Isolation of ergosterol peroxide from Alternaria dianthicola

Abstract

A second steroidal constituent of the Alternaria genus, ergosterol peroxide, isolated from A , dianthicola, may be an artefact.Exhaustive extraction of the mycelium of Alternaria dianthicola revealed the presence of ergosterol peroxide.Although ergosterol peroxide has been isolated from a number of microorganism~,~-' this is the first report of the isolation of this compound from the genus Alternaria. The only other steroid isolated from this genus was a C , , steroid by Sugiyama et aL8 However, this steroid has not been completely characterized.Identification of ergosterol peroxide was accomplished by means of spectroscopic techniques and confirmed by comparison with an authentic sample. The infrared spectra of the natural product and the synthetic sample were superimposable.It is not known, however, whether ergosterol peroxide is the actual metabolite or whether it is produced from ergosterol by photooxidation during the workup procedure. Ergosterol has previously been isolated from f~n g i l ,~ and Adam et al.' have shown that some fungal extracts contain coloured materials which are able to act as photosensitizers for the oxidation of ergosterol to ergosterol peroxide. ExperimentalMelting points were determined on a Kofler block and are uncorrected. The infrared, nuclear magnetic resonance and mass spectra were recorded on Perkin-Elmer 457, Jeol 100 and AEI MS 902 spectrometers respectively. The culture was obtained from the Department of Microbiology, University of Queensland. Kieselgel G (Woelm) was used for column chromatography.

Chemical constituents and biological activity of three Tanzanian wild mushroom species

“…In previous studies, ergosterol derivatives exhibited antitumor, cytotoxic, rheumatoid arthritis and immune promoting properties (Brown and Jacobs 1975, Bok et al 1999, Wasser and Weis 1999, the latter activity being a suitable attribute for food supplements. Therefore, due to the recently increasing demand for food supplements (functional foods), particularly for individuals with compromised immunity, the mushroom species Agaricus sp.…”

“…5,8-Peroxyergosterol was previously reported as an antitumour compound (Kocor andSzalowska 1972, Brown andJacobs 1975).…”

Peroxy natural products

“…Several of the sterol endoperoxides have been synthesized : (263),316 (263 acetate),"' (275),314,316 (265),306. 314 (272),306 and Two steroidal hydroperoxides have been identified from natural sources. The first was isolated in 1960 from Aesculus lzippocaslanum (horse chestnut) and the structure was determined to be 3cz,22r-di hydroxy-7cz-hydroperoxy-24[ethylcholesta-5(6)-ene (283).…”

Lipid Biochemistry of Fungi and Other Organisms

“…However, closely related substances are often present in sterol preparations from fungi. One of these substances is ergosta-4,6,S(14) , 22-tetraen-3-one (ETa) which has been identified as a product of several Aspergillus and Penicillium species (Seitz and Paukstelis, 1977;Price and Worth, 1974;White and Taylor, 1970;Brown and Jacobs, 1975), Fomes officinalis (Schulte et al, 1965), Lampteromyces japonicus (Endo et al, 1970), Balansia epichloe (Porter et al, 1975), and Candida utilis (Morimoto et al, 1967).…”