Hmdb loader

Showing metabocard for Pimelic acid (HMDB0000857)

Jump To Section:
IdentificationTaxonomyOntologyPhysical propertiesSpectraBiological propertiesConcentrationsLinksReferencesXML
Show more...Show more...Show more...Show more...Show more...Show more...
Record Information
Version5.0
StatusDetected and Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2023-02-21 17:15:14 UTC
HMDB IDHMDB0000857
Secondary Accession Numbers
  • HMDB00857
Metabolite Identification
Common NamePimelic acid
DescriptionPimelic acid, also known as heptanedioic acid is a dicarboxylic acid. Derivatives of pimelic acid are involved in the biosynthesis of the amino acid called lysine. Pimelic acid is one methylene longer than a related dicarboxylic acid, adipic acid, a precursor to many polyesters and polyamides. Pimelic acid is essential for the synthesis of biotin (also called vitamin B7). Biotin is a heterocyclic, S-containing monocarboxylic acid that is made from two precursors, alanine and pimeloyl-CoA. Biotin is important in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis. Biotin is found in a wide range of foods. Likewise, intestinal bacteria synthesize biotin, which is then absorbed by the host animal. Pimelic acid (which is the precursor for pimeloyl-CoA) is synthesized in many bacteria via a head-to-tail incorporation of acetate units through a modified fatty acid synthetic pathway using O-methyl esters disguised to resemble the canonical intermediates of the fatty acid synthetic pathway (PMID:21435937 ). Some bacteria and yeast synthesize pimelic acid not by biosynthesis, but via cleavage of longer chain fatty acids (such as linolenic acid) via a cytochrome P450-like enzyme (PMID:28196402 , 21435937 , 3236079 ). Pimelic acid is excreted in elevated amounts in the urine of individuals with mitochondrial beta-oxidation disorders and peroxisomal beta oxidation disorders (PMID:1527989 )
Structure
Thumb
MOL3D MOLSDF3D SDFPDB3D PDBSMILESInChI

MOL for HMDB0000857 (Pimelic acid)

  Mrv1652305271900262D          

 11 10  0  0  0  0            999 V2000
    5.8559    2.5559    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    5.1414    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    4.4270    2.5559    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    3.7125    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.9980    2.5559    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    3.7125    1.3184    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    6.5704    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    7.2849    2.5559    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    7.9993    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    8.7138    2.5559    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    7.9993    1.3184    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0  0  0  0
  2  3  1  0  0  0  0
  3  4  1  0  0  0  0
  4  5  2  0  0  0  0
  4  6  1  0  0  0  0
  1  7  1  0  0  0  0
  7  8  1  0  0  0  0
  8  9  1  0  0  0  0
  9 10  2  0  0  0  0
  9 11  1  0  0  0  0
M  END
Download

3D MOL for HMDB0000857 (Pimelic acid)

HMDB0000857
     RDKit          3D
Pimelic acid
 23 22  0  0  0  0  0  0  0  0999 V2000
    2.4459    1.4973   -0.3925 O   0  0  0  0  0  0  0  0  0  0  0  0
    3.0884    0.4275   -0.3197 C   0  0  0  0  0  0  0  0  0  0  0  0
    4.3959    0.4122   -0.7669 O   0  0  0  0  0  0  0  0  0  0  0  0
    2.4569   -0.7846    0.2321 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.0400   -0.6157    0.6568 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.0813   -0.2076   -0.4065 C   0  0  0  0  0  0  0  0  0  0  0  0
   -1.2971   -0.1020    0.2643 C   0  0  0  0  0  0  0  0  0  0  0  0
   -2.2744    0.3129   -0.8148 C   0  0  0  0  0  0  0  0  0  0  0  0
   -3.6445    0.4447   -0.2704 C   0  0  0  0  0  0  0  0  0  0  0  0
   -4.5681    0.7831   -1.0467 O   0  0  0  0  0  0  0  0  0  0  0  0
   -3.8643    0.1931    1.0665 O   0  0  0  0  0  0  0  0  0  0  0  0
    5.1725    0.3452   -0.1029 H   0  0  0  0  0  0  0  0  0  0  0  0
    3.0161   -1.1495    1.1437 H   0  0  0  0  0  0  0  0  0  0  0  0
    2.5322   -1.6369   -0.4861 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.9223    0.0843    1.5091 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.6817   -1.6073    1.0555 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.2783    0.7907   -0.8093 H   0  0  0  0  0  0  0  0  0  0  0  0
   -0.0464   -0.9715   -1.2033 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.6050   -1.1079    0.6399 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.2053    0.6459    1.0690 H   0  0  0  0  0  0  0  0  0  0  0  0
   -2.2241   -0.4353   -1.6229 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.9417    1.2830   -1.2248 H   0  0  0  0  0  0  0  0  0  0  0  0
   -3.4407    0.6797    1.8298 H   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  2  0
  2  3  1  0
  2  4  1  0
  4  5  1  0
  5  6  1  0
  6  7  1  0
  7  8  1  0
  8  9  1  0
  9 10  2  0
  9 11  1  0
  3 12  1  0
  4 13  1  0
  4 14  1  0
  5 15  1  0
  5 16  1  0
  6 17  1  0
  6 18  1  0
  7 19  1  0
  7 20  1  0
  8 21  1  0
  8 22  1  0
 11 23  1  0
M  END
Download

3D SDF for HMDB0000857 (Pimelic acid)

  Mrv1652305271900262D          

 11 10  0  0  0  0            999 V2000
    5.8559    2.5559    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    5.1414    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    4.4270    2.5559    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    3.7125    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    2.9980    2.5559    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    3.7125    1.3184    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    6.5704    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    7.2849    2.5559    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    7.9993    2.1434    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0
    8.7138    2.5559    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
    7.9993    1.3184    0.0000 O   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  1  0  0  0  0
  2  3  1  0  0  0  0
  3  4  1  0  0  0  0
  4  5  2  0  0  0  0
  4  6  1  0  0  0  0
  1  7  1  0  0  0  0
  7  8  1  0  0  0  0
  8  9  1  0  0  0  0
  9 10  2  0  0  0  0
  9 11  1  0  0  0  0
M  END
> <DATABASE_ID>
HMDB0000857

> <DATABASE_NAME>
hmdb

> <SMILES>
OC(=O)CCCCCC(O)=O

> <INCHI_IDENTIFIER>
InChI=1S/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11)

> <INCHI_KEY>
WLJVNTCWHIRURA-UHFFFAOYSA-N

> <FORMULA>
C7H12O4

> <MOLECULAR_WEIGHT>
160.1678

> <EXACT_MASS>
160.073558872

> <JCHEM_ACCEPTOR_COUNT>
4

> <JCHEM_ATOM_COUNT>
23

> <JCHEM_AVERAGE_POLARIZABILITY>
16.309765941205747

> <JCHEM_BIOAVAILABILITY>
1

> <JCHEM_DONOR_COUNT>
2

> <JCHEM_FORMAL_CHARGE>
0

> <JCHEM_GHOSE_FILTER>
0

> <JCHEM_IUPAC>
heptanedioic acid

> <ALOGPS_LOGP>
0.51

> <JCHEM_LOGP>
0.9352230276666667

> <ALOGPS_LOGS>
-1.08

> <JCHEM_MDDR_LIKE_RULE>
0

> <JCHEM_NUMBER_OF_RINGS>
0

> <JCHEM_PHYSIOLOGICAL_CHARGE>
-2

> <JCHEM_PKA>
4.8101291244285145

> <JCHEM_PKA_STRONGEST_ACIDIC>
4.045044284282043

> <JCHEM_POLAR_SURFACE_AREA>
74.6

> <JCHEM_REFRACTIVITY>
37.339999999999996

> <JCHEM_ROTATABLE_BOND_COUNT>
6

> <JCHEM_RULE_OF_FIVE>
1

> <ALOGPS_SOLUBILITY>
1.33e+01 g/l

> <JCHEM_TRADITIONAL_IUPAC>
pimelic acid

> <JCHEM_VEBER_RULE>
0

$$$$
Download

3D-SDF for HMDB0000857 (Pimelic acid)

HMDB0000857
     RDKit          3D
Pimelic acid
 23 22  0  0  0  0  0  0  0  0999 V2000
    2.4459    1.4973   -0.3925 O   0  0  0  0  0  0  0  0  0  0  0  0
    3.0884    0.4275   -0.3197 C   0  0  0  0  0  0  0  0  0  0  0  0
    4.3959    0.4122   -0.7669 O   0  0  0  0  0  0  0  0  0  0  0  0
    2.4569   -0.7846    0.2321 C   0  0  0  0  0  0  0  0  0  0  0  0
    1.0400   -0.6157    0.6568 C   0  0  0  0  0  0  0  0  0  0  0  0
    0.0813   -0.2076   -0.4065 C   0  0  0  0  0  0  0  0  0  0  0  0
   -1.2971   -0.1020    0.2643 C   0  0  0  0  0  0  0  0  0  0  0  0
   -2.2744    0.3129   -0.8148 C   0  0  0  0  0  0  0  0  0  0  0  0
   -3.6445    0.4447   -0.2704 C   0  0  0  0  0  0  0  0  0  0  0  0
   -4.5681    0.7831   -1.0467 O   0  0  0  0  0  0  0  0  0  0  0  0
   -3.8643    0.1931    1.0665 O   0  0  0  0  0  0  0  0  0  0  0  0
    5.1725    0.3452   -0.1029 H   0  0  0  0  0  0  0  0  0  0  0  0
    3.0161   -1.1495    1.1437 H   0  0  0  0  0  0  0  0  0  0  0  0
    2.5322   -1.6369   -0.4861 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.9223    0.0843    1.5091 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.6817   -1.6073    1.0555 H   0  0  0  0  0  0  0  0  0  0  0  0
    0.2783    0.7907   -0.8093 H   0  0  0  0  0  0  0  0  0  0  0  0
   -0.0464   -0.9715   -1.2033 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.6050   -1.1079    0.6399 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.2053    0.6459    1.0690 H   0  0  0  0  0  0  0  0  0  0  0  0
   -2.2241   -0.4353   -1.6229 H   0  0  0  0  0  0  0  0  0  0  0  0
   -1.9417    1.2830   -1.2248 H   0  0  0  0  0  0  0  0  0  0  0  0
   -3.4407    0.6797    1.8298 H   0  0  0  0  0  0  0  0  0  0  0  0
  1  2  2  0
  2  3  1  0
  2  4  1  0
  4  5  1  0
  5  6  1  0
  6  7  1  0
  7  8  1  0
  8  9  1  0
  9 10  2  0
  9 11  1  0
  3 12  1  0
  4 13  1  0
  4 14  1  0
  5 15  1  0
  5 16  1  0
  6 17  1  0
  6 18  1  0
  7 19  1  0
  7 20  1  0
  8 21  1  0
  8 22  1  0
 11 23  1  0
M  END
Download

PDB for HMDB0000857 (Pimelic acid)

HEADER    PROTEIN                                 27-MAY-19   NONE
TITLE     NULL                                                        
COMPND    NULL                                                        
SOURCE    NULL                                                        
KEYWDS    NULL                                                        
EXPDTA    NULL                                                        
AUTHOR    Marvin                                                      
REVDAT   1   27-MAY-19         0                                  
HETATM    1  C   UNK     0      10.931   4.771   0.000  0.00  0.00           C+0
HETATM    2  C   UNK     0       9.597   4.001   0.000  0.00  0.00           C+0
HETATM    3  C   UNK     0       8.264   4.771   0.000  0.00  0.00           C+0
HETATM    4  C   UNK     0       6.930   4.001   0.000  0.00  0.00           C+0
HETATM    5  O   UNK     0       5.596   4.771   0.000  0.00  0.00           O+0
HETATM    6  O   UNK     0       6.930   2.461   0.000  0.00  0.00           O+0
HETATM    7  C   UNK     0      12.265   4.001   0.000  0.00  0.00           C+0
HETATM    8  C   UNK     0      13.598   4.771   0.000  0.00  0.00           C+0
HETATM    9  C   UNK     0      14.932   4.001   0.000  0.00  0.00           C+0
HETATM   10  O   UNK     0      16.266   4.771   0.000  0.00  0.00           O+0
HETATM   11  O   UNK     0      14.932   2.461   0.000  0.00  0.00           O+0
CONECT    1    2    7                                                       
CONECT    2    1    3                                                       
CONECT    3    2    4                                                       
CONECT    4    3    5    6                                                  
CONECT    5    4                                                            
CONECT    6    4                                                            
CONECT    7    1    8                                                       
CONECT    8    7    9                                                       
CONECT    9    8   10   11                                                  
CONECT   10    9                                                            
CONECT   11    9                                                            
MASTER        0    0    0    0    0    0    0    0   11    0   20    0
END
Download

3D PDB for HMDB0000857 (Pimelic acid)

COMPND    HMDB0000857
HETATM    1  O1  UNL     1       2.446   1.497  -0.393  1.00  0.00           O  
HETATM    2  C1  UNL     1       3.088   0.428  -0.320  1.00  0.00           C  
HETATM    3  O2  UNL     1       4.396   0.412  -0.767  1.00  0.00           O  
HETATM    4  C2  UNL     1       2.457  -0.785   0.232  1.00  0.00           C  
HETATM    5  C3  UNL     1       1.040  -0.616   0.657  1.00  0.00           C  
HETATM    6  C4  UNL     1       0.081  -0.208  -0.406  1.00  0.00           C  
HETATM    7  C5  UNL     1      -1.297  -0.102   0.264  1.00  0.00           C  
HETATM    8  C6  UNL     1      -2.274   0.313  -0.815  1.00  0.00           C  
HETATM    9  C7  UNL     1      -3.644   0.445  -0.270  1.00  0.00           C  
HETATM   10  O3  UNL     1      -4.568   0.783  -1.047  1.00  0.00           O  
HETATM   11  O4  UNL     1      -3.864   0.193   1.066  1.00  0.00           O  
HETATM   12  H1  UNL     1       5.172   0.345  -0.103  1.00  0.00           H  
HETATM   13  H2  UNL     1       3.016  -1.149   1.144  1.00  0.00           H  
HETATM   14  H3  UNL     1       2.532  -1.637  -0.486  1.00  0.00           H  
HETATM   15  H4  UNL     1       0.922   0.084   1.509  1.00  0.00           H  
HETATM   16  H5  UNL     1       0.682  -1.607   1.056  1.00  0.00           H  
HETATM   17  H6  UNL     1       0.278   0.791  -0.809  1.00  0.00           H  
HETATM   18  H7  UNL     1      -0.046  -0.972  -1.203  1.00  0.00           H  
HETATM   19  H8  UNL     1      -1.605  -1.108   0.640  1.00  0.00           H  
HETATM   20  H9  UNL     1      -1.205   0.646   1.069  1.00  0.00           H  
HETATM   21  H10 UNL     1      -2.224  -0.435  -1.623  1.00  0.00           H  
HETATM   22  H11 UNL     1      -1.942   1.283  -1.225  1.00  0.00           H  
HETATM   23  H12 UNL     1      -3.441   0.680   1.830  1.00  0.00           H  
CONECT    1    2    2
CONECT    2    3    4
CONECT    3   12
CONECT    4    5   13   14
CONECT    5    6   15   16
CONECT    6    7   17   18
CONECT    7    8   19   20
CONECT    8    9   21   22
CONECT    9   10   10   11
CONECT   11   23
END
Download

SMILES for HMDB0000857 (Pimelic acid)

OC(=O)CCCCCC(O)=O
Download

INCHI for HMDB0000857 (Pimelic acid)

InChI=1S/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11)
Download
View in JSmolView NMR AssignmentsView Stereo Labels
Synonyms
Chemical FormulaC7H12O4
Average Molecular Weight160.1678
Monoisotopic Molecular Weight160.073558872
IUPAC Nameheptanedioic acid
Traditional Namepimelic acid
CAS Registry Number111-16-0
SMILES
OC(=O)CCCCCC(O)=O
InChI Identifier
InChI=1S/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11)
InChI KeyWLJVNTCWHIRURA-UHFFFAOYSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as medium-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 4 and 12 carbon atoms.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassFatty Acyls
Sub ClassFatty acids and conjugates
Direct ParentMedium-chain fatty acids
Alternative Parents
Substituents
  • Medium-chain fatty acid
  • Dicarboxylic acid or derivatives
  • Carboxylic acid
  • Carboxylic acid derivative
  • Organic oxygen compound
  • Organic oxide
  • Hydrocarbon derivative
  • Organooxygen compound
  • Carbonyl group
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
Ontology
Physiological effectNot Available
Disposition
Biological locationRoute of exposureSource
Process
Naturally occurring process
Role
Biological roleIndustrial application
Physical Properties
StateSolid
Experimental Molecular Properties
PropertyValueReference
Melting Point103 - 106 °CNot Available
Boiling Point342.00 °C. @ 760.00 mm HgThe Good Scents Company Information System
Water Solubility50 mg/mLNot Available
LogP0.61HANSCH,C ET AL. (1995)
Experimental Chromatographic Properties

Experimental Collision Cross Sections

Adduct TypeData SourceCCS Value (Å2)Reference
[M-H]-MetCCS_train_neg129.28630932474
[M-H]-Not Available130.8http://allccs.zhulab.cn/database/detail?ID=AllCCS00000223
Predicted Molecular Properties
Predicted Chromatographic Properties
Spectra
Biological Properties
Cellular Locations
  • Membrane
Biospecimen Locations
  • Blood
  • Feces
  • Urine
Tissue LocationsNot Available
Pathways
Normal Concentrations
Abnormal Concentrations
Associated Disorders and Diseases
Disease References
3-Hydroxydicarboxylic aciduria
  1. Hagenfeldt L, von Dobeln U, Holme E, Alm J, Brandberg G, Enocksson E, Lindeberg L: 3-Hydroxydicarboxylic aciduria--a fatty acid oxidation defect with severe prognosis. J Pediatr. 1990 Mar;116(3):387-92. [PubMed:2308028 ]
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 ]
Eosinophilic esophagitis
  1. Slae, M., Huynh, H., Wishart, D.S. (2014). Analysis of 30 normal pediatric urine samples via NMR spectroscopy (unpublished work). NA.
Associated OMIM IDs
DrugBank IDDB01856
Phenol Explorer Compound IDNot Available
FooDB IDFDB022283
KNApSAcK IDC00001199
Chemspider ID376
KEGG Compound IDC02656
BioCyc IDCPD-205
BiGG IDNot Available
Wikipedia LinkPimelic_acid
METLIN ID3280
PubChem Compound385
PDB IDNot Available
ChEBI ID30531
Food Biomarker OntologyNot Available
VMH IDPIME
MarkerDB IDMDB00000268
Good Scents IDrw1274891
References
Synthesis ReferenceMurib, Jawad H.; Kahn, John H. Production of pimelic acid by carbonylation of e-caprolactone using excess water. U.S. (1989), 3 pp.
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Guneral F, Bachmann C: Age-related reference values for urinary organic acids in a healthy Turkish pediatric population. Clin Chem. 1994 Jun;40(6):862-6. [PubMed:8087979 ]
  2. Passi S, Picardo M, Mingrone G, Breathnach AS, Nazzaro-Porro M: Azelaic acid--biochemistry and metabolism. Acta Derm Venereol Suppl (Stockh). 1989;143:8-13. [PubMed:2505463 ]
  3. Pettit BR: The analysis of thiodiglycollic acid by selected ion monitoring. Clin Chim Acta. 1986 Apr 15;156(1):85-90. [PubMed:3698320 ]
  4. Niwa T, Ohki T, Maeda K, Saito A, Kobayashi K: Pattern of aliphatic dicarboxylic acids in uremic serum including a new organic acid, 2,4-dimethyladipic acid. Clin Chim Acta. 1979 Nov 15;99(1):71-83. [PubMed:498544 ]
  5. Mahadevappa VG, Holub BJ: The molecular species composition of individual diacyl phospholipids in human platelets. Biochim Biophys Acta. 1982 Oct 14;713(1):73-9. [PubMed:7138900 ]
  6. Cronan JE, Lin S: Synthesis of the alpha,omega-dicarboxylic acid precursor of biotin by the canonical fatty acid biosynthetic pathway. Curr Opin Chem Biol. 2011 Jun;15(3):407-13. doi: 10.1016/j.cbpa.2011.03.001. Epub 2011 Mar 23. [PubMed:21435937 ]
  7. Manandhar M, Cronan JE: Pimelic acid, the first precursor of the Bacillus subtilis biotin synthesis pathway, exists as the free acid and is assembled by fatty acid synthesis. Mol Microbiol. 2017 May;104(4):595-607. doi: 10.1111/mmi.13648. Epub 2017 Mar 3. [PubMed:28196402 ]
  8. Ohsugi M, Miyauchi K, Tachibana K, Nakao S: Formation of a biotin precursor, pimelic acid, in yeasts from C18 fatty acids. J Nutr Sci Vitaminol (Tokyo). 1988 Aug;34(4):343-52. doi: 10.3177/jnsv.34.343. [PubMed:3236079 ]
  9. Bennett MJ, Ragni MC, Hood I, Hale DE: Azelaic and pimelic acids: metabolic intermediates or artefacts? J Inherit Metab Dis. 1992;15(2):220-3. doi: 10.1007/BF01799635. [PubMed:1527989 ]