| Description | Rauwolscine hydrochloride (Isoyohimbine hydrochloride) , a natural alkaloid, is a specific and reversible α2-adrenergic receptor antagonist (Ki: 12 nM) [1]. It is a stereoisomer of yohimbine, which potently antagonizes both α1- and α2-adrenergic receptors [1]. Rauwolscine hydrochloride also acts as a receptor antagonist at the serotonin 5-HT2B receptor (Ki: 14.3 nM) and as a weak partial agonist at 5-HT1A (IC50: 1.3 μM) [3]. The α2-adrenergic receptor has diverse physiological functions and antagonists like rauwolscine have numerous applications, including the modulation of mood and behavior [5]. |
| In vitro | [3H]Rauwolscine binding to the α2 adrenergic receptor is reversible, stcreospccific, and saturable. [3H]Rauwolscine specifically labels both the high and low-affinity states of the α2 adrenergic receptor in brain membranes[1]. [3H]Rauwolscine also behaves as a 5-HT1A receptor agonist, indicating that rauwolscine (as well as yohimbine) has agonistic properties at the level of 5-HT autoreceptors[2]. When using [3H]5-HT as a radioligand, rauwolscine is determined to have a relatively high affinity for the human receptor (Ki: 14.3/35.8 nM, for human and rat)[3]. Saturation studies show that the affinity of [3H]Rauwolscine is similar in mouse, rabbit, rat, dog (2.33-3.03 nM) except man where it is significantly higher (0.98 nM) [4]. |
| Target activity | α2-adrenoceptor:12 nM (Ki) |
| Synonyms | Corynanthidine hydrochloride, 盐酸育亨宾碱, 萝芙素盐酸盐, α-Yohimbine hydrochloride, Isoyohimbine hydrochloride |
| molecular weight | 390.9 |
| Molecular formula | C21H27ClN2O3 |
| CAS | 6211-32-1 |
| Storage | Powder: -20°C for 3 years | In solvent: -80°C for 1 year |
| Solubility | DMSO: 13.75 mg/mL (35.18 mM), Heating is recommended. H2O: 5 mM, Heating is recommended. |
| References | 1. Perry B D, U'Prichard D C. [3H] Rauwolscine (α-yohimbine): a specific antagonist radioligand for brain α2-adrenergic receptors[J]. European journal of pharmacology, 1981, 76(4): 461-464. 2. De Vos H, Czerwiec E, De Backer J P, et al. [3H] Rauwolscine behaves as an agonist for the 5-HTa receptors in human frontal cortex membranes[J]. European Journal of Pharmacology: Molecular Pharmacology, 1991, 207(1): 1-8. 3. Wainscott D B, Sasso D A, Kursar J D, et al. [3H] Rauwolscine: an antagonist radioligand for the cloned human 5-hydroxytryptamine2B (5-HT2B) receptor[J]. Naunyn-Schmiedeberg's archives of pharmacology, 1997, 357(1): 17-24. 4. Neylon C B, Summers R J. [3H]‐rauwolscine binding to α2‐adrenoceptors in the mammalian kidney: apparent receptor heterogeneity between species[J]. British journal of pharmacology, 1985, 85(2): 349-359. 5. Cottingham C, Wang Q. α2 adrenergic receptor dysregulation in depressive disorders: Implications for the neurobiology of depression and antidepressant therapy[J]. Neuroscience & Biobehavioral Reviews, 2012, 36(10): 2214-2225. |
| Kinase | Fresh bovine frontal cortex is incubated in triplicate with [3H]Rauwolscine (82 Ci/mM, diluted). Incubation is terminated by filtration under reduced pressure over filters, which are then rinsed with ice-cold Tris-HCl buffer, dried overnight and added to disposable glass mini vials containing 3.0 mL of a 95% Econofluor/5% Protocol solution. Samples are counted by liquid scintillation spectrometry with an efficiency of 32%. (-)- [3H]Epinephrine binding to bovine cortex membranes is conducted at 25°C[1]. |