Rapid Isolation of a Dipeptidyl Peptidase IV Inhibitor from Fritillaria cirrhosa by Thin-Layer Chromatography-Bioautography and Mass Spectrometry-Directed Autopurification System

摘要

A thin-layer chromatography (TLC). bioautography-mass spectrometry (MS) method coupled with a liquid chromatography-MS-controlled autopurification system was developed and applied for screening and isolating natural dipeptidyl peptidase IV (DPP IV) inhibitor from plant extracts. An unknown constituent with potential DPP IV inhibitory activity from bulbs of Fritillaria cirrhosa was discovered using TLC-bioautography, followed by using a TLC interface with mass spectrometry to obtain m/z of the target compound, and the purification of the compound was directly achieved with a mass-directed autopurification system for 40 runs of injection. Finally, 2.1 mg of the compound was obtained and identified as peimisine by H-1 and C-13 nuclear magnetic resonance (NMR) spectroscopy. The half maximal inhibitory concentration (IC50) of DPP IV inhibitory activity was determined at 80.5 mu M comparing to 58.0 mu M of the standard DPP IV inhibitor diprotin A by a spectrophotometric method.