Cisatracurium Besylate (51W89; Nimbex; 51 W89; 51-W89; Cisatracurium besilat), the Besylate salt of Cisatracurium, is a nondepolarizing neuromuscular blocking agent with anesthetic effects. It blocks the transmission of neuromuscular signals, counteracting the effects of acetylcholine. In order to aid in endotracheal intubation and to relax skeletal muscles during surgery or mechanical ventilation, ciprofructurium is used as an adjuvant in anesthesia. One of the ten isomers of the parent molecule, atracurium, is cisatracurium. Moreover, cisatracurium represents approximately 15% of the atracurium mixture.

Physicochemical Properties

Molecular Formula	C65H82N2O18S2
Molecular Weight	1243.48
Exact Mass	1242.5
Elemental Analysis	C, 62.78; H, 6.65; N, 2.25; O, 23.16; S, 5.16
CAS #	96946-42-8
Related CAS #	Cisatracurium; 96946-42-8 (besylate)
PubChem CID	62886
Appearance	White to off-white solid powder
Melting Point	90-93ºC
LogP	11.326
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	18
Rotatable Bond Count	26
Heavy Atom Count	87
Complexity	1560
Defined Atom Stereocenter Count	4
SMILES	S(C1C=CC=CC=1)([O-])(=O)=O.C(C1C=CC(OC)=C(OC)C=1)[C@H]1[N@@+](C)(CCC(=O)OCCCCCOC(=O)CC[N@+]2(CCC3C=C(C(=CC=3[C@H]2CC2C=CC(OC)=C(OC)C=2)OC)OC)C)CCC2=CC(=C(C=C12)OC)OC
InChi Key	XXZSQOVSEBAPGS-DONVQRBFSA-L
InChi Code	InChI=1S/C53H72N2O12.2C6H6O3S/c1-54(22-18-38-32-48(62-7)50(64-9)34-40(38)42(54)28-36-14-16-44(58-3)46(30-36)60-5)24-20-52(56)66-26-12-11-13-27-67-53(57)21-25-55(2)23-19-39-33-49(63-8)51(65-10)35-41(39)43(55)29-37-15-17-45(59-4)47(31-37)61-6;2*7-10(8,9)6-4-2-1-3-5-6/h14-17,30-35,42-43H,11-13,18-29H2,1-10H3;2*1-5H,(H,7,8,9)/q+2;;/p-2/t42-,43-,54-,55-;;/m1../s1
Chemical Name	benzenesulfonate;5-[3-[(1R,2R)-1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-2-ium-2-yl]propanoyloxy]pentyl 3-[(1R,2R)-1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxy-2-methyl-3,4-dihydro-1H-isoquinolin-2-ium-2-yl]propanoate
Synonyms	51-W89; Nimbex; 51 W89; 51W89; Cisatracurium besilat
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	Adrenergic Receptor
ln Vitro	Cisatracurium Besylate (51W89) is a skeletal muscle relaxant that belongs to the class of non-depolarizing neuromuscular-blocking medications. It is used as an adjuvant to anesthesia in order to facilitate endotracheal intubation and to provide skeletal muscle relaxation during mechanical ventilation or surgery. It is an agent with an intermediate duration of action that is bisbenzyltetrahydroisoquinolinium. One of the ten isomers of the parent molecule, atracurium, is cisatracurium besylate (51W89). Furthermore, out of the mixture of atracurium, cisatracurium makes up about 15% [1, 2].
Toxicity/Toxicokinetics	Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation No information is available on the use of cisatracurium during breastfeeding. Because it is short acting, highly polar and poorly absorbed orally, it is not likely to reach the breastmilk in high concentration or to reach the bloodstream of the infant. When a combination of anesthetic agents is used for a procedure, follow the recommendations for the most problematic medication used during the procedure. Consider using a cisatracurium product that has no benzyl alcohol preservative. ◉ Effects in Breastfed Infants Relevant published information was not found as of the revision date. ◉ Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date.
References	[1]. Identification of urinary and biliary conjugated metabolites of the neuromuscular blocker 51W89 by liquid chromatography/mass spectrometry. Rapid Commun Mass Spectrom, 1995. 9(14): p. 1457-64. [2]. Cisatracurium: myographical and electrophysiological studies in the isolated rat muscle. Fundam Clin Pharmacol, 2006. 20(3): p. 291-8.
Additional Infomation	Cisatracurium besylate is the (1R,1'R,2R,2'R)-diastereoisomer of atracurium besylate. Commercial preparations of atracurium are mixtures of 10 stereoisomers, of which cisatracurium generally constitutes about 15%. Cisatracurium besylate is about 3 times more potent than the mixture of atracurium isomers as a neuromuscular blocking agent, and is used as a muscle relaxant for endotracheal intubation, to aid controlled ventilation, and in general anaesthesia. It has a role as a muscle relaxant and a nicotinic antagonist. It is a quaternary ammonium salt, an atracurium besylate and an organosulfonate salt. It contains a cisatracurium. Cisatracurium Besylate is the besylate salt form of cisatracurium, a non-depolarizing skeletal muscle relaxant of the benzylisoquinolinium class, with skeletal muscle relaxing activity. Cisatracurium besylate acts as a competitive acetylcholine antagonist that binds to nicotinic receptors at the neuromuscular junction. This blocks neuromuscular transmission and causes neuromuscular relaxation. See also: Cisatracurium (has active moiety).

Solubility Data

Solubility (In Vitro)	DMSO: 100~249 mg/mL (80.4~200.2 mM) Water: ~47 mg/mL (~37.8 mM) Ethanol: ~249 mg/mL (~200.2 mM)
Solubility (In Vivo)	Solubility in Formulation 1: 100 mg/mL (80.42 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	0.8042 mL	4.0210 mL	8.0419 mL
	5 mM	0.1608 mL	0.8042 mL	1.6084 mL
	10 mM	0.0804 mL	0.4021 mL	0.8042 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.