Utility of l-norephedrine in the semisynthesis of novel thiourea and thiazolidine derivatives as a new class of anticancer agents

The natural alkaloid l-norephedrine 1 was utlized in the synthesis of some novel thiourea derivatives 2, 5 and thiazolidinones 4a,b and 6, 7. Structures of the synthesized compounds were confirmed by analytical and spectral data. The synthesized compounds were evaluated in vitro for anticancer activity against the human breast (MCF-7), human liver (HEPG2) and human colon (HCT116) cancer cell lines. Thiazolidinone derivative 7 was the most active against all the cell lines with values IC₅₀ = 2.60, 2.80 and 2.60 μg/mL compared with doxorubicin (IC₅₀ = 5.40, 2.97 and 5.26 μg/mL). Thiazolidinone derivative 6 exhibited higher activity with IC₅₀ value (3.20 μg/mL) against HCT116 when compared with doxorubicin with IC₅₀ value (5.26 μg/ mL) as positive control.