Tolypocladin — a new metal-chelating 2-aza-anthraquinone fromTolypocladium inflatum

A new chelator of di- and trivalent cations (tolypocladin) was isolated from the mycelium ofTolypocladium inflatum DSM 915. The structure has been determined by NMR methods as 3-methyl-5,6(7),8-trihydroxy-2-aza-anthraquinone. The ultraviolet, visible and fluorescence spectral properties of some metal complexes (in methanol) are described. The compound forms water-soluble fluorescent aluminium complexes. Its production is dependent on zinc ions in the medium. It serves as an endogenous hydrogen acceptor under oxygen limitation in the producing strain,T. inflatum.