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16 TH INTERNATIONAL SYMPOSIUM ON CAROTENOIDS sumption of fruits and vegetables (Khachik et al., 2006). Among these are hydroxycarotenoids: (3R,3'R,6'R)-lutein {1}, (3R,3'R)zeaxanthin {2}, (3R,6'R)-α-cryptoxanthin {3}, and (3R)-β-cryptoxanthin {4}. In addition, several dehydration products of {1} have also been identified in human serum, these are: (3R,6'R)-3hydroxy-3',4'-didehydro-β,γ-carotene {5} (3R,6'R)-3-hydroxy-2',3'didehydro-β,ε-carotene {6}, and (3R)-3-hydroxy-3',4'-didehydroβ, β-carotene {7}. Hydroxycarotenoids {1} and {2} appear to undergo extensive metabolism to several ketocarotenoids by a series of oxidation-reduction and double bond isomerization reactions. For example, (3R,3'S,6'R)-lutein (3'-epilutein, {8}) and (3R,3'S;meso)-zeaxanthin {9} are among the metabolites of {1} and/or {2} in human serum and ocular tissues that are formed by such reactions. The lack of commercial availability of some of these non-vitamin A active dietary carotenoids has limited the investigation of their metabolism and their biological activity. While the total synthesis of {1} and four of its stereoisomers has been reported (Khachik and Chang, 2009), the isolation of this carotenoid from marigold flowers (Tagetes erecta) on industrial scale has proven to be the most viable and inexpensive route to this carotenoid. In addition, 1 with stereocenters at 3,3',6'-positions serves as an excellent precursor in the partial synthesis of hydroxycarotenoids with ε–and β-end groups. Therefore, several semi-synthetic processes have been developed that separately transform {1} into {4} via {7} as well as {1} into {8}. While {8} is converted into {2} by base-catalyzed isomerization, {7} is transformed into {2} and its (3R,3'S;meso)-stereoisomer {9} by regioselective hydroboration followed by enzyme-mediated acylation that allows the separation of these carotenoids (Khachik et al., 2007). In another process, regioselective allylic deoxygenation of {1} afforded {3} that has been successfully transformed into (6'R)-α-cryptoxanthin {10}. The preparation and resolution of (3R)-3-hydroxy-β-ionone and its (3S)-stereoisomer that are important precursors in the total synthesis of {2} and {4} and their stereoisomers will be described. REFERENCES KHACHIK F. 2006. Distribution and metabolism of dietary carotenoids in humans as a criterion for development of nutritional supplements. Pure Appl. Chem. 78: 1551-57. KHACHIK F and CHANG AN. 2009. Total synthesis of (3R,32R,62R)-lutein and its stereoisomers. J. Org. Chem. 74: 3875-3885. KHACHIK F, CHANG AN, GANA A, MAZZOLA E. 2007. Partial synthesis of (3R,6'R)-α-cryptoxanthin and (3R)-β-cryptoxanthin from (3R,3'R,6'R)-lutein. J. Nat. Prod. 70: 220-226. Isomers and apo-carotenoids in biological matrices Steven J. Schwartz Department of Food Science and Interdisciplinary Graduate Program in Nutrition, The Ohio State University, Columbus, Ohio, USA 43210. Schwartz.177@osu.edu Conversion of carotenoids to geometrical (E, Z) isomers and more recently to apo-carotenoids and apo-lycopenoids has been the subject of various investigations. Analysis of carotenoids has revealed the formation of several geometrical isomers created during thermal processing of carotenoid rich plant foods. However, the susceptibility of carotenoids to isomerization appears to be matrix dependent and favored when carotenoids are associated with lipid. Previous reports have demonstrated that cis isomers of beta-carotene are not readily absorbed in humans. In contrast, lycopene isomers are absorbed and in-vivo isomerization reactions proceed readily following uptake. Data from clinical trials in humans show that relatively high percentage of lycopene isomers (approx. 60-80%) are found circulating in SESSION 3 blood plasma and deposited in tissues. However, the mechanism for in-vivo conversion remains to be elucidated but appears to proceed to equilibrium during absorption and circulation within the bloodstream at physiological temperatures. Although oxidative eccentric cleavage mechanisms of carotenoids have been well documented, few reports have unequivocally identified the in-vivo apo-carotenoid and apo-lycopenoid metabolic products. Our laboratory has developed highly selective and sensitive LC MS/MS methodology to analyze these compounds in foods and biological tissues. In collaboration with other researchers at the Ohio State University several eccentric cleavage products have been identified by comparison to synthesized authentic compounds and their potential biological activity demonstrated. Superlative carotenoids: the shortest, the longest, the cleanest, the fattiest, the most precious, the most water-soluble, the ultimate antireductant, the smallest aggregated and the best DNA-carrier carotenoid Hans-Richard Sliwka Department of Chemistry, Realfagbygg, Norwegian University of Science and Technology, 7491 Trondheim, Norway, hrs@nvg.ntnu.no Syntheses to carotenoids have long been the ultimate goal for carotenoid chemists. Syntheses with carotenoids are still hampered by the popular opinion that carotenoids are too sensitive for chemical manipulations. However, some of the commercially available carotenoids bear reactive functional groups such as -COOR, -CHO, -CO, -OH. A carotenoid with COOH can, therefore, be considered a highly unsaturated fatty acid, which can form highly unsaturated fatty acid alkali salts or inherently colored soaps. Highly unsaturated carotenoic acids may also replace saturated fatty acids in glycerolipids and phospholipids, which result in the formation of highly unsaturated fats. Carotenoid acids and carotenols can be esterified with hydrophilic substituents inducing water-solubility or water-dispersibility to the otherwise hydrophobic carotenoids. The C=O group in ketocarotenoids can easily be replaced with C=S, which is highly absorptive on Ag or Au for monolayer assembling. The CHO group invites to carotenoid prolongation in Wittig reactions. Other reactions with carotenoids can soon reach the reasonable limit in yield and stability. Still, low yields in a one-step synthesis may counterbalance higher yields in multistep syntheses. One positive effect of carotenoids cannot be overestimated: carotenoids introduce color to otherwise sallow compounds providing instant visual confirmation of product formation; the carotenoid color facilitates work-up procedures and allows chiroptical detection of typically "invisible" molecules, e.g. carotenoid glycerolipid enantiomers give CD spectra. The presentation illustrates the use of carotenoids in synthesis, highlights some unique results and exemplifies the use of carotenoid-modified compounds in spectroscopy, as pharmaphores, and in the study of aggregation and surface properties. Right and proper acknowledgements will be given to the many collaborators participating in this work. 50 ACTA BIOLOGICA CRACOVIENSIA Series Botanica
CHEMISTRY, ANALYSIS, CHEMICAL SYNTHESIS, AND INDUSTRIAL PRODUCTION OF CAROTENOIDS ORAL PRESENTATIONS Synthesis of water soluble PEG-carotenoid conjugates Attila Agócs, Magdolna Háda, Dóra Petrovics, Veronika Nagy, József Deli University of Pécs, Medical School, Institute of Biochemistry and Medical Chemistry, 7624 Pécs, Szigeti u. 12, attila.agocs@aok.pte.hu Natural carotenoids are hydrophobic antioxidants usually occur esterified with long chain fatty acid which make the even more lipophil. For therapeutic uses and also for food additives derivatives or formulations are needed which are water soluble to some extent. In the literature there are only a few examples for such derivatives: they are the sodium salts of lutein and astaxanthin disuccinate and diphosphate and the dilysinate of astaxanthin. The polyethyleneglycol (PEG) is widely used for the enchancement of pharmacological properties of bioactive compounds. In theory, there are several posibilities to couple a partially or fully functionalized PEG derivative to a carotenoid: esterification, etherification, cycloaddition (eg. click reaction). We have synthetized various PEG-carotenoid succinate diesters with hydroxy carotenoids (eg. capsanthin, cryptoxanthin, zeaxantin, 8'-β-apocarotenol) and carotenoid dimers with PEG spacer. Water solubility of the products varied from moderate to good depending the PEG content of the molecules. Recently, we successfully coupled carotenoid pentinoates with PEG azides via click reaction. Some of the new compounds were tested for their antioxidant activity on human liver cells and showed considerable improvement over native carotenoids. Some star-shaped trimers were also synthesized in which there is a PEG spacer between the carotenoid "arms" and the aromatic core. This study was supported by OTKA PD 77467 (Hungarian National Research Foundation). Identification of carotenoid pigments and their esterified forms in avian integuments: preliminary differences between wild and captive red-legged partridge Esther García-de Blas, Rafael Mateo, Javier Vińuela, Carlos Alonso-Álvarez Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo s/n, 13071 Ciudad Real, Spain, esther.garciablas@uclm.es, rafael.mateo@uclm.es, javier.vinuela@uclm.es, carlos.alonso@uclm.es Yellow-orange-red ornaments present in the integuments (feathers, bare parts) of birds are often produced by carotenoid pigments, serving to signal the quality of the bearer. Although carotenoid esterification in tissues is a common phenomenon, most of the work on avian carotenoids has been focused on the identification of free forms or have been done after sample saponification. In the present work, we determined free and esterified carotenoid composition in a bird species with red ornaments: the red-legged partridge (Alectoris rufa). Carotenoids from integuments were analyzed combining chromatographic techniques, and the result of this combination has been the identification of two major carotenoids and their ester- Vol. 53, suppl. 1, 2011 17–22 July 2011, Krakow, Poland ified forms present in the integuments. The main carotenoid (λ max 478 nm and [M+H] + at m/z 597.2) was identified as astaxanthin by comparison with standards. A second carotenoid (λ max between 440 and 480 nm and [M+H] + at m/z 581.3) was not identified among any of the commercially available carotenoid standards. Both the unidentified carotenoid and astaxanthin formed monoesters with fatty acids, but only astaxanthin was in its diesterified form. Monoesters were mainly formed with palmitic, stearic, oleic and linoleic acids. Differences were detected between wild and captive birds and different integuments (among others). These discrepancies will be discussed taking into account the biology of the species. This is the first chromatographic analysis of the carotenoid composition of integuments in this bird, and the first HPLC analysis of esterified carotenoids in any avian species. Structural changes of astaxanthin in a unicellular algae upon thermal stress: in situ Raman and DFT study Agnieszka Kaczor, Malgorzata Baranska Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060, Kraków, Poland, kaczor@chemia.uj.edu.pl, baranska@chemia.uj.edu.pl Haematococcus pluvialis is the biomanufacture of astaxanthin (AXT), a superpotent antioxidant. Biosynthesis of AXT in an algae is stimulated by environmental stress among others high temperature. (Boussiba, 2000) Temperature is also a very important factor causing of degradation or isomerization of carotenoids in general. (Schieber and Carle, 2005) Therefore, heat-promoted structural changes of AXT in Haematococcus were investigated in situ by means of Raman spectroscopy and DFT computations (B3LYP/6-31+G(d,p)). No visual, but discernible spectral changes in algae cells were observed upon increase of temperature from -100°C systematically up to 150°C. The exponential increase of the Raman shift of the ν C=C band at ca. 1520 cm-1 along with the change of the intensity ratio of bands at 1190 and 1160 cm-1 was observed, that correlates with the changes predicted by calculations for astaxanthin conformers ordered by decreasing energy. It is assumed that AXT molecules, initially in the form of Haggregates with the trans conformations of the end-rings, interconvert toward more stable gauche forms upon thermal stress of the algae. It was confirmed that the results, obtained for a single algae cell, can be generalized for their statistical number. The research was supported by the Polish Ministry of Science and Higher Education (grant N204311037, 2009-2012). Academic Computer Centre CYFRONET is acknowledged for CPU time. Prof. Katarzyna Turnau is acknowledged for Haematococcus pluvialis samples. REFERENCES BOUSSIBA S. 2000. Carotenogenesis in the green alga Haematococcus pluvialis: Cellular physiology and stress response. Physiologia Plantarum 108: 111-117. Schieber A, Carle R. 2005. Occurrence of carotenoid cis-isomers in food: Technological, analytical, and nutritional implications Carotenogenesis. Trends in Food Science & Technology 16: 416- 422. 51
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Index of Authors Abe K 44 Abramchik
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Szõke E 58 Szolcsány J 58 Szurkow
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ROMEO JT. 1973. A chemotaxonomic st
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