Izumiphenazine D, a New Phenazoquinoline N-Oxide from Streptomyces sp IFM 11204

A new phenazine derivative named izumiphenazine D (I), together with three known metabolites, 1-hydroxyphenazine (2), phenazine-1-carboxylic acid (3) and 6-hydroxyphenazine-1-carboxylic acid (4) has been isolated from the ethyl acetate extract of culture of Streptomyces sp. IFM 11204. The structure of I was established via spectroscopic methods, including 1D- and 2D-NMR measurements.