NMDA (N-Methyl-D-aspartic acid; LC488A; LC488 A; LC488-A; LC 488A; LC-488A) is an aspartic acid analog with an N-methyl substituent and D-configuration and a glutamate-like excitatory chemical substance. It acts as a potent and specific agonist for NMDA receptor mimicking the action of glutamate, which is a neurotransmitter acting at NMDA receptors.

Physicochemical Properties

Molecular Formula	C5H9NO4
Molecular Weight	147.13
Exact Mass	147.053
CAS #	6384-92-5
Related CAS #	6384-92-5
PubChem CID	22880
Appearance	White to off-white solid powder
Density	1.3±0.1 g/cm3
Boiling Point	258.2±30.0 °C at 760 mmHg
Melting Point	187-192 °C
Flash Point	110.0±24.6 °C
Vapour Pressure	0.0±1.1 mmHg at 25°C
Index of Refraction	1.494
LogP	-0.44
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	4
Heavy Atom Count	10
Complexity	145
Defined Atom Stereocenter Count	1
SMILES	CN[C@H](CC(=O)O)C(=O)O
InChi Key	HOKKHZGPKSLGJE-GSVOUGTGSA-N
InChi Code	InChI=1S/C5H9NO4/c1-6-3(5(9)10)2-4(7)8/h3,6H,2H2,1H3,(H,7,8)(H,9,10)/t3-/m1/s1
Chemical Name	(2R)-2-(methylamino)butanedioic acid
Synonyms	LC488A; LC488 A;LC488-A; LC 488A; LC-488A
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

Targets	N-methyl-D-aspartic acid (NMDA) receptor [1] N-methyl-D-aspartic acid (NMDA) receptor [2] N-methyl-D-aspartic acid (NMDA) receptor [3]
ln Vitro	Regardless of the incubation temperature, NMDA dramatically increases adrenal binding in a concentration-dependent manner [2]. In rat adrenal membrane preparations, NMDA (N-Methyl-D-aspartic acid) enhanced the binding of [3H]glutamate in a concentration-dependent manner. The enhancement was significant at concentrations ≥100 μM, with maximal binding increase observed at 1 mM [2] In cultured dorsal root ganglion (DRG) neurons from rats with neuropathic pain, activation of NMDA (N-Methyl-D-aspartic acid) receptor increased neuronal excitability, as indicated by enhanced action potential firing and elevated intracellular calcium concentration. This effect was blocked by NMDA receptor antagonists [3]
ln Vivo	NMDA (0.2 nM) had a substantial effect on MF, IF, IL, and EL, reducing installation and insertion frequency while shortening insertion and ejaculation times. During the 30-minute mating test, NMDA and AP-5 significantly increased and decreased ejaculation behavior, respectively. Bilateral microinjection of NMDA into the PVN significantly raised baseline LSNA, with the greatest rise happening within 5 minutes [1]. In male rats, microinjection of NMDA (N-Methyl-D-aspartic acid) into the paraventricular nucleus (PVN) of the hypothalamus induced ejaculatory responses in a dose-dependent manner. The effective dose range was 0.1-1 μg/0.5 μL, and the response was abolished by pretreatment with the NMDA receptor antagonist AP5. The ejaculatory effect was mediated via sympathetic outflow, as demonstrated by reduced responses after sympathetic nerve blockade [1] In a rat model of neuropathic pain induced by sciatic nerve ligation, decreased expression of growth and differentiation factor 10 (GDF10) led to activation of NMDA (N-Methyl-D-aspartic acid) receptor in the spinal cord. This activation contributed to mechanical allodynia and thermal hyperalgesia, which were reversed by NMDA receptor inhibition [3]
Enzyme Assay	[3H]glutamate binding assay in rat adrenal membranes: Prepare crude membrane fractions from rat adrenal glands by homogenization and differential centrifugation. Suspend membrane pellets in incubation buffer and incubate with [3H]glutamate (fixed concentration) and various concentrations of NMDA (N-Methyl-D-aspartic acid) at 25°C for 60 minutes. Terminate the reaction by rapid filtration through glass fiber filters pre-soaked in buffer. Wash filters thoroughly with ice-cold buffer to remove unbound ligand, then measure radioactivity using a liquid scintillation counter. Calculate specific binding as total binding minus non-specific binding (in the presence of excess unlabeled glutamate) [2]
Cell Assay	Dorsal root ganglion (DRG) neuron culture and excitability assay: Isolate DRG from adult rats, dissociate into single neurons by enzymatic digestion and mechanical trituration, and seed onto poly-L-lysine-coated coverslips. Culture neurons in neurobasal medium supplemented with growth factors for 3-5 days. Treat neurons with NMDA (N-Methyl-D-aspartic acid) (10-100 μM) and record action potentials using patch-clamp technique in current-clamp mode. Measure intracellular calcium concentration using a calcium-sensitive fluorescent dye, with fluorescence intensity recorded by confocal microscopy [3]
Animal Protocol	0.20 nmol in 100 nL saline Rats: Thirty male rats are paired with different receptive females for a total of three times (once every 3 days) a week prior to the experiment, only the males that ejaculated at least three times during this period are included. After selecting the male rats with normal ejaculatory ability. Saline (100 nL), NMDA (0.20 nmol in 100 nL saline), and AP-5 (10.0 nmol in 100 nL saline) are adminitration into the bilateral PVN of each male rat in random order. After 5 min, the behavioral testing is performed and recorded as described above. Copulatory behaviors occur once a week and the entire experiment lasted 4 weeks. PVN microinjection and ejaculatory response assay in rats: Adult male rats are anesthetized and placed in a stereotaxic frame. A guide cannula is implanted targeting the PVN based on stereotaxic coordinates. After a 7-day recovery period, NMDA (N-Methyl-D-aspartic acid) is dissolved in artificial cerebrospinal fluid (aCSF) and injected into the PVN at doses of 0.1, 0.5, or 1 μg/0.5 μL via an injection cannula connected to a microsyringe. Ejaculatory behavior (number of ejaculations, latency) is recorded for 30 minutes after injection. For antagonist studies, AP5 is injected 10 minutes before NMDA administration [1] Sciatic nerve ligation-induced neuropathic pain model in rats: Adult rats are anesthetized, and the left sciatic nerve is exposed and loosely ligated with chromic gut sutures. Sham-operated rats undergo nerve exposure without ligation. Two weeks after surgery, mechanical allodynia (paw withdrawal threshold to von Frey filaments) and thermal hyperalgesia (paw withdrawal latency to radiant heat) are assessed. To evaluate the role of NMDA receptor, NMDA (N-Methyl-D-aspartic acid) receptor antagonists are administered intraperitoneally, and behavioral tests are repeated 30 minutes later [3]
References	[1]. Centrally mediated ejaculatory response via sympathetic outflow in rats: role of N-methyl-D-aspartic acid receptors in paraventricular nucleus. Andrology. 2016 Nov 16. [2]. Enhancement of [3H]glutamate binding by N-methyl-D-aspartic acid in rat adrenal. Brain Res. 1987 Mar 17;406(1-2):24-31. [3]. Decrease of growth and differentiation factor 10 contributes to neuropathic pain through N-methyl-D-aspartate receptor activation. Neuroreport. 2017 May 24;28(8):444-450.
Additional Infomation	N-methyl-D-aspartic acid is an aspartic acid derivative having an N-methyl substituent and D-configuration. It has a role as a neurotransmitter agent. It is a D-alpha-amino acid, a D-aspartic acid derivative, an amino dicarboxylic acid and a secondary amino compound. An amino acid that, as the D-isomer, is the defining agonist for the NMDA receptor subtype of glutamate receptors (RECEPTORS, NMDA). NMDA (N-Methyl-D-aspartic acid) is an endogenous amino acid and a selective agonist of the NMDA receptor, a subtype of ionotropic glutamate receptors [1] Its activation of NMDA receptor requires co-binding of glutamate and glycine, leading to opening of the receptor-associated ion channel, influx of calcium and sodium ions, and subsequent neuronal excitation [2] In the hypothalamic PVN, NMDA (N-Methyl-D-aspartic acid)-induced NMDA receptor activation regulates ejaculatory function via the sympathetic nervous system, providing insights into the central control of male sexual behavior [1] In neuropathic pain, downregulation of GDF10 removes its inhibitory effect on NMDA (N-Methyl-D-aspartic acid) receptor, leading to excessive receptor activation and spinal sensitization, which contributes to pain hypersensitivity [3]

Solubility Data

Solubility (In Vitro)

DMSO: 5 mg/mL (33.98 mM) Water:30 mg/mL (203.9 mM) Ethanol:<1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 1 mg/mL (6.80 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 10.0 mg/mL clear DMSO stock solution to 400 μL of PEG300 and mix evenly; then add 50 μL of Tween-80 to the above solution and mix evenly; then add 450 μL of 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: ≥ 1 mg/mL (6.80 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 10.0 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. Solubility in Formulation 3: ≥ 1 mg/mL (6.80 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 10.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. Solubility in Formulation 4: 36.67 mg/mL (249.24 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	6.7967 mL	33.9836 mL	67.9671 mL
	5 mM	1.3593 mL	6.7967 mL	13.5934 mL
	10 mM	0.6797 mL	3.3984 mL	6.7967 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.