Complement component C5a receptor (C5aR/CD88)
PMX 205 targets the complement C5a receptor (C5aR; CD88), a G protein-coupled receptor that is activated by the complement activation product C5a. C5a is known to recruit and activate microglia and astrocytes in vitro by activation of a G protein-coupled cell-surface C5aR. By antagonizing C5aR, PMX 205 blocks C5a-mediated signaling, which is involved in inflammation, immune cell recruitment, and tissue damage. PMX 205 is a cyclic hexapeptide inhibitor of complement C5a receptors (C5aR1).

Through activation of G-protein-coupled cell surface C5aR, the complement activation product C5a is known to attract and activate microglia and astrocytes in vitro. The MTT technique 24-hour plate revealed substantial differences between each group and the negative control group. Values were reported for the EP54 group between 0.02724 and 0.1748, the PMX 205 (PMX205) group between 0.09893 and 0.2465, and the tamoxifen group between 0.09880 and 0.2464. Only two groups—PMX 205 and Tamoxifen—showed significant outcomes for the 48-hour incubation time plates. The values that were recorded varied from 0.5777 to 0.8551 and 0.04987 to 0.3273, respectively. Only one group—the antagonist group, PMX 205—showed significant results on the 72-hour plates; its values ranged from 0.02136 to 0.5322 [1].

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In vitro, PMX 205 has been studied using the MTT assay in mouse mammary tumor cell lines (4T1). Cells were plated at a density of 5.0×10⁴ cells/mL/well in 96-multiwell plates. After 24 hours of incubation, the medium was changed to serum-starve medium to synchronize the cells. In the MTT assay, PMX 205 showed significant results compared to the negative control group, with values recorded between 0.09893 to 0.2465 for the 24-hour plate. For the 48-hour plate, only PMX 205 and tamoxifen groups showed significant results. For the 72-hour plate, only PMX 205 showed a significant result.

PMX 205, sometimes known as PMX205, is a selective and active oral C5aR antagonist. When compared to rats given with a vehicle, animals treated with PMX 205 (1 mg/kg/day, p.o.) exhibited significantly longer survival times and lower terminal motor scores. In the lumbar spinal cord, mice treated with PMX 205 also displayed decreased levels of astrocyte growth. Oral administration of PMX 205 (1 mg/kg/day) was administered to SOD1G93A rats twice, on day 28 and day 70, prior to the development of significant clinical signs. There was no discernible difference in the survival times between the two treatment regimens [2], with both treatment groups showing considerably longer survival times than untreated rats (p=0.022, day 28; p=0.015, day 70). Between the ages of 12 and 15 months (n = 17), Tg2576 mice were given a 20 μg/mL dose of PMX 205 (PMX205) in their drinking water, at which time their amyloid deposits were rapidly accumulating. inside the range. Eleven untreated Tg2576 animals served as the controls. Compared to untreated animals, PMX 205-treated animals had a notably lower fibrous plaque burden (thioflavin response) after three months. In 3×Tg mice, PMX 205 likewise markedly decreased hyperphosphorylated tau (69%) [3].
PMX205 treatment (1 mg/kg/day, oral) in SOD1G93A transgenic rats significantly extended survival time (p=0.022 for day 28 start; p=0.015 for day 70 start) and reduced end-stage motor deficit scores (p=0.002 for day 28; p=0.011 for day 70) compared with untreated rats. PMX205 also significantly delayed disease onset (defined by initial body weight loss: p=0.035 for day 28; p=0.011 for day 70) and motor symptom onset (p=0.019 for day 28; p=0.008 for day 70). The time from disease onset to motor symptom onset was extended by 4-7 days. At end-stage, PMX205-treated rats showed a 47% reduction in astrocyte immunolabeling (GFAP) in the lumbar spinal cord compared with untreated SOD1G93A rats (p=0.044, n=5), but no reduction in microglial proliferation (Iba1, p=0.68). Motor scores at euthanasia were reduced by up to 40% in treated rats. [2]
In vivo, PMX 205 is an orally active, selective C5aR antagonist. Animals treated with PMX 205 (1 mg/kg/day, oral) displayed a significant extension of survival time and a reduction in end-stage motor scores compared to vehicle-treated rats. PMX 205-treated animals also displayed reduced levels of astroglial proliferation in the lumbar spinal cord. SOD1G93A rats orally dosed with PMX 205 (1 mg/kg/day) from days 28 and 70 before the onset of major clinical symptoms both had significant extension in survival time compared to untreated rats (p=0.022, day 28; p=0.015, day 70). Tg2576 mice treated with PMX 205 at 20 μg/mL in drinking water from 12 to 15 months of age showed significantly less fibrillar plaque load than untreated animals. In 3×Tg mice, PMX 205 significantly reduced hyperphosphorylated tau (69%).

PMX205 treatment from day 28 or day 70 (1 mg/kg/day) in SOD1G93A rats resulted in significant extension of survival (Kaplan-Meier, log rank test). Terminal motor scores (combined hind limb deficits, gait, and righting reflex) were significantly lower in treated groups compared to untreated. Disease onset (age at peak body weight) and motor-deficit onset (motor score ≥2) were delayed. Disease duration and motor-deficit duration were prolonged in treated groups. No significant differences were observed between the two treatment initiation time points. [2]
In non-cell-based receptor binding assays, PMX 205's affinity for the complement C5a receptor is evaluated using radioligand competition binding experiments. Membrane preparations from cells expressing recombinant human C5aR are incubated with a radiolabeled C5aR-selective ligand and varying concentrations of PMX 205. After incubation, bound and free radioligand are separated by filtration, and radioactivity is measured by scintillation counting. Competition curves are generated to determine IC50 values, which are converted to Ki values using the Cheng-Prusoff equation. These assays have established PMX 205's IC50 of 31 nM.

In vitro cellular assays for PMX 205 involve measuring its effects on C5a receptor-mediated signaling in cultured cells. The mouse mammary tumor cell line 4T1 is plated at a density of 5.0×10⁴ cells/mL/well in 96-multiwell plates in complete medium. After 24 hours of incubation, the medium is changed to serum-starve medium to synchronize the cells. Cells are treated with PMX 205, and cell viability is assessed using the MTT assay. The ability of PMX 205 to inhibit C5a-mediated cell signaling and proliferation is quantified.

In vivo animal studies for PMX 205 have been conducted in rat and mouse models. SOD1G93A rats were orally dosed with PMX 205 (1 mg/kg/day) from days 28 and 70 before the onset of major clinical symptoms. Both treatment groups had a significant extension in survival time compared to untreated rats (p=0.022, day 28; p=0.015, day 70). Tg2576 mice were treated with PMX 205 at 20 μg/mL in drinking water from 12 to 15 months of age. After 3 months, animals treated with PMX 205 showed significantly less fibrillar plaque load than untreated animals. In 3×Tg mice, PMX 205 also significantly reduced hyperphosphorylated tau (69%).

PMX205 was administered orally via drinking water at a dose of 1 mg/kg/day, starting from either day 28 or day 70 of age, continuing until the ethical endpoint (euthanasia). Control animals received water only. End-stage was defined as when rats reached a maximal righting reflex score (score = 12) or lost >20% of their peak body weight. Disease onset was determined by initial loss of body weight (age of peak body weight), and motor onset was defined as a motor score of 2 or above. Motor function was assessed using a modified motor scale scoring hind limb movement deficits (0-3 per limb), gait abnormalities (0-2), and righting reflex (0-4), with a maximal total score of 12. Rats displaying forelimb paralysis phenotype (~25% of animals) were excluded from the study to avoid confounding variables. [2]
PMX 205 is orally active. It has a molecular formula of C45H62N10O6 and a molecular weight of 839.05. The compound should be stored at -20°C, protected from light, in a cool and dry place. Powder can be stored at -80°C for 2 years or -20°C for 1 year; in solvent, it can be stored at -80°C for 6 months or -20°C for 1 month. An LC-MS/MS assay has been developed for pharmacokinetic studies of PMX 205 in mice.

Comprehensive toxicology data for PMX 205 are limited in publicly available sources. As a research compound intended for laboratory use, the compound is not intended for human use and should be handled with appropriate safety precautions. In animal studies, PMX 205 has been shown to be well-tolerated at the doses used. Its safety profile is consistent with that of other peptide-based receptor antagonists used in preclinical research.

[1]. Expression of complement C5a receptor and the viability of 4T1 tumor cells following agonist-antagonist treatment. J Cancer Res Ther. 2016 Apr-Jun;12(2):590-6.

[2]. The complement factor C5a contributes to pathology in a rat model of amyotrophic lateral sclerosis. J Immunol. 2008 Dec 15;181(12):8727-34.

[3]. Treatment with a C5aR antagonist decreases pathology and enhances behavioral performance in murine models of Alzheimer's disease. J Immunol. 2009 Jul 15;183(2):1375-83.

PMX-205 is a homocyclic peptide formed by the condensation of the carboxyl group of N(2)-(3-phenylpropionyl)-L-ornithine-L-proline-3-cyclohexyl-D-alanyl-L-tryptophanyl-L-arginine with the 5-amino group of the N(2)-acylornithine residue. It exhibits antagonistic, anti-inflammatory, and C5a receptor antagonistic activity. It is a nitrogen-containing macrocyclic compound and a homocyclic peptide.

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PMX 205 is a cyclic hexapeptide that acts as a potent antagonist of the complement C5a receptor (C5aR; IC50 = 31 nM). It is widely used to study C5aR1 pathobiology in mouse models of disease. PMX 205 has been shown to ameliorate experimentally induced colitis associated with increased IL-4 and IL-10 and to decrease pathology and enhance behavioral performance in murine models of Alzheimer's disease. It has also been studied in a rat model of amyotrophic lateral sclerosis. PMX 205 is not an approved drug and is intended for research use only.

C45H62N10O6

839.055

838.485

514814-49-4

PMX 205 Trifluoroacetate

6918845

Typically exists as solid at room temperature

5.252

8

7

12

61

1530

5

O=C1[C@@H]2CCCN2C([C@H](CCCNC([C@H](CCC/N=C(\N)/N)NC([C@H](CC2=CNC3C=CC=CC2=3)NC([C@@H](CC2CCCCC2)N1)=O)=O)=O)NC(CCC1C=CC=CC=1)=O)=O

VATFHFJULBPYLM-ILOBPARPSA-N

InChI=1S/C45H62N10O6/c46-45(47)49-24-9-18-34-40(57)48-23-10-19-35(51-39(56)22-21-29-12-3-1-4-13-29)44(61)55-25-11-20-38(55)43(60)54-36(26-30-14-5-2-6-15-30)41(58)53-37(42(59)52-34)27-31-28-50-33-17-8-7-16-32(31)33/h1,3-4,7-8,12-13,16-17,28,30,34-38,50H,2,5-6,9-11,14-15,18-27H2,(H,48,57)(H,51,56)(H,52,59)(H,53,58)(H,54,60)(H4,46,47,49)/t34-,35-,36+,37-,38-/m0/s1

N-((3R,6S,9S,15S,20aS)-6-((1H-indol-3-yl)methyl)-3-(cyclohexylmethyl)-9-(3-guanidinopropyl)-1,4,7,10,16-pentaoxoicosahydropyrrolo[1,2-a][1,4,7,10,13]pentaazacyclooctadecin-15-yl)-3-phenylpropanamide

PMX-205 PMX 205PMX205

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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.

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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).

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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)

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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).

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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

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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.

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 (Please use freshly prepared in vivo formulations for optimal results.)