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This paper shows how intergenerational trading of non-depletable natural resources may affect investment in physical capital, implying distinct patterns of overtaking between countries. Specifically, the results indicate that the elasticity of the marginal utility of natural resources plays a crucial role. When the elasticity is less than unity, a resource-abundant country may be overtaken by a resource-scarce country. In this case, savings are withdrawn from productive investment to acquire natural resources. Conversely, when it is greater than unity, the reverse pattern of overtaking may occur since investment in natural resources and in physical capital go hand in hand.

International audience; Lycopene is a predominant carotenoid in human plasma and may prevent degenerative diseases by antioxidant mechanisms. Moreover, not only lycopene itself, also its derived breakdown products, the apo-lycopenoids, could be responsible. Therefore, we analyzed the in vitro antioxidant activities of apo-60'-, apo-80'- and apo-12'-lycopenals, as well as of apo-10'-, apo-14'- and apo-11-series of lycopene (with terminal functions as alcohol, aldehyde, carboxylic acid, and ester) in various assays. We observed that the antioxidant activities, determined by measuring the ferric reducing antioxidant power (FRAP assay), the activities of bleaching 2,2'-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS(center dot+)) and the activities to scavenge peroxyl radicals (LPSC assay), were often much lower compared to lycopene itself, as recently proposed by some authors. The antioxidant activities were strongly influenced by the length of the polyene chain and the type of terminal function as well. Considering our results and the low amounts of apo-lycopenals found in plasma as well as in lycopene-rich food products compared to (all-E)-lycopene we speculate that the effects of apo-lycopenoids as direct antioxidants in food samples as well as in blood and/or target tissues can be stated as negligible. Apo-lycopenoids may act as indirect antioxidants by activation of gene expression of antioxidant-derived enzymes.

Cardiovascular diseases (CVDs) are the leading causes of human morbidity and mortality in developed countries. Specific biomarkers in this context are markers of inflammation, lipid status, thrombosis and oxidative stress. One recommendation for CVD prevention is to increase consumption of fruits and vegetables as good sources of secondary plant products, e.g. carotenoids. This review aimed to show linkages between lycopene, one main carotenoid in the human diet, and prevention of heart diseases by looking for epidemiological data, results from in vitro experiments and results from in vivo studies (animal studies and human intervention trials). In addition, patents and products within the context of lycopene and CVD prevention will be discussed with a special emphasis on health claims. Epidemiological data, in vitro data and results from animal experiments partly showed promising preventive mechanisms of lycopene. In contrast, until now, human intervention studies mostly failed to show any CVD prevention. However, there is still an encouraging situation, giving hints for antioxidant as well as anti-inflammatory effects of lycopene. These mechanisms could be the background for cardio-protective effects of tomatoes and tomato products. In summary, there are a lot of investigations needed in the future to give reliable results to establish these CVD-preventive effects.

Carotenoids and vitamin E in oils from the market - 6 rapeseed and 6 sunflower oils, half of each cold pressed and refined - and in the oils of rape, sunflower, flax and safflower as well as the respective seeds and press cakes from a local oil mill were quantified by HPLC. Furthermore, a photometric determination of carotenoid content was tested and checked against the chromatographic method. In the cold pressed oils minor amounts of xanthophylls (all-E)-lutein and (all-E)-zeaxanthin were determined. With exception of traces of (all-E)-β-carotene in cold-pressed rapeseed oil this provitamin A active compound did not occur. Cold pressed rapeseed oils contained 0.5-1.5 mg total carotenoids/100 g which was manifold the content of the further oils. Vitamin E was found in all vegetable oils at plant-typic tocopherol patterns. The photometric determination of carotenoids resulted in significantly higher concentrations compared to the HPLC. This overestimation bases on the carotenoid pattern which was validated by comparison with known high-carotenoid materials, i.e. maize flour with an abundant amount of xanthophylls and carrots with an abundant amount of carotenes.

Lycopene most likely contributes to the positive health effects of tomatoes on the cardiovascular system. However, elucidation of underlying cellular mechanisms is hampered by the intricate solubility of lycopene in aqueous solutions. Cells relevant to the cardiovascular system, including bovine aortic endothelial cells (BAECs), the monocytic cell line THP-1, and RAT-1 fibroblasts, were treated for various time periods (0–72 h) with different concentrations of lycopene (1, 5, and 10 µM), solubilized either in tetrahydrofuran (THF) or micelles as solvents. Incubation of all three cell types led to a concentration- and time-dependent increase in cellular lycopene content. Both vehicles tested, THF and micelles, proved equally effective in the delivery of lycopene to cells. A marked difference in the amount of lycopene incorporated was observed among the various cell types. Compared with THP-1 cells, the uptake of lycopene using both solvents was higher in BAECs and RAT-1 fibroblasts for all concentrations and time points tested. PRACTICAL APPLICATIONS Epidemiological data indicate a beneficial effect for consumption of tomato products in the prevention of cardiovascular diseases. Only limited data are available on the cellular uptake of lycopene in vascular cells. Lycopene was successfully delivered to different cells relevant for the cardiovascular system. These results represent an important prerequisite for the study of molecular and cellular mechanisms by which lycopene may exert its beneficial effects on the cardiovascular system.

Reactivity studies of the rhenium(VII) oxide/aluminum oxide olefin metathesis catalyst with various olefins show that initiation does not require an olefin with an allylic C-H bond, and therefore probably takes place via a pseudo-Wittig reaction. While it does not react with ethene in the absence of propene, Re 2 O 7 /Al 2 O 3 catalyses the self-metathesis of Z-stilbene and its cross-metathesis with ethene. Additionally, reaction of Re 2 O 7 /Al 2 O 3 with Z-2-butene followed by 13 C di-labelled ethene shows that it contains only 2 % of active sites.

In vitro antioxidant and antimutagenic activity of dietary chlorophyll derivatives was assessed. Anti- oxidant activity was determined by the ability of each compound to scavenge the long-lived free radicals 1,1- diphenyl-2-picrylhydrazyl (DPPH · ) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS ·+ ). Antimu- tagenic activity was assayed with a modified microscreen bacterial reverse mutagenicity assay using Salmonella typhimurium TA100 and benzo(a)pyrene as the tester strain and mutagen respectively. Derivatives of chlorophyll a were found to be more effective radical quenchers than those of chlorophyll b. Furthermore, metal-free derivatives such as chlorins, pheophytins, and pyropheophytins exhibited significantly lower antiradical capacity than metallo- derivatives such as Mg-chlorophylls, Zn-pheophytins, Zn-pyropheophytins, Cu-pheophytin a, and Cu-chlorophyllins. Both metal-free and metallo-chlorophyll derivatives demonstrated similar dose-dependent inhibitory activity against B(a)P induced mutagenesis. These results demonstrate that dietary chlorophyll derivatives prevalent in both fresh and processed foods and dietary supplements have antioxidant and antimutagenic activities.

After a 2-wk depletion period, 24 volunteers, divided into 3 groups, ingested 5 mg/d lycopene for 4-wk from 5 capsules containing tomato oleoresin or synthetic lycopene. Plasma samples were analyzed on carotenoids using C 18 HPLC with diode array detection. Basal lycopene levels (0.19 to 0.31 μmol/L) in plasma of the 3 groups were in a comparable range (p > 0.05) and significantly decreased after the 2-wk diet low in lycopene to 21 to 52 % of the basal values. Four out of 5 investigated capsules significantly (p < 0.05) enhanced the plasma lycopene levels relative to the depleted state after 1 wk of supplementation to 0.20 to 0.27 μmo/L. Increasing the surface of lycopene crystals by reducing the particle size was the most effective processing step to enhance intestinal absorption of lycopene. However, presence of tomato oil in in oleoresin and partly removal of selective fatty acids affected the intestinal absorption of lycopene too.

Five xanthophylls and six carotenes were eluted from a YMC C 30 column with a binary mobile phase gradient consisting of methyl tert-butyl ether and methanol. The effect of column temperature on the separation was tested between 15°C and 25°C. A mixture of prominent lycopene isomers was additionally analyzed to optimize their separation in relation to the main xanthophylls and carotenes. At column temperatures below 20°C (15Z)-β-carotene co-eluted with echinenone, a frequently used internal standard. For most carotenoids an optimal separation was achieved at 23 ± 1°C within one hour. In contrast, some (Z)-isomers of lycopene showed a better resolution at higher column temperatures. While these isomers were separated at 30° C and at 35 C, another (Z)-isomer co-eluted with (E)-lycopene at 35 C. Thus, column temperature is a noteworthy parameter in high performance liquid chromatography of carotenoids.

¨ This paper derives a general explicit sequential asset price process for an economy with overlapping generations of consumers. They maximize expected utility with respect to subjective transition probabilities given by Markov kernels. The process is determined primarily by the interaction of exogenous random dividends and the characteristics of consumers, given by arbitrary preferences and expectations, yielding an explicit random dynamical system with expectations feedback. The paper studies asset prices and equity premia for a parametrized class of examples with CARA utilities and exponential distributions. It provides a complete analysis of the role of risk aversion and of subjective as well as rational beliefs.