Luisols A (1) and B (2), two new aromatic tetraols, have been isolated from the cultivation broth of an estuarine marine actinomycete of the genus Streptomyces (strain #CNH-370). The structures of luisols A and B were assigned by combined spectroscopic methods, including extensive 2D NMR experiments. Luisol A appears related to the anthraquinone antibiotics of the granaticin class, while the structure of luisol B contains the rare epoxynaphtho[2,3c]furan, a structural feature found in only one natural product, the fungal metabolite anthrinone.