Madrasin

Madrasin (CAS No.: 374913-63-0) is a cell-permeable small-molecule inhibitor of pre-mRNA splicing widely used as a chemical probe to investigate spliceosome function and RNA processing in eukaryotic systems. It exerts its activity by interfering with early stages of spliceosome assembly, effectively stalling the complex at the A complex and thereby preventing the formation of both splicing intermediates and mature mRNA products. Through this mechanism, Madrasin disrupts endogenous pre-mRNA splicing patterns and modulates alternative splicing events across multiple transcripts, highlighting its utility in dissecting splicing regulatory networks. In cellular contexts, including HeLa and HEK293 models, Madrasin has been shown to induce cell cycle arrest and promote reorganization of subnuclear protein localization, reflecting its broader impact on RNA metabolism and nuclear architecture. Its inhibitory activity is typically observed in the low micromolar range in vitro, although effective concentrations vary depending on cell type and experimental conditions. Madrasin is therefore extensively applied in studies of mRNA processing, spliceosome dynamics, and disease-associated splicing dysregulation, as well as in screening platforms aimed at identifying modulators of RNA splicing, with experimental dosing tailored to specific assay requirements.