Record Information
Version 1.0
Update Date 1/22/2018 12:54:54 PM
Metabolite IDPAMDB000076
Name: alpha-Lactose
Description:Alpha-Lactose is the alpha anomoer of lactose. It is a disaccharide that consists of galactose and glucose joined by an acetal oxygen bridge in the beta orientation Lactose is a sugar substrate that can be readily used by Pseudomonas aeruginosa. The consumption of lactose by Pseudomonas aeruginosa is controlled by the lac operon. The operon includes beta-galactosidase, lactose permease, and thiogalactoside transacetylase. The lactose permease, which sits in the cytoplasmic membrane, transports lactose into the cell. Beta-galactosidase, a cytoplasmic enzyme, subsequently cleaves lactose into glucose and galactose.
  • α-D-lactose
  • α-lactose
  • (+)-lactose
  • 1-b-D-Galactopyranosyl-4-a-D-glucopyranose
  • 1-b-delta-Galactopyranosyl-4-a-delta-glucopyranose
  • 1-b-δ-Galactopyranosyl-4-a-δ-glucopyranose
  • 1-beta-D-Galactopyranosyl-4-alpha-D-glucopyranose
  • 1-beta-delta-Galactopyranosyl-4-alpha-delta-glucopyranose
  • 1-β-D-Galactopyranosyl-4-α-D-glucopyranose
  • 1-β-δ-Galactopyranosyl-4-α-δ-glucopyranose
  • 4-O-Hexopyranosylhexose
  • A-D-Lactose
  • A-Lactose
  • Aletobiose
  • Alpha-D-Lactose
  • Alpha-Lactose
  • Anhydrous lactose
  • Dilactose
  • Fast-Flo Lactose
  • Flowlac 100
  • Galactinum
  • Glc-(4-1)Gal
  • Granulac 140M
  • Lactin
  • Lactin (carbohydrate)
  • Lactin (carbohydric acid)
  • Lactobiose
  • Lactohale 300
  • Lactose
  • Lactose anhydride
  • Lactose Fast-flo
  • Milk sugar
  • Osmolactan
  • Pharmatosa DCL 21
  • Pharmatose 21
  • Pharmatose 325M
  • Pharmatose DCL 15
  • Prismalac
  • Respitose ML 003
  • Respitose SV 003
  • Saccharum lactin
  • Sachelac
  • Sorbalac 400
  • Sorbolac 400
  • Spherolac
  • Super-Tab
  • Tablettose
  • Tablettose 70
  • Tablettose 80
  • Zeparox EP
  • α-D-Lactose
  • α-Lactose
Chemical Formula: C12H22O11
Average Molecular Weight: 342.2965
Monoisotopic Molecular Weight: 342.116211546
CAS number: 63-42-3
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
Chemical Taxonomy
Taxonomy DescriptionThis compound belongs to the class of organic compounds known as o-glycosyl compounds. These are glycoside in which a sugar group is bonded through one carbon to another group via a O-glycosidic bond.
Kingdom Organic compounds
Super ClassOrganooxygen compounds
Class Carbohydrates and carbohydrate conjugates
Sub ClassGlycosyl compounds
Direct Parent O-glycosyl compounds
Alternative Parents
  • O-glycosyl compound
  • Disaccharide
  • Oxane
  • Secondary alcohol
  • Polyol
  • Hemiacetal
  • 1,2-diol
  • Oxacycle
  • Organoheterocyclic compound
  • Acetal
  • Hydrocarbon derivative
  • Primary alcohol
  • Alcohol
  • Aliphatic heteromonocyclic compound
Molecular Framework Aliphatic heteromonocyclic compounds
External Descriptors
Physical Properties
State: Solid
Melting point: 201-202 °C
Experimental Properties:
Water Solubility:195 mg/mL at 20 oC [YALKOWSKY,SH & DANNENFELSER,RM (1992)]PhysProp
Predicted Properties
Water Solubility586.0 mg/mLALOGPS
pKa (Strongest Acidic)11.25ChemAxon
pKa (Strongest Basic)-3ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count11ChemAxon
Hydrogen Donor Count8ChemAxon
Polar Surface Area189.53 Å2ChemAxon
Rotatable Bond Count4ChemAxon
Refractivity68.34 m3·mol-1ChemAxon
Polarizability30.96 Å3ChemAxon
Number of Rings2ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Biological Properties
Cellular Locations: Cytoplasm
Spectrum TypeDescriptionSplash Key
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (8 TMS)splash10-0uxs-0972000000-af8ca1bf1faa3d01a08dView in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (8 TMS; 1 MEOX)splash10-00di-9741000000-a61bf0223a1683f0402eView in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (8 TMS; 1 MEOX)splash10-00di-9641000000-12611bfab50cb066e8afView in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-03di-0901000000-bcb7aaa42261d980d488View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-000f-9300000000-1bc18b05388cd2213573View in MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-01p9-9000000000-4483af567feecb34a651View in MoNA
1D NMR1H NMR SpectrumNot Available
1D NMR13C NMR SpectrumNot Available
2D NMR[1H,1H] 2D NMR SpectrumNot Available
2D NMR[1H,13C] 2D NMR SpectrumNot Available
  • 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
  • Delaveau P: [Milk lactose. Hypothesis on its biological importance]. Ann Pharm Fr. 2003;61(5):340-2. Pubmed: 13130292
  • 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
  • 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
  • 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
  • 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
  • Kanehisa, M., Goto, S., Sato, Y., Furumichi, M., Tanabe, M. (2012). "KEGG for integration and interpretation of large-scale molecular data sets." Nucleic Acids Res 40:D109-D114. Pubmed: 22080510
  • Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590. Pubmed: 21097882
  • 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
  • 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
  • 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
  • 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
  • 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
  • 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
  • Roberson CM: Lactose intolerance. Ala Nurse. 2004 Dec-2005 Feb;31(4):23-4; quiz 24. Pubmed: 15662762
  • 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
  • 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
  • Swagerty DL Jr, Walling AD, Klein RM: Lactose intolerance. Am Fam Physician. 2002 May 1;65(9):1845-50. Pubmed: 12018807
  • Szilagyi A: Review article: lactose--a potential prebiotic. Aliment Pharmacol Ther. 2002 Sep;16(9):1591-602. Pubmed: 12197838
  • van der Werf, M. J., Overkamp, K. M., Muilwijk, B., Coulier, L., Hankemeier, T. (2007). "Microbial metabolomics: toward a platform with full metabolome coverage." Anal Biochem 370:17-25. Pubmed: 17765195
  • 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
  • Winder, C. L., Dunn, W. B., Schuler, S., Broadhurst, D., Jarvis, R., Stephens, G. M., Goodacre, R. (2008). "Global metabolic profiling of Escherichia coli cultures: an evaluation of methods for quenching and extraction of intracellular metabolites." Anal Chem 80:2939-2948. Pubmed: 18331064
  • 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
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)
External Links:
Pubchem Compound ID84571
Kegg IDC00243
ChemSpider ID76293
Ligand ExpoLBT


General function:
Involved in hydrolase activity, hydrolyzing O-glycosyl compounds
Specific function:
Hydrolysis of terminal, non-reducing beta-D- glucosyl residues with release of beta-D-glucose
Gene Name:
Locus Tag:
Molecular weight:
83 kDa
Hydrolysis of terminal, non-reducing beta-D-glucosyl residues with release of beta-D-glucose.


General function:
Involved in transmembrane transport
Specific function:
Involved in the efflux of sugars. The physiological role may be the reduction of the intracellular concentration of toxic sugars or sugar metabolites. Transports L-arabinose and to a lesser extent IPTG. Seems to contribute to the control of the arabinose regulon
Gene Name:
Locus Tag:
Molecular weight:
41.8 kDa