Synthesis and structure–activity relationships studies of brartemicin analogs as anti-invasive agents

Brartemicin is a trehalose-based inhibitor of tumor cell invasion produced by the actinomycete of the genus Nonomuraea. In order to find more potent anti-invasive agents and study the structure-activity relationships, a series of 19 brartemicin analogs were prepared via two synthetic routes from α,α-D-trehalose and evaluated for their anti-invasive activities. Compound 4f, 6,6'-bis(2,3-dimethoxybenzoyl)-α,α-D-trehalose, was more potent than the natural brartemicin. It inhibited the invasion of murine colon 26-L5, colon carcinoma SW620, melanoma B16-BL6 and breast MDA-MB-231 cells with IC50 values of 0.15, 2.35, 4.12 and 2.61 μM, respectively. Analog 4p, 6,6'-bis(3,4-dimethoxycinnamoyl)-α,α-D-trehalose, was as potent as brartemicin against invasion of murine colon 26-L5 carcinoma cells in vitro. The structure-activity relationships of these novel trehalose-based compounds were summarized.