Novel benzo[a]naphthacene quinones from an actinomycete, Frankia G-2 (ORS 020604)

NANCY N. GERBER and MARY P. LECHEVALIER. Can. J. Chem. 62, 2818 (1984). Frankia sp. G2 (ORS 020604), grown for one month without shaking, produced a mixture of 2 quinonoid pigments. The structure of one, G-2N, was shown by chemical and physical methods to be 2-methyl-4,7,9,12-tetrahydroxy-5,6-dihydro benzo[a]naphthacene-8,13-dione. The other, G-2A, has the same structure with the addition of a carboxyl group at position 10 or 11. Natural quinones with this ring system have not been reported previously.