Carvone orange

Numerous examples of the different biological effects of enantiomers are available. One of the enantiomers of limonene smells of lemons, the other of oranges one of carvone smells of caraway, the other of spearmint These differences obviously have important... 

At the cellular level, the various types of receptor, transporter, enzyme and ion charmel are all chiral in form. Thus although the enantiomers of a drug may have identical physicochemical properties, the way in which they may interact with chiral targets at the level of the cell will give rise to different pharmacod)mamic and pharmacokinetic properties. A few simple examples will illustrate how taste and olfactory receptors can differentiate between enantiomers. Thus R-carvone tastes like spearmint whereas the S-isomer tastes like caraway. Similarly, R-limolene smells like lemon whereas the S-enantiomer tastes of orange. 

The main renewable resource for L-carvone is spearmint oil (Mentha spicata), which contains up to 75% of this flavour chemical. There also exists a synthetic process for the manufacturing of L-carvone, which is based on (-t)-limonene, which is available as a by-product of the citrus juice industry as a major component of orange peel oil (Scheme 13.4). The synthesis was developed in the nineteenth century and starts with the reaction of (-t)-limonene and nitrosyl chloride, which ensures the asymmetry of the ring. Treatment with base of the nitrosyl chloride adduct results in elimination of hydrogen chloride and rearrangement of the nitrosyl function to an oxime. Acid treatment of the oxime finally results in l-carvone. 

Limonene is a monoterpene that occurs in citrus fruits. Two enantiomers of limonene produce two distinct flavours (—)-limonene is responsible for the flavour of lemons and (+)-limonene for orange. Similarly, one enantiomeric form of carvone is the cause of caraway flavour, while the other enantiomer has the essence of spearmint. 

Gas Chromatographic Analysis. The contribution of limonene-1, 2-epoxides and carvone to the development of oxidized flavor of encapsulated orange oil has been investigated (5). The concentrations of these two compounds were reported to provide a reliable index of the stability of the encapsulated orange oil. 

Cold pressed orange oil contains over 95 by weight monoterpene hydrocarbons. The principal constituent, d-limonene, ranges from 83-97 percent (9), Limonene degradation has been well docu-meted in the literature (LO, 1 1). Anandaraman identified limonene-1,2-epoxide and carvone as two of the earliest degradation products of d-limonene (12, 13). 

The fungal bioconversion of limonene was further studied [82]. Penicillium sp. cultures were isolated from rotting orange rind that utilised limonene and converted it rapidly to a-terpineol. Bowen [83] isolated two common citrus moulds, Penicillium italicum and P. digitatum, responsible for the postharvest diseases of citrus fruits. Fermentation of P. italicum on limonene yielded cis- and frans-carveol (93) (26%) as main products, together with cis- and from-p-mentha-2,8-dien-l-ol (110) (18%), (+)-carvone (94) (6%), p-mentha-1,8-dien-4-ol (111) (4%), perillyl alcohol (100) (3%), p-menth-8-ene-1,2-diol (98) (3%), Fig. (17). Conversion by P. digitatum yielded the same products in lower yields. The two alcohols />-mentha-2,8-dien-1 -ol (110) and p-mentha-1,8-dien-4-ol (111) were not described in the transformation studies where soil Pseudomonads were used [69]. 

Limonene is the major monoterpene in orange oil. This is a colorless and odorless compound at high purity. However, it rapidly oxidizes to carveol and carvone in the presence of air. Under acidic conditions, a-terpineol, P-terpineol, and y-terpineol are also produced. Many of the impurities present in limonene have much higher odor potencies. These odor potent compounds can be perceived as limonene odor . 

Orange juice Changes during processing Loss of (Z)-3-hexenal, acetaldehyde, increase of carvone [119]... 

Camphene, a- Rosemary plant, P-Pinene, Cineole, and spruce needles Camphor, Bomeol, Bomyl Acetate, Humulene Cinnamaldehyde, Cinnamon Coumarin, C15H24 Isomers Limonene, a- Orange peel P-Pinene, C15H24 Limonene, Menthol, Chewing gum Isomenthone, Carvone, Menthone, C15H24 45 0.90 300... 

Carvone is the principal odour component of spearmint oil. Both the oil and synthetic 1-carvone are used as ingredients in mint flavours. The synthetic material is made from d-limonene, which is the major component of orange oil and therefore is available as a by-product of orange juice production. Quest International is the world s major producer of 1-carvone. The classical chemistry used to produce 1-carvone is shown in Figure 4.19. The chirality of the carvone is crucial to the odour, since the enantiomeric d-carvone has an odour reminiscent of dill or caraway rather than spearmint. It is therefore important that any... 

This figure relates to the use of orange oil in perfumery. About l,500tpa are used in the manufacture of carvone. Total production exceeds 50,000 tpa. 

One enantiomer of the compound carvone is associated with the smell of spearmint the other produces the aroma of caraway seeds or dill. One mirror-image form of limonene smells like lemons the other has the aroma of oranges. 

For example, the enantiomers of limonene smell and taste like oranges or lemons, the enantiomers of phenylalanine taste bitter or sweet, the enantiomers of carvone taste like spearmint or caraway, all depending on the absolute configuration. 

After treal me.nt with the VS reagent the monoterpene alcohols and their ester.s, cineole, the aldehyde ciiral and dironellal show blue or blue-vialei colour in vis. The phenylpropane derivatives safrole, anethole, myristidn, apioi and eitgenol are brown-red/ violet, while thymol and carvon are red to red-violet pipedtone shows a typical orange colour. 

Ketones quantitated in orange oil are carvone, an oxidation product of limonene, found at 0.1% or less, and nootkatone, found at extremely low levels of < 0.01% of peel oil. 

Terpenes are widely used as pharmaceutical excipients. The odor of some terpenes such as carvone, limonene, and menthol are stereospecifically different [21-23]. For example, S-(-l-) carvone has the odor of caraway, while the R enantiomer has a spearmint odor [20]. In the case of limonene, the R isomer has an orange odor, whereas its antipode has a lemon odor. 

Methyl p-t-butylphenylacetate 33204-74-9 Carvone oxide 33239-19-9 Acid red 95 D C Orange No. 11 33467-74-2... 

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