“Dragon’s Blood” (DB), a deep red resin secreted from the fruit of the Daemonorops draco tree, has long been used as an ethnomedicine in China to invigorate blood circulation for the treatment of traumatic injuries, blood stasis and pain
[1, 2]. Flavonoids
[3, 4] and resin terpenoid acids
[5, 6] are the main constituents of DB. Currently, the quality evaluation for DB medicine is based on the content of only one marker compound, namely dracorhodin, which is one of the bioactive compounds identified so far in DB
In recent years, pharmacologic studies have demonstrated that DB medicine exerts its clinical effects by inhibiting blood platelet aggregation
[2, 7], and more components of DB have been found to be active in this process. For example, it is reported that the raw extract of DB dose-dependently inhibits myocardial ischemia and thrombus formation of the rats, and the coagulation time is extended significantly
. (2S)-5-methoxy-6-methylflavan-7-ol, a flavonoid isolated from DB, dose-dependently inhibits aggregation of washed rabbit platelets induced by collagen, arachidonic acid and adenosine diphosphate (ADP)
It is widely known that multiple constituents are probably involved in any herb's therapeutic functions, and that the content of a single marker compound cannot accurately reflect the quality of herbal products
[10, 11]. Thus, for DB as an herbal medicine, a novel quality evaluation standard based on the contents of multiple active components is needed to comprehensively assess its quality. However, accurate means for qualitative and quantitative analysis of the multiple components simultaneously have not been reported, even though the determination of dracorhodin in DB has been carried out by TLC
 and CE
, respectively. Therefore, a method for the simultaneous characterization and determination of the major active components in herbal medicines in general and DB in particular is still a top priority for accurate quality evaluation.
In the present study, a method coupling ultra-performance liquid chromatography (UPLC) with photodiode array detection (PAD) and electrospray ionization mass spectrometry (ESI-MS) was developed for the characterization and determination of six flavonoids in DB medicine. The validation results revealed that the developed method is highly efficient and reliable, and hence suitable for qualitative and quantitative analysis of DB samples. Based on the sample assay results, three major active components among the six flavonoids, namely dracorhodin, (2S)-5-methoxyflavan-7-ol and (2S)-5-methoxy-6- methylflavan-7-ol, are suggested as the index for quality evaluation of DB medicine.