Objective: An HPLC assay was established to determine and compare the contents of isoguanosine and magnoflorine in Crotonis Fructus from different areas

and used for its quality control. Method: An Accurasil C18 column (4.6 mm×250 mm

5 μm) was used with acetonitrile (A)-0.2% phosphoric acid-0.2% triethylamine solution (B) as the mobile phase (0-10 min

5%A;10-12 min

5%-15%A;12-29 min

15%A;29-30 min

15%-5%A). The flow rate was 0.8 mL·min-1. The column temperature was kept at 30 ℃. The detection wavelength was set at 275 nm. Result: Isoguanosine had good linearity in the range of 0.078 8-0.472 8 μg (r=0.999 9). The average recovery was 99.29% with RSD of 2.5%. Magnoflorine had good linearity in the range of 0.013 7-0.082 2 μg (r=0.999 9). The average recovery was 99.28% with RSD of 2.2%. The content of isoguanosine and magnoflorine in Crotonis Fructus from different areas varied notably. The content of isoguanosine from Sichuan was the highest with 17.57 mg·g-1

while the one from Guangxi was the lowest with 7.07 mg·g-1. And the Guizhou one was the highest in the content of magnoflorine with 3.42 mg·g-1

while the Guangxi one was the lowest with 1.00 mg·g-1. Conclusion: The method is convenient

rapid and accurate

which can be applied to the quality control of Crotonis Fructus.