Isolation and structure elucidation of two new antibacterial compounds produced by Chrysosporium queenslandicum.

During our investigation on bioactive antifungal pigments the strain Chrysosporium queenslandicum IFM 51121 was found to produce a series of darkish to reddish pigments which were identified as naphthaquinone-type altersolanols A, B, C1-3). Moreover, a new antifungal compound (queenslandon)4) was isolated as a new representative of the zearalenone family of mycotoxin. In addition to the above metabolites C. queenslandicum IFM 51121 co-produced new antibacterial compounds related to members of the dihydronaphthaquinone group5-7) which were given the name chrysoqueen (1) and chrysolandol (2). In this paper we report fermentation, isolation, physicochemical properties and the structure elucidation of 1 and 2. A culture sample of C. queenslandicum IFM 51121 was deposited in the microbial strain collection of the Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Japan. The mature slant culture of C. queenslandicum IFM 51121 was inoculated into a 50ml Erlenmeyer shake flask containing 25ml of a seed medium (2% glucose supplemented BHI medium). The inoculated flasks were