Peaks at 7.83 and 8.42 min were a pair of isomers. Both of them
gave a (M–H) ion at m/z 593.15, and (M–H–146) ion at m/z
469.78, and (M–H–146–162) ion at m/z 285.02, respectively.
The UV spectrum showed kmax at 242 and 345–350 nm, which suggested
that these peaks were kaempferol glycoside derivatives