoxy groups; R1 represents an unprotected or protected or unsubstituted or substituted amidino group; and R2 represents a substituted amino or substituted cyclic amino group, or the like.
