Galactose

d-Galactose
Haworth projection of; β-d-galactopyranose	Fischer projection of; d-galactose
Names
	IUPAC names Galactose; galacto-Hexose
	Systematic IUPAC name (2R,3S,4S,5R,6)-2,3,4,5,6-Pentahydroxyhexanal
	Other names Brain sugar
Identifiers
CAS Number	59-23-4 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1724619
ChEBI	CHEBI:28061 ;
ChEMBL	ChEMBL300520 ;
ChemSpider	388480 ;
IUPHAR/BPS	4646;
KEGG	D04291 ;
MeSH	Galactose
PubChem CID	439357;
UNII	X2RN3Q8DNE ;
	InChI InChI=1S/C6H12O6/c7-1-2-3(8)4(9)5(10)6(11)12-2/h2-11H,1H2/t2−,3+,4+,5−,6+/m1/s1 Key: WQZGKKKJIJFFOK-PHYPRBDBSA-N ; InChI=1/C6H12O6/c7-1-2-3(8)4(9)5(10)6(11)12-2/h2-11H,1H2/t2−,3+,4+,5−,6+/m1/s1 Key: WQZGKKKJIJFFOK-PHYPRBDBBU;
	SMILES O[C@H]1[C@@H](O)[C@H](O[C@H](O)[C@@H]1O)CO;
Properties
Chemical formula	C6H12O6
Molar mass	180.156 g·mol−1
Appearance	White solid
Odor	Odorless
Density	1.5 g/cm3
Melting point	168–170 °C (334–338 °F; 441–443 K)
Solubility in water	650 g/L (20 °C)
Magnetic susceptibility (χ)	−103.00·10−6 cm3/mol
Pharmacology
ATC code	V04CE01 (WHO) V08DA02 (WHO) (microparticles)
Hazards
NFPA 704 (fire diamond)	1 0 0
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Galactose (/ɡəˈlæktoʊs/, galacto- + -ose, 'milk sugar'), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecule linked with a glucose molecule forms a lactose molecule.

Galactan is a polymeric form of galactose found in hemicellulose, and forming the core of the galactans, a class of natural polymeric carbohydrates.

D-Galactose is also known as brain sugar since it is a component of glycoproteins (oligosaccharide-protein compounds) found in nerve tissue.