L-Homocysteic acid (L-HCA) is an endogenous excitatory amino acid (AA) that works as an NMDA receptor agonist (activator) (EC50= 14 μM). L-Homocysteic acid is neurotoxic and may be utilized in the research/study of neurological diseases.

Physicochemical Properties

Molecular Formula	C4H9NO5S
Molecular Weight	183.18296
Exact Mass	183.02
CAS #	14857-77-3
PubChem CID	177491
Appearance	White to off-white solid powder
Density	1.638g/cm3
Melting Point	261 °C
Index of Refraction	1.56
LogP	0.457
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	4
Heavy Atom Count	11
Complexity	227
Defined Atom Stereocenter Count	1
SMILES	C(CS(=O)(=O)O)[C@@H](C(=O)O)N
InChi Key	VBOQYPQEPHKASR-VKHMYHEASA-N
InChi Code	InChI=1S/C4H9NO5S/c5-3(4(6)7)1-2-11(8,9)10/h3H,1-2,5H2,(H,6,7)(H,8,9,10)/t3-/m0/s1
Chemical Name	(2S)-2-amino-4-sulfobutanoic acid
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

ln Vitro	NMDA receptors are activated by L-homocysteine at an EC50 of 14 μM[1]. In Purkinje cells, L-homocysteine (100 μM) causes strong currents (1.8 nA) that are resistant to a variety of NMDA receptor antagonists [1]. In isolated chick embryo retinas, L-homocysteine (250 μM, 30 min) efficiently causes acute excitotoxic reactions [2]. Rat primary neurons are exposed to concentration-dependent neurotoxic effects of L-homocysteine (0–2 mM, 48 h) [3].
ln Vivo	In early postnatal development, rats are given intraperitoneal injections of 4–11 mmol/kg of L-homocysteine, which causes seizures [4]. In Sprague-Dawley rats, L-homocysteine (ip, 100-1500 mg/kg) produced 61-67% of the maximum NMDA level response at doses of 1000 and 560 mg/kg, respectively, partially replacing NMDA. worth [5].
Animal Protocol	Animal/Disease Models: Wistar strain male albino rat[4] Doses: 4, 5.5, 8, 11 mM/kg Route of Administration: intraperitoneal (ip) injection, one time/day for 14 days Experimental Results: 4 mmol/kg induced flexion seizures. Resulting in intense tail wagging, spinning and movement. ECoG (electrocorticogram) activity decreases for 5-9 minutes.
References	[1]. Characterization of L-homocysteate-induced currents in Purkinje cells from wild-type and NMDA receptor knockout mice. J Neurophysiol . 1999 Nov;82(5):2820-6. [2]. L-homocysteic acid: an endogenous excitotoxic ligand of the NMDA receptor. Brain Res Bull. 1987 Nov;19(5):597-602. [3]. Inhibition of L-homocysteic acid and buthionine sulphoximine-mediated neurotoxicity in rat embryonic neuronal cultures with alpha-lipoic acid enantiomers. Brain Res. 2000 Feb 14;855(2):292-7. [4]. Convulsant action of D,L-homocysteic acid and its stereoisomers in immature rats. [5]. The discriminative stimulus effects of N-methyl-D-aspartate glycine-site ligands in NMDA antagonist-trained rats. Psychopharmacology (Berl). 2009 Apr;203(2):441-51.
Additional Infomation	L-homocysteic acid is a homocysteic acid with L-configuration. It has a role as a NMDA receptor agonist. It is an enantiomer of a D-homocysteic acid.

Solubility Data

Solubility (In Vitro)

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

Solubility (In Vivo)

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. Injection Formulations (e.g. IP/IV/IM/SC) 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). 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) Oral Formulations 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). 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 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	5.4591 mL	27.2956 mL	54.5911 mL
	5 mM	1.0918 mL	5.4591 mL	10.9182 mL
	10 mM	0.5459 mL	2.7296 mL	5.4591 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.