OBJECTIVE: To develop an RP-HPLC method for the determination of five iridoid glycosides in Phlomis younghusbandii. METHOD: HPLC analysis was performed on a Symmetry C18 (4.6 mm x 150 mm, 5 microm, Waters) column eluted with acetonitrile (A) and water (B) in gradient elution. The gradient program was as follows: 0-5 min kept 7% A; 5-10 min changed to 12% A; 10-40 min kept 12% A. The flow rate was 1.0 mL x min(-1). The column temperature was 20 degrees and the detection wavelength was 235 nm. RESULT: The linear ranges of sesamoside, shanzhiside methyl ester, 7, 8-dehydropenstemoside, penstemoside and 8-O-acetylshanzhiside methyl ester were 0.050-0.650 (r = 0.999 3), 0.050-0.350 (r = 0.999 5), 0.040-0.280 (r = 0.999 4), 0.010-0.070 (r = 0.999 6), 0.040-0. 280 (r = 0.999 7) g x L(-1), respectively. The average recoveries (n = 6) of them were all between 96% and 104%, RSD < 5.0%. CONCLUSION: The method is simple, accurate, repeatable and stable, which can be used for quality control of P. younghusbandii.
OBJECTIVE: To develop an RP-HPLC method for the determination of five iridoid glycosides in Phlomis younghusbandii. METHOD: HPLC analysis was performed on a Symmetry C18 (4.6 mm x 150 mm, 5 microm, Waters) column eluted with acetonitrile (A) and water (B) in gradient elution. The gradient program was as follows: 0-5 min kept 7% A; 5-10 min changed to 12% A; 10-40 min kept 12% A. The flow rate was 1.0 mL x min(-1). The column temperature was 20 degrees and the detection wavelength was 235 nm. RESULT: The linear ranges of sesamoside, shanzhiside methyl ester, 7, 8-dehydropenstemoside, penstemoside and 8-O-acetylshanzhiside methyl ester were 0.050-0.650 (r = 0.999 3), 0.050-0.350 (r = 0.999 5), 0.040-0.280 (r = 0.999 4), 0.010-0.070 (r = 0.999 6), 0.040-0. 280 (r = 0.999 7) g x L(-1), respectively. The average recoveries (n = 6) of them were all between 96% and 104%, RSD < 5.0%. CONCLUSION: The method is simple, accurate, repeatable and stable, which can be used for quality control of P. younghusbandii.