Gabazine free base is a novel and potent GABA receptor antagonist

Physicochemical Properties

Molecular Formula	C15H17N3O3
Molecular Weight	287.31
Exact Mass	367.053
Elemental Analysis	C, 62.71; H, 5.96; N, 14.63; O, 16.71
CAS #	105538-73-6
PubChem CID	107896
Appearance	Typically exists as solid at room temperature
Density	1.25g/cm3
Boiling Point	474.4ºC at 760 mmHg
Flash Point	240.7ºC
Vapour Pressure	8.33E-10mmHg at 25°C
Index of Refraction	1.598
LogP	2.96
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	6
Heavy Atom Count	21
Complexity	451
Defined Atom Stereocenter Count	0
SMILES	OC(CCCN1C(=N)C=CC(C2=CC=C(OC)C=C2)=N1)=O
InChi Key	ACVGNKYJVGNLIL-UHFFFAOYSA-N
InChi Code	InChI=1S/C15H17N3O3/c1-21-12-6-4-11(5-7-12)13-8-9-14(16)18(17-13)10-2-3-15(19)20/h4-9,16H,2-3,10H2,1H3,(H,19,20)
Chemical Name	4-[6-imino-3-(4-methoxyphenyl)pyridazin-1-yl]butanoic acid
Synonyms	J331.170H; Gabazine; 105538-73-6; Gabazine free base; SR-95531; CHEBI:34968; 4-(6-imino-3-(4-methoxyphenyl)pyridazin-1(6H)-yl)butanoic acid; SR95531; Gabazine free base
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	GABAA receptor (IC50 = 0.2 μM)
ln Vitro	Anesthetic drugs are known to interact with GABAA receptors, both to potentiate the effects of low concentrations of GABA and to directly gate open the ion channel in the absence of GABA; however, the site(s) involved in direct gating by these drugs is not known. We have studied the ability of alphaxalone (an anesthetic steroid) and pentobarbital (an anesthetic barbiturate) to directly activate recombinant GABAA receptors containing the alpha 1, beta 2, and gamma 2L subunits. Steroid gating was not affected when either of two mutated beta 2 subunits [beta 2 (Y157S) and beta 2 (Y205S)] are incorporated into the receptors, although these subunits greatly reduce the affinity of GABA binding. These observations indicate that steroid binding and subsequent channel gating do not require these particular residues, as already shown for barbiturates. Bicuculline or Gabazine (two competitive antagonists of GABA binding) reduced the currents elicited by alphaxalone and pentobarbital from wild-type GABAA receptors; however, Gabazine produced only a partial block of response pentobarbital or alphaxalone, and bicuculline only partially blocked responses to pentobarbital. These observations indicate that the blockers do not compete with alphaxalone or pentobarbital for a single class of sites on the GABAA receptor. Finally, at receptors containing alpha 1 beta 2 (Y157S) gamma 2L subunits, both bicuculline and gabazine showed weak agonist activity and actually potentiated responses to alphaxalone. These observations indicate that the blocking drugs can produce allosteric changes in GABAA receptors, at least those containing this mutated beta 2 subunit. We conclude that the sites for binding steroids and barbiturates do not overlap with the GABA-binding site. Furthermore, neither gabazine nor bicuculline competes for binding at the steroid or barbiturate sites. The data are consistent with a model in which both gabazine and bicuculline act as allosteric inhibitors of channel opening for the GABAA receptor after binding to the GABA-binding site [1].
References	[1]. Bicuculline and gabazine are allosteric inhibitors of channel opening of the GABAA receptor. J Neurosci. 1997 Jan 15;17(2):625-34.
Additional Infomation	SR95531 is a member of methoxybenzenes.

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	3.4806 mL	17.4028 mL	34.8056 mL
	5 mM	0.6961 mL	3.4806 mL	6.9611 mL
	10 mM	0.3481 mL	1.7403 mL	3.4806 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.