A sensitive liquid chromatography-electrospray tandem mass spectrometric method for lancemaside A and its metabolites in plasma and a pharmacokinetic study in mice.

A high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method employing electrospray ionization (ESI) has been developed for simultaneous determination of lancemaside A (3-O-beta-D-glucuronopyranosyl-3beta, 16alpha-dihydroxyolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester) and its metabolites in mouse plasma. When lancemaside A (60 mg/kg) was orally administered to mice, echinocystic acid was detected in the blood. T(max) and C(max) of the echinocystic acid were 6.5+/-1.9 h and 56.7+/-29.1 ppb. Orally administered lancemaside A was metabolized to lancemaside X (3beta, 16alpha-dihydroxyolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester) by intestinal microflora in mice, which was metabolized to echinocystic acid by intestinal microflora and/or intestinal tissues. Human intestinal microflora also metabolized lancemaside A to echinocystic acid via lancemaside X. These results suggest that the metabolism by intestinal microflora may play an important role in pharmacological effects of orally administered lancemaside A. Copyright 2010 Elsevier B.V. All rights reserved.