Protoleucomelone

Of interest to mycologists, the basidiomycete Polyporus leucomelas produces the phenolic ester protoleucomelone (2.29). 

The structure of the 4,3 ,4 -trihydroxy derivative of polyporic acid was assigned in 1942 by Akagi to the brown pigment leucomelone (47) isolated from the black edible mushroom Polyporus leucomelas (.Boletopsis leucomelaena) collected in Japan [68], From the same fungus, Akagi obtained also a colourless compound named protoleucomelone (48), established as the leuco-peracetate of 47. 

In 1987 Steglich and co-workers [69] observed that the properties of Akagi s leucomelone and protoleucomelone correspond to those of... 

In 1942 Akagi isolated a terphenylquinone, Teucomelone , from fruit bodies of the edible black mushroom Boletopsis leucomelaena (= Polyporus leucomelas) for which he proposed the formula (19) (7). The quinone formed a peracetyl derivative, m.p. 226-227° C (9), and was accompanied in the fungus by its leuco-peracetate, protoleucomelone ... 

A reinvestigation of the constituents of B. leucomelaena obtained by extraction of the fungus with acetone has afforded principally the leuco-peracetates (53) and (54) of cycloleucomelone and thelephoric acid, respectively 386). The leuco-peracetate (53) has the same melting point as Akagi s protoleucomelone and we consider these compounds to be one and the same. 

Jagers, E(lisabeth), E. Hillen-Maske, and W. Steglich Inhaltsstoffe von Boletopsis leucomelaena (Basidiomycetes) Klarung der chemischen Natur von Leucome-lon und Protoleucomelon . Z. Naturforsch., in press. 

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