Hmdb loader
Survey
You are using an unsupported browser. Please upgrade your browser to a newer version to get the best experience on Human Metabolome Database.
Record Information
Version5.0
StatusExpected but not Quantified
Creation Date2012-09-06 15:16:51 UTC
Update Date2022-03-07 02:51:52 UTC
HMDB IDHMDB0015141
Secondary Accession Numbers
  • HMDB15141
Metabolite Identification
Common NameLetrozole
DescriptionLetrozole, also known as femara, belongs to the class of organic compounds known as diphenylmethanes. Diphenylmethanes are compounds containing a diphenylmethane moiety, which consists of a methane wherein two hydrogen atoms are replaced by two phenyl groups. Letrozole is a moderately basic compound (based on its pKa). Letrozole is a potentially toxic compound. However, letrozole is effective only in post-menopausal women, in whom estrogen is produced predominantly in peripheral tissues (i.e. in adipose tissue, like that of the breast) and a number of sites in the brain. A study of 150 babies following treatment with letrozole or letrozole and gonadotropins presented at the American Society of Reproductive Medicine 2005 Conference found no difference in overall abnormalities but did find a significantly higher rate of locomotor and cardiac abnormalities among the group having taken letrozole compared to natural conception. Generally, side effects include signs and symptoms of hypoestrogenism. When used in combination with growth hormone, letrozole has been shown effective in one adolescent boy with a short stature. A larger, follow-up study with 911 babies compared those born following treatment with letrozole to those born following treatment with clomiphene.
Structure
Data?1582753263
Synonyms
ValueSource
FemaraChEBI
LetrozolChEBI
4,4'-(1H-1,2,4-Triazol-1-yl-methylene)-bis(benzonitrile)HMDB
FémaraHMDB
Novartis brand OF letrozoleHMDB
Chemical FormulaC17H11N5
Average Molecular Weight285.3027
Monoisotopic Molecular Weight285.101445377
IUPAC Name4-[(4-cyanophenyl)(1H-1,2,4-triazol-1-yl)methyl]benzonitrile
Traditional Nameletrozole
CAS Registry Number112809-51-5
SMILES
N#CC1=CC=C(C=C1)C(N1C=NC=N1)C1=CC=C(C=C1)C#N
InChI Identifier
InChI=1S/C17H11N5/c18-9-13-1-5-15(6-2-13)17(22-12-20-11-21-22)16-7-3-14(10-19)4-8-16/h1-8,11-12,17H
InChI KeyHPJKCIUCZWXJDR-UHFFFAOYSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as diphenylmethanes. Diphenylmethanes are compounds containing a diphenylmethane moiety, which consists of a methane wherein two hydrogen atoms are replaced by two phenyl groups.
KingdomOrganic compounds
Super ClassBenzenoids
ClassBenzene and substituted derivatives
Sub ClassDiphenylmethanes
Direct ParentDiphenylmethanes
Alternative Parents
Substituents
  • Diphenylmethane
  • Benzonitrile
  • Heteroaromatic compound
  • 1,2,4-triazole
  • Azole
  • Azacycle
  • Organoheterocyclic compound
  • Nitrile
  • Carbonitrile
  • Organic nitrogen compound
  • Organopnictogen compound
  • Hydrocarbon derivative
  • Organonitrogen compound
  • Aromatic heteromonocyclic compound
Molecular FrameworkAromatic heteromonocyclic compounds
External Descriptors
Ontology
Not AvailableNot Available
Physical Properties
StateSolid
Experimental Molecular Properties
PropertyValueReference
Melting Point184 - 185 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility0.08 g/LNot Available
LogP2.5Not Available
Experimental Chromatographic PropertiesNot Available
Predicted Molecular Properties
PropertyValueSource
Water Solubility0.08 g/LALOGPS
logP1.86ALOGPS
logP2.94ChemAxon
logS-3.6ALOGPS
pKa (Strongest Basic)2.17ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area78.29 ŲChemAxon
Rotatable Bond Count3ChemAxon
Refractivity94.47 m³·mol⁻¹ChemAxon
Polarizability29.59 ųChemAxon
Number of Rings3ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted Chromatographic Properties

Predicted Collision Cross Sections

PredictorAdduct TypeCCS Value (Å2)Reference
DarkChem[M+H]+164.8831661259
DarkChem[M-H]-169.93131661259
DeepCCS[M+H]+158.26430932474
DeepCCS[M-H]-155.90630932474
DeepCCS[M-2H]-189.1730932474
DeepCCS[M+Na]+164.39830932474
AllCCS[M+H]+167.632859911
AllCCS[M+H-H2O]+163.932859911
AllCCS[M+NH4]+171.032859911
AllCCS[M+Na]+172.032859911
AllCCS[M-H]-170.232859911
AllCCS[M+Na-2H]-169.532859911
AllCCS[M+HCOO]-168.832859911

Predicted Kovats Retention Indices

Underivatized

MetaboliteSMILESKovats RI ValueColumn TypeReference
LetrozoleN#CC1=CC=C(C=C1)C(N1C=NC=N1)C1=CC=C(C=C1)C#N3840.9Standard polar33892256
LetrozoleN#CC1=CC=C(C=C1)C(N1C=NC=N1)C1=CC=C(C=C1)C#N2846.9Standard non polar33892256
LetrozoleN#CC1=CC=C(C=C1)C(N1C=NC=N1)C1=CC=C(C=C1)C#N2677.6Semi standard non polar33892256
Spectra

GC-MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted GC-MSPredicted GC-MS Spectrum - Letrozole GC-MS (Non-derivatized) - 70eV, Positivesplash10-014i-5390000000-96e7cbf457562ce8f33a2017-09-01Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Letrozole GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Letrozole GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum

MS/MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-001i-0090000000-0fbd577a32ff572f73682017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-001i-0190000000-dfcab9af7893875215712017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-0006-0390000000-dbc68fd6017abe6e8adc2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-00kf-0490000000-c3fc389848a06a0122342017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-014l-0690000000-38ba597054b02b136ab62017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-00kf-1980000000-13a8827cbc5c1b36a14f2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-00kf-3940000000-e01d63313ef1cfa7477a2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-014i-9410000000-83b93aed0756bd41adaf2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , negative-QTOFsplash10-014i-9100000000-d1757f8c218d5dcc48092017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-014i-0090000000-791121bd513899b7dfc02017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-014i-0090000000-eb3996846ea4f036ccca2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-014i-0390000000-a57ce4cfb24ba743c54b2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-0006-0950000000-303d99867511fe3a013b2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-0006-0930000000-77e720374927be5113ef2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-0006-0920000000-4a93d8e76eb7d0d594812017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-03du-0910000000-8ad9f37884e8686ef7ba2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-03dr-2900000000-2274a3adb5e486f570012017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole LC-ESI-QFT , positive-QTOFsplash10-03dr-6900000000-74d56231c43250bc65ca2017-09-14HMDB team, MONAView Spectrum
Experimental LC-MS/MSLC-MS/MS Spectrum - Letrozole , positive-QTOFsplash10-014i-0490000000-7868daa9f0ec9ebda34a2017-09-14HMDB team, MONAView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Letrozole 10V, Positive-QTOFsplash10-000i-0090000000-da3910c6e2a706e174c52016-08-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Letrozole 20V, Positive-QTOFsplash10-001r-0090000000-f03b188334168da247e12016-08-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Letrozole 40V, Positive-QTOFsplash10-003r-1970000000-d83cde690a839474f8d62016-08-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Letrozole 10V, Negative-QTOFsplash10-001i-0090000000-f0fe35676feb362f08242016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Letrozole 20V, Negative-QTOFsplash10-001i-0090000000-b517dd9b4d5a4a7b26a22016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Letrozole 40V, Negative-QTOFsplash10-053r-2290000000-f5f7a0dda898f84a52af2016-08-03Wishart LabView Spectrum
Biological Properties
Cellular Locations
  • Membrane
Biospecimen Locations
  • Blood
  • Urine
Tissue LocationsNot Available
Pathways
Normal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableTaking drug identified by DrugBank entry DB01006 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableTaking drug identified by DrugBank entry DB01006 details
Abnormal Concentrations
Not Available
Predicted Concentrations
BiospecimenValueOriginal ageOriginal sexOriginal conditionComments
Blood0.000 uMAdult (>18 years old)BothNormalPredicted based on drug qualities
Blood0.000 umol/mmol creatinineAdult (>18 years old)BothNormalPredicted based on drug qualities
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDDB01006
Phenol Explorer Compound IDNot Available
FooDB IDNot Available
KNApSAcK IDNot Available
Chemspider ID3765
KEGG Compound IDC08163
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkLetrozole
METLIN IDNot Available
PubChem Compound3902
PDB IDNot Available
ChEBI ID6413
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB IDNot Available
Good Scents IDNot Available
References
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Tulandi T, Martin J, Al-Fadhli R, Kabli N, Forman R, Hitkari J, Librach C, Greenblatt E, Casper RF: Congenital malformations among 911 newborns conceived after infertility treatment with letrozole or clomiphene citrate. Fertil Steril. 2006 Jun;85(6):1761-5. Epub 2006 May 2. [PubMed:16650422 ]

Enzymes

General function:
Involved in monooxygenase activity
Specific function:
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation reactions (e.g. caffeine 8-oxidation, omeprazole sulphoxidation, midazolam 1'-hydroxylation and midazolam 4-hydroxylation) of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. Acts as a 1,8-cineole 2-exo-monooxygenase. The enzyme also hydroxylates etoposide.
Gene Name:
CYP3A4
Uniprot ID:
P08684
Molecular weight:
57255.585
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]
General function:
Involved in monooxygenase activity
Specific function:
Catalyzes the formation of aromatic C18 estrogens from C19 androgens.
Gene Name:
CYP19A1
Uniprot ID:
P11511
Molecular weight:
57882.48
References
  1. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352 ]
  2. Ebert AD, Bartley J, David M, Schweppe KW: [Aromatase inhibitors--theoretical concept and present experiences in the treatment of endometriosis]. Zentralbl Gynakol. 2003 Jul-Aug;125(7-8):247-51. [PubMed:14505258 ]
  3. Long BJ, Jelovac D, Handratta V, Thiantanawat A, MacPherson N, Ragaz J, Goloubeva OG, Brodie AM: Therapeutic strategies using the aromatase inhibitor letrozole and tamoxifen in a breast cancer model. J Natl Cancer Inst. 2004 Mar 17;96(6):456-65. [PubMed:15026471 ]
  4. Murphy MJ Jr: Molecular Action and Clinical Relevance of Aromatase Inhibitors. Oncologist. 1998;3(2):129-130. [PubMed:10388095 ]
  5. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]
General function:
Involved in monooxygenase activity
Specific function:
Exhibits a high coumarin 7-hydroxylase activity. Can act in the hydroxylation of the anti-cancer drugs cyclophosphamide and ifosphamide. Competent in the metabolic activation of aflatoxin B1. Constitutes the major nicotine C-oxidase. Acts as a 1,4-cineole 2-exo-monooxygenase. Possesses low phenacetin O-deethylation activity.
Gene Name:
CYP2A6
Uniprot ID:
P11509
Molecular weight:
56517.005
References
  1. Preissner S, Kroll K, Dunkel M, Senger C, Goldsobel G, Kuzman D, Guenther S, Winnenburg R, Schroeder M, Preissner R: SuperCYP: a comprehensive database on Cytochrome P450 enzymes including a tool for analysis of CYP-drug interactions. Nucleic Acids Res. 2010 Jan;38(Database issue):D237-43. doi: 10.1093/nar/gkp970. Epub 2009 Nov 24. [PubMed:19934256 ]