Monoterpene composition

Geographical variation in oleoresin monoterpene composition of Pinus contorta... 

Williams, RJ., Strauss, C.R., Wilson, B., Massy-Westropp, R.A. (1982b). Studies on the hydrolysis of Vitis vinifera monoterpene precursor compounds and model -D-glucosides rationalizing the monoterpene composition of grape. J. Agric. Food Chem., 30, 1219-1223. 

ABSTRACT Monoterpenoids are the components of essential oils, which are produced and accumulated, in large amounts by plants from certain families, including Labiatae, Pinaceae, Cupressaceae, Umbelliferae and Rutaceae. They are of special interest because of their industrial applications and on account of their chemical properties and biological activity. Monoterpenic composition can be useful in genetic and chemotaxonomic studies of coniferous species. 

Arising from this study (31) of the glycosides were a number of points of importance regarding the free monoterpene composition of the fruit. It was clear that hydrolysis of glycosides was a major pathway to the free compounds and the previously unexplained enrichment of llnalool, geraniol, nerol and a-terpineol in heated juice could now be accounted for by this mechanism. 

Changes in monoterpene composition with grape development. Several studies have been conducted in which changes were recorded in the concentration of free monoterpenes in ripening grapes (11,38,64-66) However, most of these works were carried out before the presence of glycosidically bound or polyhydroxylated forms of monoterpenes in fruit were recognized. 

Effect of pressings on monoterpene composition of musts and wines. 

Effect of wine ageing on monoterpene composition. Several studies have been made in which alterations in monoterpene distribution in wines over time or with increases in temperature were recorded (84-89). The effect on wine flavor of prolonged ageing or exposure to elevated temperatures is a loss of fruit bouquet. By contrast, brief heating of juices of aromatic grapes can enhance the fruit flavor by increasing the concentration of free volatile monoterpenes through hydrolysis of precursors. 

Vltlcultural aspects. Vitlcultural research would benefit from detailed investigations concerning influences of major preharvest variables on monoterpene composition of fruit. Different pruning techniques, trellis designs, soil characteristics and climatic variables have yet to be assessed for their impact on grape flavorants. Research has been carried out on some of these factors in relation to wine quality (92,93) and now their effect on fruit... 

Wannaz E.D., J.A. Zygadlo and M.L. Pignata Air pollutants effect on monoterpenes composition and foliar chemical parameters in Schinus areira L., Sci. Total Environ. 305 (2003) 177-193. 

DELORME, L., LIEUTIER, F., Monoterpene composition of the preformed and induced resins of scots pine, and their effect on bark beetles and associated fungi, Eur. J. Forest Path., 1990,20, 304-316. 

Alterations in monoterpene content can determine the degree of resistance to bark beetles and, thus, whether or not a tree is colonized. Resin monoterpenes (Fig. 1) may be either repellents or attractants to Insects or fungistatic or chemotroplc stimulants of fungal growth, depending on the precise monoterpene composition and the particular herbivore or pathogen (9-13). 

TABLE t. Effect of Wounding and Infection on the Monoterpene Composition of Lodgepole Pine Steins ... 

Sadof, C. S. and G. G. Grant. 1997. Monoterpene composition of Pinus sylvestris varieties resistant and susceptible to Dioryctria zimmermani. 23 1917 1926. 

Changes in the monoterpene composition of Mentha aquatica have been produced by gene substitution. The oxidation of pulegone (11) to mentho-furan (16) is controlled by a single gene that is not completely dominant, whereas the reduction to menthone involves a different set. Changes in favour of low menthofuran composition have been produced in Mentha aquatica by gene substitution. 

Monoterpene composition also does not conform to clinal patterns of variation. Chang and Hanover (1991) separated range-wide populations into 2 east-west clusters, with the dividing line east of the Ontario-Manitoba border. The authors suggested that the clusters represented a branching of populations during the last glaciation. 

J. Rohloff, Monoterpene composition of essential oil from peppermint with regard to leaf position using solid-phase microextraction and gas chromatography/mass spectrometry analysis, J. Agric. Food Chem. 47(9) 3782 (1999). 

Several other polyhalogenated structures with the skeleton of ochtodane (l,l-dimethyl-3-ethyl-cyclohexane) were obtained from Portieria homemannii (Kuniyoshi et al, 2003). Although the halogenated monoterpene compositions of these two species vary with the place of harvest, this difference is no more than that which occurs by growing tissue in a photobioreactor (Barahona and Rorrer, 2003). 

Franklin, E. C. Within-tree variation of monoterpene composition and yield in slash pine clones and families. Forest Sci. 22, 185—191 (1976). 

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