Developing anesthetics is not the goal of this research, though. The goal was to synthesize a naturally occurring molecule. But they did one better: They synthesized BTX and a mirror-image isomer of it known as an enantiomer. If BTX is a left-handed glove, then its enantiomer is like a right-handed glove. Since toxins typically evolve over time to fit highly selective binding sites in other animals, the scientists hypothesized that the enantiomer would not fit the binding site in the ion channel where BTX would normally fit. "Surprisingly, what we found in the lab is that the unnatural toxin enantiomer has similar potency to natural BTX but a completely different mode of action," says Logan. While BTX is an irreversible sodium channel agonist, or opener, its enantiomer is a reversible antagonist, or blocker. "This result was quite unexpected," Logan tells Popular Science.