Adenosine dialdehyde (ADOX) is primarily used as a potent inhibitor of S-adenosylhomocysteine hydrolase (SAHase), an enzyme involved in methylation reactions. By inhibiting this enzyme, ADOX leads to the accumulation of S-adenosylhomocysteine, which in turn suppresses a wide range of methyltransferase activities. This property makes ADOX a valuable tool in research settings, especially in studies involving epigenetics, RNA processing, and viral replication. It is commonly applied in cell culture experiments to modulate methylation processes and investigate the role of methylation in gene expression and protein function. ADOX has also been used in virology to study the replication mechanisms of certain RNA and DNA viruses that depend on host methylation pathways. Due to its ability to interfere with post-transcriptional modifications, it aids in understanding mRNA cap formation and tRNA modification. In biochemical assays, ADOX serves as a reference compound for evaluating the efficacy of new methyltransferase inhibitors. Its use is mostly confined to laboratory research, as it is not stable in vivo and has limited therapeutic application.