82414-35-5Relevant articles and documents
Design and synthesis of molecular umbrellas
Janout, Vaclav,Lanier, Marion,Regen, Steven L.
, p. 640 - 647 (1997)
This paper describes the design and synthesis of a series of conjugates derived from cholic acid, spermidine, and 5-(dimethylamino)-1-naphthalenesulfonyl (dansyl), which effectively shield the dansyl moiety from water. Direct coupling of cholic acid to both terminal amino groups of spermidine, and attachment of the environmentally-sensitive dansyl moiety to the remaining secondary amine, yields a 'molecular umbrella' (Ia) whose fluorescent properties (λ(max) and emission intensity) reflect a nonpolar microenvironment in water and one that is relatively polar in intermediate dimethoxyethane/water mixtures. Comparison of Ia with analogous 'single-walled' (II) and 'no-walled' (III) umbrellas further indicates that a minimum of two walls is necessary in order to have 'umbrella-like' properties. Examination of the fluorescent properties of a related double-walled umbrella, bearing a flexible (2-hydroxyethyl)carbamate moiety at the C-3 position of the sterol (Ib), reveals that 'umbrella-like' properties are present even when facial amphiphilicity is not rigorously maintained; however, the molecule's ability to shield the fluorophore, as judged by its relative emission intensity, is diminshed. 'Methyl-capping' of the (2-hydroxyethyl)carbamate (i.e., Ic) enhances the umbrella's ability to provide a hydrophobic shelter in water. A tetra-walled analogue of Ia, bearing four cholic acid units (i.e., IV), has been synthesized and its dansyl group found to have reduced exposure toward water. The potential utility of molecular umbrellas in the area of drug delivery is briefly discussed.
Unexpected Acetylation of Endogenous Aliphatic Amines by Arylamine N-Acetyltransferase NAT2
Bergdahl, Ingvar A.,Conway, Louis P.,Correia, Mário S. P.,Globisch, Daniel,Rendo, Veronica,Sj?blom, Tobias
, p. 14342 - 14346 (2020/07/13)
N-Acetyltransferases play critical roles in the deactivation and clearance of xenobiotics, including clinical drugs. NAT2 has been classified as an arylamine N-acetyltransferase that mainly converts aromatic amines, hydroxylamines, and hydrazines. Herein, we demonstrate that the human arylamine N-acetyltransferase NAT2 also acetylates aliphatic endogenous amines. Metabolomic analysis and chemical synthesis revealed increased intracellular concentrations of mono- and diacetylated spermidine in human cell lines expressing the rapid compared to the slow acetylator NAT2 phenotype. The regioselective N8-acetylation of monoacetylated spermidine by NAT2 answers the long-standing question of the source of diacetylspermidine. We also identified selective acetylation of structurally diverse alkylamine-containing drugs by NAT2, which may contribute to variations in patient responses. The results demonstrate a previously unknown functionality and potential regulatory role for NAT2, and we suggest that this enzyme should be considered for re-classification.
Ruthenium-Catalyzed Amidation of Nitriles with Amines. A Novel, Facile Route to Amides and Polyamides
Murahashi, Shun-Ichi,Naota, Takeshi,Saito, Eiichiro
, p. 7846 - 7847 (2007/10/02)
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