Mitochondrial targeted modification and anticancer mechanism of natural product ergosterol peroxide

Ergosterol peroxide (EP) isolated from the edible medicinal fungus Pleurotus ferulae has a wide range of anti-tumor activity, but poor water solubility and low bioavailability limit further application. In this study, EP was structurally modified using triphenylphosphine (TPP+), which combines mitochondrial targeting, amphiphilicity, and cytotoxicity. A series of TPP+-conjugated ergosterol peroxide derivatives (TEn) with different length linker arms were synthesized. The structure–activity relationship showed that the anticancer activity of TEn gradually decreased with the elongation of the linker arm. The compound TE3 has the optimal and broadest spectrum of antitumor effects. It mainly through targeting mitochondria, inducing ROS production, disrupting mitochondrial function, and activating mitochondria apoptosis pathway to exert anti-cervical cancer activity. Among them, TPP+ only acted as a mitochondrial targeting group, while EP containing peroxide bridge structure served as an active group to induce ROS. In vivo experiments have shown that TE3 has better anti-cervical cancer activity and safety than the first-line anticancer drug cisplatin, and can activate the immune response in mice. Although TE3 exhibits some acute toxicity, it is not significant at therapeutic doses. Therefore, TE3 has the potential for further development as an anti-cervical cancer drug.