Abstract: Based on UPLC-QE-Orbitrap-MS, the chemical components of Resina Draconis were identified and the analytical method was established for simultaneous determination of the main components in Resina Draconis. The chromatographic column employed is an ACQUITY UPLC BEH C18(1.7 μm, 2.1×100 mm)column, utilizing a mobile phase of acetonitrile-water containing 0.1% formic acid. A high-energy electrospray ionization source(HESI)used and negative ion mode scanning was applied. By integrating the precise molecular masses of each compound, the fragment information from secondary mass spectrometry, the data reported in the literature, and comparisons with reference substances, the chemical components of Resina Draconis were identified, and a method for the simultaneous determination of the mass fractions of loureirin A, loureirin B, loureirin C, loureirin D, resveratrol, and 7,4'-dihydroxyflavone in Resina Draconis was established based on UPLC-QE-Orbitrap-MS technique. The quantitative analysis method used 0.1% formic acid water(A)and 0.1% formic acid acetonitrile(B)as mobile phase, gradient elution program: 0-2 min, 22%-45%B; 2-6 min, 45%B; 6-7 min, 45%-95%B; 7-8 min, 95%-22%B; 8-11 min, 22%B. Flow rate was set as 0.25 mL/min and column temperature was set as 35 ℃. The inject volume was set as 5 μL. HESI source and parallel reaction monitoring(PRM)scan in negative ion mode was applied, with capillary temperature set as 350 ℃, spray voltage set as 2.8 kV, S-lens level set as 35 kV, sheath gas flow rate set as 35 arb, auxiliary gas flow rate set as 10 arb. The results showed that 25 compounds, 22 flavonoids and 3 stilbenes were identified, 9 of which were compared with the reference standard and identified exactly. Loureirin A, loureirin B, loureirin C, loureirin D, resveratrol, and 7,4'-dihydroxyflavone were determined to be the index components of mass fractions. The linear relationship between the six components was good(r≥0.999 2)in the mass concentration range, and the precision, repeatability and stability met the relevant requirements. The recoveries were 92.2%-105.0%. The method was feasible to determine the mass fractions of 14 batches of Resina Draconis. The mass fractions of loureirin B is 0.41%-7.25%, which is the highest component among the 6 index components. In summary, based on systematic analysis of the chemical components of Resina Draconis, the mass fractions determination methods of 6 main components were established in this study to provide reference for the pharmacodynamic material basis and quality control of Resina Draconis.

Key words: Resina Draconis, UPLC-QE-Orbitrap-MS, quality control, flavonoids, loureirin B