Octylthioglucoside

n-Octyl β-D-thioglucopyranoside

Names
IUPAC name (2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-octylsulfanyl-oxane-3,4,5-triol
Other names (1S)-Octyl-β-D-thioglucoside
Identifiers
CAS Number	85618-21-9
3D model (JSmol)	Interactive image
ChemSpider	571158
ECHA InfoCard	100.115.951
PubChem CID	656909
InChI InChI=1S/C14H28O5S/c1-2-3-4-5-6-7-8-20-14-13(18)12(17)11(16)10(9-15)19-14/h10-18H,2-9H2,1H3/t10-,11-,12+,13-,14+/m1/s1 Key: CGVLVOOFCGWBCS-RGDJUOJXSA-N
SMILES CCCCCCCCS[C@H]1[C@@H]([C@H]([C@@H]([C@H](O1)CO)O)O)O
Properties
Chemical formula	C14H28O5S
Molar mass	308.434 g/mol
Appearance	Colourless Waxy Semi-Solid
Melting point	125 to 131 °C (257 to 268 °F; 398 to 404 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

n-Octyl β-D-thioglucopyranoside (octylthioglucoside, OTG) is a mild nonionic detergent that is used for cell lysis or to solubilise membrane proteins without denaturing them. This is particularly of use in order to crystallise them or to reconstitute them into lipid bilayers. It has a critical micelle concentration of 9 mM.

It is an analog of the commonly used detergent octyl glucoside, the presence of the thioether linkage making it resistant to degradation by beta-glucosidase enzymes.

N-alkyl thioglycosides of the n-octyl-β-D-thioglucopyranoside type are not naturally occurring. However, mustard oil glycosides are common natural S-glycosides.

The synthesis of n-octyl-β-D-thioglucopyranoside starts from D-glucose (I) which is prepared with acetic anhydride and concentrated sulfuric acid to give α-D-glucopyranose pentaacetate (pentaacetylglucose) (II). Pentaacetylglucose is reacted with hydrogen bromide to give 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (acetobromo glucose) (III) which yields with thiourea in acetone almost quantitatively the isothiuronium salt 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl-1-isothiuronium bromide (IV).

The nucleophilic thiolate anion formed after neutralization and reduction with sodium sulfite to the thiol in the alkaline reacts again almost quantitatively with 1-bromoctane to n-octyl-2,3,4,6-tetra-O-acetyl-1-thio-β D-glucopyranoside (peracetylated octylthioglucoside) (V). From V, the target product n-octyl-1-thio-β-D-glucopyranoside (VI) can be obtained in an overall yield of about 80% via the quantitatively proceeding alkaline deacetylation by means of sodium hydroxide in methanol.

In the trichloroacetimidate method of Richard R. Schmidt, the peracetylated O- (α-D-glucopyranyl) trichloroacetimidate forms with 1-octanethiol via boron trifluoride-etherate catalysis upon inversion exclusively n-octyl-1-thio-β-D-glucopyranoside (after deacetylation), while the perbenzylated O-(α-D-glucopyranyl) trichloroacetimidate is converted upon retention to the n-octyl-1-thio-α-D-glucopyranoside (after debenzylation).