Oxidation of terpenes

Resin and Resinoid. Natural resins are plant exudates formed by the oxidation of terpenes. Many are acids or acid anhydrides. Prepared resins are made from oleoresins from which the essential oil has been removed. A resinoid is prepared by hydrocarbon extraction of a natural resin. 

Oxidation of methane is one of the sources of atmospheric CO. Another internal source of importance is the oxidation of terpenes and... 

Hatakeyama, S., K. Izumi, T. Fukuyama, H. Akimoto, and N. Washida, Reactions of OH with a-Pinene and /3-Pinene in Air Estimate of Global CO Production from the Atmospheric Oxidation of Terpenes, J. Geophys. Res., 96, 947-958 (1991). 

Oxidation of terpenes creates low-vapor pressure species that self-nucleate to form small aerosols, or condense on and increase the mass of existing aerosols. These secondary organic aerosols (SOAs) are of concern because they can signifi-... 

Pommer, L. (2003) Oxidation of terpenes in indoor environments a study of influencing factors. Department of Chemistry, Umea, Sweden, Umea University, PhD. 

There have been a number of previous reviews on microbial oxidations of terpenes. - Monoter-penes are often degraded progressively after an initial hydroxylation step, but di-, tri- and sesqui-terpenes can be converted more selectively, to accumulate useful quantities of hydroxylated products. Less systematic woric on the microbial oxidation of terpenoids has been carried out than in the case of steroids, and therefore prediction of the regio- and stereo-chemistry is scarcely possible. 

There is basically little difference between the mechanism of photochemical smog formation and the naturally occurring photo-oxidation of terpenes. The former, associated with a greater emission intensity of ozone precursors, however, leads to higher concentrations of those intermediates responsible for the undesirable effects of photochemical air pollution. 

Resins are obtained by oxidization of volatile oils. Resins are brittle, non-volatile, solid substances. Sometimes resins are among the products of oxidization of terpenes. The chemical composition of resins is very complex and contains various compounds including acids. Resins are soluble in alkalies, alcohol and insoluble in water. They are obtained from plant exudates and are produced in special ducts. Sometimes resins are produced as a result of injury of the plant part. Turpthein and jalapin are common resins found in Convolvulaceae. 

To define the truthful order of the reactivity of the terpenes we have carried out competitive oxidation of 1, 2 and 3 in 02/IBA/CoNaY system. As one can see from Fig.2, caryophyllene (3) is much more active than 1 and 2, the consumption of the two later olefins being started only after the quite complete consumption of 3. It should be mentioned that the results obtained in the competitive oxidation of terpenes 1-3 by O2/IBA in the presence of... 

Oxidation of methane is one of the sources of atmospheric CO. Another internal source of importance is the oxidation of terpenes and isoprenes emitted by forests (Crutzen, 1983). The carbon monoxide concentration in the atmosphere ranges from 0.05 to 0.20 ppmv in the remote troposphere (with considerable differences between the northern and southern hemispheres), which means that about 0.2 Pg of carbon is present as CO in the atmosphere. 

Lipase B from Candida antarctica Smectite group (Laponite, SWy-2 and Kunipia) and organically modified derivatives Oxidation of terpenes [56, 57]... 

Hatakeyama, S Izumi, K., Fukuyama, T., Akimoto, H., and Washida, N Reactions of OH with a-pinene and /3-pinene in air Estimate of global CO production from atmospheric oxidation of terpenes. J. Geophys. Res. 96, 947 (1991). 

The oxidation of terpene analogs by the Gif system has recently been reported [126]. Ketones have been obtained as major products. 

Scheme 16 Combination of stereoelectrcHiic factcn in the oxidation of terpenes by [Fe(pdp)...

Wisthaler, A., Jensen, N.R., Winterhalter, R., Lindinger, W., Hjorth, J. (2001) Measurements of acetone and other gas phase product yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry (PTR-MS). Atmospheric Environment, 35, 6181-6191. 

Ketones are emitted directly to the atmosphere, and their sources were discussed in detail in chapter I. In the U.K. acetone and butanone comprise about 1% and 5%, respectively, of the total anthropogenic emissions of oxygenated compounds, and 1.6% and 1.1%, respectively, of the total anthropogenic emissions of nonmethane volatile organic compounds. Ketone emissions from solvents (both industrial and personal) are substantial emissions from both gasoline- and diesel-fueled vehicles also contribute. Ketones are also formed extensively in the atmosphere in the oxidation of other compounds. Acetone, for example is formed in the OH-initiated oxidation of propane, iio-butane, iso-pentane, and neopentane and from a number of higher hydrocarbons. It is also formed in the oxidation of terpenes. The distribution, sources, and sinks of acetone in the atmosphere have been analyzed by Simpson et al. (1994). Methyl vinyl ketone is an important first generation product in the OH-initiated oxidation of isoprene. 

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