Synthesis and evaluation of benzochalcogenazole-benzimidazole derivatives as potential DNA-binding radioprotectors

Abstract

Benzothiazole 6 and benzoselenazole 7, which are closely related to the bisbenzimidazole radioprotector bisbenzimidazole M2PB 20, were prepared by reaction of a common amide intermediate 13O with Lawesson’s and Woolin’s reagents, respectively. A simpler tellurazole derivative 19 was prepared using a different synthetic strategy. The DNA binding affinity of the three chalcogenazoles 6, 7, 19 and the parent benzimidazole 20 were assessed by means of spectrophotometric DNA titration experiments using 16-mer oligonucleotides with and without a single binding site. While M2PB 20 shows clear binding to the oligonucleotide containing an AATT binding site, no strong conclusions can be made regarding..