PDC31 (THG113.31; ILGHXDYK) is an allosteric and noncompetitive inhibitor of the FP Prostaglandin Receptor. PDC31 is a D-amino acid (AA)-based oligopeptide that works as a smooth muscle contractile agent. PDC31 reduces the intensity and duration of uterine contractions in vivo and may be utilized to study preterm labor and primary dysmenorrhea (PD). PDC31 also enhances Ca2+-dependent large conductance K+ channels in human myometrial cells.

Physicochemical Properties

Molecular Formula	C45H71N13O13
Molecular Weight	1002.12455010414
Exact Mass	1001.529
CAS #	634586-40-6
PubChem CID	57392015
Appearance	White to off-white solid powder
LogP	-5.8
Hydrogen Bond Donor Count	15
Hydrogen Bond Acceptor Count	16
Rotatable Bond Count	33
Heavy Atom Count	71
Complexity	1780
Defined Atom Stereocenter Count	8
SMILES	C(O)(=O)[C@@H](CCCCN)NC(=O)[C@@H](CC1=CC=C(O)C=C1)NC(=O)[C@@H](CC(O)=O)NC(=O)[C@@H](CCCNC(N)=O)NC(=O)[C@@H](CC1N=CNC=1)NC(=O)CNC(=O)[C@@H](CC(C)C)NC(=O)[C@@H]([C@H](C)CC)N
InChi Key	IVQBXMPXSLAIFC-OSMHAOILSA-N
InChi Code	InChI=1S/C45H71N13O13/c1-5-25(4)37(47)43(68)58-31(17-24(2)3)38(63)51-22-35(60)53-33(19-27-21-49-23-52-27)41(66)54-29(10-8-16-50-45(48)71)39(64)57-34(20-36(61)62)42(67)56-32(18-26-11-13-28(59)14-12-26)40(65)55-30(44(69)70)9-6-7-15-46/h11-14,21,23-25,29-34,37,59H,5-10,15-20,22,46-47H2,1-4H3,(H,49,52)(H,51,63)(H,53,60)(H,54,66)(H,55,65)(H,56,67)(H,57,64)(H,58,68)(H,61,62)(H,69,70)(H3,48,50,71)/t25-,29-,30-,31-,32-,33-,34-,37-/m1/s1
Chemical Name	(2R)-6-amino-2-[[(2R)-2-[[(2R)-2-[[(2R)-2-[[(2R)-2-[[2-[[(2R)-2-[[(2R,3R)-2-amino-3-methylpentanoyl]amino]-4-methylpentanoyl]amino]acetyl]amino]-3-(1H-imidazol-5-yl)propanoyl]amino]-5-(carbamoylamino)pentanoyl]amino]-3-carboxypropanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]hexanoic 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 (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	FP Receptor ~30 nM (Ki) PGF2α
ln Vitro	In human myometrial smooth muscle cells, PDC31 (10 μM, 50 μM) activates BKCa channels and increases open-state channel activity by an average of 4- and 6-fold at 10 μM and 50 μM, respectively [2]. PDC31 cumulatively suppresses the spontaneous contractions of human myometrium in vitro at intervals of 20 minutes (1 nM–10 μM) [2]. The ILGHXDYK sequence, which is present in the transmembrane domain of the human PGF2a receptor, makes up PDC31 [3]. PDC31 can delay birth in preterm animal models and lessen the length and force of PGF2a-induced contractions in the muscle strip model [4].
References	[1]. Prostaglandin FP receptor antagonists: discovery, pharmacological characterization and therapeutic utility. Br J Pharmacol. 2019 Apr;176(8):1059-1078. [2]. THG113.31, a specific PGF2alpha receptor antagonist, induces human myometrial relaxation and BKCa channel activation. Reprod Biol Endocrinol. 2007 Mar 16;5:10. [3]. Specific PGF(2alpha) receptor (FP) antagonism and human uterine contractility in vitro. BJOG. 2005 Aug;112(8):1034-42. [4]. A first-in-human study of PDC31 (prostaglandin F2α receptor inhibitor) in primary dysmenorrhea. Hum Reprod. 2014 Nov;29(11):2465-73.

Solubility Data

Solubility (In Vitro)

H2O: 100 mg/mL (99.79 mM)

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	0.9979 mL	4.9894 mL	9.9787 mL
	5 mM	0.1996 mL	0.9979 mL	1.9957 mL
	10 mM	0.0998 mL	0.4989 mL	0.9979 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.