D. Erge

Incorporation of L-[U-14C]leucine into ergosine by cell-free extracts of Clavicepspurpurea (FR.) tul

A cell-free system of Clavicepspurpurea has been described which incorporates [14C] leucine into the peptide-type ergot alkaloid ergosine. Cell-free extracts may be prepared either from protoplasts or lyophilized mycelium. Production was markedly stimulated by addition of agroclavine compared with d-lysergic acid and by agitation of the incubation mixture. The synthesis of ergosine is strongly dependent on the presence of ATP in the reaction mixture.

Über Aktivierungsreaktionen bei Claviceps

Summary One may assume that the condensation of various precursors of peptide-type ergot alkaloids will proceed via “activated” intermediates. In this paper we describe first preliminary results on the activation of acetate, lysergic acid and some amino acids. The dependence of activation of acetate, lysergic acid and valine on various factors is reported. Evidence is presented that extracts of Claviceps species catalyze the formation of a coenzym A thiol ester of lysergic acid. The activations of the above mentioned ergotoxine precursors during the fermentation-course in saprophytically alkaloid producing and non-producing strains were measured. Possible correlations between alkaloid formation and activation reactions are discussed.

Biosynthesis of Ergot Alkaloids by Protoplasts of Various Claviceps purpurea Strains1

Summary Protoplasts of various peptide type alkaloids producing Claviceps purpurea strains were prepared. In a sucrose ammonium citrate medium suspended protoplasts were able to synthesize de novo ergosine, ergotomine and ergotoxine using 14C-labelled amino acids as precursors. The incorporation rate of the amino acids was remarkably increased if the incubation mixture was supplemented with d-lysergic acid.

Über den Stoffwechsel von Lysergyl-Derivaten in Claviceps purpurea (Fr.) Tulasne

Summary d-Lysergyl-L-alanine-U-14C-methyl ester and d-lysergyl-L-valine-U-14C-methyl ester were prepared by condensation of d-lysergic acid chloride hydrochloride with L-alanine-U-14C-methyl ester or L-valine-U-14C-methyl ester, respectively, in absolute methylene chloride. The metabolism of these two compounds were studied in two strains of Claviceps purpurea. One strain produces under submerged conditions ergotoxine alkaloids, the second one is saprophytically free of ergoline derivatives. Both strains are able to split the lysergyl amino acid methyl esters under replacement conditions into the corresponding lysergyl amino acids as well as lysergic acid and alanine and valine, respectively. The same reactions are catalyzed by crude enzyme preparations of both strains. Lysergylalanine or lysergylvaline were not detected by trapping experiments in C. purpurea. Apparently these lysergyl derivates are no intermediates in the formation of peptide type ergoline alkaloids.

Biosynthese der Mutterkornalkaloide. Einbau von Chanoclavin-I in Ergolin-Derivate

The reaction sequence tryptophan →chanoclavine-I → agroclavine → elymoclavine →lysergic acid derivatives was demonstrated in Claviceps. Incorporation of chanoclavine-I into ergoline derivatives ranged up to 40 per cent. No conversion of elymoclavine or agroclavine into chanoclavine-I could be demonstrated.

Biosynthese der Mutterkornalkaloide. Biogenetische Beziehungen zwischen Clavinen und Lysergsäure-Derivaten

Using Claviceps paspalum strain Li 189 and various tritium-labeled clavine alkaloids, it was demonstrated that agroclavine and elymoclavine but not penniclavine are precursors of lysergic acid derivatives. There was some incorporation of lysergene, lysergole and isolysergole, the latter two giving rise predominantly to the lysergic acid derivatives with the same configuration at carbon 8. However, these compounds cannot be considered as intermediate on the main pathway of lysergic acid formation, since their incorporations were 10 times lower than that of elymoclavine. The pathway of conversion of elymoclavine into lysergic acid derivatives is discussed.