Fruiting bodies of the fungus Dermocybe austrweneta (Cleland) Moser (Agaricaceae) are common in Eucalyptus woodlands throughout the eastern states of Australia from May to August. We report here the isolation, after extraction of D. austrweneta in the dark, of a purple pigment which is identical with the rare natural product protohypericin [1]. This is the first record of protohypericin as a fungal metabolite. In laboratory daylight the protohypericin present in extracts of D. austrweneta is rapidly transformed to the photodynamic pigment hypericin [2], which is thereafter responsible for the red-violet color and fiery red fluorescence mentioned earlier. The principal orange pigment of D. austroveneta is identified as (+)-S-skyrin [3]. Fresh mushrooms were macerated in the dark and extracted with Me2CO. Subsequent operations, all carried out in the dark, served to concentrate the extracts, distribute the pigments between EtOAc and H2O, and concentrate the coloring matters in the organic phase. Preparative tlc and gel permeation then afforded the major purple and orange pigments, each in pure form. The purple pigment (43 ppm fresh wt) was found to be identical in chromatographic behavior and electronic, ir, and nmr spectra with protohypericin [1], a synthetic sample of which was available for direct comparison. On exposure to light, protohypericin is rapidly converted to hypericin [2] (2), and we have for the first time monitored the progress of this transformation using H-nmr spectroscopy. Protohypericin [1] has previously been isolated from plants of the genus Hypericum (3,4) and from various insects (5), but this is the first report of its occurrence as a fungal metabolite. The major pigment of D. austroveneta, orange-red plates (94 ppm fresh wt) was cleaved with alkaline dithionite to give emodin [4]. It was identified as the 5,5' linked bianthraquinone skyrin [3] from this (6) and by comparison of its 'H- and 13C-nmr spectra with those of the anthraquinone 4. The unequivocal assignment of resonances in the 13C-nmr spectra of emodin and skyrin is reported here for the first time in Tables 1 and 2, respectively. Skyrin, although widespread among the microfungi (7,8), has rarely been found in macromycetes. The developing chemotaxonomic link between the Australian and South American species is made stronger by the fact that hypericin [2] has also been detected by tlc in these South American fungi (14).