Objective To establish a HPLC method for the content determination of syringin in Huoxue Tongluo Pill. Methods Chromatographic assay was performed on Kromasil C18 column (250 mm?4.6 mm,5 ?m) at room temperature,and the mixture solution of acetonitrile-1% aqueous acetic acid (10∶90,v/v) was used as mobile phase. The flow rate was 1.0 mL/min. The detection wavelength was at 270 nm. The sample size was 20 ?L. Results Good linear relationship was achieved when the concentration of syringin was in the range of 5.3～53 ?g/mL. The average recovery was 98.29% with RSD=1.71%. Conclusion The method is simple,accurate and the results are stable with good reproducibility. This method can be used for the content determination of syringin in Huoxue Tongluo Pill.

Twelve new grayanoids (-) along with five known compounds were isolated from flowers of . Their structures were fully characterized using a combination of spectroscopic analyses, computational calculations, and single crystal X-ray diffraction. Rhomollone A () possesses an unprecedented 5/6/6/5 tetra-cyclic ring system (B- grayanane) incorporating a cyclopentene-1,3-dione scaffold. Rhodomollein XLIII () is a dimeric grayanoid, containing a novel 14-membered heterocyclic ring with a symmetry axis. The antinociceptive activities of compounds , , , , and - were evaluated by an acetic acid-induced writhing test. Among them, compounds , , , and displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from 41.9% to 91.6%. Compounds and inhibited 46.0% and 39.4% of the acetic acid-induced writhes at a dose of 2 mg/kg, while compound inhibited 34.3% of the writhes at a dose of 0.4 mg/kg.