A summary of the most common chemical descriptors (InChI Key and SMILES codes) for beta-Lactose are summarized together with 3D and 2D structures and relevant physico-chemical properties.

What is the beta-Lactose?

The molecule beta-Lactose presents a molecular formula of C12H22O11 and its IUPAC name is (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol.

Lactose is a sugar molecule that belongs in milk and other dairy products. It is made up of two simple sugars, glucose and galactose, that are joined together. Lactose is also known as milk sugar..

Lactose is an essential nutrient for young mammals, who cannot digest other types of sugar. For humans, lactose is broken down into glucose and galactose by the enzyme lactase, which belongs in the small intestine..

Lactose intolerance is a condition that occurs when the body does not produce enough lactase. This can result in abdominal pain, bloating, and diarrhea..

Lactose is used in the food industry as a sweetener, thickener, and emulsifier. It is also used in the pharmaceutical industry..

Lactose is a white, crystalline powder that is soluble in water..

3D structure

Cartesian coordinates

Geometry of beta-Lactose in x, y and z coordinates (Å units) to copy/paste elsewhere. Generated with Open Babel software.

2D drawing


beta-Lactose GUBGYTABKSRVRQ-DCSYEGIMSA-N chemical compound 2D structure molecule svg


Molecule descriptors

IUPAC name(2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol
InChI codeInChI=1S/C12H22O11/c13-1-3-5(15)6(16)9(19)12(22-3)23-10-4(2-14)21-11(20)8(18)7(10)17/h3-20H,1-2H2/t3-,4-,5+,6+,7-,8-,9-,10-,11-,12+/m1/s1

Other names (synonyms)

IUPAC nomenclature provides a standardized method for naming chemical compounds. Although this system is widely used in chemistry, many chemical compounds have also other names commonly used in different contexts. These synonyms can come from a variety of sources and are used for a variety of purposes.

One common source of synonyms for chemical compounds is the common or trivial names, assigned on the basis of appearance, properties, or origin of the molecule.

Another source of synonyms are historical or obsolete names employed in the past, however replaced nowadays by more modern or standardized names.

In addition to common and historical names, chemical compounds may also have synonyms that are specific to a particular field or industry.

  • (+)-Lactose
  • (2R,3R,4R,5S,6R)-6-(Hydroxymethyl)-5-(((2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)tetrahydro-2H-pyran-2,3,4-triol
  • (2R,3R,4R,5S,6R)-6-(hydroxymethyl)-5-((2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yloxy)tetrahydro-2H-pyran-2,3,4-triol
  • (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol
  • (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)tetrahydropyran-3-yl]oxy-tetrahydropyran-3,4,5-triol
  • (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-{[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy}oxane-3,4,5-triol
  • .beta.-D-Gal-(1-->4)-.beta.-D-Glc
  • .beta.-D-Lactose
  • .beta.-Lactose
  • 13Q3A43E0S
  • 1ax1
  • 1gwv
  • 1gzc
  • 1z3v
  • 2nn8
  • 2zgm
  • 4-(beta-D-Galactosido)-D-glucose
  • 4-O-beta-D-Galactopyranosyl-D-glucose
  • 4-O-beta-D-Galactopyranosyl-beta-D-glucopyranose
  • 5965-66-2
  • 60B85732-763B-4E21-BD67-6163315FD251
  • A832404
  • Aletobiose
  • Anhydrous lactose
  • BDBM50370453
  • C01970
  • CS-0206827
  • D-(+)-Lactose
  • D-Glucose, 4-O-b-D-galactopyranosyl- (9CI)
  • D-Glucose, 4-O-beta-D-galactopyranosyl
  • D-Lactose
  • DSSTox_CID_3193
  • DSSTox_GSID_23193
  • DSSTox_RID_76916
  • Fast-flo Lactose
  • Flowlac 100
  • Galactinum
  • Galb1-4Glcb
  • Galbeta1-4Glcbeta
  • LAT
  • Lactin
  • Lactin (carbohydrate)
  • Lactobiose
  • Lactose
  • Lactose (8CI)
  • Lactose Fast-flo
  • Lactose anhydrous
  • Lactose, unspecified form
  • Lactose-electricitas
  • Lactosum anhydricum
  • Lactosum, anhydrous
  • Milk sugar
  • NCGC00255383-01
  • Osmolactan
  • Pharmatosa DCL 21
  • Pharmatose 21
  • Pharmatose 325M
  • Q127900
  • Saccharum lactin
  • Saccharum lactis
  • Sorbalac 400
  • Super-Tab
  • Tablettose
  • Tablettose 70
  • Tablettose 80
  • Zeparox EP
  • beta-D-Galp-(1->4)-beta-D-Glcp
  • beta-D-Glucopyranose, 4-O-beta-D-galactopyranosyl-
  • beta-D-Lactose
  • beta-D-galactopyranosyl-(1->4)-beta-D-glucopyranose
  • beta-D-galactopyranosyl-(1->4)-beta-D-glucose
  • beta-Lactose

Reference codes for other databases

There exist several different chemical codes commonly used in orded to identify molecules:
  • ZINC4095761
  • CAS-63-42-3
  • UNII-13Q3A43E0S
  • AKOS015950662
  • DTXSID2023193
  • DTXSID5058723
  • CHEMBL417016
  • CHEBI:36218
  • Tox21_301866
  • EINECS 227-751-9

Physico-Chemical properties

IUPAC name(2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol
Molecular formulaC12H22O11
Molecular weight342.296
Melting point (ºC)
Boiling point (ºC)
Density (g/cm3)
Molar refractivity68.12
Topological polar surface area189.5

LogP and topological polar surface area (TPSA) values were estimated using Open Babel software.

The n-octanol/water partition coeficient (Kow) data is applied in toxicology and drug research. Kow values are used, to guess the environmental fate of persistent organic pollutants. High partition coefficients values, tend to accumulate in the fatty tissue of organisms. Molecules with a log(Kow) (or LogP) greater than 5 are considered to bioaccumulate.

TPSA values are the sum of the surface area over all polar atoms or molecules, mainly oxygen and nitrogen, also including hydrogen atoms.

In medicinal chemistry, TPSA is used to assess the ability of a drug to permeabilise cells.

For molecules to penetrate the blood-brain barrier (and act on receptors in the central nervous system), TPSA values below 90 Å2 are required. Thus, molecules with a polar surface area greater than 140 Å2 tend to be poorly permeable to cell membranes.