Norisoprenoids

In the natural world, carotenoid oxidation products are important mediators presenting different properties. Volatile carotenoid-derived compounds such as noriso-prenoids are well known for their aroma properties. Examples include the cyclic norisoprenoid P-ionone and the non-cyclic pseudoionone or Neral. Carotenoid oxidation products are also important bioactive mediators for plant development, the best-known example being abscisic acid. Apo-carotenoids act as visual and volatile signals to attract pollination and seed dispersal agents in the same way as carotenoids do, but they are also plant defense factors and signaling molecules for the regulation of plant architecture. 

Bianchi, F., Careri, M., and Musci, M. (2005). Volatile norisoprenoids as markers of botanical origin of Sardinian strawberry-tree (Arbutus unedo L.) honey Characterisation of aroma compounds by dynamic headspace extraction and gas chromatography-mass spectrometry. Food Chem. 89,527-532. 

DArcy, B., Rintoul, G. B., Rowland, C. Y., and Blackman, A. J. (1997). Composition of Australian honey extractives. 1. Norisoprenoids, monoterpenes, and other natural volatiles from blue gum (Eucalyptus leucoxylon) and yellow box (Eucalyptus melliodora) honeys. /. Agric. Food Chem. 45,1834-1843. 

Hausler, M. and Montag, A. (1989). Isolation, identification and quantitative determination of the norisoprenoid (S)-(+)-dehydrovomifoUol in honey. Z. Lebensm. Inters. Forsch. 189, 113-114. 

Mathieu, S., N. Terrier et al. (2005). A carotenoid cleavage dioxygenase from Vitis vinifera L. Functional characterization and expression during grape berry development in relation to C13-norisoprenoid accumulation. J. Exp. Bot. 56(420) 2721-2731. 

The aglycon part of glycoside is often represented by monoterpenes, C13-norisoprenoids, benzene derivatives, and long-chain aliphatic alcohols (Fig. 18) [74, 75]. 

In order to expand the worldwide market, considerable efforts are being devoted to improve the image of Madeira wine. Consequently, their characteristics have to be well defined. So, in order to define and describe the particular characteristics and the authenticity of the product, secondary metabolites of grape and wines mainly linked to a specific variety, must be deeply studied. In Madeira wine, these compounds are mainly included in the chemical classes of mono and sesquiterpenoids C13 norisoprenoid higher alcohols, ethyl esters, volatile fatty acids, carbonyl compounds, sulfur compounds, furanic compounds, lactones, and polyphenols. 

Ci3 Norisoprenoids Vitispirane I 177,192 Camphor, eucalyptus, spice, wood 800... 

Natural Precursors of Thermally Induced C13 Norisoprenoids in Quince... 

However, our knowledge about the immediate precursors of norisoprenoids and the reactions by which they are formed is rather scarce. 

Several volatile C.- norisoprenoids have previously been identified in steam-distilled quince fruit oil, in which they are regarded to contribute to the overall flavor impression. These include isomeric theaspiranes, various bicydononane derivatives, 3,4-didehydro- 3-ionol, and isomeric megastigmatrienones and theaspirones (4,5). This report concerns the identification of additional norisoprenoids and their natural precursors in quince fruit. 

Recently, Japanese researchers have demonstrated that the C., norisoprenoid alcohol 7 has a key role as a flavor intermediate, but information about its natural precursor was not provided (4,5). Potential structures for the precursor of 7 comprise diols 8 and 9 in either case, simple dehydration can afford a double bond in the 3,4-position. Furthermore, the hydroxyl group of 7 could conceivably be glycosidically-bound. 

Dienones 12A-12D were also detected as trace components in quince fruit volatiles after SDE sample preparation. However, as shown in Figure 3, except for the low amount of hydrocarbon 5, the distribution of thermal degradation products from 8 did not correspond to the composition of the major norisoprenoids 5-7 obtained after SDE of quince fruit juice. Consequently, diol 8 had to be excluded as their precursor. 

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