Favolaschia

Abstract: Invasive organisms (especially plants and animal species) are considered to be one of the main causes of global biodiversity loss. Up to now, few papers have dealt with the spreading of fungi. The establishment of the geographic origin of alien organisms could be useful to assess their impact on the environment. Favolaschia calocera is a basidiomycete species which was first described from Madagascar, and successively observed in New Zealand in 1969, where it has currently been recorded in more than 200 stands. It has recently also been reported in Australia, Thailand, China, Kenya, and Reunion Island. F. calocera was found in Genoa, Italy, in 1999: this recording represented the first in Europe. Till now, Favolaschia specimens have been collected in six areas around Genoa. F. calocera was observed growing on debris of various vascular plant species (Pteridophytes, Conifers, Mono- and Dicotyledons), thus showing to be a polyphagous species. Because it is spreading, it needs to be monitored. The main goal of our research is to investigate, through molecular phylogeographic analysis, the origin of the Italian strains. The sequencing of the ribosomal DNA ITS region of the Italian specimens followed by Neighbour-joining analysis showed that they cluster with the specimens from New Zealand, Kenya, Norfolk Island and Reunion Island. Hypotheses on the origin and introduction way as well as on its mechanisms of spreading are provided.

Abstract: Two strobilurins, 9-methoxystrobilurin B (1) and 9-methoxystrobilurin G (2), two monochlorinated 2,3-dihydro-1-benzoxepin derivatives, 3 and 4a, and butenolide 5, together with four known compounds, strobilurin B, 9-methoxystrobilurin A, and oudemansins A and B, were isolated from culture BCC 18689 of the fungus Favolaschia tonkinensis. 9-Methoxystrobilurins A, B (1), and G (2) and oudemansins A and B exhibited antimalarial, antifungal, and cytotoxic activities, while compounds 3, 4a, and 5 displayed only cytotoxic activity.

Abstract: Fourteen new compounds, oudemansins 1–4, oudemansinols 5–7, favolasins 8–10, favolasinin (12), polyketides 13–15, and (R,E)-2,4-dimethyl-5-phenyl-4-pentene-2,3-diol (16), together with nine known c...

Abstract: In our ongoing search for novel biologically active metabolites from basidiomycetes an ethiopian Favolaschia species was detected as a new producer of a series of strongly antifungal compounds. Besides the strobilurins A and F, and oudemansin A, two new 9-methoxy derivatives of strobilurin A, 9-methoxystrobilurin A and K, were isolated and characterized previously1}. In the following we wish to describe the fermentation, isolation, and biological characterization of favolon (1), a new antifungal sterol from cultures of the same fungus. The small bright yellow fruiting bodies of Favolaschia sp. 87129 were found growing on wood in a forest close to Kolobo, Ethiopia. The specimen showed all characteristics of the genus2), the species, however, could not be unequivocally identified. Mycelial cultures were derived from spore prints of fruiting bodies. Voucher specimen and cultures are deposited in the collection of the Lehrbereich Biotechnologie, University of Kaiserslautern. For maintenance Favolaschia sp. 87129 was cultivated in YMGmedium composed of: Yeast extract 0.4%, malt extract 1%, glucose 0.4% and agar 1.5%, pH 5.5. For the production of favolon a well grown seed culture (150ml) in YMGwas used to inoculate 10 liters ofYMG in a Biostat V fermentation apparatus. The fermenter was incubated at 22°C with an aeration of 1.5 liters air/minutes and agitation (150 rpm). After one week this culture was used as inoculum for 100 liters of the same medium in a 150-liter stainless steel vessel (Deutsche Metrohm, temperature: 22°C, aeration: 1 5 liters/minute, stirrer speed: 150 rpm). Antifungal activity in fermentations and in fractions after chromatography were measured in the agar plate-paper disc diffusion assay using Mucor miehei as test organism. Favolon was detected only in the mycelia. 2.5kg wet weight from a 100-liter batch were extracted with 7.5 liters of methanol. Evaporation of the solvent yielded 1.5 liters of an aqueous phase from which favolon was extracted with 6 liters of ethyl acetate. Evaporation of the organic phase yielded 3.2g of crude product which wasfurther purified by chromatography on silica gel (Merck 60; elution with cyclohexane ethyl acetate 1 :1) resulting in a red fraction from which favolon readily crystallized. Recrystallization from methanol yielded 130mg of white needles (mp 188~ 190°C, Rf0.46, silica gel Merck 60, toluene-acetone-acetic acid 70: 30: 1). The physico-chemical characterization and structure