CTAP is a specific, BBB (blood-brain barrier) permeable (penetrable) μ opioid receptor antagonist (inhibitor) with IC50 of 3.5 nM. CTAP has over 1200-fold selectivity for delta opioid receptors (IC50=4500 nM) and somatostatin receptors. CTAP may be utilized to study L-dopamine-induced dyskinesia (LID) and overdose or addiction to opioid-active molecules.

Physicochemical Properties

Molecular Formula	C51H69N13O11S2
Molecular Weight	1104.30
Exact Mass	1103.468
CAS #	103429-32-9
Related CAS #	CTAP TFA
PubChem CID	10418702
Appearance	Typically exists as solid at room temperature
Density	1.5±0.1 g/cm3
Index of Refraction	1.699
LogP	0.44
Hydrogen Bond Donor Count	15
Hydrogen Bond Acceptor Count	15
Rotatable Bond Count	17
Heavy Atom Count	77
Complexity	2060
Defined Atom Stereocenter Count	10
SMILES	C[C@@H](O)[C@H](NC([C@@H]1C(C)(SSC[C@H](NC([C@H](N)CC2=CC=CC=C2)=O)C(N[C@H](C(N[C@@H](C(N[C@H](C(N[C@H](C(N1)=O)[C@H](O)C)=O)CCCNC(N)=N)=O)CC3=CNC4=CC=CC=C34)=O)CC5=CC=C(O)C=C5)=O)C)=O)C(N)=O
InChi Key	OFMQLVRLOGHAJI-FGHAYEPSSA-N
InChi Code	InChI=1S/C51H69N13O11S2/c1-26(65)39(42(53)68)62-49(75)41-51(3,4)77-76-25-38(61-43(69)33(52)21-28-11-6-5-7-12-28)47(73)59-36(22-29-16-18-31(67)19-17-29)45(71)60-37(23-30-24-57-34-14-9-8-13-32(30)34)46(72)58-35(15-10-20-56-50(54)55)44(70)63-40(27(2)66)48(74)64-41/h5-9,11-14,16-19,24,26-27,33,35-41,57,65-67H,10,15,20-23,25,52H2,1-4H3,(H2,53,68)(H,58,72)(H,59,73)(H,60,71)(H,61,69)(H,62,75)(H,63,70)(H,64,74)(H4,54,55,56)/t26-,27-,33-,35+,36+,37-,38+,39+,40+,41-/m1/s1
Chemical Name	(4R,7S,10S,13R,16S,19R)-N-[(2S,3R)-1-amino-3-hydroxy-1-oxobutan-2-yl]-19-[[(2R)-2-amino-3-phenylpropanoyl]amino]-10-[3-(diaminomethylideneamino)propyl]-7-[(1R)-1-hydroxyethyl]-16-[(4-hydroxyphenyl)methyl]-13-(1H-indol-3-ylmethyl)-3,3-dimethyl-6,9,12,15,18-pentaoxo-1,2-dithia-5,8,11,14,17-pentazacycloicosane-4-carboxamide
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
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	μ Opioid Receptor/MOR 3.5 nM (IC50) δ Opioid Receptor/DOR 4500 nM (IC50)
ln Vivo	CTAP (0–1 mg/kg, IP, single) inhibits the antinociceptive action of morphine[1]. L-DOPA-induced limb, axial, orolingual, or locomotor aberrant involuntary movements are not affected by CTAP (10 mg/kg; IP, single)[1]. Rat blood and serum contain CTAP that is stable (T1/2 > 500 min), indicating that this peptide's structure provides enzymatic resistance[2]. Rat serum proteins (84.2%) and albumin in the perfusion medium (68.2%) both have significant protein bindings for CTAP[2].
Animal Protocol	Animal/Disease Models: Male SD (Sprague-Dawley) rats[1] Doses: 0, 0.1, 0.5, 1 mg/kg Route of Administration: IP, single Experimental Results: Completely blocked morphine's antinociceptive effect at 0.5 or 1 mg/kg.
References	[1]. Highly-selective µ-opioid Receptor Antagonism Does Not Block L-DOPA-induced Dyskinesia in a Rodent Model.BMC Res Notes. [2]. Blood-brain barrier permeability and bioavailability of a highly potent and mu-selective opioid receptor antagonist, CTAP: comparison with morphine. J Pharmacol Exp Ther. 1997 Jan;280(1):402-9.

Solubility Data

Solubility (In Vitro)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	0.9056 mL	4.5278 mL	9.0555 mL
	5 mM	0.1811 mL	0.9056 mL	1.8111 mL
	10 mM	0.0906 mL	0.4528 mL	0.9056 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.