HPLC determination of aristolochic acids in plants of Aristolochia L. by static pressurized liquid extraction

Objective: To optimize static pressurized liquid extraction (PLE) method for the extraction of aristolochic acids I and II (AA I and AA II) from Fructus Aristolochiae and study the influences of related factors. Methods: The univariate design was introduced. The operational parameters, such as the type of solvent, particle size of the sample powder, extraction temperature, pressure, static time, flush volume, the number of cycles, and the amount of sample were optimized. Results: The optimized result employed methanol as extraction solvent, particle size of 100-120 meshes, extraction temperature of 120 °C, extraction pressure of 10.3 MPa, static time of 10 min, flush volume of 40%, 1 cycle, and sample amount of 1.00 g. The method was applied for four species of traditional Chinese medicinal materials including Fructus Aristolochiae, Caulis Aristolochiae Manshuriensis, Radix Aristolochiae, and Radix Arsitolochiae Fangchi. Conclusion: This method can be used to completely extract AA I and AA II from Fructus Aristolochiae in once extraction. The comparison shows that this static PLE method is better than ultrasonication and Soxhlet methods with higher extraction efficiency and less time-consuming. It is also better than the dynamic one in the extraction of AAs from Radix Aristolochiae.