AMPA receptors

LY451395 (2-propanesulfonamide, N-[(2R)-2-[4′-[2-[methylsulfonyl)amino]ethyl][1,1′-biphenyl]-4-yl]propyl]-) is a potent and highly selective potentiator of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors. LY451395 is a biaryl-bis-sulfonamide and is known to be highly metabolized in preclinical species. In those metabolism studies, the metabolite structures were proposed exclusively by the analysis of mass spectrometric data. Although mass spectrometry is clearly a technique of choice for rapid identification of drug metabolites, occasionally, nuclear magnetic resonance spectroscopy is required to unambiguously assign and characterize, particularly, the regio- and stereochemistry of metabolic changes. Nuclear magnetic resonance spectroscopy, in general, is less sensitive than other detection methods and demands several micrograms of material for the analysis. To support full structure characterization of metabolites by NMR, in this study we demonstrated the application of a microbial-based surrogate biocatalytic system to produce sufficient amounts of the mammalian metabolites of LY451395. The results revealed that incubation of LY451395 with Actinoplanes missouriensis NRRL B3342 generated several metabolites that were previously detected in the in vivo metabolism studies of the preclinical species. Subsequent large-scale bioconversion resulted in the isolation of seven mammalian metabolites in milligram quantities for structural characterization by nuclear magnetic resonance spectroscopy. Furthermore, a selected group of metabolites generated from the microbial conversion served as analytical standards to monitor and quantify drug metabolites during clinical investigations [1].

Mibampator (LY451395) being incubated with A. Multiple metabolites produced by missouriensis NRRL B3342 have been identified in in vivo metabolism studies in preclinical species [1]. In rats, the central effects of acutely toxic doses of ethanol are reversed by LY404187 and Mibampator (LY451395). In an operant task, where animals are trained to press a lever in order to receive a food reward, ethanol-induced motor coordination deficits and disruptions are significantly and dose-dependently reversed by mibampator (LY451395) [2].

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We present a substantial series of behavioral and imaging experiments, which demonstrate, for the first time, that increasing AMPA receptor-mediated neurotransmission via administration of potent and selective biarylsulfonamide AMPA potentiators LY404187 and Mibampator (LY451395) reverses the central effects of an acutely intoxicating dose of ethanol in the rat. Using pharmacological magnetic resonance imaging (phMRI), we observed that LY404187 attenuated ethanol-induced reductions in blood oxygenation level dependent (BOLD) in the anesthetized rat brain. A similar attenuation was apparent when measuring local cerebral glucose utilization (LCGU) via C14-2-deoxyglucose autoradiography in freely moving conscious rats. Both LY404187 and LY451395 significantly and dose-dependently reversed ethanol-induced deficits in both motor coordination and disruptions in an operant task where animals were trained to press a lever for food reward. Both prophylactic and acute intervention treatment with LY404187 reversed ethanol-induced deficits in motor coordination. Given that Mibampator (LY451395) and related AMPA receptor potentiators/ampakines are tolerated in both healthy volunteers and elderly patients, these data suggest that such compounds may form a potential management strategy for acute alcohol intoxication. [2]

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AMPA Receptor Potentiation Reverses Ethanol-Induced Deficits in Motor Control [2]
The ability of ethanol to disrupt tasks requiring balance and motor coordination is well documented across species (Arvola et al, 1958; Liguori et al, 1999). We therefore used two established tests of motor coordination, the tilt-plane and rotorod tests for our first investigations of the interaction between ethanol and AMPA receptor potentiation on a behavioral level.
Ethanol (2.0 g/kg) produced severe deficits in motor control in all the tilt-plane experiments. For the first experiment examining the ability of AMPA receptor potentiation to modulate ethanol's effects, pre-dosing with 1.5 and 3.0 mg/kg of both LY404187 (main effect of dose F7,72=27.84, p>0.001) and Mibampator (LY451395) (main effect of dose F5,54=44.82, p>0.001) 30 min before ethanol completely attenuated the ethanol-induced deficits (Figure 3). When we repeated the experiment to determine any prophylactic effects of AMPA receptor potentiation on the effects of ethanol, a similar reversal of these deficits was observed when LY404187 was administered 15 min after the ethanol challenge (main effect of dose F6,63=43.55, p<0.001, Figure 4).

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AMPA Receptor Potentiation Blocks Ethanol's Effects on Schedule Controlled Behavior [2]
We then assessed the interaction between ethanol and AMPA receptor potentiation on schedule-controlled response to food reward. Subjects were trained for a minimum of 11 days to press one of two levers for a food pellet before being tested under a variable interval 30 s (VI30) schedule of reinforcement. As shown in Figure 6 both the 1.5 and 3.0 mg/kg doses of LY404187 and Mibampator (LY451395) (main effect of dose F4,43=10.20, p<0.001) and the 6.0 mg/kg dose of LY404187 (main effect of dose F4,42=11.68, p<0.001) significantly attenuated ethanol-induced deficits in correct lever responding. Neither LY404187 or LY451395 alone had a significant effect on baseline lever-press response rates (both F<1) in the VI-30 assay.

Screening of Microbes. [1]
Initial biotransformation of Mibampator (LY451395) was carried out using 32 microbes consisting of bacterial, actinomycetous, and fungal strains. Among them, a single organism, Actinoplanes missouriensis, produced the most number of products that corresponded to metabolites observed in the preclinical species, including mice, rats, and dogs. Figure 2 shows the LC/UV/MS chromatograms of a small-scale bioconversion of LY451395 with A. missouriensis. This organism was chosen for...

LY404187 and Mibampator (LY451395) were used. For the phMRI experiment LY404187 was dissolved in 30% ethanol and administered subcutaneously at a volume of 2.0 ml/kg. The 30% ethanol solution was equivalent to 0.6 g/kg ethanol. For the rotorod test LY404187 was dissolved in 5% DMSO and 24% hydroxy-propyl-β-cyclodextrin and administered via oral gavage. For all other experiments LY404187 and Mibampator (LY451395) were dissolved in 5% DMSO and 24% hydroxy-propyl-β-cyclodextrin and administered subcutaneously at a volume of 2.0 ml/kg. Ethanol was diluted with distilled H2O to a 20% v/v solution and injected intraperitoneally. For the C14-2-DG, tilt plane, and rotorod tests the dose of ethanol was 2.0 g/kg, and for the variable interval 30 s (VI30) task the dose of ethanol was 1.0 g/kg. Corresponding vehicles served as control injections. All solutions were freshly prepared on test days.

[1]. Application of biocatalysis to drug metabolism: preparation of mammalian metabolites of a biaryl-bis-sulfonamide AMPA (alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) receptor potentiator using Actinoplanes missouriensis. Drug Metab Dispos. 2006 Jun;34(6):925-31.

[2]. AMPA receptor potentiation can prevent ethanol-induced intoxication. Neuropsychopharmacology. 2008 Jun;33(7):1713-23.

Mibampator has been used in trials studying the treatment of Alzheimer's Disease.
Mibampator (LY451395) (2-propanesulfonamide, N-[(2R)-2-[4'-[2-[methylsulfonyl)amino]ethyl][1,1'-biphenyl]-4-yl]propyl]-) is a potent and highly selective potentiator of the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors. It is a biaryl-bis-sulfonamide and is known to be highly metabolized in preclinical species. In those metabolism studies, the metabolite structures were proposed exclusively by the analysis of mass spectrometric data. Although mass spectrometry is clearly a technique of choice for rapid identification of drug metabolites, occasionally, nuclear magnetic resonance spectroscopy is required to unambiguously assign and characterize, particularly, the regio- and stereochemistry of metabolic changes. Nuclear magnetic resonance spectroscopy, in general, is less sensitive than other detection methods and demands several micrograms of material for the analysis. To support full structure characterization of metabolites by NMR, in this study we demonstrated the application of a microbial-based surrogate biocatalytic system to produce sufficient amounts of the mammalian metabolites of LY451395. The results revealed that incubation of LY451395 with Actinoplanes missouriensis NRRL B3342 generated several metabolites that were previously detected in the in vivo metabolism studies of the preclinical species. Subsequent large-scale bioconversion resulted in the isolation of seven mammalian metabolites in milligram quantities for structural characterization by nuclear magnetic resonance spectroscopy. Furthermore, a selected group of metabolites generated from the microbial conversion served as analytical standards to monitor and quantify drug metabolites during clinical investigations.[1]

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Using two technically independent neuroimaging techniques and a range of behavioral measures we have demonstrated, for the first time, that increasing AMPA receptor-mediated neurotransmission can reverse some of the acute effects of ethanol in the rat. The AMPA potentiator LY404187 reversed the decrease in BOLD MR signal observed in anesthetized rats receiving a vehicle solution equivalent to a low dose of ethanol (0.6 g/kg). Decreases in LCGU observed in freely moving conscious rats receiving 2.0 g/kg ethanol were also reversed by LY404187. Impaired performance in the tilt-plane test of motor control caused by ethanol (2.0 g/kg) was blocked by pretreatment with LY404187 and Mibampator (LY451395) and post-treatment with LY404187. Similarly, LY404187 reversed the effects of ethanol (2.0 g/kg) on the rotorod test. LY404187 and LY451395 also attenuated the disruptions in previously learned operant responses observed following ethanol (1.0 g/kg). When administered alone, both compounds had negligible effects on behavior and LCGU. [2]

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Using two technically independent neuroimaging techniques and a range of behavioral measures we have demonstrated, for the first time, that increasing AMPA receptor-mediated neurotransmission can reverse some of the acute effects of ethanol in the rat. The AMPA potentiator LY404187 reversed the decrease in BOLD MR signal observed in anesthetized rats receiving a vehicle solution equivalent to a low dose of ethanol (0.6 g/kg). Decreases in LCGU observed in freely moving conscious rats receiving 2.0 g/kg ethanol were also reversed by LY404187. Impaired performance in the tilt-plane test of motor control caused by ethanol (2.0 g/kg) was blocked by pretreatment with LY404187 and Mibampator (LY451395) and post-treatment with LY404187. Similarly, LY404187 reversed the effects of ethanol (2.0 g/kg) on the rotorod test. LY404187 and LY451395 also attenuated the disruptions in previously learned operant responses observed following ethanol (1.0 g/kg). When administered alone, both compounds had negligible effects on behavior and LCGU.[2]

C21H30N2O4S2

438.6039

438.164

C, 57.51; H, 6.89; N, 6.39; O, 14.59; S, 14.62

375345-95-2

9889366

White to off-white solid powder

1.2±0.1 g/cm3

609.4±65.0 °C at 760 mmHg

322.4±34.3 °C

0.0±1.7 mmHg at 25°C

1.562

3.25

2

6

10

29

679

1

C[C@@H](CNS(C(C)C)(=O)=O)C1=CC=C(C2=CC=C(CCNS(C)(=O)=O)C=C2)C=C1

ULRDYYKSPCRXAJ-KRWDZBQOSA-N

InChI=1S/C21H30N2O4S2/c1-16(2)29(26,27)23-15-17(3)19-9-11-21(12-10-19)20-7-5-18(6-8-20)13-14-22-28(4,24)25/h5-12,16-17,22-23H,13-15H2,1-4H3/t17-/m0/s1

(R)-N-(2-(4'-(2-(methylsulfonamido)ethyl)-[1,1'-biphenyl]-4-yl)propyl)propane-2-sulfonamide

LY-451395; MIBAMPATOR; 375345-95-2; LY451,395; LY 451,395; LY-451,395; (R)-N-(2-(4'-(2-(Methylsulfonamido)ethyl)-[1,1'-biphenyl]-4-yl)propyl)propane-2-sulfonamide; A9V5BW73UU; 2-PROPANESULFONAMIDE, N-[(2R)-2-[4'-[2-[(METHYLSULFONYL)AMINO]ETHYL][1,1'-BIPHENYL]-4-YL]PROPYL]-; LY 451395; LY451395;

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 : ≥ 25 mg/mL (~57.00 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.70 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.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.70 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 25.0 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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.70 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.

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