Cis-BG47 is an cis-isomer of BG47, BG47 is a prototypical histone deacetylases HDAC1 and HDAC2 selective, optoepigenetic probe. BG47 can bind to and competitively inhibits the deacetylase activity of HDAC targets upon a light-induced trans-to-cis isomerization, and increases Histone Methyltransferase H3K9 acetylation. cis-BG47 can be used for neurological disease research[1].