No abstract

A series of novel 2‐isocamphanyl thiosemicarbazone derivatives were synthesized and characterized by 1H NMR, 13C NMR, and HRMS. In in vitro anticancer activity, most derivatives showed considerable cytotoxic activity against four cancer cell lines (RPMI‐8226, A549, MDA‐MB‐231, and HepG2 cancer cells) and showed low toxicity against human gastric mucosal cells (GES‐1). Among them, compound 4h exhibited excellent antitumor activity against the tested cancer cells with IC50 values of 0.4, 1.1, 1.6, and 1.7 μM for MDA‐MB‐231, RPMI‐8226, A549, and HepG2, respectively. Further, mechanism studies indicated that compound 4h induced apoptosis in MDA‐MB‐231 cells through enhancing reactive oxygen species levels, inducing mitochondrial membrane potential decrease, and influencing the expression of Bax, Bcl‐2, caspase‐3, and caspase‐9.

Three ketene nopinone derivatives (1–3) were successfully synthesized from β-pinene derivative nopinone.