[Tissue distribution of glucuronidated icaritin metabolite in rats]

To establish an ultra-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS )method for the quantification of glucuronidated icaritin (GICT), and investigate tissue distribution of GICT in rats following a single intraperitoneal administration.

Acetonitrile was employed to precipitate protein in tissue homogenate after rat tissues were homogenized. The separation was carried out on a BEH C18 column using a gradient mobile phase of acetonitrile, water, ammonium formate and formic acid. The quantification was achieved by the selected reaction monitoring in the negative electrospray ionization mode. Rat tissues were collected for the quantification of GICT after rats were intraperitoneally administered with ICT at a single dose of 10 mg/kg.

The calibration curves were linear over the concentration range of 2-200 ng/ml with the lower limit of quantification of 2 ng/ml. The accuracy values at the levels of 5, 80 and 150 ng/ml fell in the range of 93.2-102.9%, and precisions were within 8.9%.

The UHPLC-MS/MS method was specific and accurate, suitable for the tissue distribution of GICT. GICT was widely distributed in rat's various tissues, in which the content of GICT remained relatively high in kidney and liver, and GICT was reached the highest in tissues at 8 h.