{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 464380314 | Reference = <ref>''Catalog of Organics and Fine Chemicals'', Acros Organics, 2004/05, page 1250.</ref> | ImageFile = Raspberry Ketone Structure.png | ImageSize = 200px | ImageAlt = Structural formula of raspberry ketone | ImageFile1 = Raspberry ketone 3D ball.png | ImageAlt1 = Ball-and-stick model of raspberry ketone | PIN = 4-(4-Hydroxyphenyl)butan-2-one | OtherNames = ''p''-Hydroxybenzyl acetone; 4-(''p''-Hydroxyphenyl)-2-butanone; Frambinone; Oxyphenylon; Rheosmin; Rasketone |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 20347 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 68656 | InChI = 1/C10H12O2/c1-8(11)2-3-9-4-6-10(12)7-5-9/h4-7,12H,2-3H2,1H3 | InChIKey = NJGBTKGETPDVIK-UHFFFAOYAT | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 105912 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C10H12O2/c1-8(11)2-3-9-4-6-10(12)7-5-9/h4-7,12H,2-3H2,1H3 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = NJGBTKGETPDVIK-UHFFFAOYSA-N | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 5471-51-2 | PubChem = 21648 | EINECS = 226-806-4 | SMILES = O=C(CCc1ccc(O)cc1)C | UNII = 7QY1MH15BG | UNII_Ref = {{fdacite|correct|FDA}} | Abbreviations = RK }} |Section2={{Chembox Properties | C=10|H=12|O=2 | Appearance=White needles<ref name="DoiS">{{cite journal |doi=10.1016/S0015-6264(78)80113-8 |title=4-(''p''-Hydroxyphenyl)-2-butanone |year=1978 |journal=Food and Cosmetics Toxicology |volume=16 |pages=781–2}}</ref> | Density= | MeltingPtC = 82 to 84

| BoilingPtC = 140 to 146 | BoilingPt_notes=at 0.5&nbsp;mmHg | Solubility= }} |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = | GHSPictograms = {{GHS07}} | GHSSignalWord = Warning | HPhrases = {{H-phrases|302}} | PPhrases = {{P-phrases|264|270|301+312|330|501}} }} }}

'''Raspberry ketone''' is a naturally occurring phenolic compound that is the primary aroma compound of red raspberries.

==Occurrence== Raspberry ketone occurs in a variety of fruits, including raspberries, cranberries, and blackberries.<ref>{{cite web|url=http://www.chm.bris.ac.uk/motm/raspberry-ketone/rkh.htm |title=Raspberry Ketone, Molecule of the Month |publisher=University of Bristol}}</ref> It is released by orchid flowers, e.g. ''Dendrobium superbum'' (syn ''D. anosmum''),<ref>{{cite journal|last1=Nishida |first1=R. |last2=Iwahashi |first2=I. |last3=Tan |first3=K.H. |date=1993 |title=Accumulation of ''Dendrobium'' (Orchidaceae) flower fragrance in the rectal glands by males of the melon fly, ''Dacus cucurbitae'' (Tephritidae) |journal=Journal of Chemical Ecology |volume=19 |issue=4 |pages=713–722 |doi=10.1007/BF00985003 |pmid=24249012 }}</ref> and several ''Bulbophyllum'' species<ref>{{cite journal|last2=Nishida |first2=R. |last1=Tan |first1=K.H. |date=2005 |title=Synomone or Kairomone? - ''Bulbophyllum apertum'' (Orchidaceae) flower releases raspberry ketone to attract ''Bactrocera'' fruit flies |journal=Journal of Chemical Ecology |volume=31 |number=3 |pages=509–519 |doi=10.1007/s10886-005-2023-8}}</ref><ref>{{cite journal|last1=Tan |first1=K.H. |last2=Tan |first2=L.T. |date=2018 |title=Movements of floral parts and roles of the tooth on column wall of ''Bulbophyllum praetervisum'' (Orchidaceae) flower for pollination by Dacini fruit flies (Diptera: Tephritidae) |journal=Journal of Pollination Ecology |volume=24 |number=17 |pages=157–163 |doi=10.26786/1920-7603(2018)19|doi-access=free }}</ref><ref>{{cite journal|last1=Nakahira |first1=M. |last2=Ono |first2=H. |last3=Wee |first3=S.L. |last4=Nishida |first4=R. |date=2018 |title=Floral synomone diversification of ''Bulbophyllum'' sibling species (Orchidaceae) in attracting fruit fly pollinators |journal=Biochemical Systematics and Ecology |volume=81 |pages=86–95 |doi=10.1016/j.bse.2018.10.002|hdl=2433/235528 |hdl-access=free }}</ref> to attract raspberry ketone-responsive male Dacini fruit flies. It is biosynthesized from coumaroyl-CoA.<ref>{{cite web |url=http://biocyc.org/META/new-image?type=PATHWAY&object=PWY-5393 |title=MetaCyc Pathway: raspberry ketone biosynthesis |publisher=MetaCyc |accessdate=2012-07-12}}</ref> It can be extracted from the fruit, yielding about 1–4&nbsp;mg per kg of raspberries.<ref name=Beekwilder/>

==Preparation== Since the natural abundance of raspberry ketone is very low, it is prepared industrially by a variety of methods from chemical intermediates.<ref>{{cite journal |doi=10.1021/jo00099a017 |title=Cation-Exchanged Montmorillonite-Catalyzed Facile Friedel-Crafts Alkylation of Hydroxy and Methoxy Aromatics with 4-Hydroxybutan-2-one to Produce Raspberry Ketone and Some Pharmaceutically Active Compounds |year=1994 |last1=Tateiwa |first1=Jun-Ichi |last2=Horiuchi |first2=Hiroki |last3=Hashimoto |first3=Keiji |last4=Yamauchi |first4=Takayoshi |last5=Uemura |first5=Sakae |journal=The Journal of Organic Chemistry |volume=59 |issue=20 |pages=5901–4}}</ref> One of the ways this can be done is through a Claisen-Schmidt condensation followed by catalytic hydrogenation. First, acetone is condensed with 4-hydroxybenzaldehyde to form an α,β-unsaturated ketone. Then the alkene part is reduced to the alkane. This two-step method produces raspberry ketone in 99% yield.<ref>{{cite journal |doi=10.1007/s00897960034a |title=Rheosmin ('Raspberry Ketone') and Zingerone, and Their Preparation by Crossed Aldol-Catalytic Hydrogenation Sequences |year=1996 |last1=Smith |first1=Leverett R. |journal=The Chemical Educator |volume=1 |issue=3 |pages=1–18|s2cid=94729547 }}</ref> There is a less expensive hydrogenation catalyst, nickel boride, which also demonstrates high selectivity towards hydrogenation of the double bond of enone.<ref>{{cite journal |doi=10.5560/ZNB.2014-4118 |title=Synthesis of Raspberry and Ginger Ketones by Nickel Boride-catalyzed Hydrogenation of 4-Arylbut-3-en-2-ones |year=2014 |last1=Bandarenko |first1=Mikhail |last2=Kovalenko |first2=Vitaly |journal=Zeitschrift für Naturforschung B |volume=69b |issue=8 |pages=885–888|doi-access=free }}</ref> :450px

==Uses== Raspberry ketone is sometimes used in perfumery, in cosmetics, and as a food additive to impart a fruity odor. It is one of the most expensive natural flavor components used in the food industry. The natural compound can cost as much as $20,000 per kg.<ref name=Beekwilder>{{cite journal |doi=10.1002/biot.200700076 |title=Microbial production of natural raspberry ketone |year=2007 |last1=Beekwilder |first1=Jules |last2=Van Der Meer |first2=Ingrid M. |last3=Sibbesen |first3=Ole |last4=Broekgaarden |first4=Mans |last5=Qvist |first5=Ingmar |last6=Mikkelsen |first6=Joern D. |last7=Hall |first7=Robert D. |journal=Biotechnology Journal |volume=2 |issue=10 |pages=1270–9 |pmid=17722151|s2cid=32088996 }}</ref>

==Marketing== Although products containing this compound are marketed for weight loss, there is no clinical evidence for this effect in humans.<ref name=webmd>{{cite web |url=https://www.webmd.com/diet/raspberry-ketones-uses-risks |title=Raspberry Ketones: Uses, Health Benefits, and Risks |publisher=WebMD}}</ref><ref name=webmd2> {{cite web |url=https://www.webmd.com/vitamins/ai/ingredientmono-1262/raspberry-ketone |title=Raspberry Ketone |publisher=WebMD}}</ref> They are called "ketones" because of the ketone (acetone) group at their end, which is shared with ketone bodies.

==Safety== Little is known about the long-term safety of raspberry ketone supplements,<ref name=Bredsdorff >{{cite journal | journal = Regul Toxicol Pharmacol | date = 2015 | volume = 73 | issue = 1 | pages = 196–200 | doi = 10.1016/j.yrtph.2015.06.022 | title = Raspberry ketone in food supplements - High intake, few toxicity data - A cause for safety concern? |vauthors=Bredsdorff L, Wedebye EB, Nikolov NG, Hallas-Møller T, Pilegaard K | pmid = 26160596 | s2cid = 38312188 }}</ref><ref>{{cite web | url = http://altmedicine.about.com/od/weight_Loss/a/Raspberry-Ketones-Weight-Loss.htm | title = Raspberry Ketones for Weight Loss | author = Cathy Wong | publisher = About.com | access-date = 2012-11-02 | archive-date = 2016-01-14 | archive-url = https://web.archive.org/web/20160114092612/http://altmedicine.about.com/od/weight_Loss/a/Raspberry-Ketones-Weight-Loss.htm | url-status = dead }}</ref> especially since little research has been done with humans.<ref name=Canberra>{{cite web|last1=Canberra|first1=Jules|title=What's All The Hype About Raspberry Ketone?|url=https://www.authorityhealth.com/raspberry-ketone-benefits|website=Authority Health|accessdate=30 October 2017}}</ref> Toxicological models indicate a potential for cardiotoxic effects, as well as effects on reproduction and development.<ref name=Bredsdorff/> Furthermore, in many dietary supplements containing raspberry ketones, manufacturers add other ingredients such as caffeine which may have unsafe effects.<ref name=Canberra/>

In 1965, the US Food and Drug Administration classified raspberry ketone as generally recognized as safe (GRAS) for the small quantities used to flavor foods.<ref name="DoiS" />

==See also== *Raspberry ellagitannin

== References == {{reflist}}

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Category:Flavors Category:Food additives Category:Alkanones Category:Perfume ingredients Ketone Category:4-Hydroxyphenyl compounds