Salvinorin B ethoxymethyl ether

Salvinorin B ethoxymethyl ether
Clinical data
Other names	2-O-Ethoxymethylsalvinorin B; 2-EMSB; Symmetry
Drug class	κ-Opioid receptor agonist; Hallucinogen
ATC code	None;
Legal status
Legal status	Legal/Uncontrolled;
Identifiers
	IUPAC name (2S,4aR,6aR,7R,9S,10aS,10bR)-9-(ethoxymethoxy)-2-(3-furanyl)dodecahydro -6a,10b-dimethyl-4,10-dioxo-2H-naphtho-[2,1-c]pyran-7-carboxylic acid methyl ester;
PubChem CID	24873526;
ChemSpider	23323659 ;
ChEMBL	ChEMBL272939 ;
Chemical and physical data
Formula	C24H32O8
Molar mass	448.512 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CCOCO[C@H]1C[C@H]([C@@]2(CC[C@H]3C(=O)O[C@@H](C[C@@]3([C@H]2C1=O)C)C4=COC=C4)C)C(=O)OC;
	InChI InChI=1S/C24H32O8/c1-5-29-13-31-17-10-16(21(26)28-4)23(2)8-6-15-22(27)32-18(14-7-9-30-12-14)11-24(15,3)20(23)19(17)25/h7,9,12,15-18,20H,5-6,8,10-11,13H2,1-4H3/t15-,16-,17-,18-,20-,23-,24-/m0/s1 ; Key:ICVTXAUKIHJDGV-WFOQEEKOSA-N ;
	(verify)

Salvinorin B ethoxymethyl ether, also known as 2-O-ethoxymethylsalvinorin B (2-EMSB) or as symmetry, is a semi-synthetic analogue of the natural product salvinorin A, with a longer duration of action of around 3 hours (compared to less than 30 minutes for salvinorin A), and increased affinity and intrinsic activity at the κ-opioid receptor. Like the related compound herkinorin, 2-EMSB is made from salvinorin B, which is most conveniently made from salvinorin A by deacetylation, as while both salvinorin A and salvinorin B are found in the plant Salvia divinorum, salvinorin A is present in larger quantities.

2-EMSB has an affinity (K_i) of 0.32 nM at the κ-opioid receptor, and around 3,000 times selectivity over the μ- and δ-opioid receptors, making it one of the most potent and selective κ-opioid receptor agonists yet discovered. In animal studies it fully substituted for salvinorin A and the synthetic κ-opioid receptor agonist U-69593, and was active at doses as low as 0.005 mg/kg. Human bioassays found the compound to be active at 50 μg smoked.

It has been sold online as an analytical standard.