Sinefungin

Sinefungin (CAS No.: 58944-73-3) is a solid purine nucleoside analog belonging to the class of adenosyl-ornithine derivatives, characterized by its structural mimicry of S-adenosylmethionine and its broad activity as a methyltransferase inhibitor in biochemical systems. It has been extensively utilized as a tool compound in epigenetic and enzymology research due to its ability to inhibit multiple methyltransferases, including virion mRNA (guanine-7-)-methyltransferase, mRNA (nucleoside-2′)-methyltransferase, and protein lysine methyltransferases such as SET7/9, thereby modulating methylation-dependent processes such as H3K4 histone modification. Additional reported targets include bacterial and viral methylases such as RdmB, TaqI methylase, RsrI methylase, and rRNA adenine-N6-methyltransferase, supporting its utility in studying RNA processing, gene expression regulation, and host–pathogen interactions. Sinefungin demonstrates inhibitory activity typically in the nanomolar to low micromolar range depending on the enzyme system and assay conditions, and it has been shown to suppress viral replication in cell-based models through interference with RNA capping mechanisms. In experimental settings, it is widely applied in cell-based assays, enzymatic studies, and epigenetic investigations to probe methyltransferase function and methylation-dependent signaling pathways, with concentrations or dosing regimens tailored to specific experimental designs and biological contexts.