cryptoxanthins and zeinoxanthin

The salt-tolerant unicellular alga

Topics: Algal Proteins; Amino Acid Sequence; Carotenoids; Chlorophyta; Cloning, Molecular; Cryptoxanthins; Escherichia coli; Hydroxylation; Lutein; Mixed Function Oxygenases; Phylogeny; Sequence Alignment; Substrate Specificity

Among the nutritional properties of microalgae, this study is focused in the presence of carotenoid esters in prokaryote microalgae, an event that has not been shown so far. Three carotenoid esters that accumulate in non-stressful culture conditions are identified in Aphanotece microscopica Nägeli and Phormidum autumnale Gomont, what may provide an extra value to the quality attributes of the carotenoid profile in cyanobacteria as functional foods. In addition, new data on the carotenoid characterization added quality criteria for the identification of the esterified metabolites, enabling the monitoring of these food components. Specifically, the metabolomic approach applied to the food composition analysis, has allowed to differentiate between the esters of zeinoxanthin and β-cryptoxanthin, which were undifferentiated to date during the MS characterization of carotenoids in other food sources. We propose a new qualifier product ion specific for zeinoxanthin ester, which it is not present in the MS

Topics: Beta-Cryptoxanthin; Carotenoids; Chromatography, High Pressure Liquid; Cryptoxanthins; Cyanobacteria; Esterification; Esters; Food Analysis; Tandem Mass Spectrometry

Topics: Beta-Cryptoxanthin; Calendula; Carotenoids; Cryptoxanthins; Esters; Fatty Acids; Flowers; Lutein; Tandem Mass Spectrometry; Xanthine; Xanthophylls; Zeaxanthins

Two mutants of Arabidopsis thaliana deficient in lutein have been investigated with respect to their responses to growth under a range of suboptimal conditions. The first mutant, lut1, was enriched in violaxanthin, antheraxanthin, zeaxanthin and zeinoxanthin compared with the wild-type (WT). In the second mutant, lut2, the lack of lutein was compensated for only by an increase in xanthophyll cycle (XC) carotenoids. Upon transfer of plants grown under optimal conditions to high light (HL), drought or HL + drought, both mutants acclimated during several days to the new conditions to the same extent as the WT. In contrast, transfer to chilling conditions (6 degrees C) for 6 days induced responses that were different between WT and mutants and between the mutants themselves. In contrast to the WT, the lut2 mutant in particular exhibited a large increase in the Chl a/b ratio and the XC pool size, extensive de-epoxidation and an enhanced extent of non-photochemical quenching. It is suggested that although the role of lutein in the structure and organisation of the light-harvesting complexes can be fulfilled by other xanthophylls under excess light conditions at optimal temperatures, this is not the case at low temperature.

Topics: Acclimatization; Arabidopsis; beta Carotene; Chloroplasts; Cryptoxanthins; Droughts; Intracellular Membranes; Light; Lutein; Mutation; Xanthophylls; Zeaxanthins

The monohydroxycarotenoid fraction of orange juice has been isolated by TLC and studied to determine whether the carotenoid accompanying beta-cryptoxanthin was alpha-cryptoxanthin or zeinoxanthin. The provitamin A carotenoid alpha-cryptoxanthin has been widely reported in orange juice, although its identification has been carried out mainly on the basis of its spectral features, which are virtually identical with those of its non-provitamin A isomer, zeinoxanthin. As a result of a study of the UV-vis and mass spectra of the monohydroxycarotenoid fraction and of the methylation test, it was concluded that the carotenoid accompanying beta-cryptoxanthin was the non-provitamin A carotenoid zeinoxanthin.

Topics: beta Carotene; Beverages; Chromatography, Thin Layer; Citrus sinensis; Cryptoxanthins; Fruit; Lutein; Mass Spectrometry; Spectrophotometry; Xanthophylls

Topics: beta Carotene; Carotenoids; Cryptoxanthins; Glutens; Zea mays