Synthesis and antitumor activity of some cholesterol-based selenocyanate compounds

The introduction of selenium-containing functional groups into steroids to study the biological activities of related derivatives is rarely reported in the literature. In the present study, using cholesterol as raw material, four cholesterol-3-selenocyanoates and eight B-norcholesterol selenocyanate derivatives were synthesized, respectively. The structures of the compounds were characterized by NMR and MS. The results of the in vitro antiproliferative activity test showed that the cholesterol-3-selenocyanoate derivatives did not exhibit obvious inhibitory on the tested tumor cell lines. However, the B-norcholesterol selenocyanate derivatives obtained by structural modification of cholesterol showed good inhibitory activity against the proliferation of tumor cell. Among them, compounds 9b-c, 9f and 12 showed similar inhibitory activity against tested tumor cells as positive control 2-methoxyestradiol, and better than Abiraterone. At the same time, these B-norcholesterol selenocyanate derivatives displayed a strong selective inhibitory against Sk-Ov-3 cell line. Except for compound 9g, the IC₅₀ value of all B-norcholesterol selenocyanate compounds against Sk-Ov-3 cells was less than 10 µM, and compound 9d was 3.4 µM. In addition, Annexin V-FITC/PI double staining was used to analyze the cell death mechanism. The results showed that compound 9c could induce Sk-Ov-3 cells to enter programmed apoptosis in a dose-dependent manner. Furthermore, the in vivo antitumor experiments of compound 9f against zebrafish xenograft tumor showed that 9f displayed obvious inhibitory effect on the growth of human cervical cancer (HeLa) xenograft tumor in zebrafish. Our results provide new thinking for the study of such compounds as new antitumor drugs.