Details:
Catalysis of the reaction: histone H3 N6-acetyl-L-lysine (position 18) + H2O = histone H3 L-lysine (position 18) + acetate. This reaction requires the presence of NAD, and represents the removal of an acetyl group from lysine at position 18 of the histone H3 protein. [EC:3.5.1.17, EC:3.5.1.98, GOC:sp, PMID:22722849, RHEA:24551]