Marmelo lactones

Figure 5. Major volatiles formed from glycosidic extract from quince fruit after SDE treatment (100°C pH 3.7). 5, 6, 7 cf. Fig. 4 16 = marmelo ether 17 marmelo lactone.

The decision of what should be placed in this section is not obvious. Actually all monoterpenoid furan derivatives could be classed as oxygenated dimethyloctanes, but so could most other monoterpenoids, and it is to lessen the load in other sections that we include this one. We should point out that we have already discussed eldanolide, menthofurans, marmelo lactones, and oxides, and the 7-hydroxygeranic acid derivatives, cleveolide and scobinolide. 

In the case of the C]j-isoprenoids, it is noteworthy that attractive aroma compoimds were foimd to be derived from the central part of the carotenoid chain which remains after the cleavage of the C j-endgroup. Examples are the key flavor compoimds of quince fruit, i.e. marmelo oxides and marmelo lactones (76). 

Marmelo lactone, marmelo oxMe see fruit flavors (quince flavor). 

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