HD-Phe-Pip-Arg-pNA (S-2238) di-HCl is a chromogenic substrate formed after the N-terminal portion of the fibrinogen alpha chain, the natural substrate of thrombin. HD-Phe-Pip-Arg-pNA di-HCl is specific for thrombin and is used for the determination of antithrombin heparin cofactor (AT-III). AT-III analysis using HD-Phe-Pip-Arg-pNA di-HCl is sensitive, accurate, and easy to perform.

Physicochemical Properties

Molecular Formula	C27H38CL2N8O5
Molecular Weight	625.55
Exact Mass	552.28
CAS #	62354-65-8
Related CAS #	H-D-Phe-Pip-Arg-pNA hydrochloride;160192-34-7;H-D-Phe-Pip-Arg-pNA acetate;115388-96-0;H-D-Phe-Pip-Arg-pNA;64815-81-2
PubChem CID	123853
Appearance	Typically exists as solid at room temperature
LogP	1
Hydrogen Bond Donor Count	5
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	11
Heavy Atom Count	40
Complexity	892
Defined Atom Stereocenter Count	3
SMILES	C1CCN([C@@H](C1)C(=O)N[C@@H](CCCN=C(N)N)C(=O)NC2=CC=C(C=C2)[N+](=O)[O-])C(=O)[C@@H](CC3=CC=CC=C3)N
InChi Key	YDMBNDUHUNWWRP-VJBWXMMDSA-N
InChi Code	InChI=1S/C27H36N8O5/c28-21(17-18-7-2-1-3-8-18)26(38)34-16-5-4-10-23(34)25(37)33-22(9-6-15-31-27(29)30)24(36)32-19-11-13-20(14-12-19)35(39)40/h1-3,7-8,11-14,21-23H,4-6,9-10,15-17,28H2,(H,32,36)(H,33,37)(H4,29,30,31)/t21-,22+,23+/m1/s1
Chemical Name	(2S)-1-[(2R)-2-amino-3-phenylpropanoyl]-N-[(2S)-5-(diaminomethylideneamino)-1-(4-nitroanilino)-1-oxopentan-2-yl]piperidine-2-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

References

[1]. Goodnight SH Jr, et al. Measurement of antithrombin III in normal and pathologic states using chromogenic substrate S-2238. Comparison with immunoelectrophoretic and factor Xa inhibition assays. Am J Clin Pathol. 1980;73(5):639-647. [2]. Voorthuizen H, Kluft C. Improved assay conditions for automated antithrombin III determinations with the chromogenic substrate S-2238. Thromb Haemost. 1984;52(3):350-353.

Solubility Data

Solubility (In Vitro)

H2O: 125 mg/mL (199.82 mM) DMSO: 125 mg/mL (199.82 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (3.33 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 20.8 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: ≥ 2.08 mg/mL (3.33 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 20.8 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: ≥ 2.08 mg/mL (3.33 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.5986 mL	7.9930 mL	15.9859 mL
	5 mM	0.3197 mL	1.5986 mL	3.1972 mL
	10 mM	0.1599 mL	0.7993 mL	1.5986 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.