Objective:

2

To investigate excretion of GK-A

a antitussive compound separated from Ginkgo Semen

in the urine and bile of rats.

Method:

2

UPLC-MS/MS was used to determine the concentration of GK-A in rat urine and bile samples. The separation was performed on a C

18

column

the mobile phase consisted of 0.1%formic acid aqueous solution (A) and acetonitrile (B) for gradient elution (0-1 min

95%A; 1-3 min

95%-85%A; 3-7.5 min

85%-40%A; 7.5-8 min

40%A). The detection was carried out by a triple quadrupole mass spectrometer in the positive ion mode with an electrospray ionization (ESI). Multiple reaction monitoring (MRM) mode was employed. After intragastric administration of GK-A

the urine and bile samples were collected at different time points

and the contents of GK-A in the samples were determined

and the cumulative excretion and cumulative excretion rate were calculated.

Result:

2

After 72 h of administration

the cumulative excretion of GK-A in urine was (12.35±2.69) μg

and the cumulative excretion rate was (0.58±0.13)%. Meanwhile

after 24 h of administration

the cumulative excretion of GK-A in bile was (55.16±29.22) μg

and the cumulative excretion rate was (1.57±0.83)%. Only a small amount of GK-A was excreted from urine and bile of rats with a slow speed.

Conclusion:

2

After intragastric administration

the excretion of GK-A in rat urine and bile is not the main elimination pathway.