- Design, synthesis and biological evaluation of potent azadipeptide nitrile inhibitors and activity-based probes as promising anti-Trypanosoma brucei agents
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Trypanosoma cruzi and Trypanosoma brucei are parasites that cause Chagas disease and African sleeping sickness, respectively. There is an urgent need for the development of new drugs against both diseases due to the lack of adequate cures and emerging drug resistance. One promising strategy for the discovery of small-molecule therapeutics against parasitic diseases has been to target the major cysteine proteases such as cruzain for T. cruzi, and rhodesain/TbCatB for T. brucei. Azadipeptide nitriles belong to a novel class of extremely potent cysteine protease inhibitors against papain-like proteases. We herein report the design, synthesis, and evaluation of a series of azanitrile-containing compounds, most of which were shown to potently inhibit both recombinant cruzain and rhodesain at low nanomolar/picomolar ranges. A strong correlation between the potency of rhodesain inhibition (i.e., target-based screening) and trypanocidal activity (i.e., whole-organism-based screening) of the compounds was observed. To facilitate detailed studies of this important class of inhibitors, selected hit compounds from our screenings were chemically converted into activity-based probes (ABPs), which were subsequently used for in situ proteome profiling and cellular localization studies to further elucidate potential cellular targets (on and off) in both the disease-relevant bloodstream form (BSF) and the insect-residing procyclic form (PCF) of Trypanosoma brucei. Overall, the inhibitors presented herein show great promise as a new class of anti-trypanosome agents, which possess better activities than existing drugs. The activity-based probes generated from this study could also serve as valuable tools for parasite-based proteome profiling studies, as well as bioimaging agents for studies of cellular uptake and distribution of these drug candidates. Our studies therefore provide a good starting point for further development of these azanitrile-containing compounds as potential anti-parasitic agents. Copyright
- Yang, Peng-Yu,Wang, Min,Li, Lin,Wu, Hao,He, Cynthia Y.,Yao, Shao Q.
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p. 6528 - 6541
(2012/07/13)
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- Synthesis of a novel series of L-isoserine derivatives as aminopeptidase N inhibitors
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A series of novel L-isoserine derivatives were synthesised and evaluated for their ability to inhibit aminopeptidase N (APN)/CD13. In our preliminary biological results, some of these compounds possessed a potent inhibitory activity against the APN. Within this series, compound 14b not only showed similar enzyme inhibition (IC50 of 12.2μM) compared with the positive control bestatin (half maximal inhibitory concentration (IC 50) of 7.3μM), but also had a potent antiproliferative activity against human cancer cell lines cells.
- Yang, Kanghui,Fen, Jinghong,Fang, Hao,Zhang, Lei,Gong, Jianzhi,Xu, Wenfang
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scheme or table
p. 302 - 310
(2012/07/02)
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- Esterification of unprotected a-Amino acids in ionic liquids as the reaction media
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Ionic liquid 1,3-dimethylimidazolium methanesulfonate was used to prepare a-amino acids benzylic esters from unprotected amino acids and benzyl chloride. Esterification of several amino acids was achieved with satisfactory yields: by-products can be removed by a simple work-up procedure to afford the pure product. The described method is simple, mild, rapid and save.
- Biondini, Daniele,Brinchi, Lucia,Germani, Raimondo,Goracci, Laura,Savelli, Gianfranco
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scheme or table
p. 39 - 44
(2010/08/22)
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- A class of novel carboline intercalators: Their synthesis, in vitro anti-proliferation, in vivo anti-tumor action, and 3D QSAR analysis
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Based on DOCK scores 18 N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a-r) were synthesized as anti-tumor agents. Their IC 50 values against five human carcinoma cell lines ranged from 11.1 μM to more than 100 μM. The in vivo assay identified five derivatives of them had no anti-tumor action, the anti-tumor activity of nine derivatives of them equaled that of cytarabine, and the anti-tumor activity of three derivatives of them was higher than that of cytarabine. The UV and fluorescence spectra, as well as the relative viscosity and melting temperature measurements of calf thymus DNA (CT DNA) with and without the representative compound suggested that DNA intercalation could be their action mechanism. The 3D QSAR analysis of N-(3-benzyloxycarbonylcarboline-1-yl)ethylamino acid benzylesters (6a-r) revealed that their in vivo anti-tumor activity significantly depends on the molecular electrostatic and steric fields of the side chain of the amino acid residue.
- Wu, Jianhui,Li, Chunyu,Zhao, Ming,Wang, Wenjing,Wang, Yuji,Peng, Shiqi
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experimental part
p. 6220 - 6229
(2010/10/04)
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- Study on synthesis, characteristics and catalysis properties of novel chiral metal complexes catalysts for 1,3-dipolar cycloaddition reactions of nitrone with electron-rich alkene
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As a new class of potential catalysts for 1,3-dipolar cycloaddition reactions, fourteen L-amino acid Schiff base Cu(II) and Ti(IV) complexes were synthesized, characterized, and evaluated for their catalytic activities in the reaction between C, N-diphenylnitrone and electron-rich ethyl vinyl ether under both homogeneous and in situ conditions. The methods for preparation and utilization of the catalysts were elucidated in detail, and the results of the catalytic reactions were described and discussed as well. Excellent reaction results were found in the presence of some catalysts (20 mol%) with > 90% endo-isoazolidines produced, compared with predominantly exo-isoazolidine produced without a catalyst. In addition, the reaction rate is found to be enhanced remarkably by a Cu(II) complex Schiff base catalyst at room temperature.
- You, Jun,Liu, Bo,Wang, Yi
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experimental part
p. 1010 - 1017
(2010/08/13)
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