Comparative Analysis on Terpenoids of Extraction Process from Stigma Maydis by UPLC Method

An extraction process of terpenoids from stigma maydis was discussed in this paper. Firstly, a UPLC analytical method was established based on the three standard substances tigmene F(1), 3β-hydroxy- ent-kaur-15-en-17-oic acid-18-ester(2), and 4α-hydroxy-19-nor-ent-kaur-15-en-17-oic acid (3) from stigma maydis. The chromatography condition was determined as C₁₈ 100Ȧ column (4.6 mm×150 mm, 2.6 µm) eluted with MeOH (A)-0.1% phosphoric acid (B) in gradient with the 1.0 mL/min flow rate. The column temperature was 40 ℃ with a 10 μL injection volume. The detection wavelength was set at 220 nm. Results showed that, three terpenoids had good linearity (r>0.9993) in the concentration range of 0.96~192.0 μg/mL (stigmene F) and 5.0~200.0 μg/mL (3β-hydroxy-ent-kaur-15-en-17-oic acid-18-ester and 4α-hydroxy-19-nor-ent-kaur-15-en-17-oic acid), respectively. They showed the same limits of quantitation (LOQ, S/N=10) ranged from 5.0 μg/g to 10.0 μg/g, similar average recovery rate of 89.1%~105.8%, and with could be used for quantitative analysis and provided research reference for terpenoids in stigma maydis. Finally, guided by the optimized analytical method, the extraction process for the three terpenoids from stigma maydis was determined as follows: The extract solvent was 20% MeOH-H₂O, which was 25 times weight of stigma maydis, and with refluxed extraction for 1 h.