Isolation and structure elucidation of degradation products in the potential anticancer drug PAC-1

PAC-1 was subjected to acid degradation conditions at 80 °C for 10 h. Four unknown degradation products were isolated from PAC-1 by semi-preparative high performance liquid chromatography using isocratic elution conditions. Based on the ESI-MS and NMR spectral data the structures of these four degradation products were characterized as 2-allyl-6-((E)-((E)-(2-hydroxy-3-(2-hydroxypropyl)benzylidene)hydrazono)methyl)phenol, 2-hydroxy-3-(2-propenyl)-[[2-hydroxy-3-(2-propenyl)phenyl]methylene]hydrazone, 6,6′-(1E,1′E)-hydrazine-1,2-diylidenebis(methan-1-yl-1-ylidene)bis(2-(2-hydroxypropyl)phenol) and 2-hydroxy-3-(2-hydroxypropyl)benzaldehyde.