Sinefungin is a nucleoside analog of S-adenosylmethionine. Sinefungin exhibits antibacterial, antifungal, and anti-parasitic activities. This compound inhibits Streptococcus biofilm growth as well as growth and survival of Trypanosoma and Leishmania. Sinefungin and its derivatives inhibit methyltransferases and may display potential as epigenetic modifiers. Sinefungin is primarily used in research models to explore activity of S-adenosylmethionine.