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Honey contaminated with pyrrolizidine alkaloids (PAs) could pose a risk for human consumption, being a widely consumed food product. A fast and simple LC/MS method for the analysis of pyrrolizidine alkaloids in honey was optimised to collect occurrence data. The extraction efficiency was evaluated by a systematic study of multiple solvent mixtures and clean-up procedures. The best results for PA extraction were obtained using a formic acid/methanol mixture with subsequent clean-up by the QuEChERS method, resulting in a mean recovery range of 91.8–102%. The method validation showed satisfactory intra-day (RSD < 5.1%) and inter-day precision (RSD < 9.1%). The proposed method was applied to 14 samples. A total of six PAs and two N-oxides were detected, with levels between 89 and 8188 µg/kg. This assessment highlights the potential risk of intoxication and the need for further investigations regarding an effective quality system for manufacturers to control PAs in honey. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to determine the phenolic components in the flowers and leaves of wild-growing Sambucus nigra L. Materials and Methods: Plant materials were collected from eleven localities in Kosovo. Before LC-DAD-ESI-MSn analysis, an ultrasonic-assisted method with 70% methanol for 30 min extraction was used. Results: In total, 34 and 37 phenolic compounds were identified in flower and leaf extracts, respectively, with a total content of 61321.82-85961.64 mg/kg dry weight (DW) and 36136.62-93890.37 mg/kg DW. In all of the analyzed extracts, 15 phenolic acids, 20 flavonoids, one lignan, and one coumaroyl iridoid were detected. The major components were flavonoids, especially flavonols (quercetin-3-rutinoside, caffeoyl-kaempferol, and isorhamnetin-3-rutinoside), followed by phenolic acids (dicaffeoylquinic acid isomer, caffeic acid derivative, dicaffeoylquinic acid isomer, and dicaffeoylquinic acid isomer). Conclusion: In general, the methanolic extracts of flowers have shown higher polyphenolic content than those found in leaves. The multivariate statistical analysis of the phenolic content of the samples resulted in PLS-DA models with appropriate correlation coefficients of 0.903 and 0.921 for flower and leaf extracts, respectively. The models revealed distinctive clustering patterns, and the loading scatter plots depicted the unique phenolic compounds specific to each sample group. [ABSTRACT FROM AUTHOR]

Pyrrolizidine alkaloids (PAs) are secondary plant metabolites, and their 1,2-unsaturated derivatives, which contain the retronecine, heliotridine, or otonecine type of the necine base, have raised concern due to their ability to form hepatotoxic intermediates and exhibit serious toxic effects. Several hundred individual pyrrolizidine alkaloids and their N-oxides have been identified mostly using liquid chromatography coupled with mass spectrometry, although the number of available reference standards is limited. In this work, characteristic fragment ions and their abundance in the mass spectra of different PAs were used to reveal typical fragmentation patterns for various classes of PAs that can be further employed to distinguish monoesters (retronecine, heliotridine type), open chain diesters and macrocyclic diesters, and corresponding N-oxides. Fragment ions at m/z 120 and 138 were found in all types of PAs with a different relative abundance. Additional observation of fragment ions at m/z 94 and 156 was found to be typical for monoester PAs esterified at position C9 of the necin base, whereas fragment ions at m/z 111 and 172 were characteristic for monoester N-oxides. Fragment ions at m/z 180 and 220 were found to be typical for open chain diesters with esterification at C7 with acetic and angelic acid, respectively, whereas fragment ions at m/z 214 and 254 were characteristic for the respective N-oxides. For the 3'-acetyl PA monoester or open chain diester derivatives, characteristic fragment ions were observed after loss of the acetyl moiety ([M+H]+-60), whereas for macrocyclic diesters and their N-oxides, fragment ions due to the neutral loss of CO were found ([M+H]+-28). [ABSTRACT FROM AUTHOR]