6989-98-6

white to slightly yellowish powder

antibacterial

muscle relaxant (skeletal)

Tubocurarine chloride is the only naturally occurring neuromuscular blocking agent. It is derived from the bark of the South American plant chondrodendron tomentosum, which has been used for centuries by South American Indians as an arrow poison. I t was the first non-depolarising neuromuscular blocking agent to be used in humans. I t has a marked propensity to produce histamine release and thus hypotension, with possibly a compensatory tachycardia. Historically, tubocurarine, alcuronium and gallamine have been used in clinical practice, but they are no longer available in the UK. A lcuronium chloride is a semisynthetic derivative of toxiferin, an alkaloid of calabash curare. Gallamine triethiodide is a trisquaternary amine. It was first used in France in 1948. The only recent use of gallamine in the UK was as a small pretreatment dose (10 mg) before suxamethonium.

Mecostrin,Squibb,US,1946

The initial step involves extraction of the stems and bark of the plant Chondrodendron tomentosum with water as the solvent.
Producing substantially pure d-tubocurarine chloride essentially comprises treating with picric acid the quaternary-base fraction of a crude curare of the curarine type, hydrolyzing the resulting picrate in an emulsion of hydrochloric acid and a water-immiscible organic solvent for picric acid, recovering crystalline d-tubocurarine chloride from the aqueous phase, dissolving the d_x0002_tubocurarine chloride in a minimum of hot water, allowing the solution to stand at room temperature until the bulk of the d-tubocurarine chloride precipitates, adding sufficient concentrated hydrochloric acid to bring the HCl content up to about 6% and refrigerating the solution.

Muscle relaxant

Tubocurarine chloride,( )-tubocurarine chloride hydrochloride pentahydrate, isprepared from crude curare by a process of purification andcrystallization. Tubocurarine chloride occurs as a white oryellowish white to grayish white, odorless, crystalline powderthat is soluble in water. Aqueous solutions of it are stableto heat sterilization.
The structural formula for (+)-tubocurarine was longthought to be that of Ia (see structure diagram). Throughthe work of Everett et al.,the structure is now knownto be that of Ib. The monoquaternary nature of Ib thusrevealed has caused some reassessment of thinking concerningthe theoretical basis for the blocking action, becauseall had previously assumed a diquaternary structure(i.e., Ia). Nevertheless, this does not negate the earlierconclusions that a diquaternary nature of the molecule provides better blocking action than does a monoquaternarynature (e.g., Ib is approximately fourfold lesspotent than dimethyl tubocurarine iodide). Further, (+)-isotubocurarine chloride (Ic) has twice the activity of Ib inthe particular test used.

Tubocurarine is a muscle relaxant and a nicotinic acetylcholine receptor antagonist. It can induce neuromuscular blocking.