Structure and syntheses of texazone, 2-(N-methylamino)-3H-phenoxazin-3-one-8-carboxylic acid, an actinomycete metabolite.

Cultures of actinomycete strain WRAT-210 produced a dark red crystalline metabolite which was named texazone. Spectroscopic evidence suggested that the structure of texazone is 2-(N-methylamino)-3H-phenoxazin-3-one-8-carboxylic acid. The structure was confirmed by chemical synthesis through oxidative dimerization of ethyl 3-amino-4-hydroxybenzoate with 2-(N-methylamino)phenol and subsequent hydrolysis of the resultant phenoxazinone ester.