Comprehensive identification of active triterpenoid metabolites in frankincense using a coupling strategy

• Triterpenoid metabolites in frankincense exhibit notable activities.
• Fragmentation rules of triterpenoid metabolites in frankincense were summarized.
• Complementary NMR characteristics of triterpenoid metabolites were provided.
• An coupling strategy in integrated LC-MS and LC-NMR analysis was established.
• The proposed strategy fulfills comprehensive identification of metabolic profile.

Frankincense resins are extensively used as natural remedies in regions ranging from North Africa to China. Triterpenoid metabolites from frankincense exhibit notable anti-inflammatory and anti-tumor properties. In the present paper, without the use of an isolation process, the fragmentation rules and NMR spectral characteristics of triterpenoid metabolites in frankincense are summarized through a coupling method using high performance liquid chromatography-diode array detection/electrospray ionization tandem mass spectrometry (HPLC-DAD/ESI-MSn) combined with HPLC-nuclear magnetic resonance (NMR) experiments. Based on this groundwork, a coupling strategy for the comprehensive metabolic profiling of active triterpenoid metabolites from enriched fractions of frankincense was developed. The proposed strategy may serve as a method for the holistic screening of bioactive metabolites in complex TCM samples.