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
StatusDetected and Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2019-07-23 05:44:27 UTC
Secondary Accession Numbers
  • HMDB0000475
  • HMDB00475
  • HMDB00748
Metabolite Identification
Common NameL-3-Phenyllactic acid
DescriptionL-3-Phenyllactic acid (or PLA) is a chiral aromatic compound involved in phenylalanine metabolism. It is likely produced from phenylpyruvate via the action of lactate dehydrogenase. The D-form of this organic acid is typically derived from bacterial sources while the L-form is almost certainly endogenous. Levels of phenyllactate are normally very low in blood or urine. High levels of PLA in the urine or blood are often indicative of phenylketonuria (PKU) and hyperphenylalaninemia (HPA). PKU is due to lack of the enzyme phenylalanine hydroxylase (PAH), so that phenylalanine is converted not to tyrosine but to phenylpyruvic acid (a precursor of phenylactate). In particular, excessive phenylalanine is typically metabolized into phenylketones through, a transaminase pathway route involving glutamate. Metabolites of this transamination reaction include phenylacetate, phenylpyruvate and phenethylamine. In persons with PKU, dietary phenylalanine either accumulates in the body or some of it is converted to phenylpyruvic acid and then to phenyllactate through the action of lactate dehydrogenase. Individuals with PKU tend to excrete large quantities of phenylpyruvate, phenylacetate and phenyllactate, along with phenylalanine, in their urine. If untreated, mental retardation effects and microcephaly are evident by the first year along with other symptoms which include: unusual irritability, epileptic seizures and skin lesions. Hyperactivity, EEG abnormalities and seizures, and severe learning disabilities are major clinical problems later in life. A "musty or mousy" odor of skin, hair, sweat and urine (due to phenylacetate accumulation); and a tendency to hypopigmentation and eczema are also observed. The neural-development effects of PKU are primarily due to the disruption of neurotransmitter synthesis. In particular, phenylalanine is a large, neutral amino acid which moves across the blood-brain barrier (BBB) via the large neutral amino acid transporter (LNAAT). Excessive phenylalanine in the blood saturates the transporter. Thus, excessive levels of phenylalanine significantly decrease the levels of other LNAAs in the brain. But since these amino acids are required for protein and neurotransmitter synthesis, phenylalanine accumulation disrupts brain development, leading to mental retardation.
D-3-Phenyllactic acidChEBI
(R)-Phenyllactic acidGenerator
(R)-3-(Phenyl)lactic acidGenerator
(-)-2-Hydroxy-3-phenylpropanoic acidHMDB
(-)-2-Hydroxy-3-phenylpropionic acidHMDB
(-)-3-Phenyllactic acidHMDB
(-)-b-Phenyllactic acidHMDB
(-)-beta-Phenyllactic acidHMDB
(2S)-2-Hydroxy-3-phenylpropanoic acidHMDB
(2S)-2-Hydroxy-3-phenylpropionic acidHMDB
(S)-3-Phenyl-lactic acidHMDB
(S)-3-Phenyllactic acidHMDB
(S)-a-Hydroxy-benzenepropanoic acidHMDB
(S)-alpha-Hydroxy-benzenepropanoic acidHMDB
alpha-Hydroxy-beta-phenyl-propionic acidHMDB
L-(-)-3-Phenyllactic acidHMDB
L-2-Hydroxy-3-phenyl-propionic acidHMDB
L-beta-Phenyllactic acidHMDB
L-Phenyl lactateHMDB
Phenyllactic acidHMDB
Chemical FormulaC9H10O3
Average Molecular Weight166.1739
Monoisotopic Molecular Weight166.062994186
IUPAC Name(2R)-2-hydroxy-3-phenylpropanoic acid
Traditional Name(R)-phenyllactate
CAS Registry Number20312-36-1
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as phenylpropanoic acids. Phenylpropanoic acids are compounds with a structure containing a benzene ring conjugated to a propanoic acid.
KingdomOrganic compounds
Super ClassPhenylpropanoids and polyketides
ClassPhenylpropanoic acids
Sub ClassNot Available
Direct ParentPhenylpropanoic acids
Alternative Parents
  • 3-phenylpropanoic-acid
  • Alpha-hydroxy acid
  • Monocyclic benzene moiety
  • Hydroxy acid
  • Benzenoid
  • Secondary alcohol
  • Carboxylic acid derivative
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Organic oxygen compound
  • Alcohol
  • Carbonyl group
  • Organic oxide
  • Hydrocarbon derivative
  • Organooxygen compound
  • Aromatic homomonocyclic compound
Molecular FrameworkAromatic homomonocyclic compounds
External Descriptors

Biological location:


Physical Properties
Experimental Properties
Melting Point121 - 125 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility9.8 g/LALOGPS
pKa (Strongest Acidic)4.02ChemAxon
pKa (Strongest Basic)-3.8ChemAxon
Physiological Charge-1ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area57.53 ŲChemAxon
Rotatable Bond Count3ChemAxon
Refractivity43.46 m³·mol⁻¹ChemAxon
Polarizability16.73 ųChemAxon
Number of Rings1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) (Non-derivatized)splash10-0007-0910000000-ee61dd1edcb64a115835JSpectraViewer | MoNA
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-0007-0920000000-7efa1766fa6121c5f695JSpectraViewer | MoNA
GC-MSGC-MS Spectrum - GC-EI-TOF (Non-derivatized)splash10-0007-0910000000-ee61dd1edcb64a115835JSpectraViewer | MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-0006-9300000000-750e52d0df9e2b90be09JSpectraViewer
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (2 TMS) - 70eV, Positivesplash10-006x-9540000000-c06e2865c7cf1c780f11JSpectraViewer
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-00di-0900000000-c20feab32f47edc5bb94JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-0f89-9500000000-598d564a5c5cb5a6febbJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-0ac0-9000000000-32b5f6f43141f16996a4JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-00ke-1900000000-b4165543fe4077bc8878JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-006y-4900000000-9cc77ecfa0e908d400f3JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0006-9100000000-8e08ba85783d44c725b8JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-014i-0900000000-c5b01c647718505d882aJSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-01bd-2900000000-2cd5c47ea7b35f76e87bJSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-00mo-9300000000-22457d19a65466f8e94dJSpectraViewer
1D NMR1H NMR SpectrumNot AvailableJSpectraViewer
2D NMR[1H,13C] 2D NMR SpectrumNot AvailableJSpectraViewer
Biological Properties
Cellular LocationsNot Available
Biospecimen Locations
  • Blood
  • Feces
  • Saliva
Tissue LocationsNot Available
Normal Concentrations
FecesDetected but not Quantified Adult (>18 years old)Both
FecesDetected but not Quantified Adult (>18 years old)Both
FecesDetected but not Quantified Adult (>18 years old)Both
SalivaDetected and Quantified0.427 +/- 0.354 uMAdult (>18 years old)Not Specified
    • Sugimoto et al. (...
SalivaDetected and Quantified0.596 +/- 0.337 uMAdult (>18 years old)Not Specified
    • Sugimoto et al. (...
Abnormal Concentrations
BloodDetected and Quantified0-82.9 uMChildren (1-13 years old)BothPhenylketonuria details
FecesDetected but not Quantified Adult (>18 years old)Both
Colorectal cancer
FecesDetected but not Quantified Adult (>18 years old)Both
Colorectal cancer
Associated Disorders and Diseases
Disease References
  1. Clemens PC, Schunemann MH, Hoffmann GF, Kohlschutter A: Plasma concentrations of phenyllactic acid in phenylketonuria. J Inherit Metab Dis. 1990;13(2):227-8. [PubMed:2116554 ]
Colorectal cancer
  1. 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 ]
  2. 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 ]
Associated OMIM IDs
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FoodDB IDFDB022220
KNApSAcK IDC00000150
Chemspider ID558480
KEGG Compound IDC05607
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNot Available
METLIN IDNot Available
PubChem Compound643327
PDB IDNot Available
ChEBI ID32978
Food Biomarker OntologyNot Available
VMH IDNot Available
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Tekewe A, Singh S, Singh M, Mohan U, Banerjee UC: Development and validation of HPLC method for the resolution of drug intermediates: DL-3-Phenyllactic acid, DL-O-acetyl-3-phenyllactic acid and (+/-)-mexiletine acetamide enantiomers. Talanta. 2008 Mar 15;75(1):239-45. doi: 10.1016/j.talanta.2007.11.004. Epub 2007 Nov 13. [PubMed:18371874 ]
  2. (). Andrew D. Abell, John W. Blunt, Glenn J. Foulds and Murray H. G. Munro Chemistry of the mycalamides: antiviral and antitumour compounds from a New Zealand marine sponge. Part 6.1–3 The synthesis and testing of analogues of the C(7)–C(10) fragment. J. Chem. Soc., Perkin Trans. 1, 1997, 1647 - 1654,. .