Cyaneodimycin, a Bioactive Compound Isolated from the Culture of Streptomyces cyaneofuscatus Associated with Lichina confinis

Two new compounds, cyaneodimycin (1) and cyaneomycin (2) bearing a rare methacrylate residue, were isolated from cultures of the bacterium Streptomyces cyaneofuscatus associated with the marine lichen Lichina confinis. These astonishing structures may be derived from a pyruvate biosynthetic pathway. Cyaneodimycin (1) exhibited antiproliferative properties against B16 (IC50 = 27 +/- 4 mu m), HaCaT (IC50 = 47 +/- 11 mu m) and Jurkat cell lines (IC50 = 18.5 +/- 0.5 mu m). Six known compounds 3-8 with diversified structures and interesting biological properties (diketopiperazines, actinomycin, dibenzofurane or indole derivatives) were isolated jointly with compounds 1 and 2. Among them, usnic acid (8), a common lichen compound was isolated for the first time from bacteria.