Purification and Chromatographic Analyses of Cyclopentadienone Guaianolides from Artemisia leucodes Schrenk

Five cyclopentadienone sesquiterpene lactones: austricin, 5β(H)-austricin, achillin, grossmisin and leucomisin were obtained from the plant Artemisia leucodes Schrenk. The lactone purification procedure starting from the plant leaves is described. A quality control method was developed using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). For these stereoisomeric cyclopentadienone guaianolides, the TLC and HPLC relationships “molecular structure—retention time” on the nature of the substituent in the molecular structure were studied. The chromatographic conditions were optimized and the influence of the structure of the molecule on their retention time was discussed comparing retention in both TLC and HPLC methods. The relationship between the structure of a particular cyclopentadienone guaianolide and its chromatographic retention time characterizes the sorption mechanism with the apolar stationary phase. It gives information on the compound polarity and hydrophobicity, information most relevant for these biologically active sesquiterpene γ-lactones, which are possible potent active ingredients of drugs.