β-resorcylic acid macrolide with various biological activities. Herein we report the synthesis and cytotoxicactivities of 34 zearalenone analogues against human oral epidermoid carcinoma (KB) and human breast adenocarcinoma (MCF-7) cells as well as noncancerous Vero cells. Some zearalenone analogues showed moderately enhanced cytotoxicactivities against the two cancer cell lines. We have discovered