Systematic study of extraction efficiency of pyrrolizidine alkaloids (PAs) and corresponding pyrrolizidine alkaloid N-oxides (PANOs) from plant material for subsequent LC/MS analysis was carried out. The optimal extraction was achieved with methanol and one clean up step using SPE C18 column. With the optimized LC-ESI-MS/MS method using ion trap, the distribution and diversity of PAs and PANOs in plant material (leaves, flowers and stems) obtained from wild-growing E. vulgare, E. italicum, S. officinale L., C. creticum and O. heterophylla species from Macedonia was assessed. These widespread Boraginaceae species contain various PAs and PANOs and 25 of them were identified. Based on these qualitative and quantitative analyses, the profiles of 1,2-unsaturated PAs for each sample were obtained and their toxic potential was estimated. The toxic potential of O. heterophylla and C. creticum were assumed to be highest (containing up to 4753 mg/kg and 3507 mg/kg), followed by E. vulgare (up to 1340 mg/kg), S. officinale L. (up to 479 mg/kg) and E. italicum (up to 16 mg/kg). This method can be used for monitoring the inclusion of these secondary metabolites in the food chain in order to contribute in their risk management.
Keywords: Boraginaceae; LC/MS; assessment; extraction; pyrrolizidine alkaloids; pyrrolizidine alkaloids N-oxides.
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