| Size | Price | Stock | Qty |
|---|---|---|---|
| 5mg |
|
||
| 10mg |
|
||
| 25mg |
|
||
| 50mg |
|
||
| 100mg |
|
||
| 250mg |
|
||
| 500mg | |||
| Other Sizes |
Purity: ≥98%
PF-1355 (also known as PF-06281355), a 2-thiouracil analog, is a novel, potent, selective and orally bioavailable mechanism-based MPO inhibitor used for treatment of vasculitic diseases. MPO is a critical mediator of vasculitis in mouse disease models. MPO has been associated with vasculitis, disseminated vascular inflammation typically involving pulmonary and renal microvasculature and often resulting in critical consequences. MPO contributes to vascular injury by 1) catabolizing nitric oxide, impairing vasomotor function; 2) causing oxidative damage to lipoproteins and endothelial cells, leading to atherosclerosis; and 3) stimulating formation of neutrophil extracellular traps, resulting in vessel occlusion and thrombosis. A pharmacokinetic/pharmacodynamic response model of PF-1355 exposure in relation with MPO activity was derived from mouse peritonitis. The contribution of MPO activity to vasculitis was then examined in an immune complex model of pulmonary disease. Oral administration of PF-1355 reduced plasma MPO activity, vascular edema, neutrophil recruitment, and elevated circulating cytokines. In a model of anti-glomerular basement membrane disease, formerly known as Goodpasture disease, albuminuria and chronic renal dysfunction were completely suppressed by PF-1355treatment. This study shows that MPO activity is critical in driving immune complex vasculitis and provides confidence in testing the hypothesis that MPO inhibition will provide benefit in treating human vasculitic diseases.
| Targets |
Myeloperoxidase (MPO) – a mechanism-based, irreversible inhibitor (kinact and KI constants were determined from progress curves but specific numerical values not provided in the main text; IC50 for MPO inhibition determined from percent inhibition plot, specific value not provided in the main text).
Thyroid peroxidase (TPO) – showed high selectivity over TPO (IC50 not provided, but percent inhibition data shown up to 100 μM). [1] |
|---|---|
| ln Vitro |
PF-1355 demonstrated a dose-dependent reduction in MPO activity in human neutrophils activated with phorbol ester (EC50 = 1.47 μM) and in residual MPO activity in human blood treated with lipopolysaccharide (EC50 = 2.03 μM) [1].
PF-1355 inhibited MPO activity in phorbol ester-stimulated human neutrophils as measured by taurine chlorination with an EC₅₀ of 1.47 μM. In lipopolysaccharide-treated human whole blood measuring residual MPO activity, PF-1355 showed an EC₅₀ of 2.08 μM. [1] |
| ln Vivo |
By reducing plasma MPO activity, angioedema, neutrophil recruitment, and increasing circulating cytokines, PF-1355 is administered orally. Treatment with PF-1355 completely suppressed proteinuria and chronic renal impairment in a model of glomerular basement membrane disease (previously known as Goodpasture's disease) [1].
In a murine peritonitis model, oral administration of PF-1355 reduced MPO activity in peritoneal lavage and plasma in a dose- and exposure-responsive manner. The relationship between plasma concentration and MPO activity inhibition was described by an inhibitory Imax model with an IC₅₀ of 437 ng/ml (1.4 μM). [1] In a mouse model of immune complex-mediated acute alveolitis (pulmonary vasculitis), prophylactic oral administration of PF-1355 (20 and 100 mg/kg) diminished perivascular lung edema in a dose-dependent manner (approximately 50% reduction at the high dose), reduced plasma MPO activity, suppressed neutrophil influx into bronchoalveolar lavage fluid at later time points, and markedly inhibited the elevation of circulating proinflammatory cytokines (TNF-α, MCP-1, KC, MIP-2). [1] In a mouse model of anti-glomerular basement membrane (anti-GBM) glomerulonephritis, oral administration of PF-1355 (60 mg/kg, starting 1 hour before anti-GBM serum and continued twice daily) completely suppressed the development of albuminuria and chronic renal dysfunction over a 3-week period. It also reduced plasma MPO activity and attenuated neutrophil accumulation in the kidney by >70% at 3 hours post-injury. [1] |
| Enzyme Assay |
MPO Inhibition Assay: Enzymatic activity of purified human MPO was monitored using H₂O₂ and Amplex Red as substrates. Inhibition progress curves at varying concentrations of PF-1355 (0.12–30 μM) were generated. The observed rate constants (kobs) for inactivation obtained from fitting the progress curves were plotted against [PF-1355] to determine the kinetic inhibition constants kinact and KI, indicating a two-step, time-dependent, irreversible inhibition mechanism.
Mechanism-Based Inhibition Test: MPO was pre-incubated with 5 μM PF-1355 or DMSO, with or without 2 μM H₂O₂. After 15 minutes, an aliquot was diluted 300-fold into MPO assay buffer containing H₂O₂ and Amplex Red substrates, and residual activity was monitored. No recovery of activity was observed when H₂O₂ was present during pre-incubation, confirming mechanism-based irreversible inhibition. TPO Selectivity Assay: TPO activity was measured by monitoring the oxidation of Amplex Red. Assay mixtures contained sodium phosphate buffer (pH 7.4), NaCl, H₂O₂, Amplex Red, diethylenetriamine pentaacetic acid, and DMSO. Reactions were initiated by adding TPO. The percent inhibition by PF-1355 was determined at concentrations up to 100 μM. [1] |
| Cell Assay |
MPO Chlorination Activity in Isolated Human Neutrophils: Neutrophils were isolated from human blood. PF-1355 or vehicle was added over a dilution series, and cells were stimulated with phorbol ester in media containing taurine (which traps HOCl). The resulting taurine chloramines were quantified after reaction with 3,3′,5,5′-tetramethylbenzidine and sulfuric acid, measuring absorbance at 450 nm to determine inhibition of HOCl generation.
Residual MPO Activity in Human Whole Blood: PF-1355 was incubated with heparinized human whole blood stimulated with bacterial lipopolysaccharide for 4 hours. MPO was then captured from the lysate on immobilized anti-MPO antibody-coated plates. After washing, residual MPO activity on the plate was determined using Amplex Red and H₂O₂. [1] |
| Animal Protocol |
Peritonitis Model for PK/PD: Mice received an intraperitoneal injection of 4% thioglycolate broth to recruit neutrophils. Twenty hours later, PF-1355 or vehicle (1% hydroxypropyl methylcellulose, 0.5% TRIS, 0.5% hypromellose acetate succinate, pH 9.5) was administered orally (p.o.), followed by intraperitoneal administration of opsonized zymosan or saline. Three hours later, mice were euthanized, peritoneal lavage and blood were collected for MPO activity and drug concentration analysis. [1]
IgG Immune Complex–Mediated Acute Alveolitis (Pulmonary Vasculitis): Mice were anesthetized. Lung injury was induced by intratracheal instillation of rabbit anti-bovine serum albumin (BSA) antibody followed by intravenous administration of BSA antigen. PF-1355 or vehicle was administered orally before injury induction. Mice were euthanized 4 hours post-injury. Lungs were collected for histopathology (edema quantification), bronchoalveolar lavage was performed for cell counts, and blood was collected for plasma MPO activity/mass and cytokine analysis. [1] Anti-GBM Glomerulonephritis Model: Mice received an intravenous injection of sheep anti-rat GBM serum, control sheep serum, or PBS. PF-1355 (60 mg/kg) or vehicle was administered orally 1 hour before anti-GBM serum and then continued twice daily (b.i.d.) until study endpoint. Urine was collected in metabolic cages at indicated times for albumin/creatinine ratio measurement. Mice were euthanized at 2 hours or 21 days for kidney tissue collection (for histology, immunofluorescence, confocal microscopy, transmission electron microscopy) and plasma collection (for MPO analysis). [1] |
| ADME/Pharmacokinetics |
In a mouse peritonitis model, the concentration of PF-1355 in plasma was positively correlated with the degree of inhibition of MPO activity in plasma and peritoneal lavage fluid. The IC₅₀ for MPO inhibition in plasma was estimated to be 437 ng/ml (1.4 μM). PF-1355 was administered orally in all in vivo studies. Supplementary Table 3 (cited in the text but not detailed) contains further pharmacokinetic characteristics for rats, mice, and dogs. [1]
|
| References | |
| Additional Infomation |
PF-1355 [2-(6-(2,5-dimethoxyphenyl)-4-oxo-2-thio-3,4-dihydropyrimidin-1(2H)-yl)acetamide] is a novel, selective, mechanism-based irreversible myeloperoxidase (MPO) inhibitor. Its inhibition requires MPO catalysis (the presence of H₂O₂). It is highly selective for closely related thyroid peroxidase (TPO) as well as a variety of other targets. PF-1355 has shown efficacy in preclinical models of immune complex vasculitis (lung and kidney), reducing vascular damage, neutrophil recruitment, and pro-inflammatory cytokine levels, highlighting the key role of MPO activity in these diseases and supporting its potential application in the treatment of human vasculitis. [1]
|
| Molecular Formula |
C14H15N3O4S
|
|---|---|
| Molecular Weight |
321.3516
|
| Exact Mass |
321.078
|
| CAS # |
1435467-38-1
|
| PubChem CID |
71568997
|
| Appearance |
White to off-white solid powder
|
| Density |
1.4±0.1 g/cm3
|
| Index of Refraction |
1.666
|
| LogP |
0.64
|
| Hydrogen Bond Donor Count |
2
|
| Hydrogen Bond Acceptor Count |
5
|
| Rotatable Bond Count |
5
|
| Heavy Atom Count |
22
|
| Complexity |
508
|
| Defined Atom Stereocenter Count |
0
|
| InChi Key |
LJBUZOGABRDGBR-UHFFFAOYSA-N
|
| InChi Code |
InChI=1S/C14H15N3O4S/c1-20-8-3-4-11(21-2)9(5-8)10-6-13(19)16-14(22)17(10)7-12(15)18/h3-6H,7H2,1-2H3,(H2,15,18)(H,16,19,22)
|
| Chemical Name |
2-(6-(2,5-Dimethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamide
|
| Synonyms |
PF-1355; PF 1355; PF1355; PF-06281355; PF 06281355; PF06281355;
|
| 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)
|
| Solubility (In Vitro) |
DMSO : ~50 mg/mL (~155.59 mM)
|
|---|---|
| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.08 mg/mL (6.47 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 (6.47 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. View More
Solubility in Formulation 3: ≥ 2.08 mg/mL (6.47 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 3.1119 mL | 15.5594 mL | 31.1187 mL | |
| 5 mM | 0.6224 mL | 3.1119 mL | 6.2237 mL | |
| 10 mM | 0.3112 mL | 1.5559 mL | 3.1119 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.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
 Determination of potency and reversibility of PF-1355 for MPO inhibition.J Pharmacol Exp Ther.2015 May;353(2):288-98. |
|---|
 PF-1355 and MPO deficiency protects in immune complex–induced pulmonary vasculitis.J Pharmacol Exp Ther.2015 May;353(2):288-98.
Establishing a pharmacokinetic/pharmacodynamic relationship between plasma [PF-1355] and MPO inhibition in a mouse peritonitis model. |
 MPO activity is essential for disease induction in a model of anti-GBM glomerulonephritis. |
Products are for research use only; We do not sell to patients
Copyright 2020 InvivoChem LLC | All Rights Reserved
COA
