From the resinous exudates of Heliotropium sinuatum have been isolated and characterized two compounds, pentaeicosanol 1 and 1-hydroxy-3-doeicosanone 2. Those structures and previously isolated pure compounds have been tested in their antibacterial activity on phytopathogenic bacteria. Ketone 2 and the flavonoid hesperetine 10 showed antibacterial activity on Erwinia carotovora subsp. carotovora, while the flavonoid 3-O-methylgalangine 4 showed activity on Clavibacter michiganensis subsp. michiganensis