Synthesis, and anti-proliferative, Pim-1 kinase inhibitors and molecular docking of thiophenes derived from estrone.
Heterocyclization of steroids were reported to give biologically active products where ring D modification occured. Estrone (1) was used as a template to develop new heterocyclic compounds. Ring D modification of 1 through its reaction with cyanoacetylhydrazine and elemental sulfur gave the thiophene derivative 3. The latter compound reacted with acetophenone derivatives 4a-c to give the hydrazide-hydrazone derivatives 5a-c, respectively. In addition, compound 3 formed thiazole derivatives through its first reaction with phenylisothiocyanate to give the thiourea derivative 9 followed by the reaction of the later with α-halocarbonyl compounds. In the present work a series of novel estrone derivatives were designed, synthesized and evaluated for their in vitro biological activities against c-Met kinase, and six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG and SMMC-7721). The most promising compounds 5b, 5c, 11a, 13c, 15b, 15c, 15d, 17a and 17b were further investigated against the five tyrosine kinases c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR. Compounds 5b, 15d, 17a and 17b were selected to examine their Pim-1 kinase inhibition activity where compounds 15d and 17b showed high activities. Molecular docking of some of the most potent compounds was demonstrated.