PFI-1 (PF6405761) is a novel, highly potent and selective BET (bromodomain-containing protein) inhibitor with antineoplastic activity. It inhibits BRD4 with an IC50 of 0.22 μM in cell-free assays. Co-crystal structures showed that PFI-1 acts as an acetyl-lysine (Kac) mimetic inhibitor efficiently occupying the Kac binding site in BRD4 and BRD2. PFI-1 has antiproliferative effects on leukaemic cell lines and efficiently abrogates their clonogenic growth. PFI-1 has antiproliferative effects on leukaemic cell lines and efficiently abrogates their clonogenic growth. Exposure of sensitive cell lines with PFI-1 results in G1 cell cycle arrest, down-regulation of MYC expression as well as induction of apoptosis and induces differentiation of primary leukaemic blasts.

Physicochemical Properties

Molecular Formula	C16H17N3O4S
Molecular Weight	347.39
Exact Mass	347.093
Elemental Analysis	C, 55.32; H, 4.93; N, 12.10; O, 18.42; S, 9.23
CAS #	1403764-72-6
Related CAS #	1403764-72-6
PubChem CID	71271629
Appearance	Light yellow to yellow solid powder
Density	1.4±0.1 g/cm3
Index of Refraction	1.628
LogP	0.53
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	4
Heavy Atom Count	24
Complexity	562
Defined Atom Stereocenter Count	0
SMILES	O=S(C1=CC=CC=C1OC)(NC2=CC3=C(NC(N(C)C3)=O)C=C2)=O
InChi Key	TXZPMHLMPKIUGK-UHFFFAOYSA-N
InChi Code	InChI=1S/C16H17N3O4S/c1-19-10-11-9-12(7-8-13(11)17-16(19)20)18-24(21,22)15-6-4-3-5-14(15)23-2/h3-9,18H,10H2,1-2H3,(H,17,20)
Chemical Name	2-methoxy-N-(3-methyl-2-oxo-1,2,3,4-tetrahydroquinazolin-6-yl)benzenesulfonamide
Synonyms	PFI 1; PF 6405761; PFI-1; PF-6405761; PF6405761; PFI1
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

ln Vitro	PFI-1 exhibits antiproliferative effects on leukemic cell lines and efficiently abrogates their clonogenic proliferation. Exposure of sensitive cell lines with PFI-1 resulted in G1 cell-cycle arrest, downregulation of MYC expression, as well as activation of apoptosis and causes differentiation of primary leukemic blasts. Cells treated to PFI-1 demonstrate considerable downregulation of Aurora B kinase, thus attenuating phosphorylation of the Aurora substrate H3S10, giving an additional technique for the selective suppression of this well-established oncology target[1]. PFI-1 interacts to the cyclic AMP response binding protein with Kd of 49 μM. PFI-1 has an EC50 of 1.89 μM for the suppression of IL6 generation from human blood mononuclear cells stimulated by LPS[2]. PFI-1 produces dose-dependent loss of cell viability in T4302 CD133+ cells[3]. PFI-1 inhibits the proliferation of three NET cell lines (Bon-1 generated from a pancreatic NET, and H727 and H720 produced from lung NETs)[4].
ln Vivo	The rat given PFI-1 (1 mg/kg, iv) has a half-life of one hour, a volume of distribution of one L/kg, and a plasma clearance of eighteen mL/min/kg. When PFI-1 is given orally to rats at a dose of 2 mg/kg, the oral bioavailability is as low as 32%. The mouse given PFI-1 (2 mg/kg, sc) has a half-life of roughly 2 hours, a Tmax of 1 hour, and a Cmax of 58 ng/mL[2].
Animal Protocol	Dissolved in normal saline; 1mg/kg; i.v. injection Rats model
References	[1]. PFI-1, a Highly Selective Protein Interaction Inhibitor, Targeting BET Bromodomains. Cancer Res. 2013 May 21. [Epub ahead of print]. [2]. Identification of a chemical probe for bromo and extra C-terminal bromodomain inhibition through optimization of a fragment-derived hit. J Med Chem. 2012 Nov 26;55(22):9831-7. [3]. Inhibition of BET bromodomain targets genetically diverse glioblastoma. Clin Cancer Res. 2013 Apr 1;19(7):1748-59. [4]. Epigenetic modifiers reduce proliferation of human neuroendocrine tumour cell lines. Endocrine Abstracts (2013) 31 P149.
Additional Infomation	2-methoxy-N-(3-methyl-2-oxo-1,4-dihydroquinazolin-6-yl)benzenesulfonamide is a member of quinazolines.

Solubility Data

Solubility (In Vitro)

DMSO: 69 mg/mL (198.6 mM) Water:<1 mg/mL Ethanol:<1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.20 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 (7.20 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.8786 mL	14.3930 mL	28.7861 mL
	5 mM	0.5757 mL	2.8786 mL	5.7572 mL
	10 mM	0.2879 mL	1.4393 mL	2.8786 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.