ABSTRACT
OBJECTIVE: To establish HPLC methods for the determination of betulinic acid, oleanolic acid, ursolic acid, and lupeol in Caragana sinica roots, and investigate the α-glucosidase activity of the four compounds in vitro. METHODS: An Agilent Eclipse XDB-C18 column (4.6 mm × 250 mm, 5 μm) was applied with methanol-water-phosphoric acid (85:15:0.1) as the mobile phase at a flow rate of 0.6 mL·min-1 to separate betulinic acid, ursolic acid, and oleanolic acid. An Inert Sustain C18 column (4.6 mm × 150 mm, 5 μm) was applied with acetonitrile-water (70:30) as the mobile phase at a flow rate of 0.8 mL·min-1 to separate lupeol. RESULTS: Good linearities were achieved for betulinic acid, oleanolic acid, ursolic acid, and lupeol within the range of 0.56-5.58, 0.42-4.20, 0.19-1.92, and 6.10-61.00 μg, respectively. The average recoveries were 99.79%, 98.51%, 98.05%, and 99.47%, and the RSDs were 1.53%, 1.74%, 1.78%, and 1.94%, respectively. CONCLUSION: The developed methods are accurate and can be used for the quality control of Caragana sinica. In addition to betulinic acid, the other three compounds show good α-glucosidase inhibitory activity and are expected to be developed as new hypoglycemic drugs.
ABSTRACT
Four kinds of ionic liquids [BMIM] Br, [BMIM] BF4, [BMIM] PF6, [HMIM] PF6 were used to analyze the content of oleanic acid and paeoniflorin in Paeonia lactiflora with ultrasonic-assisted extraction coupled with HPLC. The chromatographic column, Purospher star RP-C18 (4.6 mm x 250 mm, 5 μm), was used. Acetonitrile and water (90:10) as mobile phase was used to determine the content of oleanic acid with a gradient elution and flow rate at 1.00 mL · min(-1), detection wavelength at 210 nm, chromatographic column temperature at room temperature. Paeoniflorin content was determined using acetonitrile and water (18:82) as mobile phase with a gradient elution and flow rate at 1.00 mL · min(-1), detection wavelength at 250 nm, the chromatographic column temperature at room temperature. The result show that oleanic acid has the highest extraction yield when the conditions are solid-liquid ratio of 1:80 (g · mL(-1)), and the [BMIM] Br methanol solution concentration of 0.6 mol · L(-1). Under the optimal extraction conditions, the content of oleanic acid from 0.24 to 3.76 μg showed a good linearity (r = 0.9999), the average recovery was 97.20%. Paeoniflorin has the highest extraction yield when the conditions are solid-liquid ratio of 1:130 (g · mL(-1)), and the [C4 MIM] PF6 methanol solution concentration of 0.6 mol · L(-1). Under the optimal extraction conditions, paeoniflorin content from 0.42 to 4.20 μg showed a good lin- earity (r = 1.000), the average recovery was 98.84%. This method is simple and reliable, its repeatability is also very good. It has important significance in the study P. lactiflora of ionic liquid microextraction.