Native South Americans have long used arrow poisons for both hunting and defence; they are generically referred to as curare. (+)-Tubocurarine chloride (8.1), which is obtained by extracting the roots and stem of Chondrodendron tomentosum with boiling water and was once used in anaesthesiology, is the best representative of this family. It operates as an antagonist at the nicotine receptor, stopping acetylcholine binding and preventing muscular contraction, so the diaphragm is paralysed.