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Pipecolic acid

PubChem CID
849
Structure
Pipecolic acid_small.png
Pipecolic acid_3D_Structure.png
Molecular Formula
Synonyms
  • piperidine-2-carboxylic acid
  • DL-Pipecolinic acid
  • 535-75-1
  • Pipecolic acid
  • Pipecolinic acid
Molecular Weight
129.16 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2004-09-16
  • Modify:
    2025-01-18
Description
Pipecolic acid is a piperidinemonocarboxylic acid in which the carboxy group is located at position C-2. It is a conjugate acid of a pipecolate.
Pipecolic acid is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Pipecolic acid has been reported in Angelica gigas, Slafractonia leguminicola, and other organisms with data available.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Pipecolic acid.png

1.2 3D Conformer

2 Biologic Description

SVG Image
SVG Image
IUPAC Condensed
H-DL-Pip-OH
Sequence
X
HELM
PEPTIDE1{[C1CCNC(C1)C(=O)O]}$$$$
IUPAC
DL-homoproline

3 Names and Identifiers

3.1 Computed Descriptors

3.1.1 IUPAC Name

piperidine-2-carboxylic acid
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

3.1.2 InChI

InChI=1S/C6H11NO2/c8-6(9)5-3-1-2-4-7-5/h5,7H,1-4H2,(H,8,9)
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

3.1.3 InChIKey

HXEACLLIILLPRG-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

3.1.4 SMILES

C1CCNC(C1)C(=O)O
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

3.2 Molecular Formula

C6H11NO2
Computed by PubChem 2.2 (PubChem release 2021.10.14)

3.3 Other Identifiers

3.3.1 CAS

3105-95-1

3.3.3 Deprecated CAS

4043-87-2

3.3.4 European Community (EC) Number

3.3.5 UNII

3.3.6 ChEBI ID

3.3.7 ChEMBL ID

3.3.8 DSSTox Substance ID

3.3.9 HMDB ID

3.3.10 Metabolomics Workbench ID

3.3.11 Nikkaji Number

3.3.12 NSC Number

3.3.13 Wikidata

3.3.14 Wikipedia

3.4 Synonyms

3.4.1 MeSH Entry Terms

  • 2-piperidinecarboxylic acid
  • homopipecolic acid
  • L-pipecolic acid
  • pipecolic acid
  • pipecolic acid hydrochloride, (+-)-isomer
  • pipecolic acid, (+,-)-isomer
  • pipecolic acid, (-)-
  • pipecolic acid, (R)-isomer
  • pipecolic acid, (S)-isomer
  • pipecolic acid, 14C-labeled cpd, (+,-)-isomer
  • pipecolic acid, ion (1-)
  • pipecolic acid, ion(1-), (+,-)-isomer
  • pipecolic acid, ion(1-), (S)-isomer
  • pipecolic acid, monopotassium salt

3.4.2 Depositor-Supplied Synonyms

4 Chemical and Physical Properties

4.1 Computed Properties

Property Name
Molecular Weight
Property Value
129.16 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
XLogP3
Property Value
-2.3
Reference
Computed by XLogP3 3.0 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
3
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
129.078978594 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
129.078978594 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
49.3 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
9
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
114
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
1
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
1
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

4.2 Experimental Properties

4.2.1 Physical Description

Solid

4.2.2 Melting Point

264 °C

4.2.3 Solubility

314 mg/mL

4.2.4 LogP

-2.31
TSAI,RS ET AL. (1991)

4.2.5 Dissociation Constants

4.2.6 Collision Cross Section

128.9 Ų [M-H]- [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

128.3 Ų [M-H]- [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

139.4 Ų [M+Na]+ [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

138.8 Ų [M+Na]+ [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

128 Ų [M+H]+ [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

127.7 Ų [M+H]+ [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

129.3 Ų [M-H]-

127.4 Ų [M+H]+

139 Ų [M+Na]+

S50 | CCSCOMPEND | The Unified Collision Cross Section (CCS) Compendium | DOI:10.5281/zenodo.2658162

5 Spectral Information

5.1 1D NMR Spectra

1D NMR Spectra

5.1.1 1H NMR Spectra

1 of 3
View All
Spectra ID
Instrument Type
Varian
Frequency
500 MHz
Solvent
Water
pH
7.00
Shifts [ppm]:Intensity
2.22:48.04, 1.69:35.93, 2.22:50.00, 1.66:75.51, 1.64:96.95, 1.63:89.36, 3.56:52.57, 1.65:74.35, 3.58:60.48, 1.86:100.00, 1.58:55.78, 1.65:66.91, 3.55:53.11, 1.66:81.65, 2.97:42.72, 3.00:68.76, 1.55:47.86, 1.60:84.96, 3.39:58.26, 1.89:57.51, 1.84:63.34, 1.57:54.06, 2.96:35.87, 1.67:70.47, 3.01:47.86, 1.61:72.36, 1.88:58.45, 1.58:69.83, 1.68:36.50, 2.20:54.37, 3.58:48.42, 2.99:68.82, 3.41:55.76, 1.69:32.84, 1.63:71.98, 3.02:38.34, 1.56:40.89, 1.83:65.11, 1.62:68.33
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Instrument Name
Varian CFT-20
Copyright
Copyright © 2009-2024 John Wiley & Sons, Inc. All Rights Reserved.
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5.1.2 13C NMR Spectra

1 of 2
Source of Sample
Tokyo Kasei Kogyo Company, Ltd., Tokyo, Japan
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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2 of 2
Source of Sample
Fluka AG, Buchs, Switzerland
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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5.2 2D NMR Spectra

5.2.1 1H-1H NMR Spectra

2D NMR Spectra Type
1H-1H TOCSY
Spectra ID
Shifts [ppm] (F2:F1)
3.01:3.42, 1.63:1.61, 3.59:2.20, 1.87:1.59, 3.01:3.59, 1.63:1.87, 2.21:1.84, 3.01:1.68, 3.59:3.59, 2.21:2.97, 1.64:1.71, 3.59:1.68, 3.59:3.43, 2.21:1.61, 2.21:3.00, 3.01:3.03, 3.01:3.57, 2.21:2.23, 3.41:3.59, 3.01:1.87, 3.41:2.23, 3.59:1.62, 3.42:1.64, 3.59:3.03, 1.87:3.42, 3.42:1.59, 1.64:2.19, 1.63:3.00, 3.42:1.61, 3.01:2.97, 1.87:2.23, 2.21:3.39, 3.69:3.92, 2.21:2.19, 1.63:3.56, 1.87:1.87, 3.41:1.84, 3.01:3.00, 3.59:3.57, 3.59:1.84, 2.21:1.87, 1.87:1.64, 2.21:3.59, 2.21:3.03, 1.87:2.97, 3.01:1.56, 3.41:2.97, 1.87:3.03, 1.87:3.39, 1.87:1.71, 1.64:1.68, 3.41:1.56, 3.59:1.87, 1.87:3.59, 1.64:2.23, 1.87:1.61, 3.42:3.00, 3.01:3.39, 2.21:1.71, 3.41:2.20, 3.01:1.84, 1.63:1.56, 3.59:1.65, 2.21:1.64, 3.42:1.71, 1.87:1.84, 1.87:3.56, 1.87:1.68, 3.01:1.64, 3.01:1.61, 1.63:3.03, 3.42:3.42, 1.87:1.56, 3.42:1.68, 3.01:2.20, 3.42:3.39, 3.59:1.59, 1.87:2.19, 3.42:3.03, 1.63:3.39, 1.63:2.97, 2.21:3.42, 3.01:1.71, 3.59:3.00, 1.63:3.42, 1.63:1.84, 2.21:1.56, 2.21:3.56, 1.63:3.59, 1.63:1.64, 3.41:3.56, 1.63:1.59, 2.21:1.68, 3.01:2.23, 3.01:1.59, 3.42:1.87, 3.59:2.23, 1.87:3.00, 3.59:3.40, 2.21:1.59
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5.2.2 1H-13C NMR Spectra

2D NMR Spectra Type
1H-13C HSQC
Spectra ID
Instrument Type
Bruker
Frequency
600 MHz
Solvent
Water
pH
7.00
Shifts [ppm] (F2:F1):Intensity
1.87:24.55:0.48, 2.20:29.37:0.45, 3.40:46.66:0.43, 1.64:24.55:0.29, 1.64:29.37:0.21, 3.56:61.93:1.00, 2.99:46.66:0.83
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5.3 Mass Spectrometry

5.3.1 GC-MS

1 of 13
View All
Spectra ID
Instrument Type
GC-EI-TOF
Ionization Mode
positive
Top 5 Peaks

156.0 100

157.0 22.22

230.0 19.42

158.0 7.01

231.0 3.40

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Notes
instrument=Leco Pegasus IV
2 of 13
View All
Spectra ID
Instrument Type
GC-EI-TOF
Ionization Mode
positive
Top 5 Peaks

156.0 100

157.0 22.22

230.0 19.42

158.0 7.01

231.0 3.40

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Notes
instrument=Leco Pegasus IV

5.3.2 MS-MS

1 of 6
View All
Spectra ID
Instrument Type
Quattro_QQQ
Ionization Mode
Positive
Top 5 Peaks

84.043 100

129.911 100

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Notes
delivery=Flow_Injectionanalyzer=Triple_Quad
2 of 6
View All
Spectra ID
Instrument Type
Quattro_QQQ
Ionization Mode
Positive
Top 5 Peaks

56.017 100

83.989 58.21

129.849 7.09

41.323 6.44

68.988 6.34

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Notes
delivery=Flow_Injectionanalyzer=Triple_Quad

5.3.3 LC-MS

1 of 26
View All
Authors
Kakazu Y, Horai H, Institute for Advanced Biosciences, Keio Univ.
Instrument
API3000, Applied Biosystems
Instrument Type
LC-ESI-QQ
MS Level
MS2
Ionization Mode
NEGATIVE
Collision Energy
10 V
Precursor m/z
128
Precursor Adduct
[M-H]-
Top 5 Peaks

128 999

128.6 35

46 2

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License
CC BY-NC-SA
2 of 26
View All
Authors
Kakazu Y, Horai H, Institute for Advanced Biosciences, Keio Univ.
Instrument
API3000, Applied Biosystems
Instrument Type
LC-ESI-QQ
MS Level
MS2
Ionization Mode
NEGATIVE
Collision Energy
20 V
Precursor m/z
128
Precursor Adduct
[M-H]-
Top 5 Peaks

128 999

82 19

45.8 11

126.3 2

85.7 1

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License
CC BY-NC-SA

5.3.4 Other MS

1 of 3
View All
MS Category
Experimental
MS Type
Other
MS Level
MS2
Precursor Type
[M+H]+
Precursor m/z
130.08625793457
Instrument
Agilent 6550 iFunnel
Instrument Type
Q-TOF
Ionization Mode
ESI
Collision Energy
20
Top 5 Peaks

84.08082 100

56.04903 12.38

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License
CC-BY
2 of 3
View All
MS Category
Experimental
MS Type
Other
MS Level
MS2
Precursor Type
[M+H]+
Precursor m/z
130.08625793457
Instrument
Agilent 6550 iFunnel
Instrument Type
Q-TOF
Ionization Mode
ESI
Collision Energy
30
Top 5 Peaks

84.08073 100

56.04915 68.12

55.05384 6.70

67.05395 5.03

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License
CC-BY

5.4 IR Spectra

5.4.1 FTIR Spectra

1 of 2
Technique
KBr WAFER
Source of Sample
Aldrich Chemical Company, Inc., Milwaukee, Wisconsin
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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2 of 2
Instrument Name
Bruker Tensor 27 FT-IR
Technique
KBr1
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
Alfa Aesar, Thermo Fisher Scientific
Catalog Number
B23541
Lot Number
10190660
Copyright
Copyright © 2016-2024 John Wiley & Sons, Inc. All Rights Reserved.
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5.4.2 ATR-IR Spectra

1 of 2
Instrument Name
Bruker Tensor 27 FT-IR
Technique
ATR-Neat (DuraSamplIR II)
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
Alfa Aesar, Thermo Fisher Scientific
Catalog Number
B23541
Lot Number
10190660
Copyright
Copyright © 2016-2024 John Wiley & Sons, Inc. All Rights Reserved.
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2 of 2
Source of Sample
Aldrich
Catalog Number
P45850
Copyright
Copyright © 2018-2024 Sigma-Aldrich Co. LLC. - Database Compilation Copyright © 2018-2024 John Wiley & Sons, Inc. All Rights Reserved.
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5.5 Raman Spectra

Instrument Name
Bruker MultiRAM Stand Alone FT-Raman Spectrometer
Technique
FT-Raman
Source of Spectrum
Bio-Rad Laboratories, Inc.
Source of Sample
Alfa Aesar, Thermo Fisher Scientific
Catalog Number
B23541
Lot Number
10190660
Copyright
Copyright © 2016-2024 John Wiley & Sons, Inc. All Rights Reserved.
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7 Chemical Vendors

8 Drug and Medication Information

8.1 Biomarker Information

9 Pharmacology and Biochemistry

9.1 Human Metabolite Information

9.1.1 Tissue Locations

  • Intestine
  • Liver
  • Placenta
  • Prostate

9.1.2 Cellular Locations

  • Cytoplasm
  • Extracellular

10 Use and Manufacturing

10.1 General Manufacturing Information

EPA TSCA Commercial Activity Status
2-Piperidinecarboxylic acid: INACTIVE

11 Safety and Hazards

11.1 Hazards Identification

11.1.1 GHS Classification

Pictogram(s)
Irritant
Signal
Warning
GHS Hazard Statements

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

Precautionary Statement Codes

P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 47 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown.

11.1.2 Hazard Classes and Categories

Skin Irrit. 2 (100%)

Eye Irrit. 2 (100%)

STOT SE 3 (100%)

12 Toxicity

12.1 Toxicological Information

12.1.1 Acute Effects

13 Associated Disorders and Diseases

Disease
Infantile Refsum's disease
References

PubMed: 2427795, 2408988

MetaGene: Metabolic & Genetic Information Center (MIC: http://www.metagene.de)

Disease
Rhizomelic chondrodysplasia punctata
References
PubMed: 9818927
Disease
Refsum's disease
References
Disease
Peroxisomal disorders, new type, liver
References

PubMed: 7931872

MetaGene: Metabolic & Genetic Information Center (MIC: http://www.metagene.de)

Disease
Pyridoxine-dependent epilepsy
References
Disease
D-Bifunctional protein deficiency
References
Disease
Pseudoneonatal adrenoleukodystrophy
References
PubMed: 2894756
Disease
Traumatic brain injury
References
Disease
Malaria
References
Disease
Anemia
References
PubMed: 12964115
Disease
Tuberculous meningitis
References
Disease
Convulsion
References
Disease
Hyperlysinemia I, familial
References
PubMed: 23890588
Disease
Hyperpipecolatemia
References
PubMed: 5700850
Disease
Colorectal cancer
References

PubMed: 7482520, 19006102, 23940645, 24424155, 20156336, 19678709, 22148915, 25105552, 21773981, 25037050, 27015276, 27107423, 27275383, 28587349

Silke Matysik, Caroline Ivanne Le Roy, Gerhard Liebisch, Sandrine Paule Claus. Metabolomics of fecal samples: A practical consideration. Trends in Food Science & Technology. Vol. 57, Part B, Nov. 2016, p.244-255: http://www.sciencedirect.com/science/article/pii/S0924224416301984

Disease
Perillyl alcohol administration for cancer treatment
References
Disease
Pancreatic cancer
References
Disease
Periodontal disease
References
PubMed: 20300169
Disease
Periodontal Probing Depth
References
PubMed: 31026179
Disease
Peroxisomal biogenesis defect
References

PubMed: 3769211, 2921319, 12705501, 10509903, 9818927, 2418187, 7931872, 8825400

MetaGene: Metabolic & Genetic Information Center (MIC: http://www.metagene.de)

Disease
Adrenoleukodystrophy
References

PubMed: 2921319, 2408988, 7807943, 7609459

MetaGene: Metabolic & Genetic Information Center (MIC: http://www.metagene.de)

14 Literature

14.1 Consolidated References

14.2 NLM Curated PubMed Citations

14.3 Springer Nature References

14.4 Thieme References

14.5 Wiley References

14.6 Nature Journal References

14.7 Chemical Co-Occurrences in Literature

14.8 Chemical-Gene Co-Occurrences in Literature

14.9 Chemical-Disease Co-Occurrences in Literature

15 Patents

15.1 Depositor-Supplied Patent Identifiers

15.2 WIPO PATENTSCOPE

15.3 Chemical Co-Occurrences in Patents

15.4 Chemical-Disease Co-Occurrences in Patents

15.5 Chemical-Gene Co-Occurrences in Patents

16 Interactions and Pathways

16.1 Chemical-Target Interactions

17 Biological Test Results

17.1 BioAssay Results

18 Taxonomy

The LOTUS Initiative for Open Natural Products Research: frozen dataset union wikidata (with metadata) | DOI:10.5281/zenodo.5794106

19 Classification

19.1 MeSH Tree

19.2 ChEBI Ontology

19.3 ChemIDplus

19.4 ChEMBL Target Tree

19.5 UN GHS Classification

19.6 NORMAN Suspect List Exchange Classification

19.7 CCSBase Classification

19.8 EPA DSSTox Classification

19.9 EPA TSCA and CDR Classification

19.10 LOTUS Tree

19.11 EPA Substance Registry Services Tree

19.12 MolGenie Organic Chemistry Ontology

20 Information Sources

  1. CAS Common Chemistry
    LICENSE
    The data from CAS Common Chemistry is provided under a CC-BY-NC 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc/4.0/
  2. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  3. DTP/NCI
    LICENSE
    Unless otherwise indicated, all text within NCI products is free of copyright and may be reused without our permission. Credit the National Cancer Institute as the source.
    https://www.cancer.gov/policies/copyright-reuse
  4. EPA Chemicals under the TSCA
    2-Piperidinecarboxylic acid
    https://www.epa.gov/chemicals-under-tsca
    EPA TSCA Classification
    https://www.epa.gov/tsca-inventory
  5. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  6. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
    Piperidine-2-carboxylic acid
    https://chem.echa.europa.eu/100.007.835
  7. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  8. Human Metabolome Database (HMDB)
    LICENSE
    HMDB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (HMDB) and the original publication (see the HMDB citing page). We ask that users who download significant portions of the database cite the HMDB paper in any resulting publications.
    http://www.hmdb.ca/citing
  9. CCSbase
    CCSbase Classification
    https://ccsbase.net/
  10. NORMAN Suspect List Exchange
    LICENSE
    Data: CC-BY 4.0; Code (hosted by ECI, LCSB): Artistic-2.0
    https://creativecommons.org/licenses/by/4.0/
    DL-Pipecolate
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  11. ChEBI
  12. E. coli Metabolome Database (ECMDB)
    LICENSE
    ECMDB is offered to the public as a freely available resource.
    https://ecmdb.ca/citations
  13. LOTUS - the natural products occurrence database
    LICENSE
    The code for LOTUS is released under the GNU General Public License v3.0.
    https://lotus.nprod.net/
  14. ChEMBL
    LICENSE
    Access to the web interface of ChEMBL is made under the EBI's Terms of Use (http://www.ebi.ac.uk/Information/termsofuse.html). The ChEMBL data is made available on a Creative Commons Attribution-Share Alike 3.0 Unported License (http://creativecommons.org/licenses/by-sa/3.0/).
    http://www.ebi.ac.uk/Information/termsofuse.html
  15. Comparative Toxicogenomics Database (CTD)
    LICENSE
    It is to be used only for research and educational purposes. Any reproduction or use for commercial purpose is prohibited without the prior express written permission of NC State University.
    http://ctdbase.org/about/legal.jsp
  16. Natural Product Activity and Species Source (NPASS)
  17. MassBank Europe
  18. MassBank of North America (MoNA)
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    https://mona.fiehnlab.ucdavis.edu/documentation/license
  19. NIST Mass Spectrometry Data Center
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    Data covered by the Standard Reference Data Act of 1968 as amended.
    https://www.nist.gov/srd/public-law
  20. SpectraBase
  21. IUPAC Digitized pKa Dataset
  22. Japan Chemical Substance Dictionary (Nikkaji)
  23. MarkerDB
    LICENSE
    This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
    https://markerdb.ca/
  24. Metabolomics Workbench
  25. Nature Chemistry
  26. NMRShiftDB
  27. Springer Nature
  28. Thieme Chemistry
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    https://creativecommons.org/licenses/by-nc-nd/4.0/
  29. Wikidata
  30. Wikipedia
  31. Wiley
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  33. Medical Subject Headings (MeSH)
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    https://www.nlm.nih.gov/copyright.html
  34. GHS Classification (UNECE)
  35. EPA Substance Registry Services
  36. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  37. PATENTSCOPE (WIPO)
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