Occurrence of D-lysergic acid and 6-methylergol-8-ene-8-carboxylic acid in cultures of Claviceps purpurea

Comparative Ergot Alkaloid Elaboration by Selected Plectenchymatic Mycelia of Claviceps purpurea through Sequential Cycles of Axenic Culture and Plant Parasitism

Ergot alkaloids have an established place in plant pathology and toxicology. As pharmaceuticals, their sourcing is via natural or managed agricultural occurrence of sclerotia of Claviceps purpurea (Fr.) Tul. or through industrial fermentation processes with other Claviceps. The key factor for biosynthesis is differentiation of a particular mycelial anatomy. Previous study of these fungi from two disparate English grass genera, Spartina and Phragmites, has shown that only mycelia expressing a plectenchymatic sclerotium-like anatomy in specific axenic culture conditions elaborated ergot alkaloids, and then only as far as lysergic acid. The present report describes sequential cycles of axenic and parasitic cultivation for wild isolates from Dactylis and Alopecurus with intervention of a single ascospore step. This confirms the homozygous character of C. purpurea and defines several potential experimental axenic and parasitic conditions within the species for comparing genomic aspects of partial or full biosynthesis of cyclic tri-peptide alkaloids. Whereas Alopecurus ergot isolates readily parasitized rye, use of Dactylis isolates as inoculum for rye ovaries failed to cause the usual sphacelial fructification but supported growth of exceptionally thin sclerotia, sometimes two in a floret, with low alkaloid content attributed to reduced medullary component. However, after two cycles of axenic and rye-parasitic cultivation, and consistent re-selection of the plectenchymatic character in axenic mycelia, typical growth of ergot sclerotia occurred on rye. Caution thus seems necessary in tests for putative host specificity in any taxonomic realignments within the classical concept of C. purpurea. A Dactylis ergot isolate was also uniquely shown to parasitise the plumule of germinating rye seeds confirming the susceptibility of apical tissues. A key biosynthetic feature of a mycelial glyceride oil, rich in ricinoleic acid, as a prelude to axenic and parasitic formation of ergot alkaloids by C. purpurea is emphasised.

Ergot alkaloids--sources, structures and analytical methods

Natural sources, i.e. fungal strains and species producing ergot alkaloids (EA), are surveyed together with the chemical structures of EA and a list of new natural EA discovered in the last three decades. Other topics include new efficient chromatographic methods (HPLC) for the separation and isolation of new natural EA and also immunological methods of EA detection.

Isoprenoid phenol and quinone precursors of ubiguinones and dihydroubiguinones (ubiguinones (H 2 )) in fungi

1. Ten moulds and two yeasts were analysed for the presence of 2-polyprenylphenols, 2-polyprenyl(H(2))phenols, 6-methoxy-2-polyprenylphenols, 6-methoxy-2-polyprenyl(H(2))phenols, 6-methoxy-2-polyprenyl-1,4-benzoquinones, 6-methoxy-2-polyprenyl(H(2))-1,4-benzoquinones, 5-demethoxyubiquinones, 5-demethoxyubiquinones(H(2)), ubiquinones and ubiquinones(H(2)). 2. The organisms were found to be of three types: (a) those that contained only ubiquinones (Aspergillus fumigatus and Penicillium brevi-compactum) or ubiquinones(H(2)) (Alternaria solani, Claviceps purpurae and Penicillium stipitatum); (b) those that contained 5-demethoxyubiquinones and ubiquinones (Agaricus campestris, Aspergillus niger, Phycomyces blakesleeanus, Rhodotorula glutinis and Saccharomyces cerevisiae) or 5-demethoxyubiquinones(H(2)) and ubiquinones(H(2)) (Aspergillus quadrilineatus and Neurospora crassa); (c) one that contained 2-decaprenyl(H(2))phenol, 6-methoxy-2-decaprenyl(H(2))phenol, 6-methoxy-2-decaprenyl(X-H(2))-1,4-benzoquinone, 5-demethoxyubiquinone-10(X-H(2)) and ubiquinones(H(2)) (Aspergillus flavus). 3. Studies were made on the biosynthesis of ubiquinones and ubiquinones(H(2)) by Asp. flavus, Phyc. blakesleeanus and S. cerevisiae. These provided evidence that in Phyc. blakesleeanus 5-demethoxyubiquinone-9 is a precursor of ubiquinone-9 and that in S. cerevisiae 5-demethoxyubiquinone-6 is a precursor of ubiquinone-6. In addition they yielded results that may be interpreted as providing evidence that in Asp. flavus 6-methoxy-2-decaprenyl(X-H(2))-1,4-benzoquinone and 5-demethoxyubiquinone-10(X-H(2)) are precursors of ubiquinone-10(X-H(2)).

Inhibition of lactation in mice following feeding with ergot sclerotia [Claviceps fusiformis (Loveless)] from the bulrush millet [Pennisetum typhoides (Staph and Hubbard)] and an alkaloid component

Female mice fed during the latter part of pregnancy on a diet containing sclerotia of Claviceps fusiformis a t 2 to 3% failed to raise their litters. The active principle of these sclerotia in inducing the pup mortality has been shown to be the alkaloid agroclavine which was found to inhibit normal mammary hypertrophy when administered in the food a t 5 to 7 mg %. Where the alkaloid treatment continued after parturition the litters died of malnutrition. When the alkaloidal diet was discontinued on the day before parturition there was a rapid recovery from the effect of agroclavine resulting in a normal pup growth rate. Agroclavine was also found to suppress well established lactation. This inhibition of mammary hypertrophy in mice by agroclavine administered orally at a non-toxic dosage is a new pharmacological action for the clavine alkaloids.