Helminthosporium

Amino-3 -deoxyadenosine. 3 -Amino-3 -deoxyadenosine (17) is elaborated by Cordyceps militarise Aspergillus nidulanSe and Helminthosporium (3,4). The biosynthesis proceeds direcdy from adenosine. Compound (17) inhibits RNA polymerase, but not DNA polymerase, and replaces the adenosyl residue at the 3 -terminus of tRNA. Phenylalanyl-(3 -amino-3 -deoxyadenosyl)-tRNA has acceptor but not donor activity (31,32). Compound (17) also inhibits retroviral RNA-dependent DNA polymerase (33). 

As an example of the fascinating current progress, Dr. Spencer will describe a beautiful piece of research on the isolation and structure proof of the toxin from Helminthosporium sativum, an important... 

Biologically Active Agents from Helminthosporium sativum... 

During the course of this work Tamura et al. (1,14,15) isolated a metabolite from another strain of Helminthosporium sativum. By comparison with the bis-3,5-dinitrobenzoate of the diol from helminthosporal they identified it as the unsaturated aldehyde-saturated alcohol, helminthosporol (VIII, IX). 

The cytochalasins are a group of metabolites produced by certain fungi (e.g., Helminthosporium dermatoideum) that inhibit actin-dependent types of cell movement such as leukocyte locomotion, phagocytosis, cytokinesis, the retraction of... 

Colchicine is allelochemical from Colchicium genera, which binds the tubulin and prevents the mitosis (Fig. 2) Cytochalasin B, cell permeable fungal toxin from Helminthosporium dematiodeum, which inhibits cell division by blocking the active polymerization and formation of contractile actomyosin microfilaments, inhibit the germination of microspores (Roshchina, 2005a). Therefore, one mechanism of action of some allelochemicals from plants and... 

Stevenson IL (1954) Antibiotic production by actinomycetes in soil demonstrated by morphological changes induced in Helminthosporium sativam. Nature 174 598-599... 

Natural product HDAC inhibitor Helminthosporium carbonum (HC)-toxin (Fig. 14) is produced from filamentous fungus Cochliobolus carbonum Like chlamydocin, this compound is a cyclic peptide that contains both D- and L-amino acids to relieve ring strain. The epoxy group... 

Deubzer HE, Ehemann V, Kulozik AE, Westermann F, Savelyeva L, Kopp-Schneider A, Riester D, Schwab M, Witt O. (2008) Antineuroblastoma activity of Helminthosporium carbonum (HC)-toxin is superior to that of other differentiating compounds in vitro. Cancer Lett 264 21-28. 

Figure 3. Conidium of Helminthosporium sativum Treated With 10 ppm of Fenarimol.

Money et al. have accomplished the chemical functionalization of (-)-bornyl acetate, to yield (206) as the major product with smaller amounts of the 3-keto- and 6-keto-isomers of (206) and exo-(207 R = Ac), as well as microbiological hydrox-ylation using Helminthosporium sativum, to yield endo- and exo-(207 R=H) 6-exo-hydroxybofneol (208 R=H)/5 1 2/ ... 

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