Rapid analysis of lignans from leaves of Podophyllum peltatum L. samples using UPLC‐UV‐MS

A new rapid UPLC‐UV‐MS method has been developed that permits the analysis of four lignans (4′‐O‐demethylpodophyllotoxin, podophyllotoxin, α‐peltatin and β‐peltatin) in P. peltatum L. Podophyllotoxin is a natural lignan that is being used as a precursor for the semi‐synthetic anti‐cancer drugs etoposide, teniposide and etopophos. The chromatographic separation was achieved using a reversed‐phase C₁₈ column with a mobile phase of water and acetonitrile, both containing 0.05% formic acid. Analyses of P. peltatum leaves collected from different colonies within a single site indicated a significant variation in 4′‐O‐demethylpodophyllotoxin, α‐peltatin, podophyllotoxin and β‐peltatin content. Within 3.0 min four main lignans could be separated with detection limits of 0.1, 0.3, 0.3 and 0.2 μg/mL, respectively. 4′‐O‐demethylpodophyllotoxin and α‐peltatin appeared most prominently among the lignans obtained. The podophyllotoxin content was found in the range of 0.004–0.77% from 16 samples collected from 6 colonies within the same site. The content of podophyllotoxin is directly proportional to the content of 4′‐O‐demethylpodophyllotoxin and inversely proportional to α‐peltatin and β‐peltatin content. LC‐mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of four lignans in various populations of plant samples. By applying principal component analysis and hierarchical cluster analysis, Podophyllum samples collected from various colonies within a location were distinguished. Copyright © 2011 John Wiley & Sons, Ltd.