Ferulic acid

{{chembox |ImageFile = Ferulic acid.svg |ImageFile2 = Ferulic-acid-3D.png |PIN = (2''E'')-3-(4-hydroxy-3-methoxyphenyl)prop-2-enoic acid |OtherNames = 2-propenoic acid, 3-(4-hydroxy-3-methoxyphenyl)- ferulic acid 3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid 3-(4-hydroxy-3-methoxyphenyl)acrylic acid 3-methoxy-4-hydroxycinnamic acid 4-hydroxy-3-methoxycinnamic acid (2''E'')-3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid Coniferic acid trans-ferulic acid (''E'')-ferulic acid |Section1={{Chembox Identifiers |ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |ChemSpiderID = 393368 |InChI = 1/C10H10O4/c1-14-9-6-7(2-4-8(9)11)3-5-10(12)13/h2-6,11H,1H3,(H,12,13)/b5-3+ |InChIKey = KSEBMYQBYZTDHS-HWKANZROBE |StdInChI_Ref = {{stdinchicite|correct|chemspider}} |StdInChI = 1S/C10H10O4/c1-14-9-6-7(2-4-8(9)11)3-5-10(12)13/h2-6,11H,1H3,(H,12,13)/b5-3+ |StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |StdInChIKey = KSEBMYQBYZTDHS-HWKANZROSA-N |CASNo_Ref = {{cascite|correct|CAS}} |CASNo = 537-98-4  |UNII_Ref = {{fdacite|correct|FDA}} |UNII = AVM951ZWST |ChEMBL_Ref = {{ebicite|correct|EBI}} |ChEMBL = 32749 |PubChem = 445858 |DrugBank_Ref = {{drugbankcite|correct|drugbank}} |DrugBank = DB07767 |ChEBI_Ref = {{ebicite|correct|EBI}} |ChEBI = 17620 |SMILES = COc1cc(ccc1O)/C=C/C(=O)O }} |Section2={{Chembox Properties |C = 10 | H = 10 | O = 4 |Appearance = Crystalline powder |MeltingPtC = 168 to 172 | pKa = 4.61<ref name="Mota-2008">{{cite journal|last1=Mota|first1=Fátima L.|last2=Queimada|first2=António J.|last3=Pinho|first3=Simão P.|last4=Macedo|first4=Eugénia A.|title=Aqueous Solubility of Some Natural Phenolic Compounds|journal=Industrial & Engineering Chemistry Research|date=August 2008|volume=47|issue=15|pages=5182–5189|doi=10.1021/ie071452o|hdl=10198/1506|url=https://hal.archives-ouvertes.fr/hal-01637105/file/galley.pdf |hdl-access=free}}</ref> | Solubility = 0.78 g/L<ref name="Mota-2008" /> }} |Section3={{Chembox Hazards | NFPA-H = 2 | NFPA-F = 1 | NFPA-R = 0 }} }}

'''Ferulic acid''' is a hydroxycinnamic acid derivative and a phenolic compound. It is an organic compound with the formula (CH3O)HOC6H3CH=CHCO2H. The name is derived from the genus ''Ferula'', referring to the giant fennel (''Ferula communis''). Classified as a phenolic phytochemical, ferulic acid is an amber colored solid. Esters of ferulic acid are found in plant cell walls, covalently bonded to hemicellulose such as arabinoxylans.<ref name="De Oliveira-2015">{{cite journal |doi=10.1111/pbi.12292|title=Ferulic acid: A Key Component in Grass Lignocellulose Recalcitrance to Hydrolysis|year=2015|last1=De Oliveira|first1=Dyoni Matias|last2=Finger-Teixeira|first2=Aline|last3=Rodrigues Mota|first3=Thatiane|last4=Salvador|first4=Victor Hugo|last5=Moreira-Vilar|first5=Flávia Carolina|last6=Correa Molinari|first6=Hugo Bruno|last7=Craig Mitchell|first7=Rowan Andrew|last8=Marchiosi|first8=Rogério|last9=Ferrarese-Filho|first9=Osvaldo|last10=Dantas Dos Santos|first10=Wanderley|journal=Plant Biotechnology Journal|volume=13|issue=9|pages=1224–1232|pmid=25417596|doi-access=free|bibcode=2015PBioJ..13.1224D }}</ref> Salts and esters derived from ferulic acid are called '''ferulates'''.

== Occurrence in nature == Ferulic acid is ubiquitous in the plant kingdom, including a number of vegetable sources. It occurs in particularly high concentrations in popcorn and bamboo shoots.<ref>{{cite journal|last1=Zhao|first1=Zhaohui|last2=Moghadasian|first2=Mohammed H.|title=Chemistry, natural sources, dietary intake and pharmacokinetic properties of ferulic acid: A review|journal=Food Chemistry|date=August 2008|volume=109|issue=4|pages=691–702|doi=10.1016/j.foodchem.2008.02.039|pmid=26049981}}</ref><ref>{{cite journal|last1=Kumar|first1=Naresh|last2=Pruthi|first2=Vikas|title=Potential applications of ferulic acid from natural sources|journal=Biotechnology Reports|date=December 2014|volume=4|pages=86–93|doi=10.1016/j.btre.2014.09.002|pmid=28626667|pmc=5466124}}</ref> It is a major metabolite of chlorogenic acids in humans along with caffeic and isoferulic acid, and is absorbed in the small intestine, whereas other metabolites such as dihydroferulic acid, feruloylglycine, and dihydroferulic acid are produced from chlorogenic acid in the large intestine by the action of gut flora.<ref>{{cite book|last1=Bagchi|first1=Debasis|last2=Moriyama|first2=Hiroyoshi|last3=Swaroop|first3=Anand|title=Green Coffee Bean Extract in Human Health|date=2016|publisher=CRC Press|isbn=9781315353982|page=92|url=https://books.google.com/books?id=S5WKDQAAQBAJ&pg=PT92|access-date=23 September 2017|language=en}}</ref>

In cereals, ferulic acid is localized in the bran – the hard outer layer of grain. In wheat, phenolic compounds are mainly found in the form of insoluble bound ferulic acid and may be relevant to resistance to wheat fungal diseases.<ref>{{cite journal | doi = 10.1111/j.1365-2621.2005.01057.x | title = Effect of wheat variety, farming site, and bread-baking on total phenolics | date = 2006 | last1 = Gelinas | first1 = Pierre | last2 = McKinnon | first2 = Carole M. | journal = International Journal of Food Science and Technology | volume = 41 | issue = 3 | pages = 329–332}}</ref> The highest known concentration of ferulic acid glucoside has been found in flaxseed ({{val|4.1|0.2|u=g/kg}}).<ref>{{cite journal | doi = 10.1002/pca.973 | pmid = 17623361 | title = Microwave-assisted extraction of the main phenolic compounds in flaxseed | date = 2007 | last1 = Beejmohun | first1 = Vickram | last2 = Fliniaux | first2 = Ophélie | journal = Phytochemical Analysis | volume = 18 | issue = 4 | pages = 275–285| bibcode = 2007PChAn..18..275B }}</ref> It is also found in barley grain.<ref>{{cite journal|title=Phenolic Compounds of Barley Grain and Their Implication in Food Product Discoloration|first1=Zory|last1=Quinde-Axtell|first2=Byung-Kee|last2=Baik|journal=J. Agric. Food Chem.|date=2006|volume=54|issue=26|pages=9978–84|doi=10.1021/jf060974w|pmid=17177530|bibcode=2006JAFC...54.9978Q }}</ref>

Asterid eudicot plants can also produce ferulic acid. The tea brewed from the leaves of yacón (''Smallanthus sonchifolius''), a plant traditionally grown in the northern and central Andes, contains quantities of ferulic acid. In legumes, the white bean variety navy bean is the richest source of ferulic acid among the common bean (''Phaseolus vulgaris'') varieties.<ref>{{cite journal | last1 = Luthria | first1 = Devanand L. | last2 = Pastor-Corrales | first2 = Marcial A. | date = 2006 | title = Phenolic acids content of fifteen dry edible bean (''Phaseolus vulgaris'' L.) varieties | journal = Journal of Food Composition and Analysis | volume = 19 | issue = 2–3| pages = 205–211 | doi=10.1016/j.jfca.2005.09.003}}</ref> It is also found in horse grams (''Macrotyloma uniflorum'').{{Citation needed|date=December 2019|reason=removed citation to predatory publisher content}}

Although there are many sources of ferulic acid in nature, its bioavailability depends on the form in which it is present: free ferulic acid has limited solubility in water, and hence poor bioavailability. In wheat grain, ferulic acid is found bound to cell wall polysaccharides, allowing it to be released and absorbed in the small intestine.<ref>{{cite journal | doi = 10.1016/j.jcs.2008.12.001 | title =Bioavailability of ferulic acid is determined by its bioaccessibility| date = 2009 | last1 = Anson | first1 = Nuria Mateo | last2 = van den Berg | first2 = Robin | last3 = Bast | first3 = Aalt | last4 = Haenen | first4 = Guido R. M. M. | journal = Journal of Cereal Science | volume = 49 | issue = 2 | pages = 296–300}}</ref>

=== In processed foods === Cooking sweetcorn releases increased levels of ferulic acid.<ref>{{cite web| url = https://www.news.cornell.edu/releases/Aug02/CornLiu.bpf.html | title = Cooking sweet corn boosts its ability to fight cancer and heart disease by freeing healthful compounds, Cornell scientists find | publisher = Cornell News | access-date = 2009-09-07}}</ref> As plant sterol esters, this compound is naturally found in rice bran oil, a popular cooking oil in several Asian countries.<ref>{{cite book |title=Bailey's Industrial Oil and Fat Products |last=Orthoefer |first=F. T. |edition=6th |volume=2 |editor1-first=F. |editor1-last=Shahidi |date=2005 |publisher=John Wiley & Sons, Inc. |isbn=978-0-471-38552-3 |page=465 |chapter=Chapter 10: Rice Bran Oil |chapter-url=https://books.google.com/books?id=wG-0QgAACAAJ |access-date=2012-03-01}}</ref>

Ferulic acid glucoside can be found in commercial breads containing flaxseed.<ref>{{cite journal | doi = 10.1016/j.foodchem.2008.02.088 | pmid = 26047292 | title = Phenolic glucosides in bread containing flaxseed | date = 2008 | last1 = Strandås | first1 = C. | last2 = Kamal-Eldin | first2 = A. | last3 = Andersson | first3 = R. | last4 = Åman | first4 = P. | journal = Food Chemistry | volume = 110 | issue = 4 | pages = 997–999}}</ref> Rye bread contains ferulic acid dehydrodimers.<ref>{{cite journal|last1=Boskov Hansen|first1=H.|last2=Andreasen|first2=M.|last3=Nielsen|first3=M.|last4=Larsen|first4=L.|last5=Knudsen|first5=Bach K.|last6=Meyer|first6=A.|last7=Christensen|first7=L.|last8=Hansen|first8=Å.|title=Changes in dietary fibre, phenolic acids and activity of endogenous enzymes during rye bread-making|journal=European Food Research and Technology|volume=214|issue=1|date=2014|pages=33–42|issn=1438-2377|doi=10.1007/s00217-001-0417-6|s2cid=85239461}}</ref>

== Metabolism == [[File:CaffeicAcIn.png|thumb|300px|left|In plants, ferulic acid (right) is derived from phenylalanine (not shown), which is converted to 4-hydroxycinnamic acid (left) and then caffeic acid (center).]]

=== Biosynthesis === Ferulic acid is biosynthesized in plants from caffeic acid by the action of the enzyme caffeate ''O''-methyltransferase.<ref>{{cite book |last1= Shahadi |first1=Fereidoon|last2=Naczk |first2=Marian|title= Phenolics in Food and Nutraceuticals|url= https://archive.org/details/phenolicsfoodnut00shah_938 |url-access= limited |publisher= CRC Press|location= Florida|isbn= 978-1-58716-138-4|page= [https://archive.org/details/phenolicsfoodnut00shah_938/page/n12 4] |date= 2004}}</ref><ref name="De Oliveira-2015"/>

In a proposed ferulic acid biosynthetic pathway for ''Escherichia coli'', L-tyrosine is converted to 4-coumaric acid by tyrosine ammonia lyase, which is converted to caffeic acid by Sam5, which is then converted to ferulic acid by caffeic acid methyltransferase.<ref>{{cite journal |last1=Kang |first1=Sun-Young |last2=Choi |first2=Oksik |last3=Lee |first3=Jae Kyung |last4=Hwang |first4=Bang Yeon |last5=Uhm |first5=Tai-Boong |last6=Hong |first6=Young-Soo |title=Artificial biosynthesis of phenylpropanoic acids in a tyrosine overproducing Escherichia coli strain |journal=Microbial Cell Factories |date=December 2012 |volume=11 |issue=1 |pages=153 |doi=10.1186/1475-2859-11-153 |pmid=23206756 |pmc=3554431 |doi-access=free }}</ref>

Ferulic acid, together with dihydroferulic acid, is a component of lignocellulose, serving to crosslink the lignin and polysaccharides, thereby conferring rigidity to the cell walls.<ref>{{cite journal|last1=Iiyama|first1=K.|last2=Lam|first2=T. B.-T.|last3=Stone|first3=B. A.|title=Covalent Cross-Links in the Cell Wall|journal=Plant Physiology|volume=104|issue=2|date=1994|pages=315–320|issn=0032-0889|doi=10.1104/pp.104.2.315|pmid=12232082|pmc=159201}}</ref>

It is an intermediate in the synthesis of monolignols, the monomers of lignin, and is also used for the synthesis of lignans.

=== Biodegradation === Ferulic acid is converted by certain strains of yeast, notably strains used in brewing of wheat beers, such as ''Saccharomyces delbrueckii'' (''Torulaspora delbrueckii''), to 4-vinylguaiacol (2-methoxy-4-vinylphenol) which gives beers such as Weissbier and Wit their distinctive clove-like flavor. ''Saccharomyces cerevisiae'' (dry baker's yeast) and ''Pseudomonas fluorescens'' are also able to convert ''trans''-ferulic acid into 4-vinylguaiacol.<ref>{{Cite journal | last1 = Huang | first1 = Z. | last2 = Dostal | first2 = L. | last3 = Rosazza | first3 = J. P. | title = Microbial transformations of ferulic acid by ''Saccharomyces cerevisiae'' and ''Pseudomonas fluorescens '' | journal = Applied and Environmental Microbiology | volume = 59 | issue = 7 | pages = 2244–2250 | date = 1993 | doi = 10.1128/AEM.59.7.2244-2250.1993 | pmid = 8395165 | pmc = 182264 | bibcode = 1993ApEnM..59.2244H }}</ref> In ''P. fluorescens'', a ferulic acid decarboxylase has been isolated.<ref>{{Cite journal | last1 = Huang | first1 = Z. | last2 = Dostal | first2 = L. | last3 = Rosazza | first3 = J. P. | title = Purification and characterization of a ferulic acid decarboxylase from ''Pseudomonas fluorescens'' | journal = Journal of Bacteriology | volume = 176 | issue = 19 | pages = 5912–5918 | date = 1994 | pmid = 7928951 | pmc = 196807 | doi=10.1128/jb.176.19.5912-5918.1994 }}</ref>

== Ecology == Ferulic acid is one of the compounds that initiate the ''vir'' (virulence) region of ''Agrobacterium tumefaciens'', inducing it to infect plant cells.<ref>{{cite journal|last1=Kalogeraki|first1=Virginia S.|last2=Zhu|first2=Jun|last3=Eberhard|first3=Anatol|last4=Madsen|first4=Eugene L.|last5=Winans|first5=Stephen C.|title=The phenolic ''vir'' gene inducer ferulic acid is ''O''-demethylated by the VirH2 protein of an ''Agrobacterium tumefaciens'' Ti plasmid|journal=Molecular Microbiology|date=November 1999|volume=34|issue=3|pages=512–522|doi=10.1046/j.1365-2958.1999.01617.x|pmid=10564493|s2cid=28658847|doi-access=free}}</ref>

== Extraction == It can be extracted from wheat bran and maize bran using concentrated alkali.<ref>{{cite journal|last1=Buranov|first1=Anvar U.|first2=G.|last2=Mazza|title=Extraction and purification of ferulic acid from flax shives, wheat and corn bran by alkaline hydrolysis and pressurised solvents|journal=Food Chemistry|date=2009|volume=115|issue=4|pages=1542–1548|doi=10.1016/j.foodchem.2009.01.059}}</ref>

[[File:Ferulicacidspectrum.PNG|thumb|right|UV–visible spectrum of ferulic acid, with ''λ''max at 321 nm and a shoulder at 278 nm]]

== See also == * Caffeic acid * Coumaric acid * Diferulic acids * Eugenol * Isoferulic acid, an isomer of ferulic acid

== References == {{reflist}}

{{Hydroxycinnamic acid}} Category:Phenylogous carboxylic acids Category:Phenol antioxidants Category:O-methylated hydroxycinnamic acids Category:Bitter-masking compounds