Furthermore, we were able to
detect the induction of scopoletin and umbelliferone by SC and SB,
even when present at low amounts, thanks to an HPLC protocol
set up to chromatographically separate and thus accurately quantify
the three phytoalexins using fluorescence light. Indeed, unlike
scoparone, little attention has been paid to scopoletin and umbelliferone
detection and quantification in previous studies, possibly
because of their inefficient extraction from the peel tissues, usually
conducted using less polar solvents such as dichloromethane.