RESUMEN
This present study is to develop an HPLC method for simultaneous determination of four diester diterpenoid alkaloids, beiwutine, mesaconitine, hypaconitine and aconitine in the leaves of Aconitum kusnezoffii, so as to provide evidence of the quality control of this herb. The four constituents were measured on a Waters XBridge CC₁₈ column(4.6 mmχ250 mm, 5 μm). The mobile phase was acetonitrile-40 mmol·L⁻¹ ammonium acetate solution(adjusted pH to 10.5 with ammonia solution)(33:67) with isocratic elution at a flow rate of 1.0 mL·min⁻¹; the detection wavelength was 235 nm; the column temperature was 30 °C, and the injection volume was 10 μL. Next, this contents of the four diester diterpenoid alkaloids in 12 samples were 0.025 5-0.088 5, 0.039 1-0.071 5, 0.026 6-0.081 0 and 0.008 12-0.031 2 mg·g⁻¹, respectively. Next, this method has been successfully applied to the analysis of A. kusnezoffii folium in different harvest periods. The contents of the four alkaloids decreased primarily, and then increased with the postponing of harvest. The established method is proved to be accurate and sensitive for the determination of alkaloids in A. kusnezoffii folium, and may be useful for the quality improvement of this herbal medicine. Moreover, these results indicated the scientific significance for the toxicity and the suitable harvest time of this herb.