Abstract
The production, isolation, chemical and physical characteristics and biological properties of the new antiviral antibiotics, xanthocillin X mono- and dimethylether, and methoxy-xanthocillin X dimethylether are described. They were produced by two strains of Aspergillus sp. isolated from soil samples. The active principles were extracted from the mycelium, and isolated as yellowish crystals. They were identified as derivatives of xanthocillin X by physical methods. All three were effective against Newcastle disease, vaccinia and herpes simplex viruses in plate assays, and all inhibited the growth of Bacillus subtilis.
