“…Cyanobacterin (1) thereby seems to target a different binding site than DCMU, since DCMU-resistant mutants are still sensitive to 1. 6,7 Interestingly, the anhydro isomer 3 2 resulting from dehydratation of 1, lacks this biological activity. 4 Owing to its strong biological activity, 1 is a promising lead structure for the development of potent phytotoxins, for example, for agrochemical applications.…”