Raspberry ketone

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

Raspberry ketone^[1]

Names
Preferred IUPAC name 4-(4-Hydroxyphenyl)butan-2-one
Other names p-Hydroxybenzyl acetone; 4-(p-Hydroxyphenyl)-2-butanone; Frambinone; Oxyphenylon; Rheosmin; Rasketone
Identifiers
CAS Number	5471-51-2 Y
3D model (JSmol)	Interactive image
Abbreviations	RK
ChEBI	CHEBI:68656 Y
ChEMBL	ChEMBL105912 Y
ChemSpider	20347 Y
ECHA InfoCard	100.024.370
EC Number	226-806-4
PubChem CID	21648
UNII	7QY1MH15BG Y
CompTox Dashboard (EPA)	DTXSID5044495
InChI InChI=1S/C10H12O2/c1-8(11)2-3-9-4-6-10(12)7-5-9/h4-7,12H,2-3H2,1H3 Y Key: NJGBTKGETPDVIK-UHFFFAOYSA-N Y InChI=1/C10H12O2/c1-8(11)2-3-9-4-6-10(12)7-5-9/h4-7,12H,2-3H2,1H3 Key: NJGBTKGETPDVIK-UHFFFAOYAT
SMILES O=C(CCc1ccc(O)cc1)C
Properties
Chemical formula	C10H12O2
Molar mass	164.204 g·mol−1
Appearance	White needles[2]
Melting point	82 to 84 °C (180 to 183 °F; 355 to 357 K)
Boiling point	140 to 146 °C (284 to 295 °F; 413 to 419 K) at 0.5 mmHg
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302
Precautionary statements	P264, P270, P301+P312, P330, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Occurrence

Raspberry ketone occurs in a variety of fruits, including raspberries, cranberries, and blackberries.^[3] It is detected and released by orchid flowers, e.g. Dendrobium superbum (syn D. anosmum),^[4] and several Bulbophyllum species^[5][6][7] to attract raspberry ketone-responsive male Dacini fruit flies. It is biosynthesized from coumaroyl-CoA.^[8] It can be extracted from the fruit, yielding about 1–4 mg per kg of raspberries.^[9]

Preparation

Since the natural abundance of raspberry ketone is very low, it is prepared industrially by a variety of methods from chemical intermediates.^[10] 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.^[11] There is a less expensive hydrogenation catalyst, nickel boride, which also demonstrates high selectivity towards hydrogenation of the double bond of enone.^[12]

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.^[9]

Marketing

Although products containing this compound are marketed for weight loss, there is no clinical evidence for this effect in humans.^[13][14] 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,^[15][16] especially since little research has been done with humans.^[17] Toxicological models indicate a potential for cardiotoxic effects, as well as effects on reproduction and development.^[15] Furthermore, in many dietary supplements containing raspberry ketones, manufacturers add other ingredients such as caffeine which may have unsafe effects.^[17]

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.^[2]

See also

• Raspberry ellagitannin