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Biomedical subjects

Robert Epple

Publications and source records attributed to Robert Epple.

9 recordsLinked to original sources

Bicyclic carbamates as inhibitors of papain-like cathepsin proteases.

A 6-oxa-1-aza-bicyclo[3.2.1]octan-7-one system inhibits the proteolytic activity of several cysteine proteases belonging to the papain family. In vitro mechanistic studies and in silico calculations suggest that the minimal pi-overlap between the bridgehead nitrogen and the carbonyl leads to a considerable weakening of the urethane system, making it susceptible to nucleophilic attack from the active site thiol group. The resulting covalent adduct is slowly hydrolyzed, releasing the hydroxypiperidine product of the inhibitor. Synthesis and testing of a set of analogs led to variable protease subtype selectivities ranging from micromolar to nanomolar potencies.

Binding Sites↗

3,4,5-Trisubstituted isoxazoles as novel PPARdelta agonists. Part 2.

A series of PPARdelta-selective agonists was investigated and optimized for a favorable in vivo pharmacokinetic profile. Isoxazole LCI765 (17d) was found to be a potent and selective PPARdelta agonist with good in vivo PK properties in mouse (C(max)=5.1 microM, t(1/2)=3.1 h). LCI765 regulated expression of genes involved in energy homeostasis in relevant tissues when dosed orally in C57BL6 mice. A co-crystal structure of compound LCI765 and the LBD of PPARdelta is discussed.

Animals↗

Synthesis and SAR of arylaminoethyl amides as noncovalent inhibitors of cathepsin S: P3 cyclic ethers.

The synthesis and structure-activity relationship of a series of arylaminoethyl amide cathepsin S inhibitors are reported. Optimization of P3 and P2 groups to improve overall physicochemical properties resulted in significant improvements in oral bioavailability over early lead compounds. An X-ray structure of compound 37 bound to the active site of cathepsin S is also reported.

Administration, Oral↗

3,4,5-Trisubstituted isoxazoles as novel PPARdelta agonists: Part 1.

We report the identification of a novel series of trisubstituted isoxazoles as PPAR activators from a high-throughput screen. A series of structural optimizations led to improved efficacy and excellent functional receptor selectivity for PPARdelta. The isoxazoles represent a series of agonists which display a scaffold that lies outside the typical PPAR agonist motif.

Amino Acid Motifs↗

1,3,5-Trisubstituted aryls as highly selective PPARdelta agonists.

A series of highly potent and selective PPARdelta agonists is described using the known non-selective ligand GW2433 as a structural template. Compound 1 is bioavailable, potent (10 nM), and shows no cross-activity with other PPAR subtypes up to 10 microM, making it a useful tool in studying the biological effects of selective PPARdelta activation.

Butyrates↗

Synthesis and evaluation of arylaminoethyl amides as noncovalent inhibitors of cathepsin S. Part 3: heterocyclic P3.

A series of N(alpha)-2-benzoxazolyl-alpha-amino acid-(arylaminoethyl)amides were identified as potent, selective, and noncovalent inhibitors of cathepsin S. Structure-activity relationships including strategies for modulating the selectivities among cathepsins S, K, and L, and in vivo pharmacokinetics are discussed. A X-ray structure of compound 3 bound to the active site of cathepsin S is also reported.

Amides↗

Solid-phase synthesis of nucleoside analogues.

The synthesis of a 25 000 member library of nucleoside analogues as discrete compounds in milligram quantities is described. The use of the Nanokan technology developed by IRORI (Discovery Partners International) together with macroporous solid support allowed us to develop a highly reliable and practical synthetic route for the high-throughput derivatization of both the pyrimidine and purine nucleoside scaffold. A 2',3'-acetal linkage of the scaffolds to the solid support proved to be stable enough for the chemical transformations employed, yet labile enough for mild cleavage conditions to yield final products in high purity. The publication represents an example for combining synthetic organic chemistry on advanced scaffolds with the latest technologies of combinatorial chemistry in order to provide both industrial and academic institutions with compounds in high number and quality, thereby accelerating the search for novel biological targets and drug development.

Combinatorial Chemistry Techniques↗