A Turmerone

GC-MS analysis of rhizome oils from five different Curcuma species shows variations in the major components, e.g. ar-turmerone (2.6-70.3%), a-turmerone (trace 6.2%) and zingiberene (trace-36.8%). Li et al. (1997) analysed a series of oils produced from several Zingiberaceae plants, including the rhizome oil of turmeric, using GC-MS. Thirty-five components were identified and turmerone (49%), ar-curcumene (15%) and ar-turmerone (6.4%) were the major compounds. 

Turmeric oil ar-Turmerone a- Turmerone P-Turmerone alginate nanocapsules, chitosan-alginate nanocapsules antibacterial, antifungal, insect repellent [3,69]... 

Simple synthetic routes to bisabolol-3-one (35) (a-bisabololone) (c/. Vol. 6, p. 58) and ar-turmerone (36) have been achieved by condensing the kinetic enolate... 

N.A. Volatile oil, zingiberen, turmerone, curcumin, resin.99,511 Stimulate secretion of bile, antibacterial, antiinflammatory, relieve stomach pain, antioxidant. 

The possibility of conversion of the dithioacctal into the corresponding ketone without reconjugation of the double bond is a noteworthy j feature of this synthetic scheme. The syntheses of iso-ar-turmerone and isoartemisia ketone mentioned above proceeded similarly via a carbophilic pathway. In the latter case a p-ethylenic dithioester was not isomerized during the following overall sequence carbophilic addition-methylation-dithioacetalization [343]. ... 

When R2 was a methallyl group a mixture of conjugated and unconjugated ketones was obtained. Treatment by DBU or piperidine yielded the conjugated ketone. The last example in Table 4.2 corresponds to ar-turmerone. 

The reaction provides the key step in a synthesis of ar-turmerone (2), equation... 

Sandur SK, Pandey MK, Sung B, Ahn KS, Murakami A, Sethi G, Limtrakul P, Badmaev Y, Aggarwal BB. 2007. Curcumin, demethoxycurcumin, bisdemethoxy-curcumin, tetrahydrocurcumin and turmerones differentially regulate anti-inflammatory and anti-proliferative responses through a ROS-independent mechanism. Carcinogenesis 28 1765-1773. 

When the ylid derived from the oxide 7 was treated with benzaldehyde, a 2-methoxy-l,3-diene was formed. This led us to attempt a synthesis of (i) ar-turmerone by a sequence (Scheme 3) in which 7 effectively acts as an acyl anion equivalent. The required aldehyde 8 was synthesized in good yield using initially diphenyl(methoxymethyl)phosphine oxide (3), and then chlorotri-methylsilane-sodium iodide (12) to cleave the enol ether. 

Mori, K. (2005). Synthesis of (R)-ar-turmerone and its conversion to (R)-ar-himachalene, a pheromone component of the flea beetle (R)-ar-himachalene is dextrorotatory in hexane, while levorotatory in chloroform. Tetrahedron Asymmetr., 16, 685-692. 

Dried rhizomes and leaves are used industrially to extract the volatile oil. Dried rhizomes contain 5-6% and leaves contain about 1.0-1.5% oil. Generally, the oil is extractedby steam distillation. Supercritical extraction using liquid carbon dioxide is a relatively new technique for extracting volatile oil and oleoresin. The peculiar turmeric aroma is imparted by ar-turmerone, the major aroma principle in the oil. 

The ratio of turmerone to ar-turmerone as reported by Rupe et al. (1934) is 60 40, while analysis of the volatile oils from commercial oleoresin shows a ratio of 80 20 (Salzer, 1977). The physico-chemical properties of turmerone and ar-turmerone are given in Table 6.3. The effect of maturity on the major components of rhizome oil from turmeric grown in Sri Lanka also indicated ar-turmerone (24.7-48.9%) and turmerone (20-39%) as the major compounds (Cooray et al., 1988 Nigam and Ahmed, 1991). Golding et al. (1982) demonstrated the... 

Separation and purification of three turmerones, e.g. ar-turmerone, a- and P-turmerone, from turmeric oil extracted by supercritical carbon dioxide gave 71% purify by weight. Subsequently, purification using a normal-phase silica gel 60 column could separate and purify three major turmerones with 86% purify by weight of ar-turmerone and 81% purity by weight of a- and P-turmerone. These were identified by liquid-solid chromatography, NMR qualification and HPLC quantification, respectively (Li-Hsun Chang et al., 2006). 

The composition of essential oil extracted using SC-C02 has been compared with that of steam-distilled oil by GC-MS (Gopalan et al., 2000b). Out of the 21 components identified, ar-turmerone and turmerone constituted about 60% of the total oil. Analysis of the cyclohexane extract of turmeric by GC-MS coupled with Pseudo Sadtler retention indices reveals a series of saturated and unsaturated fatty acids, along with sesquiterpenes. The fatty acids reported are tetradecanoic... 

Rupe, H., Clar, G., Pfau, A.St and Planner, P. (1 934) Volatile plant constituents. II. Turmerone, the aromatic principle of turmeric oils (in German). Idelvetica Chimica Acta 17, 372. 

New syntheses of ( )-ar-turmerone (79) and ( )-nuciferal (80) have been reported (Schemes 10 and 11 ) whereas Meyers and Smith have used the (+)-oxazoline (81) to good effect in an asymmetrically induced synthesis of (+)-ar-turmerone (82) (Scheme 12). A neat one-pot synthesis of /3-curcumene (83) has been developed which involves only two steps (Scheme 13). In a synthesis of the aromatic analogue, (-)-a-curcumene (84), Kumada et al. have used an asymmetrically induced cross-coupling Grignard reaction in the presence of a nickel complex of (85) to produce (84) in 66% enantiomeric excess (Scheme 14). A Vilsmeier-Haack-Arnold formylation of (-f-)-limonene has been used as... 

The last example formulates a two step synthesis of ar-turmerone from mesityl oxide. 

The dithioacetal is hydrolysed (mechanism like that on p. 1255), silver and cadmium being instead of mercury (not much gain in environmental friendliness there ), and the double be -moves into conjugation with the resulting ketone to complete the synthesis of ar-turmerone cart out at Caen by A. Thuillier and group, /. Org. Chem., 1979, 44, 2807. 

Lewis acid catalyzed alkylations of cross-conjugated silyl dienol ethers provide routes to a -alkylated ketones. A short synthesis of the sesquiterpene ( )-ar-turmerone has been accomplished using the cross-conjugated TMS dienol ether of mesityl oxide (equation 9). ... 

Motoyoshiya, J., Miyajima, M., Hirakawa, K., and Kakurai, T., Dimethyl (2-oxo-4-methyl-3-pente-nyljphosphonate as a precursor of a.a -dienones. Short syntheses of ( )-a-atlantone and ( )-flr-turmerone, J. Org. Chem., 50, 1326, 1985. 

More recently, Rousseau and Blanco reacted 3-methylbut-2-enoyl chloride with a number of silyl ketene acetals to produce -Yid-ethylenic P-keto esters, with yields in the range 62-80% neither but-2-enoyl chloride nor propenoyl chloride reacted under these conditions. They employed this reaction in a new synthesis of ( )-turmerone (6 Scheme 12). 

Valeton), Zingiberaceae Habit. India, China, East Indies. Constit. Yellow coloring matter (curcumin), p.p-dihydroxy -dicinnamoyImethane, p-hyd roxycinnamoyIferu loylmethane, p.a -dimethyibenzyl alcohol, 1 -methyl -4 -acetyl -1 -cyclohex -ene. turmerone. a -phellandrene, sabinene, zingiberene, cine-ol. borneol, caprylic acid, lsoln of curcumin from turmeric Janaki, Bose, J. Indian Chem. Soc. 44, 985 (1967). 

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