Inhibition of aflatoxin B₁ biosynthesis by piperlongumine isolated from Piper longum L

The alkaloids, piperlongumine, piperine, pipernonaline, and piperoctadecalidine, isolated from Piper longum L., were found to inhibit the biosynthesis of aflatoxin B₁ (AFB₁) in Aspergillus flavus WRRC 3-90-42-12. Piperlongumine was the most active among the compounds tested, with a 96% inhibition of AFB₁ biosynthesis at 0.2% (w/v) supplement in a potato dextrose agar (PDA) medium. The three other piperidine alkaloids, piperine, pipernonaline, and piperoctadecalidine, also inhibited the biosynthesis of AFB₁. Of these three alkaloids, piperoctadecalidine exhibited a potent inhibitory activity with a 100% inhibition of AFB₁ production at 0.7% (w/v) supplement in a PDA medium. Therefore, piperlongumine and piperoctadecalidine could be used as antiaflatoxigenic agents an agricultural industries. To determine the antiaflatoxigenic mode of action of piperlongumine, further studies are needed.