Abstract:The RP-HPLC analysis of was performed on a Merck C18 column(4.6×250 mm, 5 μm) for simultaneous determination of the contents of five alkaloids(strychnine, brucine, strychnine N-oxide, brucine N-oxide and vomicine) in Strychnos nux-vomica L.. The mobile phase was a mixture of acetonitrile(A) and aqueous(B), gradient elution, the flow rate was 1.0 mL/min, the detection wavelength was at 260 nm, and the column temperature was at 35 ℃. The linear range of strychnine, brucine, strychnine N-oxide, brucine N-oxide and vomicine was 14.64~468.48 μg/mL, 11.625~372.0 μg/mL, 0.555~17.76 μg/mL, 0.891~28.512 μg/mL and 2.5~80.0 μg/mL, respectively. The average recovery of these five alkaloids was 100.3%, 101.7%, 97.7%, 98.8% and 99.6%, respectively. With the total content of five alkaloids as the indexes, the extraction conditions of total alkaloids from S. nux-vomica, such as solvent amounts, concentration and extraction times, were optimized by L9(33) orthogonal experimental design. The optimal extraction process was heat reflux extraction with 20-fold, 70% acidic alcohol for 4 times, one hour for each time. Under this optimum condition, the total content of the five alkaloids of the extraction was 3.633%. The RP-HPLC method was simple, accurate and suitable for simultaneous determination of strychnine, brucine, strychnine N-oxide, brucine N-oxide and vomicine of S. nux-vomica. The optimization of the extraction process of the total alkaloids was more comprehensive and reliable because of the total content of the five alkaloids as the indicator.
