Ro 67-7476 is a novel and selective positive allosteric modulator of mGlu1 receptors. It can enhance glutamate-induced calcium release with an EC 50 of 60.1 nM and shows no activity at human mGlu1 receptors. While agonist-stimulated responses were not directly activated by Ro 67-7476, they were significantly potentiated, meaning that their maximum efficacy was increased. A radiolabeled glutamate-site agonist's affinity was enhanced upon binding of Ro 67-7476 at its extracellular N-terminal binding site. The amino acids necessary for these enhancing properties were located in the receptor transmembrane region using chimeric and mutant receptors. Lastly, in rat brain slices, the compounds increased synaptically evoked mGlu1 receptor responses. The possibility of creating a class of drugs for other family 3 G protein-coupled receptors is made possible by the discovery of selective positive allosteric modulators of mGlu1 receptors.

Physicochemical Properties

Molecular Formula	C17H18FNO2S
Molecular Weight	319.393726825714
Exact Mass	319.104
Elemental Analysis	C, 63.93; H, 5.68; F, 5.95; N, 4.39; O, 10.02; S, 10.04
CAS #	298690-60-5
Related CAS #	298690-60-5
PubChem CID	32681978
Appearance	White to yellow solid powder
LogP	4.678
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	3
Heavy Atom Count	22
Complexity	460
Defined Atom Stereocenter Count	1
SMILES	O=S(N1[C@H](C2=CC=C(F)C=C2)CCC1)(C3=CC=C(C)C=C3)=O
InChi Key	DAEHFYNGSSBGSS-KRWDZBQOSA-N
InChi Code	InChI=1S/C17H18FNO2S/c1-13-4-10-16(11-5-13)22(20,21)19-12-2-3-17(19)14-6-8-15(18)9-7-14/h4-11,17H,2-3,12H2,1H3/t17-/m0/s1
Chemical Name	(2S)-2-(4-fluorophenyl)-1-(4-methylphenyl)sulfonylpyrrolidine
Synonyms	Ro 67-7476; Ro-67-7476; Ro 67-7476
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	mGluR1a ( EC50 = 60.1 nM )
ln Vitro	Ro 67-7476 increases the amplitude of mGluR1 excitatory postsynaptic potentials (EPSCs) elicited by picrotoxin, AP5, or 2,3-dihydroxy-6-nitro-7-sulfamoylbenzoquionxaline in the Purkinje cells of rat cerebellar slices[3]. Ro 67-7476 triggers the phosphorylation of ERK1/2 even in the absence of external glutamate addition (EC50=163.3 nM). The EC50 for calcium mobilization potentiation and full P-ERK1/2 activation for Ro 67-7476 are almost the same[3]. Ro 67-7476 raises basal cAMP synthesis by about 8%. With an EC50 value of 17.7 μM, it increased threshold responses to glutamate in the cAMP accumulation assay[3].
References	[1]. Positive allosteric modulators of metabotropic glutamate 1 receptor: characterization, mechanism of action, and binding site. Proc Natl Acad Sci U S A. 2001 Nov 6;98(23):13402-7 [2]. A novel class of positive allosteric modulators of metabotropic glutamate receptor subtype 1 interact with a site distinct from that of negative allosteric modulators. Mol Pharmacol. 2006 Aug;70(2):616-26. [3]. Allosteric potentiators of metabotropic glutamate receptor subtype 1a differentially modulate independent signaling pathways in baby hamster kidney cells. Neuropharmacology. 2008 Sep;55(4):419-27.

Solubility Data

Solubility (In Vitro)

DMSO: ≥ 40 mg/mL (~125.2 mM) Water: N/A Ethanol: N/A

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.83 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (7.83 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.1310 mL	15.6548 mL	31.3097 mL
	5 mM	0.6262 mL	3.1310 mL	6.2619 mL
	10 mM	0.3131 mL	1.5655 mL	3.1310 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.