(-)-Neplanocin A is primarily utilized in biochemical research due to its potent inhibitory effects on S-adenosylhomocysteine hydrolase (SAH hydrolase). This inhibition plays a crucial role in studying methylation processes, as it affects the methylation of DNA, RNA, and proteins, which are vital for various cellular functions. Researchers employ (-)-Neplanocin A to explore the mechanisms of viral replication, particularly in RNA viruses, where methylation is a key step. Additionally, it is investigated for its potential antiviral and anticancer properties, as disrupting methylation can hinder the proliferation of viruses and cancer cells. Its application in these areas provides valuable insights into developing novel therapeutic strategies targeting methylation-dependent pathways.