10466-61-2Relevant articles and documents
LAT1 activity of carboxylic acid bioisosteres: Evaluation of hydroxamic acids as substrates
Zur, Arik A.,Chien, Huan-Chieh,Augustyn, Evan,Flint, Andrew,Heeren, Nathan,Finke, Karissa,Hernandez, Christopher,Hansen, Logan,Miller, Sydney,Lin, Lawrence,Giacomini, Kathleen M.,Colas, Claire,Schlessinger, Avner,Thomas, Allen A.
, p. 5000 - 5006 (2016)
Large neutral amino acid transporter 1 (LAT1) is a solute carrier protein located primarily in the blood–brain barrier (BBB) that offers the potential to deliver drugs to the brain. It is also up-regulated in cancer cells, as part of a tumor's increased metabolic demands. Previously, amino acid prodrugs have been shown to be transported by LAT1. Carboxylic acid bioisosteres may afford prodrugs with an altered physicochemical and pharmacokinetic profile than those derived from natural amino acids, allowing for higher brain or tumor levels of drug and/or lower toxicity. The effect of replacing phenylalanine's carboxylic acid with a tetrazole, acylsulfonamide and hydroxamic acid (HA) bioisostere was examined. Compounds were tested for their ability to be LAT1 substrates using both cis-inhibition and trans-stimulation cell assays. As HA-Phe demonstrated weak substrate activity, its structure–activity relationship (SAR) was further explored by synthesis and testing of HA derivatives of other LAT1 amino acid substrates (i.e., Tyr, Leu, Ile, and Met). The potential for a false positive in the trans-stimulation assay caused by parent amino acid was evaluated by conducting compound stability experiments for both HA-Leu and the corresponding methyl ester derivative. We concluded that HA's are transported by LAT1. In addition, our results lend support to a recent account that amino acid esters are LAT1 substrates, and that hydrogen bonding may be as important as charge for interaction with the transporter binding site.
Regioselective hydration and deprotection of chiral, dissymmetric iminodinitriles in the scope of an asymmetric strecker strategy
Rossi, Jean-Christophe,Marull, Marc,Boiteau, Laurent,Taillades, Jacques
, p. 662 - 668 (2007/10/03)
The controlled, selective decomposition of dissymmetric iminodinitriles (DIDN) of formula RCH(CN)-NH-C(CN)R′R″ (considered as N-protected alpha-aminonitriles), is a critical issue for an original asymmetric Strecker strategy previously outlined by us for the enantioselective synthesis of amino acids. This strategy, derived from Harada's work, involves a double sequence of (i) stereoselective Strecker condensation of a chiral ketone R′R″CO with NH3 and HCN, followed by (ii) stereoselective Strecker condensation with an aldehyde RCHO and HCN, then (iii) regioselective retro-Strecker decomposition of the DIDN intermediate to release the target alpha-aminonitrile. In addition to the use of quite simple, cheap cyclic ketones (e.g. carvone derivatives) as chiral auxiliaries, another great advantage of this strategy is that step (iii) enables the recovery of the chiral ketone and hence its reuse. While our previous investigations on step (iii) under various conditions, either preceded or followed by the hydration of the secondary nitrile group RH(CN)- into an amide, had shown insufficient selectivity, we succeeded in the regioselective hydration of the secondary nitrile of DIDN without significant racemisation, by using a large excess of hydrogen peroxide in methanolic/aqueous ammonia (pH 12.5) at low temperature. The resulting imino nitrile/amide compound was then classically decomposed in acidic medium through a retro-Strecker reaction, affording the chiral alpha-amino amide. Alternately, the regioselective retro-Strecker decomposition of the tertiary moiety of the DIDN was achieved by reaction with silver cation in aqueous nitric acid, also without significant racemisation, thus establishing an original, enantioselective synthesis of alpha-aminonitriles. In both reactions, the chiral ketonic auxiliary resulting from DIDN decomposition was recovered in good yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Synthesis of α-amino dithioesters and endothiodipeptides
Hartke, Klaus,Barrmeyer, Stephan
, p. 251 - 256 (2007/10/03)
The α-amino ester hydrochlorides (1) are converted into N-protected α-amino amides (3), α-amino thioamides (4) and α-amino dithiomethylesters (5). Condensation of 5 with the alkali salts of α-amino acids gives rise to the endothiodipeptide alkali salts (7). Johann Ambrosius Barth 1996.
