Claviceps sp.

Mycotoxins of most interest are those found in human food or in the feed of domestic animals. They include the ergot alkaloids produced by Claviceps sp aflatoxins and related compounds produced by Aspergillus sp and the tricothecenes produced by several genera of fungi imperfecti, primarily Fusarium sp. 

Ergot alkaloids Claviceps sp. A. fumigatus P. chermesinum neurotrophy St. Anthony s fire ergotism... 

Glucans containing )8-D-( 1- 3)- and /3-D-(l— 6)-linkages have been obtained from Pullularia pullulans, Sclerotium glucanicum, Claviceps sp. Tyler s 47A and Plectania occidentalisP These... 

Ergot species of tropical regions were divided into three clades. The first one contained African Claviceps sp. Hyp, C. pusilla, C. cynodontis, (both widespread in Old World tropics), and two South American anamorphic species,... 

Claviceps spp. SG (from Setaria geniculata) and PM (from P. maximum). Conidial morphology of the latter two isolates was not sufficiently related to described teleomorphic species to allow for their unequivocal association. Claviceps sp. Hyp was described by Loveless (1964b, 1985) on various Hyparrhenia species. A characteristic of this species is wide truncated macroconidia. Sclerotia are hidden in glumes, and their germination was never... 

Recently, a Claviceps sp. on Hyparrhenia rufa was found in southern Africa (Frederickson and Pazoutova, unpublished) whose conidia were very similar to C. africana, and its sclerotia were of the same shape as seeds of the host plant. RAPD patterns showed that it is indeed another population of C. africana, but more different than any of the sorghum isolates, which may be the beginning of speciation based on host adaptation. Although Hyparrhenia plants were neighbors of a sorghum field, no RAPD pattern similar to that of Hyparrhenia population was found among sorghum isolates. 

Amtz C, Tudzynski P. Identification of genes induced in alkaloid producing cultures of Claviceps sp. Curr Genet 31 357-360, 1997. 

Use of washed mycehum of To study the mode of C Claviceps sp. SD58 ring formation in ergot... 

To test this hypothesis, feeding experiments were performed with (5S)- and (5i )-[2- C, 5- Hi] mevalonate to cultures of Claviceps sp. strain SD58. Based on the mass spectra fragmentation patterns of the elymoclavine produced under these conditions the authors concluded that This experiment thus suggests that the scrambling of C from C-2 of mevalonate between C-7 and C-17 of elymoclavine and that of from C-5 of mevalonate between the two allyUc hydrogen positions of the the isoprenoid unit occur independently of each other (although not necessarily in different reaction steps). ... 

The second step in the pathway is believed to be N-methylation of the trypto-phyl a-amino group by S-adenosylmethionine. Support for this notion was reported by Floss et al. as illustrated in Scheme 56 [85]. Synthesis and feeding of [a- N, N -Me- H3]DMAT and [ N, N-Me- H3]dimethylallyltryptamine to cultures of Claviceps sp. SD58 was conducted to test this hypothesis. It was found that the labeled DMAT was efficiently incorporated into elymoclavine but, that the labeled tryptamine derivative was not incorporated. This demonstrates that... 

In the course of their studies on the biosynthesis of ergot alkaloids. Robbers and Floss isolated clavidpitic acid, a new indolic amino acid [89]. Based on the X-ray crystal data of the major isomer and the assumption that the stereocenter at C-5 retains its stereochemistry from L-tryptophan, the structure shown in Scheme 59 was assigned [90]. By performing feeding experiments on Claviceps sp. SD 58 with clavicipitic acid (biosynthetically labeled), the laboratories of Floss [90] and Anderson [91] independently determined that clavicipitic acid is not a precursor to elymoclavine. Instead, Floss argues that it arises from ... a derailment of the metabolism leading to the tetracyclic ergolines between the first and second pathway-specific steps, the isoprenylation of tryptophan and the N-methylation of 4-(y,y-dimethylallyl)-tryptophan (DMAT). Anderson and co-workers isolated an enzyme, DMAT oxidase, from Claviceps sp. which catalyzes the formation of clavicipitic acid from DMAT [92]. The enzyme, which requires... 

Boichenko LV, Zelenkova NF, Arinbasarov MU, Reshetilova TA (2003) Optimization of conditions for storage and cultivation of the fungus Claviceps sp., a producer of the ergot alkaloid agroclavine. Appl Biochem Microbiol 39 294—299... 

Recently, genes coding for hydrophobin-type proteins have been isolated from a Claviceps sp. (Arntz and Tudzynski, 1997) and from C. purpurea (V.Garre and P.Tudzynski, pers. communication, see chapter 4 in this volume), in addition. 

Table 1 Genes (or fragment of genes) available from Claviceps sp.

Brauei K.L. and Robbers, J.E. (1987) Induced parasexual processes in Claviceps sp. strain SD58. Appl. Environ. Microbiol., 53, 70-73. 

Figure 5 Biosynthetic pathway of ergoline ring formation in Claviceps sp. denotes label (e.g. ) originally present in C-2 of R-mevalonate...

Cress, W.A., Chayet, L.T. and Rilling, H.C. (1981) Crystallization and partial characterization of dimethylally 1 pyrophosphate L-Tryptophan Dimethylallyltransferase from Claviceps sp. SD 58. /. Biol. Chem., 256, 10917-10923. 

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