Neurokinin A TFA (Substance K TFA) is a bioactive peptide neurotransmitter of the tachykinin family that acts through the NK-2 receptor. Serves as a major mediator in human airway and gastrointestinal tissues.

Physicochemical Properties

Molecular Formula	C52H81F3N14O16S
Molecular Weight	1247.34
Exact Mass	1246.562
CAS #	2828433-19-6
Related CAS #	Neurokinin A;86933-74-6
PubChem CID	137700150
Appearance	White to off-white solid powder
Hydrogen Bond Donor Count	17
Hydrogen Bond Acceptor Count	23
Rotatable Bond Count	37
Heavy Atom Count	86
Complexity	2120
Defined Atom Stereocenter Count	10
SMILES	C(F)(F)(F)C(=O)O.[C@@H](NC(=O)[C@H](CO)NC(=O)[C@H](CC(=O)O)NC(=O)[C@]([H])([C@H](O)C)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](N)CC1N=CNC=1)(C(=O)N[C@@H](C(C)C)C(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N[C@H](C(=O)N)CCSC)CC1C=CC=CC=1
InChi Key	CPQMHLIZWAQHOV-LEUAYMAXSA-N
InChi Code	InChI=1S/C50H80N14O14S.C2HF3O2/c1-26(2)18-34(45(73)58-32(42(53)70)15-17-79-6)57-38(67)23-55-49(77)40(27(3)4)63-47(75)35(19-29-12-8-7-9-13-29)60-48(76)37(24-65)62-46(74)36(21-39(68)69)61-50(78)41(28(5)66)64-44(72)33(14-10-11-16-51)59-43(71)31(52)20-30-22-54-25-56-30;3-2(4,5)1(6)7/h7-9,12-13,22,25-28,31-37,40-41,65-66H,10-11,14-21,23-24,51-52H2,1-6H3,(H2,53,70)(H,54,56)(H,55,77)(H,57,67)(H,58,73)(H,59,71)(H,60,76)(H,61,78)(H,62,74)(H,63,75)(H,64,72)(H,68,69);(H,6,7)/t28-,31+,32+,33+,34+,35+,36+,37+,40+,41+;/m1./s1
Chemical Name	(3S)-3-[[(2S,3R)-2-[[(2S)-6-amino-2-[[(2S)-2-amino-3-(1H-imidazol-5-yl)propanoyl]amino]hexanoyl]amino]-3-hydroxybutanoyl]amino]-4-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[2-[[(2S)-1-[[(2S)-1-amino-4-methylsulfanyl-1-oxobutan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-2-oxoethyl]amino]-3-methyl-1-oxobutan-2-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-4-oxobutanoic acid;2,2,2-trifluoroacetic acid
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, avoid exposure to moisture.
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

ln Vitro

Within the tachykinin family of peptide neurotransmitters, neurokinin A (substance K) has the potential to play a significant role as a key mediator in human gastrointestinal and airway tissues. Through the NK-2 receptor, which is thought to be found on smooth muscle cells and pharmacologically linked to a GTP-binding protein, neurokinin A exerts its action. Tachykinins are a family of peptide neurotransmitters that includes neurokinin A. These peptides have a broad tissue distribution and are connected to both the peripheral and central nervous systems. Substance P and Neurokinin A or Substance K are the most well-known members of the chykinin family, which is characterized by the same COOH-terminal structure of Phe-X-Gly-Leu-Met-NH[1].

References

[1]. The human neurokinin A (substance K) receptor. Molecular cloning of the gene, chromosome localization, and isolation of cDNA from tracheal and gastric tissues. J Biol Chem. 1990 Nov 25;265(33):20455-62.

Solubility Data

Solubility (In Vitro)

DMSO: 100 mg/mL (80.17 mM) H2O: 50 mg/mL (40.09 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (2.00 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (2.00 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (2.00 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. Solubility in Formulation 4: 25 mg/mL (20.04 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	0.8017 mL	4.0085 mL	8.0171 mL
	5 mM	0.1603 mL	0.8017 mL	1.6034 mL
	10 mM	0.0802 mL	0.4009 mL	0.8017 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.