HPLC-DAD and HPLC-ESI-MS separation, determination and identification of the spin-labeled diastereoisomers of podophyllotoxin.

Spin-labeled nitroxide derivatives of podophyllotoxin had better antitumor activity and less toxicity than that of the parent compounds. However, the 2-H configurations of these spin-labeled derivatives cannot be determined by nuclear magnetic resonance (NMR) methods. In the present paper, a high-performance liquid chromatography-diode array detection (HPLC-DAD) and a high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS) method were developed and validated for the separation, identification of four pairs of diastereoisomers of spin-labeled derivatives of podophyllotoxin at C-2 position.

Separation, determination and identification of the diastereoisomers of podophyllotoxin and its esters by high-performance liquid chromatography/tandem mass spectrometry.

A rapid and stable high-performance liquid chromatography-diode array detection (HPLC-DAD) and a high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS) method were developed and validated for the separation, determination, and identification of eight pairs of diastereoisomers of podophyllotoxin and its esters at C-2 position. The separation was carried out on BDS Hypersil C18 column with CH3OH-CH3CN-H2O as the mobile phase in a gradient program. Interestingly, every 2alpha-H compound migrated before its corresponding 2beta-H epimer under optimum conditions.