Synthesis and biological activities of benzothiazole derivatives bearing a 1,3,4-thiadiazole moiety

A series of benzothiazole derivatives bearing a 1,3,4-thiadiazole moiety were designed, synthesized and evaluated for their antibacterial, antifungal and antiviral activities. The bioassay results indicated that most of target compounds showed good antiviral activities against tobacco mosaic virus (TMV) and antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (Rs). Especially, the anti-Xoo effect of title compounds 5k (N-(5-methoxybenzo[d]thiazol-2-yl)-2-((5-(2-tolyl)-1,3,4-thiadiazol-2-yl)thio)acetamide) and the anti-Rs effect of title compounds 5a (N-(5-nitrobenzo[d]thiazol-2-yl)-2-((5-(4-(trifluorom ethyl)phenyl)-1,3,4-thiadiazol-2-yl)thio)acetmide) respectively reached 52.4% and 71.6% at 100 mu g/mL, which are superior to that of bismerthiazol (32.0% and 52.3%). In addition, the protective and inactivation activities of title compound 5i (N-(5-methoxybenzo [d]thiazol-2-yl)-2-((5-(4-nitrophenyl)-1,3,4-thiadiazol-2-yl)thio)acetamide) against TMV were 79.5% and 88.3%, respectively, which are better than that of ningnanmycin (76.4% and 86.8%). The above research showed that benzothiazole derivatives bearing a 1,3,4-thiadiazole moiety may be used as potential molecular templates in searching for highly-efficient antiviral and antibacterial agents.