{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 408609343 | ImageFile = L-Mimosine.png | ImageSize = 200px | ImageAlt = Structural formula of L-mimosine | ImageFile1 = L-Mimosine zwitterion ball.png | ImageAlt1 = Ball-and-stick model of the L-mimosine zwitterion | IUPACName = (2''S'')-2-Amino-3-(3-hydroxy-4-oxopyridin-1-yl)propanoic acid | OtherNames = leucenol |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 3728 | InChI = 1/C8H10N2O4/c9-5(8(13)14)3-10-2-1-6(11)7(12)4-10/h1-2,4-5,12H,3,9H2,(H,13,14) | InChIKey = WZNJWVWKTVETCG-UHFFFAOYAK | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 29063 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 251433 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C8H10N2O4/c9-5(8(13)14)3-10-2-1-6(11)7(12)4-10/h1-2,4-5,12H,3,9H2,(H,13,14) | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = WZNJWVWKTVETCG-UHFFFAOYSA-N | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 500-44-7 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = Z46B1LUI5N | PubChem = 3862 | DrugBank_Ref = {{drugbankcite|changed|drugbank}} | DrugBank = DB01055 | SMILES = O=C(O)C(N)CN/1/C=C\C(=O)C(\O)=C\1 }} |Section2={{Chembox Properties | C=8 | H=10 | N=2 | O=4 | Appearance = | Density = | MeltingPtC = 291 | BoilingPt = | Solubility = }} |Section3={{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }} '''Mimosine''' or '''leucenol''' is a toxic non-protein amino acid chemically similar to tyrosine. It occurs in some ''Mimosa'' spp. (including ''M. pudica'') and all members of the closely related genus ''Leucaena''.

This compound, also known as leucenol, was first isolated from the seeds of ''Leucaena glauca'' Benth.,<ref>{{cite journal | last1 = Mascré | first1 = Marcel | year = 1937 | url = http://visualiseur.bnf.fr/CadresFenetre?O=NUMM-3156&I=890&M=tdm | title = Le leucaenol, principe défini retiré des graines de ''Leucaena glauca'' Benth. (Légumineuses Papilionacées) | journal = Comptes Rendus | volume = 204 | pages = 890–891 }}{{Dead link|date=January 2026 |bot=InternetArchiveBot }}</ref><ref name=henry>{{cite book |last=Henry |first=Thomas Anderson |date=1949 |edition=4th |title=The Plant Alkaloids |location= |publisher=The Blakiston Company |pages=2–3 |section=Leucenol |isbn=}}</ref> and was later investigated by Adams and coworkers.<ref>{{cite journal | doi = 10.1021/ja01217a032 | last1 = Adams | first1 = Roger | author-link2 = Stanley J. Cristol | last2 = Cristol | first2 = Stanley J. | last3 = Anderson | first3 = Arthur A. | last4 = Albert | first4 = Alfred A. | journal = J. Am. Chem. Soc. | year = 1945 | volume = 67 | pages = 89–92 | title=The Structure of Leucenol. I| issue = 1 | bibcode = 1945JAChS..67...89A }}</ref><ref name=henry />

==Properties== Mimosine melts with decomposition. The hydrochloride salt melts at 174.5–175.0&nbsp;°C with decomposition; the hydrobromide decomposes at 179.5&nbsp;°C, and the hydroiodide decomposes at 183–183.5&nbsp;°C.<ref name=henry /> Mimosine only forms monobasic acids, but the methyl ester forms a dihydrochloride, C<sub>7</sub>H<sub>9</sub>O<sub>2</sub>N<sub>2</sub>(COOMe)•2 HCl•½ H<sub>2</sub>O, mp. 175–6&nbsp;°C.{{Citation needed|date=July 2010}}

==Biological effects== Mimosine arrests dividing cells in the late G1 phase by inhibiting DNA replication initiation.<ref>T. Krude Exp. Cell Res. Volume 247, Issue 1, 1999, Pages 148-159</ref> In ruminants, mimosine is degraded to 3,4- and 2,3-dihydroxypyridone (3,4- and 2,3-DHP).

Although toxicosis has occurred in Australia, Papua New Guinea, Africa and Florida, it has not been recorded in any other tropical and subtropical regions. Goats in Burma lost hair when fed a diet containing 50% of ''Leucaena''. Goats and cattle in Hawaii are able to degrade the 3,4-DHP ruminally. Tolerance might be related to the presence or absence of microbes tolerant to mimosine and 3,4-DHP. It is known that at least Australian goats do not share the abilities of their Hawaiian counterparts.

Bickel and Wibaut<ref>''Rec. Trav. Chim.,'' 1946, '''65''' 65; Wibaut, ''Helv. Chim. Acta,'' 1946, '''29''' 1669; (with Kleipol), ''Rec. Trav. Chim.,'' 1947, '''66''' 24, 459.</ref> found in feeding experiments with rats and mice that leucenol is probably the toxic constituent of ''Leucaena glauca'' seeds, but they did not observe with these animals the loss of hair that seems to occur when these seeds are fed to cattle.<ref>{{cite journal | last1 = Mascré | last2 = Ottenwälder | year = 1941 | journal = Bull. Sci. Pharmacol. | volume = 3 | issue = 3| page = 65 }}</ref> Aung from Myanmar isolated the new subspecies of ''Klebsiella pneumoniae'' that can degrade mimosine.<ref>{{Cite journal |last1=Aung |first1=A. |last2=ter Meulen |first2=U. |last3=Gessler |first3=F. |last4=Böhnel |first4=H. |date=2013 |title=Development, isolation and characterization of a new non-virulent mimosine-degrading Klebsiella pneumoniae strain from the rumen liquor of German steers by using IBT-Göttinger bioreactor |url=http://www.tropicalgrasslands.info/index.php/tgft/article/view/38/11 |journal=Tropical Grasslands – Forrajes Tropicales |language=en |volume=1 |issue=1 |pages=45 |doi=10.17138/TGFT(1)45-47|doi-access=free }}</ref> Besides, Moe Thida Htun, from Myanmar also found another new sub-species of Bacillus aureus that can degrade mimosine.{{cn|date=July 2024}}

Some rhizobia are known to produce rhizomimosinase, which consumes pyridoxal 5′-phosphate to degrade mimosine into 3,4 dihydroxypyridine, pyruvate, and ammonium.<ref>{{cite journal |vauthors=Negi VS, Bingham JP, Li QX, Borthakur D | year = 2013 | title = ''midD''-encoded 'rhizomimosinase' from ''Rhizobium'' sp. strain TAL1145 is a C–N lyase that catabolizes L-mimosine into 3-hydroxy-4-pyridone, pyruvate, and ammonia | journal = Amino Acids | volume = 44 | issue = 6 | pages = 1537–47 | doi = 10.1007/s00726-013-1479-z | pmid = 23462928| s2cid = 18592674 }}</ref> A similar enzyme, mimosinase, is produced by ''Leucaena leucocephala''.<ref>{{cite journal |vauthors=Negi VS, Bingham JP, Li QX, Borthakur D | year = 2014 | title = A Carbon–Nitrogen Lyase from ''Leucaena leucocephala'' Catalyzes the First Step of Mimosine Degradation | journal = Plant Physiology | volume = 164 | issue = 2 | pages = 922–934 | doi = 10.1104/pp.113.230870 | pmid = 24351687 | pmc=3912116}}</ref>

== See also == *Hordenine *Meteloidine

==References== {{Reflist}}

Category:2,3-Diaminopropionic acids Category:4-Pyridones Category:Plant toxins Category:Toxic amino acids