Tandospirone (SM-3997) HCl is a potent and specific 5-HT1A receptor partial agonist with Ki of 27 nM. Tandospirone HCl has anxiolytic (anti-anxiety) and antidepressant effects. Tandospirone HCl may be utilized in the research/study of central nervous system diseases and their underlying mechanisms.

Physicochemical Properties

Molecular Formula	C21H30CLN5O2
Molecular Weight	419.94820356369
Exact Mass	419.209
CAS #	99095-10-0
Related CAS #	Tandospirone;87760-53-0
PubChem CID	13422623
Appearance	Typically exists as solid at room temperature
LogP	2.152
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	6
Heavy Atom Count	29
Complexity	572
Defined Atom Stereocenter Count	4
SMILES	Cl.O=C1[C@@H]2[C@H](C(N1CCCCN1CCN(C3N=CC=CN=3)CC1)=O)[C@H]1CC[C@@H]2C1
InChi Key	ACVFJYKNBOHIMH-DPFKZJTMSA-N
InChi Code	InChI=1S/C21H29N5O2.ClH/c27-19-17-15-4-5-16(14-15)18(17)20(28)26(19)9-2-1-8-24-10-12-25(13-11-24)21-22-6-3-7-23-21;/h3,6-7,15-18H,1-2,4-5,8-14H2;1H/t15-,16+,17+,18-;
Chemical Name	(1R,2S,6R,7S)-4-[4-(4-pyrimidin-2-ylpiperazin-1-yl)butyl]-4-azatricyclo[5.2.1.02,6]decane-3,5-dione;hydrochloride
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	Low potency (Ki values ranging from 1300 to 41000 nM) is seen for tandospirone (SM-3997) hydrochloride at 5-HT2, 5-HT1C, α1-adrenergic, α2-adrenergic, and dopamine D1 and D2 receptors. Orders of magnitude 2-HT1A to 3[1]. When it comes to β-adrenergic, muscarinic cholinergic, 5-HT1B, benzodiazepine, and 5-HT absorption sites, tandospirenone hydrochloride is almost inert [1]. By activating postsynaptic 5-HT1A receptors connected to G protein (Gi/o), tandospirone hydrochloride inhibits both neuronal activity and protein kinase A (PKA)-mediated protein phosphorylation [1].
ln Vivo	A rat model of conditioned fear stress-induced catalepsy shows inhibition of freezing behavior in response to tandospirone (SM-3997) hydrochloride (10-80 mg/kg; i.p.) [3]. At 0.5 hours, but not at 4 hours, tandospirenone hydrochloride shows plasma concentration-dependent anxiolytic effects [3].
Animal Protocol	Animal/Disease Models: Sevenweeks old male SD (SD (Sprague-Dawley)) rats (260-300 g), rat model of conditioned fear stress-induced catalepsy behavior [3] Doses: 10 mg/kg, 20 mg/kg, 40 mg/kg , 80 mg/kg Route of Administration: intraperitoneal (ip) injection Experimental Results: Inhibited freezing behavior in a dose-dependent manner.
References	[1]. Analysis of tandospirone (SM-3997) interactions with neurotransmitter receptor binding sites. Biol Psychiatry. 1990 Jul 15;28(2):99-109. [2]. Role of tandospirone, a 5-HT1A receptor partial agonist, in the treatment of central nervous system disorders and the underlying mechanisms. Oncotarget. 2017 Nov 24; 8(60): 102705–102720. [3]. The pharmacokinetics and pharmacodynamics of tandospirone in rats exposed to conditioned fear stress. Eur Neuropsychopharmacol. 2006 Jul;16(5):376-82.

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	2.3812 mL	11.9062 mL	23.8124 mL
	5 mM	0.4762 mL	2.3812 mL	4.7625 mL
	10 mM	0.2381 mL	1.1906 mL	2.3812 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.