Related Experiment Video
Updated: May 13, 2026

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs
Published on: May 15, 2019
Optimization of 3,5-dimethylisoxazole derivatives as potent bromodomain ligands
David S Hewings1, Oleg Fedorov, Panagis Filippakopoulos
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
Abstract:
The bromodomain protein module, which binds to acetylated lysine, is emerging as an important epigenetic therapeutic target. We report the structure-guided optimization of 3,5-dimethylisoxazole derivatives to develop potent inhibitors of the BET (bromodomain and extra terminal domain) bromodomain family with good ligand efficiency. X-ray crystal structures of the most potent compounds reveal key interactions required for high affinity at BRD4(1). Cellular studies demonstrate that the phenol and acetate derivatives of the lead compounds showed strong antiproliferative effects on MV4;11 acute myeloid leukemia cells, as shown for other BET bromodomain inhibitors and genetic BRD4 knockdown, whereas the reported compounds showed no general cytotoxicity in other cancer cell lines tested.
Related Concept Videos
Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Cholinergic Antagonists: Chemistry and Structure-Activity Relationship
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
