Using an authentic sample of 2-hydroxy-9-(p-hydroxyphenyl)-phenalen-1-one, a 
banana phenalenone-type phytoalexin, we studied its dynamic of accumulation 
during pathogenesis of banana plants (Musa acuminata (AAA), Grand Nain) 
inoculated with Fusarium oxysporum f.sp. cubense (FOC), Race 4, the causal agent 
of Panama disease. The results obtained demonstrate that banana plants treated 
prior inoculation with menadione sodium bisulfite (MSB), an inducer of plant 
defenses, are capable of changing the dynamic of accumulation (higher amount and 
speed of biosynthesis) of this banana phytoalexin, biosynthesized by the banana 
plant during pathogenesis.