IPTG

Athanor · official

C₉H₁₈O₅S · 238.3 g/mol

IUPAC name: (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-propan-2-ylsulfanyloxane-3,4,5-triol

Also called isopropyl beta-D-1-thiogalactopyranoside, lac inducer

Reagents

Open in Athanor

Drawn from its SMILES with RDKit

WarningHarmful if swallowed · Harmful in contact with skin · Harmful if inhaled

Names and identifiers

IUPAC name: (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-propan-2-ylsulfanyloxane-3,4,5-triol
Synonyms: isopropyl beta-D-1-thiogalactopyranoside, lac inducer, Isopropyl-beta-D-thiogalactopyranoside
+ 37 more
Isopropyl beta-D-thiogalactopyranoside, ISOPROPYL THIOGALACTOSIDE, Isopropyl-beta-D-thiogalactoside, Isopropyl beta-D-1-thiogalactopyranoside, Isopropyl beta-D-thiogalactoside, Isopropyl 1-Thio-beta-D-galactopyranoside, DTXSID6041052, X73VV2246B, (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-propan-2-ylsulfanyloxane-3,4,5-triol, CHEBI:61448, beta-D-Galactopyranoside, 1-methylethyl 1-thio-, (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-propan-2-ylsulfanyl-oxane-3,4,5-triol, Thiogalactoside, Isopropyl, isopropyl beta-thiogalactoside, Isopropyl 1 Thio beta D galactopyranoside, 1-Thio-beta-D-galactopyranoside, Isopropyl, RefChem:389084, DTXCID4021052, (3R,4R,6S)-2-(hydroxymethyl)-6-isopropylsulfanyl-tetrahydropyran-3,4,5-triol, 206-703-0, (2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-(isopropylthio)tetrahydro-2H-pyran-3,4,5-triol, Isopropy-beta-D-thiogalactopyranoside, b-D-Galactopyranoside, 1-methylethyl 1-thio-, MFCD00063273, Isopropyl |A-D-thiogalactoside, 1-Methylethyl 1-thio-beta-D-galactopyranoside, .beta.-D-Galactopyranoside, 1-methylethyl 1-thio-, C9H18O5S, (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-(propan-2-ylsulfanyl)oxane-3,4,5-triol, Isopropyl ss-D-Thiogalactopyranoside, Dioxane Free, IPTG (dioxane free), IPTG (isopropyl-|A-D-thiogalactopyranoside), isopropyl |A-D-thiogalactopyranoside, UNII-X73VV2246B, Isopropyl beta- thiogalactoside, 3dyo, 3muz
Molecular formula: C₉H₁₈O₅S
Empirical formula: C₉H₁₈O₅S
Molecular weight: 238.3 g/mol
Exact mass: 238.08749
CAS number: 367-93-1
PubChem CID: 656894
Canonical SMILES: CC(C)SC1C(C(C(C(O1)CO)O)O)O
Isomeric SMILES: CC(C)S[C@H]1[C@@H]([C@H]([C@H]([C@H](O1)CO)O)O)O
InChI: InChI=1S/C9H18O5S/c1-4(2)15-9-8(13)7(12)6(11)5(3-10)14-9/h4-13H,3H2,1-2H3/t5-,6+,7+,8-,9+/m1/s1
InChIKey: BPHPUYQFMNQIOC-NXRLNHOXSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Calculated

Heavy atoms: 15
Rings: 1
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 1
H-bond donors: 4
H-bond acceptors: 6
Rotatable bonds: 3
TPSA (Å²): 90.2 computed here · PubChem 115
Formal charge: 0
XLogP3: -0.5 PubChem
Complexity: 201 PubChem
Stereocenters: 5 definedCIP: C3: R · C5: S · C10: R · C12: S · C14: R
Double-bond geometry: None specified
Point group: C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C45.36%
H7.61%
O33.57%
S13.46%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: -1.07 Crippen (Wildman and Crippen 1999)
log S (water solubility): -0.44 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.98 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 238.31
log P ≤ 5 (Crippen): -1.07
H-bond donors ≤ 5: 4
H-bond acceptors ≤ 10: 6

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Warning

Most widely reported: 142 company reports to ECHA. Source [1].

Harmful or irritant

H302Harmful if swallowed (12% of reports)
H312Harmful in contact with skin (12% of reports)
H332Harmful if inhaled (12.7% of reports)

Precautionary statements: P261, P264, P270, P271, P280, P301+P317, P302+P352, P304+P340, P317, P321, P330, P362+P364, P501

View all classifications (2)

[1] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 81% (115 of 142) of all reports.
[1] European Chemicals Agency (ECHA) · 142 reports · WarningH302, H312, H332

Safety data sheets on the supplier’s page: Accela ChemBio Inc., Alfa Chemistry, Enamine.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[2]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[3]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.