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Record Information
StatusDetected and Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2020-04-29 21:30:08 UTC
Secondary Accession Numbers
  • HMDB01392
Metabolite Identification
Common Namep-Aminobenzoic acid
Descriptionp-Aminobenzoic acid, also known as 4-aminobenzoic acid or PABA, is an organic compound with molecular formula C7H7NO2. PABA is a white crystalline substance that is only slightly soluble in water. It consists of a benzene ring substituted with an amino group and a carboxylic acid. PABA is an essential nutrient for some bacteria and is sometimes called vitamin Bx. However, PABA is not essential for humans and it varies in its activity from other B vitamins. PABA is sometimes marketed as an essential nutrient under the premise that it can stimulate intestinal bacteria. Certain bacteria in the human intestinal tract such as E. coli generate PABA from chorismate. Humans lack the enzymes to convert PABA into folate, and therefore require folate from dietary sources such as green leafy vegetables. Although some intestinal bacteria can synthesize folate from PABA and some E. coli can synthesize folate this requires six enzymatic activities in folate synthesis which are not all done in the same bacteria. PABA used to be a common sunscreen agent until it was found to also be a sensitizer. The potassium salt of PABA is used therapeutically in fibrotic skin disorders. PABA can also be found in Acetobacter (DOI: 10.3181/00379727-52-14147).
4-Amino-benzoic acidChEBI
gamma-Aminobenzoic acidChEBI
Para-aminobenzoic acidChEBI
4-Aminobenzoic acidKegg
RVPaba lipstickKegg
g-Aminobenzoic acidGenerator
Γ-aminobenzoic acidGenerator
acido P-AminobenzoicoHMDB
Acidum paraminobenzoicumHMDB
Aminobenzoic acidHMDB, MeSH
Aniline-4-carboxylic acidHMDB
Anti-chromotrichia factorHMDB
Anticanitic vitaminHMDB
Anticantic vitaminHMDB
Antichromotrichia factorHMDB
Bacterial vitamin H1HMDB
Chromotrichia factorHMDB
HacheminaHMDB, MeSH
Kyselina P-aminobenzoovaHMDB
P-amino-Benzoic acidHMDB
ParaminolHMDB, MeSH
PotabaHMDB, MeSH
Super shade by coppertoneHMDB
Trichochromogenic factorHMDB
Trochromogenic factorHMDB
Vitamin BXHMDB
Vitamin h'HMDB
4 Aminobenzoic acidMeSH, HMDB
4 Aminobenzoic acid, potassium saltMeSH, HMDB
EpitelplastMeSH, HMDB
Jumer brand OF aminobenzoic acidMeSH, HMDB
Medea brand OF aminobenzoic acidMeSH, HMDB
ParaminanMeSH, HMDB
4-Aminobenzoate, potassiumMeSH, HMDB
Epit vitMeSH, HMDB
Llorens brand OF aminobenzoic acidMeSH, HMDB
PabasanMeSH, HMDB
Potassium aminobenzoateMeSH, HMDB
4-Aminobenzoic acid, potassium saltMeSH, HMDB
Aminobenzoate, potassiumMeSH, HMDB
Glenwood brand OF potassium aminobezoateMeSH, HMDB
Llorens brand OF aminobenzoic acid sodium saltMeSH, HMDB
Magnesium para-aminobenzoateMeSH, HMDB
Potassium 4 aminobenzoateMeSH, HMDB
Potassium 4-aminobenzoateMeSH, HMDB
P Aminobenzoic acidMeSH, HMDB
Para aminobenzoic acidMeSH, HMDB
Para-aminobenzoate, magnesiumMeSH, HMDB
p-Aminobenzoic acidChEBI
Chemical FormulaC7H7NO2
Average Molecular Weight137.136
Monoisotopic Molecular Weight137.047678473
IUPAC Name4-aminobenzoic acid
Traditional Namesunbrella
CAS Registry Number150-13-0
InChI Identifier
Chemical Taxonomy
Description Belongs to the class of organic compounds known as aminobenzoic acids. These are benzoic acids containing an amine group attached to the benzene moiety.
KingdomOrganic compounds
Super ClassBenzenoids
ClassBenzene and substituted derivatives
Sub ClassBenzoic acids and derivatives
Direct ParentAminobenzoic acids
Alternative Parents
  • Aminobenzoic acid
  • Benzoic acid
  • Benzoyl
  • Aniline or substituted anilines
  • Amino acid or derivatives
  • Amino acid
  • Carboxylic acid derivative
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Amine
  • Organonitrogen compound
  • Organooxygen compound
  • Primary amine
  • Hydrocarbon derivative
  • Organic oxide
  • Organopnictogen compound
  • Organic oxygen compound
  • Organic nitrogen compound
  • Aromatic homomonocyclic compound
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptors

Route of exposure:


Biological location:


Industrial application:

Physical Properties
Experimental Molecular Properties
Melting Point188.5 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility6.11 mg/mLNot Available
LogP0.83HANSCH,C ET AL. (1995)
Predicted Molecular Properties
Water Solubility4.41 g/LALOGPS
pKa (Strongest Acidic)4.77ChemAxon
pKa (Strongest Basic)2.69ChemAxon
Physiological Charge-1ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area63.32 ŲChemAxon
Rotatable Bond Count1ChemAxon
Refractivity38.01 m³·mol⁻¹ChemAxon
Polarizability13.44 ųChemAxon
Number of Rings1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted Spectral Properties

Collision Cross Sections

NameAdductTypeData SourceValueReference
AllCCS[M-H]-ExperimentalNot Available128.1
AllCCS[M+H]+ExperimentalNot Available131.9
DarkChem[M+H]+PredictedNot Available129.17431661259
DarkChem[M-H]-PredictedNot Available124.09131661259
AllCCS[M+H]+PredictedNot Available129.5532859911
AllCCS[M-H]-PredictedNot Available125.71932859911

Retention Indices


Not Available


p-Aminobenzoic acid,1TMS,#11664.9746
p-Aminobenzoic acid,1TMS,#21814.4705
p-Aminobenzoic acid,1TBDMS,#11894.7963
p-Aminobenzoic acid,1TBDMS,#22098.68


Spectrum TypeDescriptionSplash KeyDeposition DateView
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (Non-derivatized)splash10-00yl-1960000000-b22b04854c131470802a2014-06-16View Spectrum
GC-MSGC-MS Spectrum - GC-MS (1 TMS)splash10-0fkc-2900000000-dec9b6851633ff2c426c2014-06-16View Spectrum
GC-MSGC-MS Spectrum - GC-MS (2 TMS)splash10-00yl-2890000000-b299bfaaed61286c2ff62014-06-16View Spectrum
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-0079-9600000000-075c262f1e5d23ef097d2017-09-12View Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-00yl-1960000000-b22b04854c131470802a2017-09-12View Spectrum
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-0fkc-2900000000-dec9b6851633ff2c426c2017-09-12View Spectrum
GC-MSGC-MS Spectrum - GC-MS (Non-derivatized)splash10-00yl-2890000000-b299bfaaed61286c2ff62017-09-12View Spectrum
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-00yl-1960000000-4d7d9e3e3a7a741c72ca2017-09-12View Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-00kr-5900000000-8244277f60fc465369b82016-09-22View Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (1 TMS) - 70eV, Positivesplash10-006x-4900000000-299c72af4aa4008292bc2017-10-06View Spectrum
MSMass Spectrum (Electron Ionization)splash10-00dr-8900000000-bface88b2e77a7dce6e12015-03-01View Spectrum
MSMass Spectrum (Electron Ionization)splash10-0a4i-9800000000-24fa3ff739ff064312ab2021-09-18View Spectrum
MSMass Spectrum (Electron Ionization)splash10-0a4i-8900000000-5b42adf83e422cffefb62021-09-18View Spectrum


Spectrum TypeDescriptionSplash KeyDeposition DateView
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-00ku-4900000000-ab0d2860a4f23e4fcad42012-07-24View Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-00mo-9100000000-667a53f89529678400c72012-07-24View Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-014i-9000000000-0bbc34587525655f98ef2012-07-24View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 10V, Negativesplash10-000i-0900000000-8f6c193895f5adf391be2012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 20V, Negativesplash10-0006-9200000000-78f63538a3011f0365512012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 30V, Negativesplash10-0006-9000000000-521edb7d484c452d0da32012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 40V, Negativesplash10-0006-9000000000-7ae0035594587960bab72012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 50V, Negativesplash10-00kf-9000000000-35088605171b150e8b082012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 10V, Positivesplash10-00di-3900000000-d67f9d252f758529a83c2012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 20V, Positivesplash10-00di-1900000000-e4d34d9516fe889137f62012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 30V, Positivesplash10-00di-6900000000-387d1a3c2d588c6f85522012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 40V, Positivesplash10-00r6-9200000000-9ef61d003f891b00406f2012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 50V, Positivesplash10-014i-9000000000-eaf693e5f0cde39a548e2012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) , Positivesplash10-000i-7900000000-225973eab49386396fa92012-08-31View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-000i-0900000000-8f6c193895f5adf391be2017-09-14View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-0006-9200000000-78f63538a3011f0365512017-09-14View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-0006-9000000000-521edb7d484c452d0da32017-09-14View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-0006-9000000000-7ae0035594587960bab72017-09-14View Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , negativesplash10-00kf-9000000000-35088605171b150e8b082017-09-14View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0079-0900000000-173f144fba431cca91642016-09-12View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-00di-1900000000-ab3524c5aadc6fdc28cb2016-09-12View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0006-9200000000-67cea679b40b94c39ac02016-09-12View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-000i-3900000000-682d5d9d22372ece770b2016-09-12View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-000f-9600000000-8d4bba3f647000005bb02016-09-12View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0006-9100000000-5d9b80bb0601c2f238c22016-09-12View Spectrum


Spectrum TypeDescriptionDeposition DateView
1D NMR1H NMR Spectrum (1D, 600 MHz, H2O, experimental)2012-12-04View Spectrum
1D NMR1H NMR Spectrum (1D, 400 MHz, DMSO-d6, experimental)2015-03-01View Spectrum
1D NMR1H NMR Spectrum (1D, D2O, experimental)2016-10-22View Spectrum
2D NMR[1H, 1H] 2D NMR Spectrum (predicted)2012-12-04View Spectrum
2D NMR[1H, 13C] NMR Spectrum (2D, 600 MHz, H2O, predicted)2012-12-05View Spectrum
Biological Properties
Cellular LocationsNot Available
Biospecimen Locations
  • Blood
  • Feces
  • Urine
Tissue Locations
  • Epidermis
  • Fibroblasts
  • Intestine
  • Liver
  • Placenta
  • Prostate
Normal Concentrations
BloodDetected and Quantified15.0 (5.01-32.0) uMAdult (>18 years old)BothNormal details
FecesDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.11 umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.36 (0.15-0.63) umol/mmol creatinineAdult (>18 years old)BothNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
Abnormal Concentrations
FecesDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothColorectal Cancer details
FecesDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothColorectal Cancer details
FecesDetected but not QuantifiedNot QuantifiedAdult (>18 years old)Both
Colorectal cancer
Associated Disorders and Diseases
Disease References
Colorectal cancer
  1. Goedert JJ, Sampson JN, Moore SC, Xiao Q, Xiong X, Hayes RB, Ahn J, Shi J, Sinha R: Fecal metabolomics: assay performance and association with colorectal cancer. Carcinogenesis. 2014 Sep;35(9):2089-96. doi: 10.1093/carcin/bgu131. Epub 2014 Jul 18. [PubMed:25037050 ]
  2. Brown DG, Rao S, Weir TL, O'Malia J, Bazan M, Brown RJ, Ryan EP: Metabolomics and metabolic pathway networks from human colorectal cancers, adjacent mucosa, and stool. Cancer Metab. 2016 Jun 6;4:11. doi: 10.1186/s40170-016-0151-y. eCollection 2016. [PubMed:27275383 ]
  3. Sinha R, Ahn J, Sampson JN, Shi J, Yu G, Xiong X, Hayes RB, Goedert JJ: Fecal Microbiota, Fecal Metabolome, and Colorectal Cancer Interrelations. PLoS One. 2016 Mar 25;11(3):e0152126. doi: 10.1371/journal.pone.0152126. eCollection 2016. [PubMed:27015276 ]
Associated OMIM IDs
DrugBank IDDB02362
Phenol Explorer Compound IDNot Available
FooDB IDFDB001037
KNApSAcK IDC00001401
Chemspider ID953
KEGG Compound IDC00568
BiGG IDNot Available
Wikipedia Link4-Aminobenzoic_acid
PubChem Compound978
PDB IDNot Available
ChEBI ID30753
Food Biomarker OntologyNot Available
MarkerDB IDNot Available
Synthesis ReferenceSato, Ryu; Kimura, Koichi; Takahashi, Akira. Preparation of p-aminobenzoic acid from styrene polymers. Jpn. Kokai Tokkyo Koho (2007), 13pp.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Derewlany LO, Knie B, Koren G: Arylamine N-acetyltransferase activity of the human placenta. J Pharmacol Exp Ther. 1994 May;269(2):756-60. [PubMed:8182542 ]
  2. Laufer D, Cleghorn G, Forstner G, Ellis L, Koren G, Durie P: The bentiromide test using plasma p-aminobenzoic acid for diagnosing pancreatic insufficiency in young children. The effect of two different doses and a liquid meal. Gastroenterology. 1991 Jul;101(1):207-13. [PubMed:2044909 ]
  3. Nathan D, Sakr A, Lichtin JL, Bronaugh RL: In vitro skin absorption and metabolism of benzoic acid, p-aminobenzoic acid, and benzocaine in the hairless guinea pig. Pharm Res. 1990 Nov;7(11):1147-51. [PubMed:2293213 ]
  4. Lankisch PG, Brauneis J, Otto J, Goke B: Pancreolauryl and NBT-PABA tests. Are serum tests more practicable alternatives to urine tests in the diagnosis of exocrine pancreatic insufficiency? Gastroenterology. 1986 Feb;90(2):350-4. [PubMed:3484456 ]
  5. Szewczuk A, Wellman-Bednawska M: The use of gamma-glutamyl-p-aminobenzoic acid as the substrate for determination of gamma-glutamyltranspeptidase activity in blood serum. Clin Chim Acta. 1978 Mar 1;84(1-2):19-26. [PubMed:25149 ]
  6. Kiss Z, Wolfling J, Csati S, Nagy F, Lonovics J, Schneider G: [The ursodeoxycholic acid-p-aminobenzoic acid test in the diagnosis of small bowel bacterial overgrowth syndrome]. Orv Hetil. 1997 May 18;138(20):1255-8. [PubMed:9244859 ]
  7. Szewczuk A, Wellman-Bednawska M: Acyl derivatives of p-aminobenzoic acid as new substrates for the assay of serum acylase activity. Clin Chim Acta. 1978 Mar 1;84(1-2):27-31. [PubMed:305833 ]
  8. Derewlany LO, Knie B, Koren G: Human placental transfer and metabolism of p-aminobenzoic acid. J Pharmacol Exp Ther. 1994 May;269(2):761-5. [PubMed:8182543 ]
  9. Ito S, Maruta K, Imai Y, Kato T, Ito M, Nakajima S, Fujita K, Kurahashi T: Urinary p-aminobenzoic acid determined in the pancreatic function test by liquid chromatography, with electrochemical detection. Clin Chem. 1982 Feb;28(2):323-6. [PubMed:6976857 ]
  10. Durie PR, Yung-Jato LY, Soldin SJ, Verjee Z, Ellis L: Bentiromide test using liquid-chromatographic measurement of p-aminobenzoic acid and its metabolites for diagnosing pancreatic insufficiency in childhood. J Pediatr. 1992 Sep;121(3):413-6. [PubMed:1517919 ]