(Chemical Equation Presented) Coding control: Protein arginine methyltransferases (PRMTs) and histone lysine methyltransferases (HKMTs) are epigenetic enzymes involved in regulation of gene expression and cellular processes. A new series of histone/protein methyltransferase inhibitors based on the 1,5-diphenyl-1,4-pentadien-3-one scaffold is reported. The described compounds showed various degrees of selectivity against the tested PRMTs (PRMT1 and CARM1) and HKMT (SET7). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.