Abstract
Sphaerospermopsis torques-reginae is a planktonic cyanobacterial species with broad distribution in several Brazilian aquatic environments. Some strains of this species are known to produce the neurotoxic organophosphate anatoxin-a(s) (ANS), which is a powerful irreversible inhibitor of the acetylcholinesterase,enzyme, that acts in the peripheral nervous system of mammals. The ANS structu…