Discovery and structure-activity analysis of 4-((5-nitropyrimidin-4-yl)amino)benzimidamide derivatives as novel protein arginine methyltransferase 1 (PRMT1) inhibitors

Despite a potential application of PRMT1 inhibitors in cancer treatment, very few of PRMT1 inhibitors have been reported. To obtain novel potent PRMT1 inhibitors, structure optimizations towards a hit compound, 4-((6-chloro-5-nitropyrimidin-4-yl)amino)benzimidamide, were carried out. A series of 4-((5-nitropyrimidin-4-yl)amino)benzimidamide derivatives were synthesized. Structure-activity relationship analysis led to the discovery of a number of PRMT1 inhibitors. The most potent compound corresponds to compound 6d, which showed an IC50 value of 2.0 mu M against PRMT1. This compound also displayed a considerable anti-proliferative activity against three tumor cell lines, DLD-1, T24 and SH-SY-5Y, with IC50 values of 4.4 mu M, 13.1 mu M and 11.4 mu M, respectively. (C) 2015 Elsevier Ltd. All rights reserved.