VOLUCRISPORIN: ISOLATION, STRUCTURE, AND SYNTHESIS OF THE METHYL ETHER

A new pigment, volucrisporin, has been isolated from shaken cultures of the Hyphomycete Volucrisporaaurantiaca Haskins, and characterized as 2,5-(m-hydroxyphenyl)-1,4-benzoquinone. The structure has been confirmed by synthesis of the dimethyl ether.

MYCOCHRYSONE: II. CARBON SKELETON, PRINCIPAL CHROMOPHORE, AND OXYGEN FUNCTIONS

A mono-and di-methyl ether and two diacetates of mycochrysone have been prepared. Elemental analyses of these derivatives and of the purified pigment itself are consistent with a revised C20H12O7 formula for mycochrysone.The formation of a leucohexaacetate suggests that the molecule contains two hydroxyl or potential hydroxyl oxygen functions in addition to the quinonoid and phenolic (or enolic) groups already shown to be present. The infrared spectra of mycochrysone and derivatives provide evidence that the remaining oxygen atom is ketonic. The principal chromophore of mycochrysone is related to 8-hydroxy-1,2-naphthoquinone. Hydrogenation experiments indicate that the pigment has a perylene carbon skeleton.

THELEPHORIC ACID

The electronic and infrared absorption spectra of thelephoric acid and its leucoacetate indicate that the structure at present accepted for the pigment is incorrect. It is suggested from an interpretation of these spectra, together with a re-evaluation of the reported properties of thelephoric acid and its derivatives, that the substance may be a hydroxylated terphenyl containing internal quinhydrone and benzofuran systems (e.g. (V)).

MYCOCHRYSONE: I. ISOLATION, PROPERTIES, AND PRELIMINARY CHARACTERIZATION

Mycochrysone, an orange-red crystalline pigment, has been isolated from in vitro cultures of an inoperculate discomycetous fungus. It possesses quinonoid properties and forms a monoquinoxaline derivative. At least two phenolic or enolic groups are present, one of which is in the peri position to a quinone carbonyl. Reduction of the pigment with a zinc dust –zinc chloride mixture gives perylene, together with some hydroperylenes. The pigment shows limited antibiotic activity.