- Effect of Cyclodextrins on the Hydrolysis of Amides
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The hydrolysis of p-nitrotrifluoroacetanilide (1), trifluoroacetanilide (2), m-nitrotrifluoroacetanilide (3), and p-nitroacetanilide (4) was studied in the presence of cyclodextrins.The reactions of 1 are catalyzed by α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) and also by hydroxypropyl)cyclodextrin (HPCD).The hydrolysis of 4 is catalyzed by β-CD.The reaction of 2 is inhibited by β-CD and so is the reaction of 3 by HPCD.Copounds 1 and 4 form two types of inclusion coplexes with β-CD, a 1:1 and a 1:2 substrate:cyclodextrin complex.Both types of complexesreact faster than the free substrate, and for 1 at pH = 7 all the catalysis is due to the reaction of the 1:2 complex since the 1:1 complex reacts at about the same rate as the free substrate.The results are explained in terms of two mechanisms: one which involves the acylation of CD by the amides and another which predominates at neutral pH where the two cyclodextrins coplexing the substrate stabilize the transition state for water addition.
- Granados, Alejandro,Rossi, Rita H. de
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Read Online
- A one-pot procedure for trifluoroacetylation of arylamines using trifluoroacetic acid as a trifluoroacetylating reagent
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A convenient procedure for the preparation of aryl trifluoroacetamides from aryl amines is described that employs 2-4 M equiv of trifluoroacetic acid in refluxing xylene as a trifluoroacetylating agent. Addition of an amount of pyridine that is equimolar to the amount of trifluoroacetic acid present in the reaction mixture facilitates the trifluoroacetylation of rather basic arylamines.
- Ohtaka, Junpei,Sakamoto, Takeshi,Kikugawa, Yasuo
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experimental part
p. 1681 - 1683
(2009/09/05)
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- Inhibitors of IMPDH enzyme
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The present invention relates to a novel class of compounds which are IMPDH inhibitors. This invention also relates to pharmaceutical compositions comprising these compounds. The compounds and pharmaceutical compositions of this invention are particularly well suited for inhibiting IMPDH enzyme activity and consequently, may be advantageously used as therapeutic agents for IMPDH mediated processes. This invention also relates to methods for inhibiting the activity of IMPDH using the compounds of this invention and related compounds.
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Page column 30
(2010/02/04)
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- N-nitrosoanilines: A new class of caspase-3 inhibitors
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Caspases are a family of cysteine proteases activated during apoptosis. In cultured human endothelial cells, physiological levels of NO prevent apoptosis and interfere with the activation of the caspase cascade. Previous studies have demonstrated that NO
- Guo, Zhengmao,Xian, Ming,Zhang, Wei,McGill, Andrea,Wang, Peng George
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