Objective: To investigate the tissue distribution of 3

29-dibenzoyl rarounitriol from Trichosanthis Semen in rats after oral administration. Method: The stomach

heart

liver

spleen

lung and kidney in healthy male SD rats were taken at 0.5

1

3

6 h after intragastric administration

tissue homogenates and pretreatment were performed.ZORBAX C18 column(2.1 mm×50 mm

3.5 μm) was adopted with mobile phase of 10 mmol·L-1 ammonium acetate (containing 0.1% formic acid)-methanol for gradient elution

flow rate was 0.5 mL·min-1

the injection volume of 10 μL.A triple quadrupole tandem mass spectrometry equipped with electrospray ionization source was used as detector and operated by multiple reaction monitoring (MRM) positive ion mode of the transitions m/z 684.7-527.6

m/z 472.4-436.4 for 3

29-dibenzoyl rarounitriol and terfenadine

respectively. Result: After intragastric administration of 3

29-dibenzoyl rarounitriol in rats

peak concentration in the lung reached at 0.5 h

that in the heart

liver

spleen and kidney reached at 1.0 h

but that in the stomach at 3.0 h.The distribution of drug in the stomach and lung is large

its concentration in the stomach at 3.0 h was (405.8±114.8) ng·g-1;but the drug distributed fastest in the lung

it can reached a high concentration of (338.8±85.5) ng·g-1 at 0.5 h

distribution of 3

29-dibenzoyl rarounitriol in the heart

liver

spleen and kidney was low

the drug concentration in each organ were significantly reduced at 6.0 h. Conclusion: After intragastric administration of 3

29-dibenzoyl rarounitriol

it can be distributed to each organ tissue

which has high concentration in the stomach and lung

and this drug can still maintain a high level after 3 h

but its concentrations in the heart

liver

spleen and kidney are relatively low

which may be related to the nature characteristics and the acting features of itself.