(S)-Terazosin is the S-enantiomer of Terazosin, which is a selective α1-adrenoceptor antagonist used for treatment of symptoms of BPH (benign prostatic hyperplasia, an enlarged prostate).

Physicochemical Properties

Molecular Formula	C19H25N5O4
Molecular Weight	387.432904005051
Exact Mass	387.191
CAS #	109351-33-9
Related CAS #	Terazosin hydrochloride dihydrate; 70024-40-7; (R)-Terazosin; 109351-34-0; Terazosin; 63590-64-7; Terazosin hydrochloride; 63074-08-8
PubChem CID	969465
Appearance	White to off-white solid
LogP	1.64
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	4
Heavy Atom Count	28
Complexity	544
Defined Atom Stereocenter Count	1
SMILES	O1CCC[C@H]1C(N1CCN(C2N=C(C3C=C(C(=CC=3N=2)OC)OC)N)CC1)=O
InChi Key	VCKUSRYTPJJLNI-AWEZNQCLSA-N
InChi Code	InChI=1S/C19H25N5O4/c1-26-15-10-12-13(11-16(15)27-2)21-19(22-17(12)20)24-7-5-23(6-8-24)18(25)14-4-3-9-28-14/h10-11,14H,3-9H2,1-2H3,(H2,20,21,22)/t14-/m0/s1
Chemical Name	[4-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperazin-1-yl]-[(2S)-oxolan-2-yl]methanone
Synonyms	(S)-Terazosin; (S)-Terazocin; 109351-33-9; [4-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperazin-1-yl]-[(2S)-oxolan-2-yl]methanone; Piperazine, 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-[(tetrahydro-2-furanyl)carbonyl]-, (S)-; (S)-(4-(4-Amino-6,7-dimethoxyquinazolin-2-yl)piperazin-1-yl)(tetrahydrofuran-2-yl)methanone; NCGC00016903-01; MLS001165675; BIDD:GT0682;
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	α1a-adrenoceptor ( Ki = 3.91 nM ); α1b-adrenoceptor ( Ki = 0.79 nM ); α1d-adrenoceptor ( Ki = 1.16 nM ); α2a-adrenoceptor ( Ki = 729 nM ); α2Ba-adrenoceptor ( Ki = 3.5 nM ); α2c-adrenoceptor ( Ki = 46.4 nM )
ln Vitro	The racemic compound and both of its enantiomers exhibit strong and seemingly equal affinity for α1-adrenoceptor subtypes with Ki values in the low nanomolar range. In isolated tissues, the enantiomers also demonstrate potent antagonistic effects on α1-adrenoceptors, with the enantiomers roughly equipotent to the racemate at each subtype. Racemate or (S)-Terazosin binds more potently at α2b sites than (R)-Terazosin[1].
ln Vivo	(S)-Terazosin exhibits antagonistic effects on a rat atrial α2B receptor, sporting a pEC30 of 6.93. (s)-Terazosin exhibits antagonistic effects on the α1A and α2A receptors in the rat vas deferens, with corresponding pA2 values of8.3 and 6.12.[1]
Enzyme Assay	Terazosin and its enantiomers, antagonists of alpha 1-adrenoceptors, were studied in radioligand binding and functional assays to determine relative potencies at subtypes of alpha 1- and alpha 2-adrenoceptors in vitro. The racemic compound and its enantiomers showed high and apparently equal affinity for subtypes of alpha 1-adrenoceptors with Kl values in the low nanomolar range, and showed potent antagonism of alpha 1-adrenoceptors in isolated tissues, with the enantiomers approximately equipotent to the racemate at each alpha 1-adrenoceptor subtype. At alpha 2b sites, R(+) terazosin bound less potently than either the S(-) enantiomer or racemate. R(+) terazosin was also less potent than the S(-) enantiomer or the racemate at rat atrial alpha 2B receptors. These agents were not significantly different in their potencies at alpha 2a or alpha 2A sites. Since the high affinity for alpha 2B sites of quinazoline-type alpha-adrenoceptor antagonists has been used to differentiate alpha 2-adrenoceptor subtypes, the low affinity of R(+) terazosin for these sites was unexpected. Because terazosin or its enantiomers are approximately equipotent at alpha 1-adrenoceptor subtypes, the lower potency of R(+) terazosin at alpha 2B receptors indicates a somewhat greater selectivity for alpha 1-compared to alpha 2B adrenoceptor subtypes. The possible pharmacological significance of this observation is discussed[1].
References	[1]. Actions of terazosin and its enantiomers at subtypes of alpha 1- and alpha 2-adrenoceptors in vitro. J Recept Signal Transduct Res. 1995 Sep-Dec;15(7-8):863-85.

Solubility Data

Solubility (In Vitro)

DMSO: ~150 mg/mL (~387.2 mM)

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	2.5811 mL	12.9056 mL	25.8111 mL
	5 mM	0.5162 mL	2.5811 mL	5.1622 mL
	10 mM	0.2581 mL	1.2906 mL	2.5811 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.