Pinolenic acid

Six different A PMI PUFAs have been identified in pine nut as shown in Figure 17.1. Pinolenic acid is the most prevalent A PMI PUFA in most pine nut species, though contents vary greatly across species. Table 17.1 shows the A PMI PUFA composition of selected pine nut species that are most commonly available in the food supply and/or are researched for their health-promoting qualities. A more extensive listing of pine species and their seed fatty acid compositions was done by Wolff etal. [12]. 

In summary, pine nut shows promise in lowering cholesterol and therefore risk for CVD. The research is at times contradictory and sometimes shows detrimental effects. This is possibly due to the use of animal models that are inherently and sometimes unknowingly limited in (heir appUcabihty to human diseases. Additional animal and human studies are required to understand the effects of pine nut or its individual components, such as pinolenic acid, on plasma lipids and ultimately CVD risk. It deserves mention that other chemical components in pine nut oils such as phytochemicals may contribute to its observed biological effects, and other components in the nut such as dietary fiber may also have potential cholesterol-lowering activity. Additional research is essential to investigate other components in pine nut and its effects on blood lipids. 

Matsuo, N., Osada, K., Kodama, T., Lim, B.O., Nakao, A., Yamada, K., and Sugano, M., Effects of y-linolenic acid and its positional isomer pinolenic acid on immune parameters of Brown-Norway rats. Prostag. Leukotr. Ess., 55, 223-229,1996. 

Pinolenic acid (5c,9c,12c-18 3) occurs generally in the seed oils of coniferous trees, such as Korean pine. The seed oil has been shown to be an inhibitor of linoleic acid metabolism (17). Consumption of this oil results in a reduction of tissue levels of eicosanoids in rats (17). 

Tall oil fatty acids are a by-product of paper making, and there is no naturally occurring oil. Tall oil of Scandinavian origin contains the trienoic isomer pinolenic acid rather than linolenic acid as shown in Table 3.5. 

All tree species, both softwoods and hardwoods, contain fatty acids, typically 0.5-1% of the wood, mainly in the form of triglycerides or steryl esters. The predominant fatty acids are the oleic, linoleic and pinolenic acids with 18C-atoms and one, two and three double bonds, respectively (Figure 3.1). 

American CTOs contain smaller amounts of polyunsaturated fatty acids than Nordic CTOs. This difference is also reflected in the tall oil distillates, with lower amounts of linoleic and pinolenic acids than in corresponding Nordic products. This difference is related to the warmer climate in the southeastern US, but this trend can also be noticed even within Finland and Sweden. 

The pH where 50% of an acid is retained in the Upohilic colloidal droplets (1) and the other half is dissolved in the water phase (w), was termed pKi. Dehydroabietic acid having an aromatic ring had the lowest pKi, of 5.3. The other resin acids were rather similar, with pKi values of 6.8-7.1. The pinolenic acid with three double bonds behaved similarly to the resin acids, and linoleic acid similarly to palmitic acid. However, oleic acid dissolved at a clearly higher pH than the polyunsaturated fatty acids. The saturated stearic acid was preferentially in the colloidal phase, even at pH 10. The long-chain fatty acids with 20-24 C-atoms were dissolved only to a small extent, even at pH 11. 

With all of this information in hand, along with the knowledge that all of the double bonds have the cis configuration, we can propose the following structure for pinolenic acid ... 

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