HPLC-TOF/MS in identifying steroidal saponins in rat urine after oral administration of Paris polyphylla extract / 第二军医大学学报

ABSTRACT

Objective To use high-performance liquid chromatography-time of flight mass spectrometry (HPLC-TOF/ MS) for examining the steroidal saponins in rat urine after oral administration of Paris polyphylla extract, so as to lay a foundation for studying the metabolism of steroidal saponins in vivo. Methods SD rats were administered with an oral dose of 1 6 g Paris polyphylla extracts/kg body weight. The urine samples were collected 24 h after administration by oral gavage. The sample analysis was carried out on a reverse phase MG-C18 column (3. 0 mm× 100 3. 0μm) using a gradient mobile phase system of acetonitrile-water containing 0. 1% formic acid. TOF/MS was applied for qualitative analysis under positive and negative ion modes. The steroidal saponins in rat urine were identified by using the accurate molecular weight obtained by TOF/ MS and formula database. Results A total of 20 steroidal saponins were identified in the rat urine, and two pairs of isomers were deduced through their fragment ions and standards polyphyllin VI and pennogenin-3-0-α-L-rhamnopyranosyl(l →4)-α-L-rhamnopyranosyl (1 → 3)-[-α--rhamnopyranosyl (1 → 2)]-β-D-glucopyranoside; and gracillin and pennogenin-3-O-α-L-rhamnopyranosyKl → 4)-α-L-rhamnopyranosyl (1 → 4)-β-D-glucopyranoside. Conclusion The established analysis method is accurate, reliable for identifying steroidal saponins in vivo, which paves a way for further pharmacokinetics and pharmacodynamics study of Paris polyphylla.