Carotenoid degradation products

Moreover, carotenoids themselves are very susceptible to oxidative damage and their oxidation products include deleterious aldehydes (Failloux et al., 2003 Hurst et al., 2005 Rozanowski and Rozanowska, 2005 Siems et al., 2000, 2002 Sommerburg et al., 2003). Therefore it is of interest to find out how carotenoids can offer antioxidant protection in cellular systems, how stable the carotenoids are within cells, and what the fate of the carotenoid degradation products is. 

Nucleic acids are not the only biomolecules susceptible to damage by carotenoid degradation products. Degradation products of (3-carotene have been shown to induce damage to mitochondrial proteins and lipids (Siems et al., 2002), to inhibit mitochondrial respiration in isolated rat liver mitochondria, and to induce uncoupling of oxidative phosphorylation (Siems et al., 2005). Moreover, it has been demonstrated that the degradation products of (3-carotene, which include various aldehydes, are more potent inhibitors of Na-K ATPase than 4-hydroxynonenal, an aldehydic product of lipid peroxidaton (Siems et al., 2000). 

Pyranoid monoterpenoid alkaloids have been reviewed, " and halogenated members of this class, (84) and (85), have already been discussed in the halogenated monoterpenoids section. " " The monoterpenoid ether (245) is reported from Artemisia tridentata-, from reported mass spectral data it may well be identical with the previously reported (and uncited) arthole (Vol. 7, p. 20), the characterization of which is still not published. Loliolide (246) is claimed to be an in vivo carotenoid degradation product in Canscora decussata additional spectral data have been published. ... 

Enantioselectivity of Biogenetic Routes. The enantiomeric composition of natural aroma compounds is known to reflect the enantioselectivity of their biogenesis (22). Thus, by elaborating the chiral composition of Cp-norisoprenoids in fruits, we expected to obtain some information about step II m the formation of Ci3-notiso-prenoids, i.e. the enzymatic transformation(s) of the primary carotenoid degradation products into labile aroma precursors (cf. Fig. 3). 

Use of Microorganisms for the Bioconversion of Primary Carotenoid Degradation Products. Microbial systems are frequently used for biotransformation... 

The characteristic scent of violet flowers is due to carotenoid degradation products... 

Theaspiranes and Vitispiranes. The shrub Osmanthus fragrans is a member of the oleaceae family which grows in eastern Asia. It is a rich source of carotenoid degradation products, many of which have also been found in other plant sources. Some of these are shown in Figure 8.26 and it is evident in the figure how they are related to each other and to the ionones. 

Among the most prized of essential oils are those of sandalwood, which contains the santalenes (78 and 79), and patchouli, which contains patchouli alcohol (80) (Fig. 21.19). Other components such as 3-ionone (81) (actually a tetrater-pene or carotenoid degradation product) and a-( — )-bisabo-... 

Other Carotenoid Degradation Products There are a number of other groups of volatile carotenoid degradation products that occur in nature and contribute to the odors of the plants in which they are found. Many of these are commercially available in small quantities at high price. Examples include the theaspiranes (369), which are found in tea, pas-sionfruit, and tobacco vitispiranes (370) found in some oils, such as lemon balm edulans (371) found in passionfruit, osmanthus, and tobacco and dihydroactindiolide (372) found in tea, osmanthus, tomato, ambergris, and tobacco. 

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