ChEBI: Tubocurarine is a benzylisoquinoline alkaloid muscle relaxant which constitutes the active component of curare. It has a role as a nicotinic antagonist, a muscle relaxant and a drug allergen. It derives from a hydride of a tubocuraran.NCI Thesaurus (NCIt): Tubocurarine Chloride is the chloride salt form of tubocurarine, a naturally occurring curare alkaloid isolated from the bark and stem of Chondodendron tomentosum with a muscle relaxant property. Tubocurarine chloride competes with acetylcholine for the nicotinic receptors at the neuromuscular junction of skeletal muscles, thereby inhibiting the action of acetylcholine and blocking the neural transmission without depolarizing the postsynaptic membrane. This may lead to skeletal muscle relaxation and paralysis.