Streptomyces echinoruber sp. nov. produces several red pigments. The major component, rubrolone, has been identified as 8(R), 9(R), 10(S), 10a(R)-tetrahydro-9, 10, 1Oa, 11-tetrahydroxy-3, 8-dimethyl-l-propyl-6aH(S)-pyrano[2'', 3'': 5', 4]furo[2', 3': 5, 6]azuleno[2, 3-c]pyridine-5, 13-di one (1) by single crystal X-ray analysis of a suitable derivative. A second pigment, B, is probably structurally closely related.
