On-line identification of further flavone C- and O-glycosides from sugarcane (Saccharum officinarum L., Gramineae) by HPLC-UV-MS.

HPLC-UV-MS (APCI-MS/MS and CID/MS) was utilised for the identification of eight additional flavone glycosides from sugarcane (Saccharum officinarum L., Gramineae) extracts of bagasse, leaves and juice ('garapa'). Relevant information about substitution patterns was obtained through UV detection using post-column addition of shift reagents, while tandem MS provided structural information confirming the proposed structures of the C-glycosides vitexin, orientin, luteolin-8-C-(rhamnosylglucoside), 4',5'-dimethyl-luteolin-8-C-glycoside and the isomeric pair schaftoside-isoschaftoside, besides the O-glycosides tricin-7-O-neohesperidoside and tricin-7-O-glycoside.