Figure 1. The biosynthetic route towards saxitoxin (STX, 1) and intermediates (2, 3, 4, 5, 6) proposed by Kellmann et al.31 with 7, which was found by us34.
Molecules 3, 4 and 7 were identified in the cyanobacterium A. circinalis (TA04) and the dinoflagellate A. tamarense (Axat-2), and the structure of 4 was drawn as we reported33,34.
