A rapid and systematic tandem LC-MS protocol is utilized to identify oligostilbenes in three Dryobalanops species (D. rappa,
D. lanceolata and D. aromatica; family Dipterocarpaceae). Analyses were performed by a newly developed dereplication
system on a liquid chromatography-ion trap-mass spectrometry (LC-IT-MS) with electrospray ionization (ESI) interface. The
combination of effective separation by an HPLC and multiple fragmentation steps for specific masses in MS enable fast and
sensitive analysis of various degrees of oligostilbenes condensation.