6
is relatively facile to compare chemical constituents of each sample and to see if
intraspecific similarities are present or not.
The following conditions for LC-MS measurement were used: HPLC 1100 system with a DAD detector and an automatic sample injector (column, 5C18-MS-II
(COSMOSIL) 4.6  ×  150  mm; solvent, MeOH-H 2 O gradient; flow rate, 0.5  cm
3
/
min). An Agilent 1100 series LC/MSD mass spectrometer was employed with an
atmospheric pressure chemical ionization interface (APCI) (capillary voltage,
3.5 kV; corona current, 4 μA; capillary exit voltage (fragmentor), 90 V; drying temperature, 330°C; drying flow, 9 dm
3
/min; nebulizer pressure, 50 psig; positive ion
mode; scan range, m/z 100–1000 amu).
Plate 3 Typical TLC patterns visualized by spraying Ehrlich’s reagent. Left: the L type of L. virgaurea; the largest pink spot is ligularol (160). Right: the V type of L. virgaurea; the two yellow
spots are virgaurenones A (273) and B (272)
500
400
300
200
100
0
0
5
10
15
20
25
min
Plate 4 Typical TIC profiles of L. virgaurea; from top to bottom: the L, V, C, H, and N types
M. Tori and C. Kuroda