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Zeaxanthin
Selected AbstractsThe Influence of Dietary Lutein and Zeaxanthin on Visual PerformanceJOURNAL OF FOOD SCIENCE, Issue 1 2010James M. Stringham ABSTRACT:, The idea that normal constituents of the diet can influence visual function is not new. As early as 1782, Buzzi identified the yellow of the macula and Schulze (1866) specifically postulated that the yellow pigments led to improvements in human vision. These pigments were later found to be derived from dietary lutein and zeaxanthin that are known to be oxygenated carotenoids (xanthophylls). Walls and Judd (1933) postulated that these yellow intraocular pigments could improve visual performance by absorbing light scattered both within (for example, glare) and outside of the eye (increasing visual range by absorbing blue light scattered in the atmosphere), and by improving spatial vision through enhancing contrast and reducing chromatic blur. In this article, evidence for these ideas is reviewed with particular emphasis towards more recent data on glare effects. [source] Lutein in patients with cataracts and age-related macular degeneration: a long-term supplementation studyJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2001B Olmedilla Abstract Lutein, a non-provitamin A xanthophyll, is widely distributed in fruits and vegetables frequently consumed. In human serum, lutein is transported by lipoproteins and selectively accumulated in certain tissues (eg the retina). Epidemiological studies suggest that high intake and serum levels of lutein are associated with a lower risk of cataracts and age-related maculopathy. Subjects diagnosed with cataracts (CA; n,,=,5) or age-related macular degeneration (ARMD; n,,=,5) agreed to take three lutein capsules per week. Each capsule potentially provided about 12,mg of all- trans -lutein, 3,mg of 13/15- cis -lutein and 3.3,mg of ,-tocopherol, as revealed by HPLC. Zeaxanthin was not detected. Average supplementation time was 13 months (range 4,20 months) for ARMD subjects and 26 months (range 16,36 months) for CA subjects. Blood samples for carotenoid analysis were collected every 3 months, coinciding with ophthalmological revision. In serum, concentrations of lutein, 13- cis -lutein and two ketocarotenoids increased significantly. Maximum increments were observed at 3,6 months, reaching levels above the 95th percentile of the reference population (>0.44,µmol,l,1). Ophthalmological evaluation showed an average increment in visual acuity of 0.4, and glare sensitivity also improved. No significant side effects such as hypercarotenemia, carotenodermia or changes in biochemical or haematological profile were observed. Thus, lutein supplementation at achievable dietary levels increased and maintained serum lutein levels, which were associated with an improvement in the visual function of the patients. © 2001 Society of Chemical Industry [source] Functional implications of pigments bound to a cyanobacterial cytochrome b6f complexFEBS JOURNAL, Issue 2 2005Stephan-Olav Wenk A highly purified cytochrome b6f complex from the cyanobacterium Synechocystis sp. PCC 6803 selectively binds one chlorophyll a and one carotenoid in analogy to the recent published structure from two other b6f complexes. The unknown function of these pigments was elucidated by spectroscopy and site-directed mutagenesis. Low-temperature redox difference spectroscopy showed red shifts in the chlorophyll and carotenoid spectra upon reduction of cytochrome b6, which indicates coupling of these pigments with the heme groups and thereby with the electron transport. This is supported by the correlated kinetics of these redox reactions and also by the distinct orientation of the chlorophyll molecule with respect to the heme cofactors as shown by linear dichroism spectroscopy. The specific role of the carotenoid echinenone for the cytochrome b6f complex of Synechocystis 6803 was elucidated by a mutant lacking the last step of echinenone biosynthesis. The isolated mutant complex preferentially contained a carotenoid with 0, 1 or 2 hydroxyl groups (most likely 9- cis isomers of ,-carotene, a monohydroxy carotenoid and zeaxanthin, respectively) instead. This indicates a substantial role of the carotenoid , possibly for strucure and assembly , and a specificity of its binding site which is different from those in most other oxygenic photosynthetic organisms. In summary, both pigments are probably involved in the structure, but may also contribute to the dynamics of the cytochrome b6f complex. [source] Time-resolved fluorescence analysis of the recombinant photosystem II antenna complex CP29FEBS JOURNAL, Issue 2 2001Effects of zeaxanthin, phosphorylation Nonradiative dissipation of excitation energy is the major photoprotective mechanism in plants. The formation of zeaxanthin in the antenna of photosystem II has been shown to correlate with the onset of nonphotochemical quenching in vivo. We have used recombinant CP29 protein, over-expressed in Escherichia coli and refolded in vitro with purified pigments, to obtain a protein indistinguishable from the native complex extracted from thylakoids, binding either violaxanthin or zeaxanthin together with lutein. These recombinant proteins and the native CP29 were used to measure steady-state chlorophyll fluorescence emission and fluorescence decay kinetics. We found that the presence of zeaxanthin bound to CP29 induces a ,,35% decrease in fluorescence yield with respect to the control proteins (the native and zeaxanthin-free reconstituted proteins). Fluorescence decay kinetics showed that four components are always present but lifetimes (,) as well as relative fluorescence quantum yields (rfqy) of the two long-lived components (,3 and ,4) are modified by the presence of zeaxanthin. The most relevant changes are observed in the rfqy of ,3 and in the average lifetime (, 2.4 ns with zeaxanthin and 3.2,3.4 ns in the control proteins). When studied in vitro, no significant effect of acidic pH (5.2,5.3) is observed on chlorophyll a fluorescence yield or kinetics. The data presented show that recombinant CP29 is able to bind zeaxanthin and this protein-bound zeaxanthin induces a significant quenching effect. [source] Maternal carotenoid supplementation does not affect breeding performance in the Great Tit (Parus major)FUNCTIONAL ECOLOGY, Issue 4 2007VLADIMÍR REME Summary 1Carotenoids are micronutrients with many beneficial health-related effects. They are effective antioxidants and stimulants of the immune system. Carotenoids cannot be synthesized in animals and must be obtained from food. As such, they may limit reproductive output and performance, and on the proximate level mediate reproductive trade-offs. 2We studied carotenoid limitation in wild Great Tits (Parus major) by supplementing prelaying and laying females with lutein, the most abundant carotenoid in this species. We followed the effects of this supplementation on egg yolk carotenoid composition, and offspring and parental performance. 3Females transferred the supplemented lutein into egg yolks, increasing lutein concentration to the upper limit of naturally occurring concentrations in control pairs. Concentrations of zeaxanthin, ,-carotene and ,-carotene did not differ between supplemented and control pairs. 4Effects on offspring and parental performance were generally absent or weak. There were no effects on timing of laying, clutch size, hatching success, nestling survival, nestling mass (day 6 and 14), tarsus length or T-cell mediated immune response. Males on supplemented nests fed their young more than those on control nests. There was no positive effect on female feeding or mass. 5Negligible effects of lutein supplementation on offspring and parental performance might be explained by high natural abundance of carotenoids or other antioxidants, where additional carotenoids bear no strong advantage to the birds. Additionally, conflicting results of different studies may be explained by species-specific features of their life-histories. [source] Carotenoid accumulation strategies for becoming a colourful House Finch: analyses of plasma and liver pigments in wild moulting birdsFUNCTIONAL ECOLOGY, Issue 4 2006K. J. MCGRAW Summary 1Male House Finches (Carpodacus mexicanus) colour their sexually selected plumage with carotenoid pigments, and there has been much interest in the factors that affect their ability to become bright red rather than drab yellow. 2There is good support for the notions that health, nutritional condition and total carotenoid intake influence colour expression, but there are also suggestions that acquiring particular types of carotenoids from the diet may be important for developing red plumage. 3We used high-performance liquid chromatography (HPLC) to analyse the types and amounts of endogenous (in plasma and liver) and integumentary (in newly grown feathers) carotenoids in a wild, native population of moulting male and female House Finches from the south-western United States to determine the carotenoid-accumulation strategies for becoming optimally colourful. 4Four plant carotenoids , lutein, zeaxanthin, ,-cryptoxanthin and ,-carotene , were detected in plasma and liver. However, as was found previously, 11 carotenoids were observed in colourful plumage, with xanthophylls (e.g. lutein, dehydrolutein) predominant in yellow feathers and ketocarotenoids (e.g. adonirubin, 3-hydroxy-echinenone) in red feathers. This indicates endogenous modification of ingested carotenoids. 5Birds that accumulated more of one type of carotenoid in plasma and liver did not necessarily accumulate more of all other types, suggesting that individuals are not employing a simple ,more is better' strategy for coloration. Instead, when forward stepwise regression was used to examine the ability of individual types of carotenoids in plasma and liver to explain variation in red plumage pigments and plumage redness, we found that the lone variable remaining in all models was ,-cryptoxanthin concentration. 6This supports the idea that, unlike some other songbirds (e.g. yellow Carduelis finches), there is a specialized biochemical strategy that male House Finches follow to become red and most sexually attractive , to accumulate as much ,-cryptoxanthin in the body as possible. ,-Cryptoxanthin is a less common dietary carotenoid than the typical xanthophylls and carotenes in grains and fruits and may be limited enough in the diet that, to become colourful, House Finches might adopt selective foraging strategies for the most ,-cryptoxanthin-rich foods. [source] Dietary carotenoids and risk of colon cancer: Case-control studyINTERNATIONAL JOURNAL OF CANCER, Issue 1 2004André Nkondjock Abstract Some epidemiological studies suggest that consumption of fruits and vegetables with a high carotenoid content may protect against colon cancer (CC). The evidence, however, is not completely consistent. Given the inconsistencies in findings in previous studies and continued interest in identifying modifiable risk factors for CC, a case-control study of French-Canadian in Montreal, Canada, was undertaken to examine the possible association between dietary carotenoids and CC risk and to investigate whether this association varies in relation to lifestyle factors such as smoking or diet, and particularly the high consumption of long-chain polyunsaturated fatty acids (LCPUFA). A total of 402 colorectal cases (200 males and 202 females) and 688 population-based controls matched for age, gender and place of residence were interviewed. Dietary intake was assessed through a validated food frequency questionnaire that collected information on over 200 food items and recipes. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in unconditional logistic regression models. After adjustment for important variables such as total energy intake, no association was found between dietary intake of carotenoids and CC risk. For women with high intakes of LCPUFA, an inverse association was found between lutein + zeaxanthin and CC risk. ORs were 0.41; 95%CI (0.19,0.91), p=0.03 for eicosapentaenoic acid, and OR=0.36, 95%CI (0.19,0.78), p=0.01 for docosahexaenoic acid, when the upper quartiles of intake were compared to the lower. Among never-smokers, a significantly reduced risk of CC was associated with intake of ,-carotene [OR=0.44, 95%CI (0.21,0.92) and p=0.02], whereas an inverse association was found between lycopene intake and CC risk [OR=0.63, 95%CI (0.40,0.98) and p=0.05] among smokers. The results of our study suggest that a diet rich in both lutein + zeaxanthin and LCPUFAs may help prevent CC in French-Canadian females. © 2004 Wiley-Liss, Inc. [source] Characteristics of pigment composition and colour value by the difference of harvesting times in Korean red pepper varieties (Capsicum annuum, L.)INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2008Suna Kim Summary The main pigments of Capsicum annuum cv. Hanbando and Dabotop in dried red fruits were capsanthin, zeaxanthin, beta-cryptoxanthin and beta-carotene. Total carotenoid contents were twice as high at the fourth harvest compared with the second harvest in both varieties. The ratios of capsanthin to yellow fraction were above 1.0 in Hanbando and below 1.0 in Dabotop. Zeaxanthin content at the third harvest was about three times higher than at the second harvest in Dabotop. ASTA colour values harvested in the second, third and fourth weeks were 114, 152 and 178 in Hanbando and 115, 137 and 140 in Dabotop. Hue value of Hanbando was below 1.0 at all harvests and that of Dabotop was above 1.0 at the second and fourth harvests. The comparison of the C* values of two varieties revealed that Hanbando had the most vivid redness at the fourth harvest, whereas Dabotop was most vivid at the second harvest. [source] Theoretical investigation of carotenoid ultraviolet spectraINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4 2009João B. L. Martins Abstract We have determined the , band-gaps of the main carotenoids present in poly(methyl)methacrylate/buriti blends, namely, trans- ,-carotene, 13- cis- ,-carotene, 9- cis- ,-carotene, phytofluene, and zeaxanthin. Semiempirical, model Hamiltonian, and density functional calculations were carried out to study these structures. The geometries were fully optimized using AM1, PM3, and B3LYP/6-31G(d,p) methods. The TD-DFT and ZINDO/S methods were applied for the calculation of the electronic absorption spectra of the optimized B3LYP geometries. The calculated spectra using the polarizable continuum model for the solvent effects were compared with the available experimental. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Red-winged blackbirds Agelaius phoeniceus use carotenoid and melanin pigments to color their epauletsJOURNAL OF AVIAN BIOLOGY, Issue 6 2004Kevin J. McGraw Over the past three decades, the red-winged blackbird Agelaius phoeniceus has served as a model species for studies of sexual selection and the evolution of ornamental traits. Particular attention has been paid to the role of the colorful red-and-yellow epaulets that are striking in males but reduced in females and juveniles. It has been assumed that carotenoid pigments bestow the brilliant red and yellow colors on epaulet feathers, but this has never been tested biochemically. Here, we use high-performance liquid chromatography (HPLC) to describe the pigments present in these colorful feathers. Two red ketocarotenoids (astaxanthin and canthaxanthin) are responsible for the bright red hue of epaulets. Two yellow dietary precursors pigments (lutein and zeaxanthin) are also present in moderately high concentrations in red feathers. After extracting carotenoids, however, red feathers remained deep brown in color. HPLC tests show that melanin pigments (primarily eumelanin) are also found in the red-pigmented barbules of epaulet feathers, at an approximately equal concentration to carotenoids. This appears to be an uncommon feature of carotenoid-based ornamental plumage in birds, as was shown by comparable analyses of melanin in the yellow feathers of male American goldfinches Carduelis tristis and the red feathers of northern cardinals Cardinalis cardinalis, in which we detected virtually no melanins. Furthermore, the yellow bordering feathers of male epaulets are devoid of carotenoids (except when tinged with a carotenoid-derived pink coloration on occasion) and instead are comprised of a high concentration of primarily phaeomelanin pigments. The dual pigment composition of red epaulet feathers and the melanin-only basis for yellow coloration may have important implications for the honesty-reinforcing mechanisms underlying ornamental epaulets in red-winged blackbirds, and shed light on the difficulties researchers have had to date in characterizing the signaling function of this trait. As in several other birds, the melanic nature of feathers may explain why epaulets are used largely to settle aggressive contests rather than to attract mates. [source] Effects of LDL-immunoapheresis on plasma concentrations of vitamin E and carotenoids in patients with familial hypercholesterolemiaJOURNAL OF CLINICAL APHERESIS, Issue 4 2004Edmund Cauza Abstract Recently very potent extracorporeal cholesterol-lowering treatment options have become available for patients with hypercholesterolemia. LDL immunoapheresis treatment selectively removes LDL and lipoprotein(a) from the circulation. Since LDL is the major carrier of lipophilic antioxidants in plasma, the purpose of the present study was to assess the effects of a single LDL apheresis treatment on plasma concentrations of tocopherols (,- and ,-tocopherol) and carotenoids (,- and ,-carotene, zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, and retinol). Plasma antioxidant concentrations were determined by HPLC in 7 patients with familial hypercholesterolemia before and after LDL immunoapheresis treatment. Plasma concentrations of both ,- and ,-tocopherol and the different carotenoids were significantly reduced by LDL apheresis. However, when standardized for cholesterol to adjust for cholesterol removal, ,- and ,-tocopherol, retinol, and the more polar carotenoids lutein and zeaxanthin increased in response to apheresis treatment, while the more unpolar carotenoids such as ,-carotene and lycopene did not change. These data demonstrate that a single LDL immunoapheresis treatment affects tocopherols and individual carotenoids differently. This may be explained by differences in chemical structure and preferential association with different lipoproteins. These results further imply that tocopherols, lutein, zeaxanthin, and retinol, are associated in part with lipoproteins and other carriers such as retinol-binding protein that are not removed during apheresis treatment. J. Clin. Apheresis 19:174,179, 2004. © 2004 Wiley-Liss, Inc. [source] The Influence of Dietary Lutein and Zeaxanthin on Visual PerformanceJOURNAL OF FOOD SCIENCE, Issue 1 2010James M. Stringham ABSTRACT:, The idea that normal constituents of the diet can influence visual function is not new. As early as 1782, Buzzi identified the yellow of the macula and Schulze (1866) specifically postulated that the yellow pigments led to improvements in human vision. These pigments were later found to be derived from dietary lutein and zeaxanthin that are known to be oxygenated carotenoids (xanthophylls). Walls and Judd (1933) postulated that these yellow intraocular pigments could improve visual performance by absorbing light scattered both within (for example, glare) and outside of the eye (increasing visual range by absorbing blue light scattered in the atmosphere), and by improving spatial vision through enhancing contrast and reducing chromatic blur. In this article, evidence for these ideas is reviewed with particular emphasis towards more recent data on glare effects. [source] Flowers and Leaves of Tropaeolum majus L. as Rich Sources of LuteinJOURNAL OF FOOD SCIENCE, Issue 9 2005P.Y. Niizu ABSTRACT: As increasing evidence supports the role of lutein and zeaxanthin in reducing the risk of cataract and macular degeneration, food sources of these carotenoids are being sought. In the present study, the lutein content of the edible flowers and leaves of Tropaeolum majus L. was determined by high-performance liquid chromatography-photodiode array detector (HPLC-PDAD), complemented by HPLC-mass spectrometry (MS) for identification. Chemical reactions were also used as identifying parameters. The yellow and brownish orange flowers had 450 ± 60 ,g/g and 350 ± 50 ,g/g lutein, respectively. Violaxanthin, antheraxanthin, zeaxanthin, zeinoxanthin, ,-cryptoxanthin, ,-carotene, and ,-carotene were also detected at very low levels. The leaves had 136 ± 18 ,g/g lutein, 69 ± 7 ,g/g ,-carotene, 74 ± 23 ,g/g violaxanthin, and 48 ± 13 ,g/g neoxanthin. Lutein was partly esterified in the flowers and unesterified in the leaves. The flowers of T. majus are therefore excellent food sources of lutein and the leaves good sources of both lutein and the provitamin A ,-carotene. [source] Simultaneous HPLC-DAD-MS (ESI+) determination of structural and geometrical isomers of carotenoids in mature grapes,JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 9 2010Pasquale Crupi Abstract Carotenoids are uniquely functional polyene pigments ubiquitous in nature; aside from being responsible for the color of a wide variety of vegetables, interest is being focused on food carotenoids due to their likely health benefits. From analytical point of view, it is important to unequivocally identify individual carotenoid compounds in many food stuffs. Therefore, isolation of standards from natural sources must be encouraged for accurate identifications. Like many fruits, mature grape berries contain numerous carotenoid compounds, mostly found in the skin at levels two to three times higher than in the pulp. Carotenoid compounds in a typical wine grape variety (Negroamaro) grown in Apulian region were investigated by reversed-phase C30 (RP-30) HPLC-DAD-MS (ESI+) analysis. As a consequence of an unusual ionization process of carotenoids, their mass spectra registered in the positive ion mode comprised both protonated molecules and molecular ion radicals with little fragmentation. Additionally, selective collision-induced dissociation (CID) experiments, together with fine structures of the UV,vis spectra, were used to differentiate structural and geometrical isomers. This technique allowed the simultaneous determination of regio- and cis -isomers of lutein (zeaxanthin, 9Z and 9,Z -lutein) and a cis -isomer of ,-carotene (9Z - ,-carotene), 5,6-epoxy xanthophylls (violaxanthin, (9,Z)-neoxanthin, lutein-5,6-epoxide) and 5,8-epoxy xanthophylls diasteroisomers (neochrome, auroxanthin, luteoxanthin, flavoxanthin, chrysanthemaxanthin). Copyright © 2010 John Wiley & Sons, Ltd. [source] Balance of xanthophylls molecular and protonated molecular ions in electrospray ionizationJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 7 2005Thais Guaratini Abstract This paper reports the chemical evidence of the balance between radical molecular ions and protonatedmolecules of xanthophylls (an oxygen-containing carotenoid) with a conjugated ,-system (polyene) and oxygen as a heteroatom in ESI and HRESI mass spectrometry. The ionization energy of neutral xanthophylls was calculated by semi-empirical methods. The results were compared with those previously published for carotenoids and retinoids, which have also been shown in ESI-MS to form M+, and [M + H]+, respectively. This study demonstrates, for the first time, the correlation of an extended conjugation and the presence of oxygen in the formation and balance of M+, or [M + H]+ for the carotenoids, neoxanthin, lutein, violaxanthin and zeaxanthin. Copyright © 2005 John Wiley & Sons, Ltd. [source] PHOTOINHIBITION IN RED ALGAL SPECIES WITH DIFFERENT CAROTENOID PROFILES,JOURNAL OF PHYCOLOGY, Issue 6 2008Nadine Schubert Members of the Rhodophyta present different carotenoid profiles. In a majority of the species, lutein constitutes >50% of the total carotenoid content, while in other species, it is replaced by zeaxanthin or antheraxanthin. Given that carotenoids have specific roles in photoprotection, different carotenoid profiles of red algae species could be related to their capacity to cope with photoinhibitory stress. Therefore, in the present work, the sensitivity to light stress of red algal species with different carotenoid profiles was investigated. Photoinhibition of photosynthesis induced by high-light stress and the subsequent recovery in dim-light conditions was measured using maximal PSII quantum efficiency (Fv/Fm). The degree of decrease and recovery of Fv/Fm and their respective kinetics were related to the carotenoid profile of the species. Although no relationship between sensitivity to high-light stress and the carotenoid profile was observed, there were clear carotenoid profile-related differences in the decrease and recovery kinetics. In species with zeaxanthin or antheraxanthin as the major carotenoid, Fv/Fm reduction and recovery was principally associated with slowly activated and relaxed processes. In contrast, in species with lutein as the major carotenoid, rapidly activated processes appear to play a major role in the down-regulation of photosynthesis during light-stress conditions. In these species, the repair of D1 is also important during light-stress conditions. This finding could imply differential expression of mechanisms involved in photoprotection in red algae that seems to be related to the carotenoid profile of the species. [source] BENTHIC AND PLANKTONIC ALGAL COMMUNITIES IN A HIGH ARCTIC LAKE: PIGMENT STRUCTURE AND CONTRASTING RESPONSES TO NUTRIENT ENRICHMENT,JOURNAL OF PHYCOLOGY, Issue 6 2005Sylvia Bonilla We investigated the fine pigment structure and composition of phytoplankton and benthic cyanobacterial mats in Ward Hunt Lake at the northern limit of High Arctic Canada and the responses of these two communities to in situ nutrient enrichment. The HPLC analyses showed that more than 98% of the total pigment stocks occurred in the benthos. The phytoplankton contained Chrysophyceae, low concentrations of other protists and Cyanobacteria (notably picocyanobacteria), and the accessory pigments chl c2, fucoxanthin, diadinoxanthin, violaxanthin, and zeaxanthin. The benthic community contained the accessory pigments chl b, chl c2, and a set of carotenoids dominated by glycosidic xanthophylls, characteristic of filamentous cyanobacteria. The black surface layer of the mats was rich in the UV-screening compounds scytonemin, red scytonemin-like, and mycosporine-like amino acids, and the blue-green basal stratum contained high concentrations of light-harvesting pigments. In a first bioassay of the benthic mats, there was no significant photosynthetic or growth response to inorganic carbon or full nutrient enrichment over 15 days. This bioassay was repeated with increased replication and HPLC analysis in a subsequent season, and the results confirmed the lack of significant response to added nutrients. In contrast, the phytoplankton in samples from the overlying water column responded strongly to enrichment, and chl a biomass increased by a factor of 19.2 over 2 weeks. These results underscore the divergent ecophysiology of benthic versus planktonic communities in extreme latitudes and show that cold lake ecosystems can be dominated by benthic phototrophs that are nutrient sufficient despite their ultraoligotrophic overlying waters. [source] Introductory studies on the growth and characterization of carotenoid solids: an approach to carotenoid solid engineeringJOURNAL OF RAMAN SPECTROSCOPY, Issue 6-7 2001Yuzo Mori Solids of seven all- trans isomeric carotenoids, ,-carotene, ,-apo-8,-carotenal, astaxanthin, canthaxanthin, spheroidene, lycopene and zeaxanthin, were studied in the forms of KBr disks, aggregates, thin films and single crystals in an effort to understand and control the molecular arrangement of the solids. Optical absorption and resonance Raman scattering were adopted to characterize the arrangements. Card-packed arrangements and head-to-tail arrangements were realized by changing either the end groups or the growth process. These studies, which reveal the elementary engineering of solid growth and its characterization, may open up carotenoid solid engineering to develop useful applications of the materials in the fields of electronics, photonics and mechanical engineering. Copyright © 2001 John Wiley & Sons, Ltd. [source] Effects of lutein and zeaxanthin on aspects of eye healthJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2010Le Ma Abstract Lutein and zeaxanthin are members of the oxygenated carotenoids found particularly in egg yolks and dark-green leafy vegetables. A great deal of research has focused on their beneficial roles in eye health. The present article summarises the current literature related to the bioactivity of these carotenoids, emphasising their effects and possible mechanisms of action in relation to human eye health. Available evidence demonstrates that lutein and zeaxanthin are widely distributed in a number of body tissues and are uniquely concentrated in the retina and lens, indicating that each has a possible specific function in these two vital ocular tissues. Most of epidemiological studies and clinical trials support the notion that lutein and zeaxanthin have a potential role in the prevention and treatment of certain eye diseases such as age-related macular degeneration, cataract and retinitis pigmentosa. The biological mechanisms for the protective effects of these carotenoids may include powerful blue-light filtering activities and antioxidant properties. Although most studies point towards significant health benefits from lutein and zeaxanthin, further large-scale randomised supplementation trials are needed to define their effects on ocular function in health and disease. Copyright © 2009 Society of Chemical Industry [source] Possible nutritional and health-related value promotion in orange juice preserved by high-pressure treatment,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2002Begoña de Ancos Abstract Effects of high-pressure treatment on the orange juice carotenoids (,-carotene, ,-carotene, zeaxanthin, lutein and ,-cryptoxanthin) associated with nutritional (vitamin A) and health-related (radical-scavenging capacity) values were investigated. Various high-pressure treatments (50,350 MPa) combined with different temperatures (30 and 60,°C) and times (2.5, 5 and 15,min) of treatment were assayed. The carotenoid content of the orange juice was analysed by HPLC-UV, the vitamin A value was determined as retinol equivalents (RE) and the free radical-scavenging capacity was evaluated using the DPPH (2,2-diphenyl-1,1-picrylhydrazyl) radical model system. A storage study was carried out at refrigeration temperature (4,°C). High-pressure treatments at 350,MPa produced significant increases of 20,43% in the carotenoid content of fresh orange juice (from 3.99 to 4.78,5.70,mg,l,1). A non-uniform behaviour of high-pressure treatments was detected. An increase in time (beyond 5,min) or temperature (above 30,°C) of treatment did not improve the amount of carotenoids extracted. Owing to better extraction of carotenoids, an increase in vitamin A value from 164 to 238,RE,l,1 (45%) was achieved with the 350,MPa/30,°C/5,min treatment. No correlation was found between the increase in carotenoid amount extracted and the free radical-scavenging activity. © 2002 Society of Chemical Industry [source] Carotenoids in pungent and non-pungent peppers at various developmental stages grown in the field and glasshouse,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2002M Russo Abstract Carotenoids in edible portions of plants can provide health benefits to humans. How growing conditions affect levels of carotenoids in pepper fruits as they mature is not well known. Five cvs of bell pepper (Bell Captain, Melody, North Star, Ranger, Red Beauty) and five cvs of pungent-type peppers (Anaheim, Ancho, Cayenne, Pimento, Red Cherry) were grown in a glasshouse and in the field. Fruits were harvested at the green, turning (50% green) and mature red stages and analysed for levels of the carotenoids ,-cryptoxanthin, ,-carotene, ,-carotene, capsanthin, lutein and zeaxanthin and totals of these carotenoids. Levels of provitamin A: retinol equivalents (RE) were derived from levels of ,-cryptoxanthin, ,-carotene and ,-carotene. Levels of most carotenoids and RE were significantly higher in glasshouse-grown plants, and most were higher in fruits at the red stage. Fruits of Ancho type had the most ,-cryptoxanthin, ,-carotene, ,-carotene, total carotenoids and RE, while fruits of Red Cherry type had the most capsanthin and zeaxanthin, and fruits of Bell Captain had the most lutein. Interactions of the main effects variables, ie location of production (field vs glasshouse), stage of development and cultivar, indicated differences in patterns of carotenoid levels and RE. The data indicated that growing conditions influenced carotenoid levels. The more consistent and protected conditions in the glasshouse may have caused carotenoid levels to be increased, especially at the red stage. Published in 2002 for SCI by John Wiley & Sons, Ltd [source] Effect of Dietary Carotenoids on Skin Color and Pigments of False Clownfish, Amphiprion ocellaris, CuvierJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2010Inayah Yasir This study evaluated the role of supplemented dietary carotenoids in regulating the skin color and pigments of the false clownfish, Amphiprion ocellaris. Three carotenoid types, such as astaxanthin, ,-carotene, and canthaxanthin, were added to the basal diet at four pigment doses (0, 20, 50, and 100 ppm). Carotenoid diets were feed for 5 wk and then withdrawn from the diet for three additional wk during an 8-wk trial. The dose of each diet did not change the overall color hue, brightness, or saturation, but astaxanthin was the only carotenoid that enhanced red hue by the end of Week 5. The withdrawal of astaxanthin from the diet did not reduce the red hue, but reduced saturation. In contrast, the withdrawal of dietary ,-carotene or canthaxanthin reduced color saturation and brightness, but did not affect color hue. Dietary astaxanthin increased skin astaxanthin in Week 1 and skin zeaxanthin in Week 5. The withdrawal of astaxanthin escalated skin canthaxanthin and zeaxanthin by Week 8. Dietary ,-carotene suppressed skin ,-carotene, but enhanced skin zeaxanthin by Week 8. Although skin canthaxanthin was enhanced by dietary ,-carotene from Week 5 onward, dietary ,-carotene at 100 ppm maximized skin canthaxanthin by Week 8. Interestingly, dietary canthaxanthin suppressed skin canthaxanthin and zeaxanthin, but increased ,-carotene. This study suggests that astaxanthin has the potential to enhance the red hue on clownfish skin and its withdrawal from the diet did not fade the red hue of the skin. [source] The Effect of Dietary Carotenoids on Gonad Production and Carotenoid Profiles in the Sea Urchin Lytechinus variegatusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2002Larry R. Plank Although dietary carotenoids are generally considered important in sea urchin aquaculture only for their effect on gonad color, they also have important biological roles. The effects of dietary carotenoids on gonad production and organ carotenoid profiles of Lytechinus variegatus were examined. Individuals were collected in January 1999 and fed a replete diet with a level of 0.60 mg carotenoids/kg for 4 wk, followed by one of four prepared diets for 8 wk: one without supplemental carotenoids, one with ,-carotene (16.92 mg carotenoids/kg feed), and two carotenoid mixtures, one high in zeaxanthin (5.28 mg carotenoids/kg feed) and another high in capsanthin (9.63 mg carotenoids/kg feed). The carotenoid profiles of the body compartments differed. The primary carotenoid in gonads of males and females was echi-nenone. The carotenoid profile of the test was similar to that of the gonad. The carotenoid profile of the gut varied with diet, but was not identical to composition of the diet. The gut profiles included echinenone but at lower concentrations than in the gonad and test. The carotenoid profile in the gut probably results from the presence of the carotenoids absorbed and those metabolized. The results suggest that several pathways exist to metabolize dietary carotenoids and that some of them are in the gut. The concentration of carotenoids in the gut (g wet weight) was higher than that of the gonad, which was higher than that of the test. The gonads increased significantly in size regardless of diet, indicating carotenoids are not required for gonad production under the conditions of this experiment. Although the concentration of carotenoids in the gonad decreased over time, the absolute amount of carotenoids increased with the increase in gonad size. Either gonad growth was more rapid than carotenoid deposition or differential deposition in nutritive cells and gametogenic cells occurred, or the amount of carotenoids used in the diets was too low to have an effect. [source] The giant kelp Macrocystis pyrifera presents a different nonphotochemical quenching control than higher plantsNEW PHYTOLOGIST, Issue 3 2007Ernesto García-Mendoza Summary ,,Here the mechanisms involved in excitation energy dissipation of Macrocystis pyrifera were characterized to explain the high nonphotochemical quenching of chlorophyll a (Chla) fluorescence (NPQ) capacity of this alga. ,,We performed a comparative analysis of NPQ and xanthophyll cycle (XC) activity in blades collected at different depths. The responses of the blades to dithiothreitol (DTT) and to the uncoupler NH4Cl were also assayed. ,,The degree of NPQ induction was related to the amount of zeaxanthin synthesized in high light. The inhibition of zeaxanthin synthesis with DTT blocked NPQ induction. A slow NPQ relaxation upon the addition of NH4Cl, which disrupts the transthylakoid proton gradient, was detected. The slow NPQ relaxation took place only in the presence of de-epoxidated XC pigments and was related to the epoxidation of zeaxanthin. ,,These results indicate that in M. pyrifera, in contrast to higher plants, the transthylakoid proton gradient alone does not induce NPQ. The role of this gradient seems to be related only to the activation of the violaxanthin de-epoxidase enzyme. [source] Winter down-regulation of intrinsic photosynthetic capacity coupled with up-regulation of Elip-like proteins and persistent energy dissipation in a subalpine forestNEW PHYTOLOGIST, Issue 2 2006C. Ryan Zarter Summary ,,Overwintering, sun-exposed and photosynthetically inactive evergreens require powerful photoprotection. The goal of this study was to seasonally characterize photosynthesis and key proteins/components involved in electron transport and photoprotection. ,,Maximal photosystem II (PSII) efficiency and photosynthetic capacity, amounts of zeaxanthin (Z), antheraxanthin (A), pheophytin and proteins (oxygen-evolving 33 kDa protein (OEC), PSII core protein D1 and subunit S (PsbS) protein, and members of the early light-inducible protein (Elip) family) were assessed in five conifer species at high altitude and in ponderosa pine (Pinus ponderosa) at moderate altitude during summer and winter. ,,Relative to summer, winter down-regulation of photosynthetic capacity and loss of PSII efficiency at the high-altitude sites were paralleled by decreases in OEC, D1, and pheophytin; massive nocturnal retention of (Z + A) and up-regulation of two to four proteins cross-reactive with anti-Elip antibodies; and no change in PsbS amount. By contrast, ponderosa pine at moderate altitude exhibited no down-regulation of photosynthetic capacity, smaller depressions in PSII efficiency, and less up-regulation of Elip family members. ,,These results support a function for members of the Elip family in the acclimation of sun-exposed needles that down-regulate photosynthesis during winter. A possible role in sustained photoprotection is considered. [source] Obesity, Lutein Metabolism, and Age-Related Macular Degeneration: A Web of ConnectionsNUTRITION REVIEWS, Issue 1 2005Elizabeth J. Johnson PhD Age-related macular degeneration (AMD) is a major cause of visual impairment in the United States. Currently there is no effective cure for this disease. Risk factors include decreased lutein and zeaxanthin status and obesity. Obesity is also an increasing public health concern. The alarming increase in the prevalence of obesity further exacerbates the public health concern of AMD. The mechanism by which obesity increases the risk of AMD may be related to the physiologic changes that occur with this condition. These include increased oxidative stress, changes in the lipoprotein profile, and increased inflammation. These changes would also result in an increased destruction and a decreased circulatory delivery of lutein and zeaxanthin to the macula of the eye. Therefore, the mechanism by which obesity is related to AMD risk may be through indirect effects on changes in lutein and zeaxanthin status and metabolism. [source] Macular pigment optical density at four retinal loci during 120 days of lutein supplementationOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2007Adam J. Wenzel Abstract Background:, Increased consumption of lutein and zeaxanthin has been shown to increase macular pigment optical density (MPOD) in some individuals. Most interventions either obtained infrequent measures of MPOD or measured MPOD at a single retinal locus. Purpose:, The aim of this study was to measure acute changes in MPOD at four retinal loci during lutein intervention. Methods:, For 120 days, three subjects consumed 30 mg of lutein and 2.7 mg of zeaxanthin supplement per day. MPOD was measured with heterochromatic flicker photometry at 20,, 30,, 60, and 120, eccentricity three or four times per week. High-performance liquid chromatography was used to measure serum carotenoid concentrations in blood samples collected at baseline and at 30-day intervals. Results:, At the two most central loci, MPOD significantly increased in all three subjects with a mean change of approximately 0.09 log units at 20, eccentricity and 0.08 log units at 30, eccentricity. MPOD significantly increased in two subjects at 60, eccentricity, and in one subject at 120, eccentricity. The increases in MPOD appeared to be linear and continued after treatment was ended. In all three subjects, log sensitivity at the reference locus decreased linearly. Serum lutein and serum zeaxanthin increased from baseline, reaching peak concentrations after 30 days of supplementation. Conclusion:, The changes in MPOD suggest that carotenoid deposition occurs linearly and may be biased towards the central retina. Further, carotenoid deposition may occur outside the central fovea in interventions with pharmacological doses of carotenoid, resulting in underestimations of psychophysical measures of MPOD. [source] Supplementation with the carotenoids lutein or zeaxanthin improves human visual performanceOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2006Jessica Kvansakul Abstract Background:, Macular pigment (MP) is found in diurnal primate species when vision spans a range of ambient illumination and is mediated by cone and rod photoreceptors. The exact role of MP remains to be determined. In this study we investigate two new hypotheses for possible MP functions. Objective:, As MP absorption coincides partly with that of rhodopsin, MP may reduce rod signal effectiveness in the mesopic range, thus extend the usefulness of cone-mediated vision into the mesopic range. Forward light scatter in the eye can reduce retinal image contrast. If blue light contributes significantly to intraocular scatter, selective blue light absorption by MP could reduce the effects of scatter. Design:, We investigated 34 subjects from a carotenoid supplementation trial. The measurements included high mesopic contrast acuity thresholds (CATs), macular pigment optical density (MPOD), wavefront aberrations, and scattered light. The measurements were made after 6 months of daily supplementation with zeaxanthin (Z, OPTISHARPÔ), lutein (L), a combination of the two (C), or placebo (P), and again after a further 6 months of doubled supplementation. Results:, The data reveal a trend toward lower CATs in all groups supplemented, with a statistically significant improvement in the lutein group (p = 0.001), although there was no correlation with MPOD. Light scattering in the eye and the root-mean-square wavefront aberrations show decreasing trends as a result of supplementation, but no correlation with MPOD. Conclusions:, The results suggest that supplementation with L or Z increases MPOD at the fovea and at 2.5°, and that supplementation can improve CATs at high mesopic levels and hence visual performance at low illumination. [source] Effects of sulfur limitation on photosystem II functioning in Chlamydomonas reinhardtii as probed by chlorophyll a fluorescencePHYSIOLOGIA PLANTARUM, Issue 2 2006Taras K. Antal Chlorophyll fluorescence methods were applied to probe in vivo photosystem II (PSII) function in Chlamydomonas reinhardtii grown in sulfur-depleted media under aerobic conditions. The rates of oxygen evolution and dark reduction decreased during a 24-h incubation in sulfur-deficient medium, while the respiration rate increased. The analysis of chlorophyll fluorescence induction curves suggests that electron transport was perturbed on both the acceptor and donor sides of PSII. Light-induced violaxanthin de-epoxidation and non-photochemical fluorescence quenching were suppressed, owing to dark accumulation of zeaxanthin. Also sulfur-deprived cells showed elevated concentrations of violaxanthin and lutein. Sulfur deprivation stimulated a pronounced (three- to four-fold) increase in chlorophyll a fluorescence intensity (parameters Fo and Fm), probably due to greater light absorption by carotenoids and changes in the excitation energy transfer and deactivation in PSII of C. reinhardtii. [source] Short- and long-term modulation of the lutein epoxide and violaxanthin cycles in two species of the Lauraceae: sweet bay laurel (Laurus nobilis L.) and avocado (Persea americana Mill.)PLANT BIOLOGY, Issue 3 2008R. Esteban Abstract Short- and long-term responses of the violaxanthin (V) and lutein epoxide (Lx) cycles were studied in two species of Lauraceae: sweet bay laurel (Laurus nobilis L.) and avocado (Persea americana L.). The Lx content exceeded the V content in shade leaves of both species. Both Lx and V were de-epoxidised on illumination, but only V was fully restored by epoxidation in low light. Violaxanthin was preferentially de-epoxidised in low light in L. nobilis. This suggests that Lx accumulates with leaf ageing, partly because its conversion to lutein is limited in shade. After exposure to strong light, shade leaves of avocado readjusted the total pools of ,- and ,-xanthophyll cycles by de novo synthesis of antheraxanthin, zeaxanthin and lutein. This occurred in parallel with a sustained depression of Fv/Fm. In Persea indica, a closely related but low Lx species, Fv/Fm recovered faster after a similar light treatment, suggesting the involvement of the Lx cycle in sustained energy dissipation. Furthermore, the seasonal correlation between non-reversible Lx and V photoconversions and pre-dawn Fv/Fm in sun leaves of sweet bay supported the conclusion that the Lx cycle is involved in a slowly reversible downregulation of photosynthesis analogous to the V cycle. [source] | |||||||||||||||||||