- 2-Trifluoromethyl-2-Hydroxypropionamide Derivatives as Novel Reversal Agents of ABCG2 (BCRP)-Mediated Multidrug Resistance: Synthesis and Biological Evaluations
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It has been postulated that one of the biggest impediments to a successful chemotherapy is the phenomena of multidrug resistance (MDR) in cancer cells. One of the main mechanisms of MDR is overexpression of the ATP-binding cassette (ABC) transporters in c
- Kathawala, Rishil J.,Li, Tianwen,Yang, Danwen,Guo, Hui-Qin,Yang, Dong-Hua,Chen, Xiang,Cheng, Changmei,Chen, Zhe-Sheng
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- Delivering Structural Information on the Polar Face of Membrane-Active Peptides:19F-NMR Labels with a Cationic Side Chain
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Conformationally constrained non-racemizing trifluoromethyl-substituted lysine isosteres [(E)- and (Z)-TCBLys] with charged side chains are presented as a new type of19F-NMR labels for peptide studies. Design of the labels, their synthesis, incorporation into peptides and experimental demonstration of their application for solid state NMR studies of membrane-active peptides are described. A series of fluorine-labeled analogues of the helical amphipathic antimicrobial peptide PGLa(Nle) was obtained, in which different lysine residues in the original peptide sequence were replaced, one at a time, by either (E)- or (Z)-TCBLys. Antimicrobial activities of the synthesized analogues were practically the same as those of the parent peptide. The structural and orientational parameters of the helical PGLa(Nle) peptide in model bilayers, as determined using the novel labels confirmed and refined the previously known structure. (E)- and (Z)-TCBLys, as a set of cationic19F-NMR labels, were shown to deliver structural information about the charged face of amphipathic peptides by solid state19F-NMR, previously inaccessible by this method.
- Michurin, Oleg M.,Afonin, Sergii,Berditsch, Marina,Daniliuc, Constantin G.,Ulrich, Anne S.,Komarov, Igor V.,Radchenko, Dmytro S.
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- Oxazolones as potent inhibitors of 11β-hydroxysteroid dehydrogenase type 1
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2,5,5-Trisubstituted oxazolones were identified as potent inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). The synthesis, structure-activity relationship and metabolic stability of these compounds are presented.
- Sutin, Lori,Andersson, Soeren,Bergquist, Lars,Castro, Victor M.,Danielsson, Eva,James, Stephen,Henriksson, Martin,Johansson, Lars,Kaiser, Christina,Flyren, Katarina,Williams, Meredith
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p. 4837 - 4840
(2008/02/11)
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- Selection, purification, characterisation, and cloning of a novel heat-stable stereo-specific amidase from Klebsiella oxytoca, and its application in the synthesis of enantiomerically pure (R)- and (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acids and (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide
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We isolated, characterised, and cloned an enantio-specific amidase from Klebsiella oxytoca and used it to resolve (R,S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide, giving (R)3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid and (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide. The (S)-amide could then be hydrolysed chemically to (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid. The process can therefore be adapted to produce both (R)-and (S)-enantiomers of 3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid, or (S)-3,3,3-trifluoro-2-hydroxy-2-methylpropionamide. The biocatalytic step is part of a combined chemical and biocatalytic route that starts from ethyl trifluoroacetoacetate. The products typically have a purity of greater than 98% and ee values of essentially 100% after isolation. The process has been used to produce 100-g amounts of the (S)-acid, and successfully scaled up to produce 100-kg amounts of the (R)-acid, with the biotransformation carried out at the 1500-L scale.
- Shaw, Nicholas M.,Brieden, Walter,De Riedmatten, Patricia,Roduit, Jean-Paul,Zimmermann, Bertin,Neumueller, Roman,Naughton, Andrew,Robins, Karen,Tinschert, Andreas,Schmid, Evelyne,Hischier, Marie-Louise,Venetz, Veronika,Werlen, Josef,Zimmermann, Thomas
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p. 497 - 504
(2013/09/06)
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