The new generic and species name Amorosia littoralis gen. sp. nov. is introduced for the conidial dematiaceous hyphomycete isolated from the littoral zone in The Bahamas and reported in 2001 to produce the novel aza-anthraquinone scorpinone, and also caffeine. No satisfactory generic placement was found at the time, but subsequent morphological and molecular investigations reveal that a new generic name is required. The new genus has some similarity to several fungi described in Trichocladium, but differs substantially from the type species of that genus in the form of the conidia and the lack of ornamentation. BLAST studies using the 18S and 28S rDNA gene sequences place the new genus in the Sporormiaceae. In addition to the morphological studies, an ultrastructural examination of the conspicuous porate septa of hyphae showed that they do not belong to a basidiomycete.
Scorpinone (1), 3-methyl-6,8-methoxy-2-aza-9,10-anthraquinone, has been isolated from the mycelium of a cultured sterile fungus of Caribbean origin. The structure was elucidated by X-ray crystallography, and 2D NMR spectral data have been assigned. The compound is one of very few known fungal azaanthraquinones.
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In screening for antifungal metabolites a novel compound, cladobotryal, was isolated from the mycoparasitic fungus Cladobotryum varium. Its structure was established as (+)-(2R*,3R*)-2-[(Z)-2-buten-2-yl]-3, 7-dihydro-3-formyl-3-methyl-5-phenylfuro[2,3-b]pyridin-4(2H)-one on the basis of spectroscopic evidence and single crystal X-ray analysis of its methyl hemiacetal. The fused furo[2,3-b]pyridinone skeleton of cladobotryal seems unprecedented within the chemical literature.
The new species Penicillium discolor, frequently isolated from nuts, vegetables and cheese is described. It is characterised by rough, dark green conidia, synnemateous growth on malt agar and the production of the secondary metabolites chaetoglobosins A, B and C, palitantin, cyclopenin, cyclopenol, cyclopeptin, dehydrocyclopeptin, viridicatin and viridicatol. It also produces the mouldy smelling compounds geosmin and 2-methyl-isoborneol, and a series of specific orange to red pigments on yeast extract sucrose agar, hence the epithet discolor. P. discolor resembles P. echinulatum morphologically but on basis of the secondary metabolites is also related to P. expansum, P. solitum and P. crustosum.
Oxysporidinone (1), a novel 3,5-disubstituted N-methyl-4-hydroxy-2-pyridone, was isolated from fermentations of Fusarium oxysporum (CBS 330.95) by counter-current chromatography. The structure was determined by spectroscopic methods including NMR, MS, IR, and UV analysis. Oxysporidinone exhibited growth inhibitory activity against several common plant pathogenic fungi.
Insulicolide A (6 beta-[(4-nitrobenzoyl)oxy]-9 alpha,14-dihydroxycinnamolide) has been isolated from the chemically unexplored fungus Aspergillus insulicola and the structure determined by X-ray crystallography and NMR. The metabolite production of marine and terrestrial specimens of the fungus has been compared by HPLC diode-array analysis.
The fungus Hamigera avellanea is found to be the source of two metabolites, hamigerone (C25H32O5) and dihydrohamigerone (C25H34O5), the former exhibiting in vitro growth inhibitory activity against phytopathogenic fungi. Their chemical structures and configurations, save for details related to the stereochemistry, have been established by a variety of spectroscopic techniques. Feeding the fungus with specifically labelled C-13-precursors served to establish the biosynthetic derivation of the two metabolites from ten intact acetate and five methionine-derived C-1-units.
This review discusses enantiocontrol in some palladium- and copper-catalyzed reactions and the general theme involves the use of products from palladium-catalyzed 1,4-oxidation of conjugated dienes. In the first part the use of 1,4-diacetoxy-2-alkenes in desymmetrization reactions is described. A combination of enzyme and palladium catalysis leads to a useful enantiocontrol. In the second part 4-amino-2-alkenol derivatives as hey intermediates for the synthesis of 2,5-disubstituted pyrrolidines and pyrrolidine-containing alkaloids are discussed. These amino-alcohol derivatives are available from palladium-catalyzed 1,4-oxidation of conjugated dienes but an alternative procedure for their enantioselective preparation will be presented. Finally, in the third part some recent results in enantioselective copper-catalyzed allylic substitution are presented.