*3.4. Biological Assay*

The antimicrobial activities of compounds **1**–**12** against *Staphylococcus aureus*, *Escherichia coli*, and *Bacillus subtilis* were evaluated using a previous method [16], and levofloxacin was used as a positive control. The cytotoxicities of compounds **1**–**12** against DU145, SW1990, Huh7, and PANC-1 human cancer cell lines were determined using the CCK-8 method [17], with cisplatin used as a positive control. The immunosuppressive activities of compounds **1**–**12** against ConA-induced T cell proliferation were performed as previously described [18], with cyclosporin A as a positive control.
