Human Metabolome Database Version 3.5

Showing metabocard for Alpha-Lactose (HMDB00186)

Record Information
Version 3.5
Creation Date 2005-11-16 08:48:42 -0700
Update Date 2013-05-29 13:24:57 -0600
Secondary Accession Numbers
  • HMDB05761
Metabolite Identification
Common Name Alpha-Lactose
Description alpha-Lactose is the major sugar present in milk and the main source of energy supplied to the newborn mammalian in its mother's milk. Lactose is also an important osmotic regulator of lactation. It is digested by the intestinal lactase (EC, an enzyme expressed in newborns. Its activity declines following weaning. As a result, adult mammals are normally lactose-intolerant and more than 75% of the human adult population suffers from lactase deficiency. Lactase deficiency is present in up to 80 percent of blacks and Latinos, and up to 100 percent of American Indians and Asians. Persons with lactose intolerance are unable to digest significant amounts of lactose. Common symptoms include abdominal pain and bloating, excessive flatus, and watery stool following the ingestion of foods containing lactose. A sizable number of adults believe they are lactose intolerant but do not actually have impaired lactose digestion, and some persons with lactase deficiency can tolerate moderate amounts of ingested lactose. A diagnosis of lactose intolerance can usually be made with a careful history supported by dietary manipulation. If necessary, diagnosis can be confirmed by using a breath hydrogen or lactose tolerance test. These mostly uncomfortable symptoms of lactose maldigestion are blamed for a variably dairy consumption. There is, however, emerging evidence that certain lactic acid-producing bacteria, which selectively consume prebiotics, may be beneficial against some lower intestinal diseases. Lactose maldigestion and lactose should perhaps be re-evaluated as a potential provider of such a prebiotic. Treatment consists primarily of avoiding lactose-containing foods. Lactase enzyme supplements may be helpful. The degree of lactose malabsorption varies greatly among patients with lactose intolerance, but most of them can ingest up to 350 mL of milk daily without symptoms. Lactose-intolerant patients must ensure adequate calcium intake. (PMID: 13130292 Link_out, 12216958 Link_out, 12197838 Link_out, 12018807 Link_out).
Structure Thumb
Download: MOL | SDF | PDB | SMILES | InChI
Display: 2D Structure | 3D Structure
  1. (+)-lactose
  2. 1-beta-D-Galactopyranosyl-4-alpha-D-glucopyranose
  3. 1-beta-delta-Galactopyranosyl-4-alpha-delta-glucopyranose
  4. 4-O-Hexopyranosylhexose
  5. a-Lactose
  6. Aletobiose
  7. alpha-Lactose
  8. Anhydrous lactose
  9. Dilactose
  10. Fast-Flo Lactose
  11. Flowlac 100
  12. Galactinum
  13. Glc-(4-1)Gal
  14. Granulac 140M
  15. Lactin
  16. Lactin (carbohydrate)
  17. Lactobiose
  18. Lactohale 300
  19. Lactose
  20. Lactose anhydride
  21. Lactose Fast-flo
  22. Milk sugar
  23. Osmolactan
  24. Pharmatosa DCL 21
  25. Pharmatose 21
  26. Pharmatose 325M
  27. Pharmatose DCL 15
  28. Prismalac
  29. Respitose ML 003
  30. Respitose SV 003
  31. Saccharum lactin
  32. Sachelac
  33. Sorbalac 400
  34. Sorbolac 400
  35. Spherolac
  36. Super-Tab
  37. Tablettose
  38. Tablettose 70
  39. Tablettose 80
  40. Zeparox EP
Chemical Formula C12H22O11
Average Molecular Weight 342.2965
Monoisotopic Molecular Weight 342.116211546
IUPAC Name (2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-{[(2R,3S,4R,5R,6S)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy}oxane-3,4,5-triol
Traditional IUPAC Name α-lactose
CAS Registry Number 63-42-3
SMILES OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)[C@@H](O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
InChI Identifier InChI=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
Chemical Taxonomy
Kingdom Organic Compounds
Super Class Carbohydrates and Carbohydrate Conjugates
Class Disaccharides
Sub Class Dihexoses
Other Descriptors
  • Aliphatic Heteropolycyclic Compounds
  • lactose(ChEBI)
  • 1,2 Diol
  • Acetal
  • Glycosyl Compound
  • Hemiacetal
  • O Glycosyl Compound
  • Oxane
  • Primary Alcohol
  • Secondary Alcohol
Direct Parent Dihexoses
Status Detected and Quantified
  • Endogenous
  • Component of Galactose metabolism
  • Component of Glycerolipid metabolism
  • Component of Glycosphingolipid metabolism
  • Component of Keratan sulfate biosynthesis
  • Component of N-Glycan biosynthesis
Application Not Available
Cellular locations
  • Cytoplasm
  • Extracellular
  • Lysosome
  • Golgi apparatus
Physical Properties
State Solid
Experimental Properties
Property Value Reference
Melting Point 201 - 202 °C Not Available
Boiling Point Not Available Not Available
Water Solubility 195 mg/mL at 20 °C Not Available
LogP Not Available Not Available
Predicted Properties
Property Value Source
Water Solubility 586 g/L ALOGPS
LogP -3.01 ALOGPS
LogP -4.7 ChemAxon
LogS 0.23 ALOGPS
pKa (strongest acidic) 11.25 ChemAxon
pKa (strongest basic) -3 ChemAxon
Hydrogen Acceptor Count 11 ChemAxon
Hydrogen Donor Count 8 ChemAxon
Polar Surface Area 189.53 A2 ChemAxon
Rotatable Bond Count 4 ChemAxon
Refractivity 68.34 ChemAxon
Polarizability 30.96 ChemAxon
Formal Charge 0 ChemAxon
Physiological Charge 0 ChemAxon
Gas-MS Spectrum
1H NMR Spectrum
13C NMR Spectrum
MS/MS Spectrum Quattro_QQQ 10
MS/MS Spectrum Quattro_QQQ 25
MS/MS Spectrum Quattro_QQQ 40
MS/MS Spectrum GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies)
MS/MS Spectrum GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies)
MS/MS Spectrum GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies)
[1H,1H] 2D NMR Spectrum
[1H,13C] 2D NMR Spectrum
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
  • Lysosome
  • Golgi apparatus
Biofluid Locations
  • Blood
  • Urine
Tissue Location
  • Bladder
  • Gut
  • Intestine
  • Muscle
  • Platelet
  • Skin
  • Spleen
Name SMPDB Link KEGG Link
Lactose Synthesis SMP00444 Not Available
Galactose Metabolism SMP00043 map00052 Link_out
Lactose Degradation SMP00457 Not Available
Normal Concentrations
Biofluid Status Value Age Sex Condition Reference
Blood Expected but not Quantified
Not Applicable Not Available Not Available Comment Normal
  • Not Applicable
Urine Detected and Quantified
11.8 (1.0-24.2) umol/mmol creatinine Adult (>18 years old) Both Comment Normal
Urine Detected and Quantified
30.0 (13.0-49.0) umol/mmol creatinine Infant (0-1 year old) Both Normal
  • Geigy Scient...
Urine Detected and Quantified
1.45 (0.63-3.45) umol/mmol creatinine Adult (>18 years old) Both Normal
  • Geigy Scient...
Urine Detected and Quantified
36.31 +/- 6.60 umol/mmol creatinine Adult (>18 years old) Not Specified Comment Normal
Urine Detected and Quantified
66.02 +/- 6.60 umol/mmol creatinine Adult (>18 years old) Not Specified Comment Normal
Urine Detected and Quantified
676.75 +/- 85.83 umol/mmol creatinine Newborn (0-30 days old) Not Specified Comment Normal
Urine Detected and Quantified
6.08 +/- 6.07 umol/mmol creatinine Infant (0-1 year old) Both Normal
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease References None
Associated OMIM IDs None
DrugBank ID DB04465 Link_out
DrugBank Metabolite ID Not Available
Phenol Explorer Compound ID Not Available
Phenol Explorer Metabolite ID Not Available
FoodDB ID FDB001145
KNApSAcK ID C00001136 Link_out
Chemspider ID 76293 Link_out
KEGG Compound ID C00243 Link_out
BioCyc ID LACTOSE Link_out
BiGG ID 34366 Link_out
Wikipedia Link Lactose Link_out
NuGOwiki Link HMDB00186 Link_out
Metagene Link HMDB00186 Link_out
METLIN ID 267 Link_out
PubChem Compound 84571 Link_out
PDB ID LBT Link_out
ChEBI ID 36219 Link_out
Synthesis Reference Ruffing, Anne; Mao, Zichao; Ruizhen Chen, Rachel. Metabolic engineering of Agrobacterium sp. for UDP-galactose regeneration and oligosaccharide synthesis. Metabolic Engineering (2006), 8(5), 465-473.
Material Safety Data Sheet (MSDS) Download (PDF)
General References
  1. Jung SK, Fujimoto D: A novel beta-galactoside-binding lectin in adult rat kidney. J Biochem (Tokyo). 1994 Sep;116(3):547-53. Pubmed: 7852273 Link_out
  2. Oozeer R, Furet JP, Goupil-Feuillerat N, Anba J, Mengaud J, Corthier G: Differential activities of four Lactobacillus casei promoters during bacterial transit through the gastrointestinal tracts of human-microbiota-associated mice. Appl Environ Microbiol. 2005 Mar;71(3):1356-63. Pubmed: 15746338 Link_out
  3. Dimopoulos MA, Anagnostopoulos A: Thalidomide in relapsed/refractory multiple myeloma: pivotal trials conducted outside the United States. Semin Hematol. 2003 Oct;40(4 Suppl 4):8-16. Pubmed: 15015891 Link_out
  4. Muthusamy A, Erickson DR, Sheykhnazari M, Bhavanandan VP: Enhanced binding of modified pentosan polysulfate and heparin to bladder--a strategy for improved treatment of interstitial cystitis. Urology. 2006 Jan;67(1):209-13. Pubmed: 16413377 Link_out
  5. Johnson JD, Simoons FJ, Hurwitz R, Grange A, Mitchell CH, Sinatra FR, Sunshine P, Robertson WV, Bennett PH, Kretchmer N: Lactose malabsorption among the Pima indians of Arizona. Gastroenterology. 1977 Dec;73(6):1299-304. Pubmed: 578795 Link_out
  6. Lustenberger RW: [A 23-year old patient with chronic diarrhea. Celiac disease and lactose intolerance] Schweiz Rundsch Med Prax. 2005 Feb 2;94(5):163-4. Pubmed: 15745382 Link_out
  7. Sharma A, DiCioccio RA, Allen HJ: Identification and synthesis of a novel 15 kDa beta-galactoside-binding lectin in human leukocytes. Glycobiology. 1992 Aug;2(4):285-92. Pubmed: 1421750 Link_out
  8. Rana SV, Bhasin DK, Vinayak VK: Lactose hydrogen breath test in Giardia lamblia-positive patients. Dig Dis Sci. 2005 Feb;50(2):259-61. Pubmed: 15745082 Link_out
  9. Mitchell JD, Brand J, Halbisch J: Weight-gain inhibition by lactose in Australian Aboriginal children. A controlled trial of normal and lactose hydrolysed milk. Lancet. 1977 Mar 5;1(8010):500-2. Pubmed: 65606 Link_out
  10. Soupene E, van Heeswijk WC, Plumbridge J, Stewart V, Bertenthal D, Lee H, Prasad G, Paliy O, Charernnoppakul P, Kustu S: Physiological studies of Escherichia coli strain MG1655: growth defects and apparent cross-regulation of gene expression. J Bacteriol. 2003 Sep;185(18):5611-26. Pubmed: 12949114 Link_out
  11. Yeoh E, Horowitz M, Russo A, Muecke T, Robb T, Chatterton B: The effects of abdominal irradiation for seminoma of the testis on gastrointestinal function. J Gastroenterol Hepatol. 1995 Mar-Apr;10(2):125-30. Pubmed: 7787155 Link_out
  12. Bondesson E, Bengtsson T, Borgstrom L, Nilsson LE, Norrgren K, Olsson B, Svensson M, Wollmer P: Dose delivery late in the breath can increase dry powder aerosol penetration into the lungs. J Aerosol Med. 2005 Spring;18(1):23-33. Pubmed: 15741771 Link_out
  13. Roberson CM: Lactose intolerance. Ala Nurse. 2004 Dec-2005 Feb;31(4):23-4; quiz 24. Pubmed: 15662762 Link_out
  14. Kim KI, Lee WS, Benevenga NJ: Feeding diets containing high levels of milk products or cellulose decrease urease activity and ammonia production in rat intestine. J Nutr. 1998 Jul;128(7):1186-91. Pubmed: 9649604 Link_out
  15. Gunther S, Patterson RE, Kristal AR, Stratton KL, White E: Demographic and health-related correlates of herbal and specialty supplement use. J Am Diet Assoc. 2004 Jan;104(1):27-34. Pubmed: 14702580 Link_out
  16. Delaveau P: [Milk lactose. Hypothesis on its biological importance]. Ann Pharm Fr. 2003;61(5):340-2. Pubmed: 13130292 Link_out
  17. Vilotte JL: Lowering the milk lactose content in vivo: potential interests, strategies and physiological consequences. Reprod Nutr Dev. 2002 Mar-Apr;42(2):127-32. Pubmed: 12216958 Link_out
  18. Szilagyi A: Review article: lactose--a potential prebiotic. Aliment Pharmacol Ther. 2002 Sep;16(9):1591-602. Pubmed: 12197838 Link_out
  19. Swagerty DL Jr, Walling AD, Klein RM: Lactose intolerance. Am Fam Physician. 2002 May 1;65(9):1845-50. Pubmed: 12018807 Link_out

Name: Lactase-phlorizin hydrolase
Reactions: Not Available
Gene Name: LCT
Uniprot ID: P09848 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
Name: Beta-1,4-galactosyltransferase 2
Reactions: Not Available
Gene Name: B4GALT2
Uniprot ID: O60909 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
Name: Alpha-lactalbumin
Reactions: Not Available
Gene Name: LALBA
Uniprot ID: P00709 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
Name: Beta-1,4-galactosyltransferase 1
Reactions: Not Available
Gene Name: B4GALT1
Uniprot ID: P15291 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
Name: Beta-galactosidase
Reactions: Not Available
Gene Name: GLB1
Uniprot ID: P16278 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA
Name: Glycolipid transfer protein
Reactions: Not Available
Gene Name: GLTP
Uniprot ID: Q9NZD2 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA