GPR109a (high affinity niacin receptor) – EC₅₀ = 1.3 μM (in a whole cell cAMP assay, racemic acifran) [2]

GPR109b (low affinity niacin receptor) – EC₅₀ = 4.2 μM (in a whole cell cAMP assay, racemic acifran) [2]

Acifran is a full agonist of GPR109a, with comparable agonist efficacy to the natural ligand β-hydroxybutyrate, and it is able to fully reverse the cAMP elevating effect of forskolin. It also fully reverses the cAMP elevating effect of forskolin in the GPR109b assay. The agonist potency of acifran in a whole cell cAMP assay was around 1 μM for GPR109a and it showed approximately 3-4 fold selectivity for GPR109a over GPR109b. [2]

In comparison, niacin and acipimox showed no effect up to 30 μM in the GPR109b assay. [2]

Acifran was clinically evaluated and was shown to lower free fatty acids in humans. [2]

The agonist activity of Acifran at GPR109a and GPR109b was determined using a whole cell cAMP assay. Cells stably transfected with the receptor (N-terminal HA-tagged GPR109a or GPR109b cloned into pcDNA3.1) were selected by G418 selection, and positive clones were identified by anti-HA immunostaining. Compound potencies were measured using a 96-well adenylyl cyclase activation FlashPlate assay. The assay was optimized for the appropriate receptor stable clone: 5 μM forskolin was used for stimulation, and 50,000 cells were used per well. Positive controls (200%) were defined as cAMP generated by cells without forskolin stimulation, and negative controls (100%) were defined as cAMP generated by cells with 5 μM forskolin stimulation. [2]

Rats: Male albino Sprague-Dawley rats (body wt 240-300 g) were housed in individual metabolism cages and fed Purina Rat Chow. They were not fasted before dosing. [1]

- For p.o. administration, Acifran was given in 1 ml of 2% Tween-80. For i.v. administration, it was given in 1 ml of 0.5% aqueous Na₂CO₃ solution. [1]

- Serial blood samples (approx. 250 μl) were collected from the jugular vein at various time points after dosing. In some studies, groups of four rats were decapitated at specified times (10, 20, 30, 45 min, 1, 1.5, 2, 2.5, 3, 4, 5, 6 h) for tissue collection. [1]

- For multiple dosing, rats received acifran p.o. at 10 mg/kg per day for 14 consecutive days. [1]

- Bile duct cannulation was performed in rats to study enterohepatic circulation; sham-operated rats served as controls. [1]

- For excretion studies, rats were placed in glass metabolism cages for 24 h to collect expired ¹⁴CO₂, or in individual metabolism cages for urine and feces collection at 24 h intervals for 14 days. [1]

- Whole-body autoradiography was performed on rats killed at 20 min, 1, 3, 6, 24, 72, and 120 h after oral administration of ¹⁴C-acifran (27 μCi) at a dose of 10 mg/kg. Sagittal sections (20 μm) were exposed to X-ray film for three weeks at -20°C. [1]

- Dogs: Male and female Beagle dogs (body wt 9-11 kg) were housed in individual metabolism cages. [1]

- Dogs received doses by gastric intubation in 20 ml of 1% Na₂CO₃ solution, or by i.v. injection in 5 ml of 0.75% Na₂CO₃. [1]

- In a crossover design, six dogs received ¹⁴C-acifran (50 μCi) at doses of 10 mg/kg p.o., 50 mg/kg p.o., and 10 mg/kg i.v., with three-week intervals. Blood (approx. 5 ml) was withdrawn at 0, 15, 30, 60, 90 min, 2, 3, 4, 5, 6, 9, 12, 24, 31, 48, 72, 96 h, plus additional 45 min and 2.5 h after i.v. injection. [1]

- For multiple dosing, four dogs received a compressed tablet containing 450 mg (approx. 40 mg/kg) of acifran p.o. for 14 consecutive days. Blood was collected at 20, 40, 60 min, 2, 3, 4, 6, 8, 10, 12, 15, 24, 48, 54, 72 h after single and last multiple doses. [1]

- Food effect study: 24 Beagle dogs (12 males, 12 females) were fasted overnight then given one 300 mg acifran tablet either 30 min after a meal (300 g horsemeat) or remained fasted, in a crossover design with a one-week interval. Blood samples were taken at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 h. [1]

- For excretion study, four dogs received ¹⁴C-acifran (50 μCi) at 10 mg/kg p.o. or i.v. in a crossover design with three-week intervals; urine and feces were collected at 24 h intervals for 14 days. [1]

Absorption: Acifran was rapidly absorbed. In rats, peak serum concentration (Cmax) was attained within 15 min after p.o. administration; in dogs, within 60 min. [1]

- Oral absorption: About 65% of a p.o. dose was absorbed in rats (based on p.o./i.v. AUC₀₋₃₁ₕ of ¹⁴C), and at least 88% in dogs. [1]

- Food effect: Food reduced the bioavailability of acifran by 27% in the dog (based on AUC₀₋₁₂ₕ of acifran after a 300 mg tablet). [1]

- Dose proportionality: Serum levels of acifran increased proportionally with dose (10 and 50 mg/kg) in rats. [1]

- Pharmacokinetic model: Two-compartment open model. [1]

- Elimination half-life (t₁/₂): 1.5 h in rat, 3 h in dog; unaffected by increasing dose or by daily multiple doses. [1]

- Intravenous pharmacokinetics in rat (10 mg/kg): distribution t₁/₂α = 0.17 h, elimination t₁/₂β = 1.5 h, total body clearance (Cl) = 126 ml/kg·h, volume of distribution (Vd) = 280 ml/kg. At 50 mg/kg i.v.: t₁/₂β = 1.5 h, Cl = 120 ml/kg·h, Vd = 259 ml/kg. [1]

- Intravenous pharmacokinetics in dog (10 mg/kg): t₁/₂α = 0.47 h, t₁/₂β = 3.0 h, Cl = 127 ml/kg·h, Vd = 4286 ml/kg. [1]

- Protein binding: Acifran was partially bound to serum proteins. Unbound drug (%): at 10 μg/ml – rat 16.8%, dog 29.7%, human 12.2%; at 50 μg/ml – rat 18.7%, dog 37.3%, human 14.2%. [1]

- Distribution: Radioactivity did not accumulate in tissues except kidney (¹⁴C concentration five times higher than in serum). Highest ¹⁴C levels in liver, kidneys, heart, lung, blood; lowest in brain, testes, fat, muscle. Elimination from tissues similar to serum. [1]

- Metabolism: No detectable biotransformation. Virtually all (>95%) of urinary ¹⁴C was unchanged acifran. No ¹⁴CO₂ in expired air, indicating the ¹⁴C-label was metabolically stable. [1]

- Excretion: Most absorbed dose excreted in urine. In rats, i.v.: 84.1% in urine (0-7 d), 4.8% in feces; p.o.: 61.6% urine, 29.0% feces. In dogs, i.v.: 90.6% urine, 2.4% feces; p.o.: 89.5% urine, 2.4% feces. About 90% of dose recovered, ~95% excreted within first 24 h. [1]

- Bile excretion: Only about 1% of i.v. dose detected in rat bile; no enterohepatic circulation. [1]

Drug-drug interaction: Acifran displaced protein-bound warfarin in rat and dog serum but not in human serum. At 10 μg/ml acifran, a small increase in free warfarin was observed. At 50 μg/ml acifran, free warfarin increased by about 17% in rat serum and 23% in dog serum (statistically significant only in dog); no significant change in human serum (3.5% increase). [1]

[1]. The metabolic disposition of acifran, a new antihyperlipidemic agent, in rats and dogs. Xenobiotica. 1986 Mar;16(3):251-63.

[2]. Analogues of acifran: agonists of the high and low affinity niacin receptors, GPR109a and GPR109b. J Med Chem. 2007 Apr 5;50(7):1445-8.

Acyclovir is a niacin receptor agonist that mimics the effect of niacin in increasing high-density lipoprotein (HDL) levels. Acyclovir produces these effects at lower doses and does not cause side effects such as skin flushing like niacin treatment.

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Acifran is a racemic compound. Chiral versions of acifran have been prepared, and all of the activity of racemic acifran could be assigned to the (S)-enantiomer, as the (R)-enantiomer was completely inactive. The absolute configuration was not confirmed experimentally. The activity for GPR109b tracked closely with that for GPR109a, and no improvement in selectivity was obtained following resolution, likely due to the exceptionally high homology between the two receptors. [2]

Acifran (5a, R1=Ph, R2=Me) served as the lead compound for the synthesis of a series of analogs described in the paper. Modifications to the phenyl ring, particularly meta-halo substitutions, yielded compounds with improved potency, but acifran itself remained a reference standard. [2]

C12H10O4

218.21

218.058

72420-38-3

72420-38-3;

51576

Off-white to light yellow solid powder

1.343 g/cm3

378.4ºC at 760 mmHg

149.4ºC

1.591

1.469

1

4

2

16

352

0

DFDGRKNOFOJBAJ-UHFFFAOYSA-N

InChI=1S/C12H10O4/c1-12(8-5-3-2-4-6-8)10(13)7-9(16-12)11(14)15/h2-7H,1H3,(H,14,15)

4,5-Dihydro-5-methyl-4-oxo-5-phenyl-2-furancarboxylic acid

Acifran Reductol

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)

DMSO : ~125 mg/mL (~572.84 mM)

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.)