Synthesis and Antibacterial Activity of Novel Substituted Purine Derivatives

A series of novel N ‐substituted‐2‐(6‐morpholino‐9 H ‐purin‐9‐yl)acetamide and 4‐(9‐((5‐substituted‐1,3,4‐oxadiazole/thiadiazole‐2‐yl)methyl)‐9 H ‐purin‐6‐yl)‐morpholine derivatives were synthesized and evaluated their antibacterial activities against rice bacterial leaf blight and tobacco bacterial wilt caused by Xanthomonas oryzae pv . oryzae ( Xoo ) and Ralstonia solanacearum ( R . solanacearum ) via the turbidimeter test in vitro . Antibacterial bioassay indicated that most compounds demonstrated good inhibitory effect against Xoo and R . solanacearum . Especially, compound 6a demonstrated the best inhibitory effect against Xoo with half‐maximal effective concentration (EC 50 ) value of 8.39 μ g/mL, which was even better than those of commercial agents Bismerthiazol and Thiodiazole copper. The synthesized purine derivatives containing amide and 1,3,4‐oxadiazole/thiadiazole moieties exhibited excellent antibacterial activities against Xanthomonas oryzae pv . oryzae and R. solanacearum in vitro .