Studies on the probing stimulants for the white-backed planthopper, Sogatella furcifera (Homoptera: Delphacidae) in rice plant (Oryza sativa L.)

To elucidate the probing stimulants in rice plants for the white-backed planthopper, Sogatella furcifera, bioassay-guided separations were conducted, which led to the isolation of four active compounds. Using NMR and LC-MS spectra, their structures were determined as isoorientin 2″-O-(6‴-(E)-feruloyl)glucoside, isoorientin 2″-O-(6‴-(E)-p-coumaroyl)glucoside, tricin 5-O-glucoside, and isoscoparin 2″-O-(6‴-(E)-feruloyl)glucoside.