Semi-vioxanthin

Several new dihydroisocoumarins, e.g. (233), have been isolated from a fungus Fusarium larvarum) which is a pathogen of some insects. Another fungus Aspergillus terreus ARRL 6273), sometimes present in hay, produces several toxins, including a new compound called terretonin (234). Penicillium citreo-viride produces several compounds which have bactericidal and insecticidal activity. One of these is semi-vioxanthin (235). Streptomyces rosa also produces compounds which have antibacterial action for example, nanomycin E (236), which is an epoxy-derivative of nanomycin A. ... 

C30H22O12, Mr 574.50, yellow-red crystals, decomp, at 264 °C. A hydroxynaphthoquinone produced by various species of fungi (e. g., Trichophyton, Penicillium, Aspergillus). X. is formed biosynthetically on the polyketide pathway and often occurs together with its precursors (e. g., semi-vioxanthin, vioxanthin, viomel-lein). X. is a mycotoxin, it has antibacterial and insecticidal activities and influences oxidative phosphorylation in rat liver mitochondria. 

Zeeck, a., P. Rub, H. Laatsh, W. Loeffler, H. Wehole, H. Zahner, and H. Holst Isolation of the Antibiotiv Semi-vioxanthin from Penicillium citreo-viride and Synthesis of Xanthomegnin. Chem. Ber. 112, 957 (1979). 

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