OAC1 is a Octamer-binding transcription factor 4 (Oct4)-activating compound; enhances the iPSC reprogramming efficiency and accelerated the reprogramming process. IC50 value: Target: Oct4 activator in vitro: OAC1 enhances the formation of Oct4-GFP+ colonies and accelerates the dynamics of reprogramming. OAC1 enhanced reprogramming efficiency through a mechanism that is independent of endogenous Oct4 promoter demethylation. OAC1 enhanced reprogramming efficiency through a mechanism that is distinct from suppressing p53-p21 expression. Luciferase assay revealed that OAC1 had no effect on Topflash activity, although BIO activated the Topflash reporter potently. OAC1 functions through a mechanism that is independent of the Wnt signaling.