TLC-electrostatic field induced spray ionization-MS analysis of diverse structural skeletons and its coupling with TLC bioautography for characterization of lipase inhibitory components in American ginseng.

•Direct coupling of TLC to MS via EFISI for analysis of structurally diverse natural compounds.•The negative ion mode of the TLC-EFISI-MS method was optimized for improving suitability for the first time.•The methanol extract of American ginseng was separated by TLC and visualized by TLC bioautography.•Nine lipase inhibitory components were identified by the optimized TLC-MS method.