Two new polyamine alkaloids from the Bufo viridis toad venom.

Two new polyamine alkaloids (bufonines A-B), together with four known alkaloids, bufotenidine ( 3 ), bufotenine ( 4 ), 1-( β -d-ribofuranosyl)-l H -1,2,4-triazone ( 5 ) and proline ( 6 ) were isolated from the Bufo viridis toad venom. Their structures were identified by UV, HR-ESI-MS, NMR spectral analyses, and comparison of theoretical and experimental ECD data. All compounds were tested in vitro cytotoxicity against three human cancer cell lines (HT-29, A549 and Hela). None of the compounds showed cytotoxicity towards all tested cell lines. To the best of our knowledge, this is the first report of alkaloid components from Bufo viridis toad venom.