Ein neues Alkaloid aus dem Mycel einesClaviceps purpurea-Stammes. Zur Biogenese von Ergocristin

D-Lysergyl Peptide Synthetase from the Ergot Fungus Claviceps purpurea

“…The reaction product is proposed to undergo ring closure to yield the corresponding ergopeptine most probably in a nonenzymatic reaction (8). Ergopeptams arise by spontaneous epimerization of D-lysergyl (L,L,L)tripeptide lactams in the proline residue (5). Because of the D-configuration of proline, they cannot be converted into the corresponding ergopeptines and ergopeptams thus accumulate in cultures (4).…”

Liquid chromatography–tandem mass spectrometry characterization of ergocristam degradation products

“…Both compounds were previously described as products of ergocristam degradation. In contrast to M2 no structural characterization of M1 was available in the literature [8]. Since no data were available also on the influence of extraction conditions on degradation of ergocristam this process was studied in details.…”

“…5A. The structures of the A1 and M2 degradation products of ergocristam previously described [8,16,20,21] were confirmed by collection of PSD or collision spectra. The suggested fragments of corresponding mass peaks from acquired CID fragmentation analysis are presented in Fig.…”

“…Structures of these compounds were assigned by 1 H and/or 13 C NMR and mass spectrometry with electron impact [8,9] and fast atom bombardment ionization [10]. A role of ergopeptams in biogenesis of the peptide part of ergot alkaloids has been studied by Floss and co-workers [11][12][13] who described an effect of competitive reaction bringing about a reversal of configuration of optically active carbon of l-proline to the d-configuration.…”

“…Ergopeptams were isolated from different Claviceps purpurea strains producing ergot alkaloids namely of ergotoxine group [1,2,6,8]. Structures of these compounds were assigned by 1 H and/or 13 C NMR and mass spectrometry with electron impact [8,9] and fast atom bombardment ionization [10].…”