Biomedical subjects
Publications and source records attributed to J M Dener.
Truncation of potent and selective dibasic inhibitors afforded monocharged inhibitors of human mast-cell tryptase. Using two classes of analogues as lead structures, several monocharged derivatives were identified with K(i) values ranging from 0.084 to 0.21 microM against the enzyme.
A survey of charged groups and linkers for a series of symmetrical and unsymmetrical dibasic inhibitors is described, leading to several classes of potent and selective inhibitors. In particular, the benzamidine functionality was identified as the most potent charged group investigated.
The synthesis and optimization of a novel class of reversible and active-site directed dibasic inhibitors of human mast cell tryptase are described. The compounds were shown to be both remarkably potent and selective for tryptase with Ki values for optimized inhibitors in the picomolar range.
Detailed structure activity relationships (SARs) for a series of dibasic human tryptase inhibitors are presented. The structural requirements for potent inhibitory activity are remarkably broad with a range of core template modifications being well tolerated. Optimized inhibitors demonstrate potent anti-asthmatic activity in a sheep model of allergic asthma. APC-2059, a dibasic tryptase inhibitor with subnanomolar activity, has been advanced to phase II clinical trials for the treatment of both psoriasis and ulcerative colitis.
Irlbacholine and a series of related analogues were synthesized and their antifungal activities against Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus were assessed. The natural bisphosphocholine, irlbacholine, was the most potent compound, its 22-carbon chain length appearing to be optimal.
The first structure-activity study involving the 1,2-dithiin class of compounds (1,2-dithiacyclohexadienes) is herein reported. A series of 3,6-disubstituted 1,2-dithiins was synthesized from dithiins 1d and 1e and evaluated as antifungal agents. A new and versatile synthesis of dithiins 1d and 1e is reported which is amenable to scale-up at the kilogram level. The novelty of the process derives from the use of beta-mercaptopropionitrile as the thiophile, relying on a beta-elimination strategy and subsequent oxidation to create the 1,2-dithiin ring. Optimal geometries of dithiins 1d, 18i, and 45 and model dithiin 61 were determined by molecular mechanics and Hartree-Fock molecular orbital calculations. Two possible mechanisms of action are presented for the 1,2-dithiin class of compounds to explain their observed antifungal activities against Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus.
The library synthesis of alkoxyprolines was achieved using an acid-stable, nucleophile-cleavable solid support. A hydroxythiophenol linker derived from Merrifield resin was esterified with the corresponding ethers of BOC-hydroxyproline. Removal of the BOC protecting group with trifluoroacetic acid followed by acylation gave solid-supported hydroxyproline derivatives. Cleavage from the solid support with excess primary amines or excess secondary amines followed by purification of the crude products from the excess amine by supported liquid-liquid extraction gave the alkoxyproline library in high purity.
A series of libraries containing the 2,4-diaminoquinazoline ring system were prepared, starting from polymer-bound amines. The key steps included reaction of the support-bound amine with 6,7-dimethoxy-2,4-dichloroquinazoline, followed by displacement of the second chlorine with an amine and subsequent TFA-mediated cleavage of the product from the support. When a symmetrical or unsymmetrical diamine was used in the displacement step, the free amine could be acylated with an activated acid to generate another set of compounds. The optimization of conditions for the reductive amination and displacement steps will be discussed as well as the final choice of resin for library production. In addition, quality control methods for library analysis is also described.