[Study on the dynamic variation of active components in Geranium carolinianum from different collection time].

Objective: To determine the contents of the active components, gallic acid and ellagic acid in Geranium carolinianum from different collection time and to define the best collection time for this herb.

Methods: The contents of gallic acid and ellagic acid in each samples of Geranium carolinianum were determined by HPLC. The HPLC method was performed on a Diamonsil C, 8 column (150 mm x 4.6 mm, 5 microm) with acetonitrile-0.1% H3PO4 as mobile phase. The flow rate was 1.0 mL/min, the detection wavelength was 274 nm and the column temperature was 25 degrees C.

Results: The calibration curve of gallic acid and ellagic acid were linear in the range of 0.075-5.00 microg (r = 0.9995) and 0.05-2.00 microg (r = 0.9995), respectively. The average recovery of gallic acid and ellagic acid were 99.88% (RSD = 1.19%) and 99.08% (RSD = 2.81%), respectively.

Conclusion: The content of gallic acid and ellagic acid in Geranium carolinianum both began to increase in flowering stage and increased to the maximum value in immature-fruit stage.