Isolation, synthesis, and biological activity of biphenyl and m-terphenyl-type compounds from Dictyostelium cellular slime molds

From the fruiting bodies of Dictyostelium polycephalum, we obtained four aromatic compounds: dictyobiphenyl A (1) and B (2) and dictyoterphenyl A (3) and B (4). The synthesis of 1–4 was performed to confirm the structures and obtain sufficient material for biological evaluation. Compound 3 was the first example of nitrogen-containing natural m-terphenyls, and the isolation of novel classes of compounds such as 3 shows that cellular slime molds are promising sources in natural product chemistry. Moreover, dictyoterphenyl A (3) showed cancer cell-selective antiproliferative activity (IC50 2.3–8.6 μM).