Selenium-functionalized cyclic ethers derived from natural terpenic alcohols – biological in vitro profile

Terpenic alcohols linalool, nerolidol and α-terpineol were subjected to the PhSe-induced cyclization, where corresponding cyclic ethers were obtained. The heterocyclic product derived from α-terpineol is a derivate of the natural product eucalyptol, while linalool cyclization produces precursors of the natural product karahanaenone. All three cyclic ether products have an organoselenium moiety in the side chain, which can represent a significant source of bioactivities. Biological evaluation of obtained products, in vitro cytotoxicity and redox status parameters, was performed on two model systems: HCT-116 – immortalized colon cancer cell line, and MRC-5 – healthy fibroblasts isolated from lung pleura. The results indicate a strong prooxidative character of all compounds on colon cancer HCT-116 and healthy MRC-5 cells in the highest applied concentrations. Selectivity towards cancer cells was not observed, except when nerolidol-derived product was used for longer exposure time. A biological evaluation was conducted to establish the quantitative relationship between enhanced radical species formation and cell viability.