<?xml version="1.0" encoding="UTF-8"?>
<metabolite>
  <version>1.0</version>
  <creation_date>2016-09-30 22:19:45 UTC</creation_date>
  <update_date>2020-05-21 16:27:05 UTC</update_date>
  <accession>BMDB0000118</accession>
  <secondary_accessions>
    <accession>BMDB00118</accession>
  </secondary_accessions>
  <name>Homovanillic acid</name>
  <description>Homovanillic acid, also known as vanillacetate or homovanillate, belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety. Homovanillic acid exists as a solid, possibly soluble (in water), and an extremely weak basic (essentially neutral) compound (based on its pKa) molecule. Homovanillic acid exists in all living species, ranging from bacteria to humans. Homovanillic acid participates in a number of enzymatic reactions, within cattle. In particular, Homovanillic acid can be biosynthesized from homovanillin; which is catalyzed by the enzyme aldehyde dehydrogenase, dimeric nadp-preferring. In addition, Homovanillic acid and pyrocatechol can be biosynthesized from 3,4-dihydroxybenzeneacetic acid and guaiacol through its interaction with the enzyme catechol O-methyltransferase. In cattle, homovanillic acid is involved in the metabolic pathway called the tyrosine metabolism pathway. Homovanillic acid is a potentially toxic compound.</description>
  <synonyms>
    <synonym>(4-Hydroxy-3-methoxyphenyl)acetic acid</synonym>
    <synonym>3-Methoxy-4-hydroxyphenylacetate</synonym>
    <synonym>3-Methoxy-4-hydroxyphenylacetic acid</synonym>
    <synonym>4-Hydroxy-3-methoxybenzeneacetic acid</synonym>
    <synonym>HVA</synonym>
    <synonym>Vanillacetic acid</synonym>
    <synonym>(4-Hydroxy-3-methoxyphenyl)acetate</synonym>
    <synonym>4-Hydroxy-3-methoxybenzeneacetate</synonym>
    <synonym>Vanillacetate</synonym>
    <synonym>Homovanillate</synonym>
    <synonym>3-Methoxy-4-hydroxy-phenylacetic acid</synonym>
    <synonym>4-Hydroxy 3-methoxyphenylacetic acid</synonym>
    <synonym>4-Hydroxy-3-methoxyphenylacetic acid</synonym>
    <synonym>Homovanilate</synonym>
    <synonym>Homovanilic acid</synonym>
    <synonym>Homovanillinic acid</synonym>
    <synonym>Vanilacetate</synonym>
    <synonym>Vanilacetic acid</synonym>
    <synonym>3 Methoxy 4 hydroxyphenylacetic acid</synonym>
    <synonym>Acid, 3-methoxy-4-hydroxyphenylacetic</synonym>
    <synonym>Acid, 4-hydroxy-3-methoxyphenylacetic</synonym>
    <synonym>4 Hydroxy 3 methoxyphenylacetic acid</synonym>
    <synonym>Acid, homovanillic</synonym>
    <synonym>3'-Methoxy-4'-hydroxyphenylacetic acid</synonym>
    <synonym>3’-methoxy-4’-hydroxyphenylacetic acid</synonym>
    <synonym>4'-Hydroxy-3'-methoxy-phenylacetic acid</synonym>
    <synonym>2-(4-Hydroxy-3-methoxyphenyl)acetic acid</synonym>
    <synonym>4'-Hydroxy-3'-methoxyphenylacetic acid</synonym>
  </synonyms>
  <chemical_formula>C9H10O4</chemical_formula>
  <average_molecular_weight>182.1733</average_molecular_weight>
  <monisotopic_moleculate_weight>182.057908808</monisotopic_moleculate_weight>
  <iupac_name>2-(4-hydroxy-3-methoxyphenyl)acetic acid</iupac_name>
  <traditional_iupac>homovanillic acid</traditional_iupac>
  <cas_registry_number>306-08-1</cas_registry_number>
  <smiles>COC1=CC(CC(O)=O)=CC=C1O</smiles>
  <inchi>InChI=1S/C9H10O4/c1-13-8-4-6(5-9(11)12)2-3-7(8)10/h2-4,10H,5H2,1H3,(H,11,12)</inchi>
  <inchikey>QRMZSPFSDQBLIX-UHFFFAOYSA-N</inchikey>
  <taxonomy>
    <description> belongs to the class of organic compounds known as methoxyphenols. Methoxyphenols are compounds containing a methoxy group attached to the benzene ring of a phenol moiety.</description>
    <kingdom>Organic compounds</kingdom>
    <super_class>Benzenoids</super_class>
    <class>Phenols</class>
    <sub_class>Methoxyphenols</sub_class>
    <direct_parent>Methoxyphenols</direct_parent>
    <alternative_parents>
      <alternative_parent>1-hydroxy-2-unsubstituted benzenoids</alternative_parent>
      <alternative_parent>Alkyl aryl ethers</alternative_parent>
      <alternative_parent>Anisoles</alternative_parent>
      <alternative_parent>Carbonyl compounds</alternative_parent>
      <alternative_parent>Carboxylic acids</alternative_parent>
      <alternative_parent>Hydrocarbon derivatives</alternative_parent>
      <alternative_parent>Methoxybenzenes</alternative_parent>
      <alternative_parent>Monocarboxylic acids and derivatives</alternative_parent>
      <alternative_parent>Organic oxides</alternative_parent>
      <alternative_parent>Phenoxy compounds</alternative_parent>
    </alternative_parents>
    <substituents>
      <substituent>1-hydroxy-2-unsubstituted benzenoid</substituent>
      <substituent>Alkyl aryl ether</substituent>
      <substituent>Anisole</substituent>
      <substituent>Aromatic homomonocyclic compound</substituent>
      <substituent>Carbonyl group</substituent>
      <substituent>Carboxylic acid</substituent>
      <substituent>Carboxylic acid derivative</substituent>
      <substituent>Ether</substituent>
      <substituent>Hydrocarbon derivative</substituent>
      <substituent>Methoxybenzene</substituent>
      <substituent>Methoxyphenol</substituent>
      <substituent>Monocarboxylic acid or derivatives</substituent>
      <substituent>Monocyclic benzene moiety</substituent>
      <substituent>Organic oxide</substituent>
      <substituent>Organic oxygen compound</substituent>
      <substituent>Organooxygen compound</substituent>
      <substituent>Phenol ether</substituent>
      <substituent>Phenoxy compound</substituent>
    </substituents>
    <molecular_framework>Aromatic homomonocyclic compounds</molecular_framework>
    <external_descriptors>
      <external_descriptor>monocarboxylic acid</external_descriptor>
      <external_descriptor>monomethoxybenzene</external_descriptor>
      <external_descriptor>phenols</external_descriptor>
    </external_descriptors>
  </taxonomy>
  <experimental_properties>
    <state>Solid</state>
    <property>
      <kind>melting_point</kind>
      <value>138 - 140 °C</value>
      <source/>
    </property>
    <property>
      <kind>water_solubility</kind>
      <value>17 mg/mL</value>
      <source/>
    </property>
    <property>
      <kind>logp</kind>
      <value>0.33</value>
      <source>LAHANN,TR ET AL. (1989)</source>
    </property>
  </experimental_properties>
  <predicted_properties>
    <property>
      <kind>logp</kind>
      <value>1.02</value>
      <source>ALOGPS</source>
    </property>
    <property>
      <kind>logs</kind>
      <value>-1.83</value>
      <source>ALOGPS</source>
    </property>
    <property>
      <kind>logp</kind>
      <value>1.15</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>pka_strongest_acidic</kind>
      <value>3.74</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>pka_strongest_basic</kind>
      <value>-4.9</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>iupac</kind>
      <value>2-(4-hydroxy-3-methoxyphenyl)acetic acid</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>average_mass</kind>
      <value>182.1733</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>mono_mass</kind>
      <value>182.057908808</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>smiles</kind>
      <value>COC1=CC(CC(O)=O)=CC=C1O</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>formula</kind>
      <value>C9H10O4</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>inchi</kind>
      <value>InChI=1S/C9H10O4/c1-13-8-4-6(5-9(11)12)2-3-7(8)10/h2-4,10H,5H2,1H3,(H,11,12)</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>inchikey</kind>
      <value>QRMZSPFSDQBLIX-UHFFFAOYSA-N</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>polar_surface_area</kind>
      <value>66.76</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>refractivity</kind>
      <value>45.81</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>polarizability</kind>
      <value>17.74</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>rotatable_bond_count</kind>
      <value>3</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>acceptor_count</kind>
      <value>4</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>donor_count</kind>
      <value>2</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>physiological_charge</kind>
      <value>-1</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>formal_charge</kind>
      <value>0</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>number_of_rings</kind>
      <value>1</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>bioavailability</kind>
      <value>1</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>rule_of_five</kind>
      <value>Yes</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>ghose_filter</kind>
      <value>Yes</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>veber_rule</kind>
      <value>Yes</value>
      <source>ChemAxon</source>
    </property>
    <property>
      <kind>mddr_like_rule</kind>
      <value>Yes</value>
      <source>ChemAxon</source>
    </property>
  </predicted_properties>
  <pathways>
    <pathway>
      <name>Tyrosine Metabolism</name>
      <smpdb_id>SMP0087235</smpdb_id>
      <kegg_map_id/>
    </pathway>
  </pathways>
  <spectra>
    <spectrum>
      <type>Specdb::EiMs</type>
      <spectrum_id>952</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsIr</type>
      <spectrum_id>183</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsIr</type>
      <spectrum_id>184</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsIr</type>
      <spectrum_id>185</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>333</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>1439</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>2673</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>27758</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>30084</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>30626</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>31003</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>32275</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>37301</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>151887</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>1050349</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>1050351</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>1050353</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>1050355</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::CMs</type>
      <spectrum_id>1050357</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrTwoD</type>
      <spectrum_id>958</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrTwoD</type>
      <spectrum_id>1148</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>168</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>169</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>170</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2903</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2904</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2905</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2906</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2907</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>10931</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>10932</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>10933</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>17603</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>17604</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>17605</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>437860</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>437861</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>437862</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>437863</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>437864</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>439681</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>439682</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>440166</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2235866</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2237219</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::MsMs</type>
      <spectrum_id>2237495</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>1090</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>2330</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>3031</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>5071</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>5072</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142270</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142271</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142272</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142273</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142274</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142275</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142276</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142277</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142278</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142279</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142280</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142281</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142282</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142283</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142284</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142285</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142286</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142287</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142288</spectrum_id>
    </spectrum>
    <spectrum>
      <type>Specdb::NmrOneD</type>
      <spectrum_id>142289</spectrum_id>
    </spectrum>
  </spectra>
  <normal_concentrations>
    <concentration>
      <biospecimen>Brain</biospecimen>
      <concentration_value/>
      <concentration_units/>
      <references>
        <reference>
          <reference_text>Wishart DS, Feunang YD, Marcu A, Guo AC, Liang K, Vazquez-Fresno R, Sajed T, Johnson D, Li C, Karu N, Sayeeda Z, Lo E, Assempour N, Berjanskii M, Singhal S, Arndt D, Liang Y, Badran H, Grant J, Serra-Cayuela A, Liu Y, Mandal R, Neveu V, Pon A, Knox C, Wilson M, Manach C, Scalbert A: HMDB 4.0: the human metabolome database for 2018. Nucleic Acids Res. 2018 Jan 4;46(D1):D608-D617. doi: 10.1093/nar/gkx1089.</reference_text>
          <pubmed_id>29140435</pubmed_id>
        </reference>
      </references>
    </concentration>
    <concentration>
      <biospecimen>Fibroblasts</biospecimen>
      <concentration_value/>
      <concentration_units/>
      <references>
        <reference>
          <reference_text>Wishart DS, Feunang YD, Marcu A, Guo AC, Liang K, Vazquez-Fresno R, Sajed T, Johnson D, Li C, Karu N, Sayeeda Z, Lo E, Assempour N, Berjanskii M, Singhal S, Arndt D, Liang Y, Badran H, Grant J, Serra-Cayuela A, Liu Y, Mandal R, Neveu V, Pon A, Knox C, Wilson M, Manach C, Scalbert A: HMDB 4.0: the human metabolome database for 2018. Nucleic Acids Res. 2018 Jan 4;46(D1):D608-D617. doi: 10.1093/nar/gkx1089.</reference_text>
          <pubmed_id>29140435</pubmed_id>
        </reference>
      </references>
    </concentration>
    <concentration>
      <biospecimen>Kidney</biospecimen>
      <concentration_value/>
      <concentration_units/>
      <references>
        <reference>
          <reference_text>Wishart DS, Feunang YD, Marcu A, Guo AC, Liang K, Vazquez-Fresno R, Sajed T, Johnson D, Li C, Karu N, Sayeeda Z, Lo E, Assempour N, Berjanskii M, Singhal S, Arndt D, Liang Y, Badran H, Grant J, Serra-Cayuela A, Liu Y, Mandal R, Neveu V, Pon A, Knox C, Wilson M, Manach C, Scalbert A: HMDB 4.0: the human metabolome database for 2018. Nucleic Acids Res. 2018 Jan 4;46(D1):D608-D617. doi: 10.1093/nar/gkx1089.</reference_text>
          <pubmed_id>29140435</pubmed_id>
        </reference>
      </references>
    </concentration>
    <concentration>
      <biospecimen>Milk</biospecimen>
      <concentration_value/>
      <concentration_units/>
      <comment>Fermented milk, by capillary electrophoresis-TOFMS</comment>
      <references>
        <reference>
          <reference_text>Hagi T, Kobayashi M, Nomura M: Metabolome analysis of milk fermented by gamma-aminobutyric acid-producing Lactococcus lactis. J Dairy Sci. 2016 Feb;99(2):994-1001. doi: 10.3168/jds.2015-9945. Epub 2015 Dec 10.</reference_text>
          <pubmed_id>26686724</pubmed_id>
        </reference>
      </references>
    </concentration>
  </normal_concentrations>
  <kegg_id>C05582</kegg_id>
  <drugbank_id/>
  <foodb_id>FDB001783</foodb_id>
  <chemspider_id>1675</chemspider_id>
  <pubchem_compound_id>1738</pubchem_compound_id>
  <pdbe_id/>
  <chebi_id>545959</chebi_id>
  <phenol_explorer_compound_id>574</phenol_explorer_compound_id>
  <knapsack_id>C00029504</knapsack_id>
  <meta_cyc_id>CPD-7651</meta_cyc_id>
  <wikipedia_id>Homovanillic_acid</wikipedia_id>
  <bigg_id>46066</bigg_id>
  <metlin_id>971</metlin_id>
  <synthesis_reference/>
  <general_references>
    <reference>
      <reference_text>Hagi T, Kobayashi M, Nomura M: Metabolome analysis of milk fermented by gamma-aminobutyric acid-producing Lactococcus lactis. J Dairy Sci. 2016 Feb;99(2):994-1001. doi: 10.3168/jds.2015-9945. Epub 2015 Dec 10.</reference_text>
      <pubmed_id>26686724</pubmed_id>
    </reference>
  </general_references>
  <protein_associations>
    <protein>
      <protein_accession>BMDBP00421</protein_accession>
      <name>Catechol O-methyltransferase</name>
      <uniprot_id>A7MBI7</uniprot_id>
      <gene_name>COMT</gene_name>
      <protein_type>Enzyme</protein_type>
    </protein>
  </protein_associations>
</metabolite>
