Objective: To study the content changes of gallic acid

5-hydroxymethyl furfural

emodin

2

3

5

4’-tetrahydroxystilbene-2-O-β-D-glucoside and emodin monomethyl ether in Polygohum muhiflorum during processing and establish a method of determination by HPLC. Method: The separation was performed on a KinetexTM C18 column(4.6 mm×100 mm

2.6 μm)

using acetonitrile and water(0.5% acetic acid pH 2.9)as the mobile phase with gradient elution. The flow rate was 1.8 mL·min-1; column temperature was at 30 ℃ and the detection wavelength was 254

270

284

320 nm

respectively. Result: The linear ranges of gallic acid

5-hydroxymethylfurfural

emodin

2

3

5

4’-tetrahydroxystilbene-2-O-β-D-glucoside and emodin monomethyl ether were 0.585-58.5

0.54-53.5

1.07-107

1.23-123

0.564-16.92 mg·L-1

respectively. The content of gallic acid was increased significantly and 5-HMF was a new component after processing

and timing had a little effect on the content change of gallic acid

however

the content change of 5-HMF was higher and higher in the process of time till 72 h. Meanwhile

the content of stilbene glycoside was decreased in the process of time during processing and dissociative anthraquinone

emodin and emodin monomethyl ether

both of them were increased by processing after 32 h the content reach the maximum. Conclusion: The method is simple

accurate and can be used for quality control of P. muhiflorum. Further research of the correlation between the content changes of these 5 components in P. muhiflorum and pharmacodynamics as well as dose-effect relationship should be done.