Synthesis and biological evaluation of a novel human stem/progenitor cells proliferation activator: 4-(4-(5-mercapto-1,3,4-oxadiazol-2-yl)phenyl) thiosemicarbazide (Stemazole)

Stem/progenitor cells are crucial for cell-based therapy and regenerative medicine, and their application in clinical and basic research requires a large supply of cells. To identify effective stem/progenitor cell proliferation activators, we synthesised a series of new 4-(4-(5-mercapto-1,3,4-oxadiazol-2-yl)phenyl) thiosemicarbazide (named Stemazole) derivatives. Preliminary evaluation of the structure-activity relationship (SAR) and the biological activities of the compounds were determined with a luminescent cell viability assay. The identified leading compound, Stemazole, exhibited remarkable proliferation-promoting activity in human hippocampal stem/progenitor cells (HSCs) in a time-dependent and concentration-dependent manner. The proliferation-promoting activity of Stemazole was further confirmed against a panel of human stem/progenitor cells derived from each of the three blastoderm layers. In conclusion, Stemazole is a novel activator of stem cells proliferation.