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Fig. 1. Common structures of ergoamides (a), ergopeptines (b) and ergopeptams (c) and representative ergot alkaloids for each class. M: molecular weight.

Figure 1 Common structures of ergoamides (a), ergopeptines (b) and ergopeptams (c) and representative ergot alkaloids for each class. M: molecular weight.

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Fig. 2. Fourth-generation collisionally-induced dissociation (CID) spectra acquired for ergotamine (a), ergokryptine (b) and ergocornine (c) demonstrating the loss of the f substituent from the main skeleton. R?: -CHPh (for ergotamine), -CH2CH(CH3)2 (for ergokryptine) and —CH(CH3), (for ergocornine).
Fig. 2. Fourth-generation collisionally-induced dissociation (CID) spectra acquired for ergotamine (a), ergokryptine (b) and ergocornine (c) demonstrating the loss of the f substituent from the main skeleton. R?: -CHPh (for ergotamine), -CH2CH(CH3)2 (for ergokryptine) and —CH(CH3), (for ergocornine).
Fig. 3. Proposed fragmentation mechanism for the loss of the R? substituent from the main skeleton of ergosine and ergokryptine (a), and ergocornine (b).
Fig. 3. Proposed fragmentation mechanism for the loss of the R? substituent from the main skeleton of ergosine and ergokryptine (a), and ergocornine (b).
Fig. 4. Proposed common fragmentation pathway of ergopeptines and ergoamides.
Fig. 4. Proposed common fragmentation pathway of ergopeptines and ergoamides.
Fig. 6. Proposed strategy for identification of novel ergopeptines and ergopeptams. Fig. 5. Proposed fragmentation pathway of ergopeptam ergot alkaloids. The fragment at m/z 223 was identical to that shown in Supplemental Fig. S2, thereby following the same pathway.
Fig. 6. Proposed strategy for identification of novel ergopeptines and ergopeptams. Fig. 5. Proposed fragmentation pathway of ergopeptam ergot alkaloids. The fragment at m/z 223 was identical to that shown in Supplemental Fig. S2, thereby following the same pathway.
Fig. 7. Parent scan total ion chromatogram of a rye feed sample. Em: ergometrine; Emn: ergometrinine; Es: ergosine; Esn: ergosinine; Et: ergotamine; Etn: ergotaminine Eco: ergocornine; Econ: ergocorninine; Ekr: ergokryptine; Ekrn: ergokryptinine; Ecr: ergocristine; Ecrn: ergocristinine; Unk: unknown. The fragmentation study of ergot alkaloids standards showed that the ion at m/z 223 was common for all the ergopeptines, ergoamides and ergopeptams. This observation has been previously described [9,10]. Therefore, detection of MS signals using m/z 223-parent scan experiments could point to possible occurrence of ergot alkaloids in real samples. The proposed identification strategy was applied for the screening of ergot alkaloid derivatives in grain samples. Parent scan monitoring of the m/z 223 ion revealed the presence of possible ergot alkaloid derivatives in several feed samples. Among 19 analyzed samples, four were free of ergot alkaloids. Ergometrine, ergosine, ergota- mine, ergocornine, «-ergokryptine, ergocristine and their corre- sponding -inine epimers were identified in the remaining 15 samples by comparison with reference standards. Other presumed ergot alkaloid derivatives could not be identified at this stage. These unknowns were studied by fitting their mass spectral data into the proposed fragmentation pathway (described in section “Fragmentation pattern of ergot alkaloids”). Firstly, the authenti- city of the ion at m/z 223 was checked through accurate mass measurements. Then, the ion trap fragmentation study was carried out for each unknown ergot alkaloid derivative. The obtained information was coupled with the exact mass data obtained with the Orbitrap instrument.
Fig. 7. Parent scan total ion chromatogram of a rye feed sample. Em: ergometrine; Emn: ergometrinine; Es: ergosine; Esn: ergosinine; Et: ergotamine; Etn: ergotaminine Eco: ergocornine; Econ: ergocorninine; Ekr: ergokryptine; Ekrn: ergokryptinine; Ecr: ergocristine; Ecrn: ergocristinine; Unk: unknown. The fragmentation study of ergot alkaloids standards showed that the ion at m/z 223 was common for all the ergopeptines, ergoamides and ergopeptams. This observation has been previously described [9,10]. Therefore, detection of MS signals using m/z 223-parent scan experiments could point to possible occurrence of ergot alkaloids in real samples. The proposed identification strategy was applied for the screening of ergot alkaloid derivatives in grain samples. Parent scan monitoring of the m/z 223 ion revealed the presence of possible ergot alkaloid derivatives in several feed samples. Among 19 analyzed samples, four were free of ergot alkaloids. Ergometrine, ergosine, ergota- mine, ergocornine, «-ergokryptine, ergocristine and their corre- sponding -inine epimers were identified in the remaining 15 samples by comparison with reference standards. Other presumed ergot alkaloid derivatives could not be identified at this stage. These unknowns were studied by fitting their mass spectral data into the proposed fragmentation pathway (described in section “Fragmentation pattern of ergot alkaloids”). Firstly, the authenti- city of the ion at m/z 223 was checked through accurate mass measurements. Then, the ion trap fragmentation study was carried out for each unknown ergot alkaloid derivative. The obtained information was coupled with the exact mass data obtained with the Orbitrap instrument.
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ChemistryAnalytical ChemistryMedicineClaviceps purpureaHigh Pressure Liquid ChromatographyLiquid Chromatography / Electrospray Ionization Mass Spectrometry
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