{{Use dmy dates|date=May 2021}} {{chembox | Watchedfields = changed | verifiedrevid = 443720196 | Name = | Reference =<ref>[http://www.sigmaaldrich.com/catalog/search/ProductDetail/SIGMA/E2271 Ectoine] at Sigma-Aldrich</ref> | ImageFile = Ectoine.svg | ImageSize = 120px | PIN = (4''S'')-2-Methyl-3,4,5,6-tetrahydropyrimidine-4-carboxylic acid | OtherNames = {{plainlist|*Ectoine sodium salt monohydrate * THP(B) * RonaCare * Pyrostatin B}} | SystematicName = | Section1 = {{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 112069 | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = C06231 | InChI = 1/C6H10N2O2/c1-4-7-3-2-5(8-4)6(9)10/h5H,2-3H2,1H3,(H,7,8)(H,9,10)/t5-/m0/s1 | InChIKey = WQXNXVUDBPYKBA-YFKPBYRVBN | SMILES1 = O=C(O)[C@H]1N\C(=N/CC1)C | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C6H10N2O2/c1-4-7-3-2-5(8-4)6(9)10/h5H,2-3H2,1H3,(H,7,8)(H,9,10)/t5-/m0/s1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = WQXNXVUDBPYKBA-YFKPBYRVSA-N | CASNo_Ref = {{cascite|correct|??}} | CASNo=96702-03-3 | PubChem=126041 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 7GXZ3858RY | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 27592 | SMILES=CC1=NCCC(N1)C(=O)O }} | Section2 = {{Chembox Properties | C=6 | H=10 | N=2 | O=2 | Appearance=White powder | Density=1.568 g/cm<sup>3</sup> | MeltingPt= | BoilingPt= | Solubility=Soluble in water }} | Section3 = {{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = | NFPA-F = 1 | NFPA-H = 1 | NFPA-R = 0 | NFPA-S = | NFPA_ref =<ref>[https://www.spectrumchemical.com/MSDS/E0210.pdf Ectoine SDS]</ref> }} | Section4 = | Section5 = | Section6 = }}
'''Ectoine''' (3,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) is a natural compound found in several species of bacteria. It is a compatible solute which serves as a protective substance by acting as an osmolyte and thus helps organisms survive extreme osmotic stress.<ref>{{Cite journal |last1=Galinski |first1=Erwin A. |last2=Trüper |first2=Hans G. |date=1985 |title=Die Kristallstruktur des Ectoin, einer neuen osmoregulatorisch wirksamen Aminosäure |url=https://www.degruyter.com/document/doi/10.1515/znc-1985-11-1206/html |journal=Zeitschrift für Naturforschung C |volume=40 |pages=780–784 |doi=10.1515/znc-1985-11-1206 |via=De Gruyter|doi-access=free }}</ref> Furthermore it was shown to protect DNA against ionizing and ultraviolet radiation serving as a radical scavenger.<ref>{{Cite journal |last1=Hahn |first1=Marc Benjamin |last2=Meyer |first2=Susann |last3=Schröter |first3=Maria-Astrid |last4=Kunte |first4=Hans-Jörg |last5=Solomun |first5=Tihomir |last6=Sturm |first6=Heinz |date=2017-09-27 |title=DNA protection by ectoine from ionizing radiation: molecular mechanisms |journal=Physical Chemistry Chemical Physics |language=en |volume=19 |issue=37 |pages=25717–25722 |doi=10.1039/C7CP02860A |issn=1463-9084|doi-access=free |bibcode=2017PCCP...1925717H }}</ref> Ectoine is found in high concentrations in halophilic microorganisms and confers resistance towards salt and temperature stress. Ectoine was first identified in the microorganism ''Ectothiorhodospira halochloris'',<ref name="r2" /><ref name="r1" /> but has since been found in a wide range of Gram-negative and Gram-positive bacteria. Other species of bacteria in which ectoine was found include: * ''Brevibacterium linens''<ref name="r1">{{cite journal |doi=10.1099/00221287-139-1-129 |url=http://www.microbiologyresearch.org/docserver/fulltext/micro/139/1/mic-139-1-129.pdf |title=Ectoine accumulation and osmotic regulation in ''Brevibacterium linens'' |journal=Journal of General Microbiology |volume=139 |pages=129–136 |year=1993 |last1=Bernard |first1=T. |last2=Jebbar |first2=M. |last3=Rassouli |first3=Y. |last4=Himdi-Kabbab |first4=S. |last5=Hamelin |first5=J. |last6=Blanco |first6=C. |issue=1 |doi-access=free |bibcode=1993JGMic.139..129B }}</ref> * ''Halomonas elongata''<ref name="r2">{{cite journal |doi=10.1016/0378-1097(90)90049-V |pmid=1601286 |title=The biosynthesis of ectoine |journal=FEMS Microbiology Letters |volume=71 |issue=2 |pages=157–61 |year=1990 |last1=Peters |first1=P |last2=Miwatani |first2=T |last3=Honda |first3=T|doi-access=free }}</ref><ref name="r4" /> * ''Marinococcus halophilus''<ref name="r3">{{cite journal |pmid=9141677 |year=1997 |last1=Louis |first1=P |title=Characterization of genes for the biosynthesis of the compatible solute ectoine from ''Marinococcus halophilus'' and osmoregulated expression in ''Escherichia coli'' |journal=Microbiology |volume=143 |issue=4 |pages=1141–9 |last2=Galinski |first2=E. A. |doi=10.1099/00221287-143-4-1141 |doi-access=free}}</ref> * ''Pseudomonas stutzeri''<ref name="r4">{{cite journal |pmid=21725014 |pmc=3165526 |year=2011 |last1=Stöveken |first1=N |title=A specialized aspartokinase enhances the biosynthesis of the osmoprotectants ectoine and hydroxyectoine in ''Pseudomonas stutzeri'' A1501 |journal=Journal of Bacteriology |volume=193 |issue=17 |pages=4456–68 |last2=Pittelkow |first2=M |last3=Sinner |first3=T |last4=Jensen |first4=R. A. |last5=Heider |first5=J |last6=Bremer |first6=E |doi=10.1128/JB.00345-11 |bibcode=2011JBact.193.4456S }}</ref> * ''Halomonas titanicae''<ref>{{cite web |last1=Augenstein |first1=Seth |title='Extremophile Bacteria' Will Eat Away Wreck of the Titanic |url=http://www.laboratoryequipment.com/news/2016/09/extremophile-bacteria-will-eat-away-wreck-titanic-2030 |website=laboratoryequipment.com |date=6 September 2016 |access-date=10 February 2017 |archive-date=7 September 2016 |archive-url=https://web.archive.org/web/20160907153846/http://www.laboratoryequipment.com/news/2016/09/extremophile-bacteria-will-eat-away-wreck-titanic-2030 }}</ref><ref>{{cite journal |last1=Zaccai |first1=Giuseppe |last2=Bagyan |first2=Irina |last3=Combet |first3=Jérôme |last4=Cuello |first4=Gabriel J. |last5=Demé |first5=Bruno |last6=Fichou |first6=Yann |last7=Gallat |first7=François-Xavier |last8=Galvan Josa |first8=Victor M. |last9=von Gronau |first9=Susanne|last10=Haertlein|first10=Michael |last11=Martel |first11=Anne |last12=Moulin |first12=Martine |last13=Neumann |first13=Markus |last14=Weik |first14=Martin |last15=Oesterhelt |first15=Dieter |title=Neutrons describe ectoine effects on water H-bonding and hydration around a soluble protein and a cell membrane |journal=Scientific Reports |date=16 August 2016 |volume=6 |article-number=31434 |doi=10.1038/srep31434 |pmid=27527336 |pmc=4985633 |bibcode=2016NatSR...631434Z}}</ref> * ''Halorhodospira halophila''<ref>"HAMAP: Halorhodospira halophila (strain DSM 244 / SL1) (Ectothiorhodospira halophila (strain DSM 244 / SL1)) complete proteome [http://expasy%20proteomics%20server.%20swiss%20institute%20of%20bioinformatics/ ExPASy Proteomics Server. Swiss Institute of Bioinformatics]{{dead link|date=August 2019 |bot=InternetArchiveBot |fix-attempted=yes }} http://hamap.expasy.org/proteomes/HALHL.html</ref> * ''Halomonas ventosae''<ref>{{cite journal |last1=Zhu |first1=Daochen |last2=Niu |first2=Lili |last3=Wang |first3=Chenxiang |last4=Nagata |first4=Shinichi |title=Isolation and characterisation of moderately halophilic bacteriumHalomonas ventosae DL7 synthesizing ectoine as compatible solute |journal=Annals of Microbiology |date=September 2007 |volume=57 |issue=3 |pages=401–406 |doi=10.1007/BF03175080 |s2cid=43421438 |url=http://www.lib.kobe-u.ac.jp/repository/90000871.pdf |access-date=5 December 2019 |archive-date=2 October 2020 |archive-url=https://web.archive.org/web/20201002004056/http://www.lib.kobe-u.ac.jp/repository/90000871.pdf }}</ref>
== Biosynthesis == Ectoine is synthesized in three successive enzymatic reactions starting from aspartic β-semialdehyde. The genes involved in the biosynthesis are called ''ectA'', ''ectB'' and ''ectC'', and they encode the enzymes L-2,4-diaminobutyric acid transaminase, L-2,4-diaminobutyric acid acetyltransferase, and L-ectoine synthase, respectively.<ref name="r3" /><ref name="r4" />
{{chemrxn|width=75%| {{chemrxn/cpd|L-Aspartic-4-semialdehyde|caption=aspartic β-semialdehyde }} {{chemrxn/arw|uppercaption=''ectA'' }} {{chemrxn/cpd|qid=Q27094699|caption=2,4-diaminobutyrate }} {{chemrxn/arw|uppercaption=''ectB'' }} {{chemrxn/cpd|qid=Q27107481|caption=N-acetyl-2,4-diaminobutyrate }} {{chemrxn/arw|uppercaption=''ectC'' }} {{chemrxn/cpd|ectoine|upright=0.3 }} }}
== Use in cosmetics == Ectoine is used as an active ingredient in skin care and sun protection products.<ref name="Gerday Glansdorff 2009 p. 303">{{cite book |last1=Gerday |first1=C. |last2=Glansdorff |first2=N. |title=EXTREMOPHILES – Volume II |publisher=Eolss Publishers |series=Encyclopedia of life support systems |year=2009 |isbn=978-1-905839-94-0 |url=https://books.google.com/books?id=i5zEDAAAQBAJ&pg=PA303 |access-date=18 May 2021 |page=303 ff}}</ref> It stabilizes proteins and other cellular structures and protects the skin from stresses like UV irradiation and dryness.<ref name="r4" /><ref>{{cite journal | last1=Becker | first1=Judith | last2=Wittmann | first2=Christoph | title=Microbial production of extremolytes — high-value active ingredients for nutrition, health care, and well-being | journal=Current Opinion in Biotechnology | date=2020 | volume=65 | pages=118–128 | doi=10.1016/j.copbio.2020.02.010 | pmid=32199140 | doi-access=free }}</ref><ref>{{cite journal | last1=Maresca | first1=Emanuela | last2=Carbone | first2=Micaela | last3=Gallo | first3=Giovanni | last4=Fusco | first4=Salvatore | last5=Aulitto | first5=Martina | title=Extremophile-Derived Bioactives in Cosmeceuticals: Bridging Nutraceuticals and Skincare for Holistic Wellness | journal=Life | date=2025 | volume=15 | issue=12 | page=1787 | doi=10.3390/life15121787 | doi-access=free | pmid=41465727 | pmc=12734273 | bibcode=2025Life...15.1787M }}</ref>
== Medical use == Due to its protein stabilizing properties, ectoine has been evaluated as a topical treatment for hay fever. Effectiveness of a nasal spray containing ectoine is comparable to cromoglycate and is reported to be well tolerated by the patients.<ref>{{Cite journal |last1=Werkhäuser |first1=Nina |last2=Bilstein |first2=Andreas |last3=Sonnemann |first3=Uwe |date=2014-06-01 |title=Treatment of Allergic Rhinitis with Ectoine Containing Nasal Spray and Eye Drops in Comparison with Azelastine Containing Nasal Spray and Eye Drops or with Cromoglycic Acid Containing Nasal Spray |journal=Journal of Allergy |volume=2014 |pages=1–13 |doi=10.1155/2014/176597 |pmid=24982680 |issn=1687-9783|pmc=4058592 |doi-access=free }}</ref> It is available over the counter in the European Union.
== References == {{reflist}}
Category:Amidines Category:Carboxylic acids