Raspberry ketone

Raspberry ketone^[1]

Names
IUPAC name 4-(4-Hydroxyphenyl)butan-2-one
Other names p-Hydroxybenzyl acetone; 4-(p-Hydroxyphenyl)-2-butanone; Frambinone; Oxyphenylon; Rheosmin; Rasketone
Identifiers
Abbreviations	RK
CAS Registry Number	5471-51-2 N
ChEBI	CHEBI:68656 N
ChEMBL	ChEMBL105912 Y
ChemSpider	20347 Y
EC number	226-806-4
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
Jmol-3D images	Image
PubChem	21648
SMILES O=C(CCc1ccc(O)cc1)C
UNII	7QY1MH15BG N
Properties
Molecular formula	C10H12O2
Molar mass	164.20 g·mol−1
Appearance	White needles[2]
Melting point	82 °C (180 °F; 355 K)
Boiling point	140 °C (284 °F; 413 K) at 0.5 mmHg
Hazards
R-phrases	R22
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
N verify (what is: Y/N?)
Infobox references

Raspberry ketone is a natural 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.^[3] It is biosynthesized from coumaroyl-CoA.^[4] Extraction of pure raspberry ketone is usually 1–4 mg per kg of raspberries.^[5]

Preparation

Since the natural abundance of raspberry ketone is very low, it is prepared industrially by a variety of methods from chemical intermediates.^[6] One of the ways this can be done is through a crossed aldol-catalytic hydrogenation. In acetone and sodium hydroxide, 4-hydroxybenzaldehyde can form the α,β-unsaturated ketone. This then goes through catalytic hydrogenation to produce raspberry ketone. This method produces a 99% yield.^[7]

Uses

Raspberry ketone is 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.^[5] Synthetic raspberry ketone is cheaper, with estimates ranging from a couple of dollars per pound^[8] to one fifth of the cost of natural product.^[9]

Putative health effects

Although products containing this compound are marketed for weight loss, there is no clinical evidence for this effect in humans.^[10] The average daily intake of dietary raspberry ketone has been estimated as 0.42 mg/kg/day.^[11] Early studies in rats looking into the potential toxicity of raspberry ketone found no effects on the body weight of rats with doses up to 100 mg/kg, 238 times greater than the estimated intake for humans or 0.01% of body weight.^[11] A more recent study demonstrated that when mice were fed very high doses of raspberry ketone, up to 20 g/kg, 2% of body weight or 4761 times greater than estimated human intake, there was a statistically significant prevention of high-fat-diet-induced elevation in body weight.^[12] The high dose effect is reported to stem from the alteration of lipid metabolism, increasing norepinephrine-induced lipolysis and fatty acid oxidation in cultured adipocytes.^[13]

Nutritional supplement manufacturer Andrew Lessman criticized and countered sensationalized media and marketing claims about raspberry ketone’s purported weight-loss benefits and strongly cautioned against its use.^[14]

Safety

Little is known about the long term safety of raspberry ketone supplements.^[15] In 1965, the US Food and Drug Administration placed raspberry ketone on generally recognized as safe (GRAS) status for the small quantities used as a food additive.^[2] Whereas in the UK there are certain extracts that are termed 'novel' by the Food Standards Agency and so are on the unauthorised list.^[16]

References