Objective: To study the urinary excretion of daphnoretin and glucuronidated daphnoretin in rats. Method: Suspended in solution

daphnoretin was orally administered to rats at the dose of 50

100

200 mg·kg-1. At various time intervals

the urine was collected. The urine was treated with β-glucuronidase. The daphnoretin in urine was extracted by acetic ether.The organic phase was removed into the tubes and then dried in pressure blowing concentrator. The residue was dissolved in 200 μL of mobile phase. The solution of 20 μL was drawn and detected by high-perormance liquid chromatography. Result: The cumulative urine excretion of daphnoretin was (23.13±2.36)

(41.74±2.02) and (80.01±3.21) μg at the dose of 50

100

200 mg·kg-1

respectively. The cumulative urine excretion of glucuronidated daphnoretin was (37.51±4.51)

(61.17±3.90) and (131.25±13.85) μg at the dose of 50

100

200 mg·kg-1

respectively. Conclusion: The cumulative urine excretion of glucuronidated daphnoretin is more than cumulative urine excretion of daphnoretin. The daphnoretin and glucuronidated daphnoretin are excreted in the manner of linear dose-dependent.