Abstract: A Chiralpak IC column (250 mm×4.6 mm, 5μm) was used to establish normal phase high performance liquid chromatographic (NP-HPLC) method for the chiral separation of epigoitrin (R-goitrin) and goitrin (S-goitrin) in Isatidis Radix. The composition of mobile phase, flow rate and column temperature were optimized to get better resolution. The final chromatographic conditions were established as follows: n-hexane-isopropanol (90:10, v/v) as the mobile phase with a flow rate of 0.8 mL/min, the detection wavelength at 245 nm and the column temperature at 20 ℃. Under the above optimized chromatographic conditions, the resolution of 3.4 was achieved for epigoitrin and goitrin. The limit of detection (LOD) was 2.0 mg/L. The linear range was 0.02~2.0 g/L. The average recovery was 101% with the relative standard deviation (RSD) lower than 3.0% (n=6). The proposed method was exclusive by determining the antivirus epigoitrin and its enantiomer separately, which provided the effective quality control of Isatidis Radix.

Key words: goitrin (S-goitrin), Isatidis Radix, chiral high performance liquid chromatography, epigoitrin (R-goitrin)