Xanthophylls development

In order to verify the minimum number of carotenoids in an extract or fraction, a very easy and fast test can be carried out with only one small piece of silica gel thin layer plate, consecutively developed with 10% diethyl ether or 4% acetone in petroleum ether for carotene separation, followed by 70% diethyl ether or 15% acetone in petroleum ether for visualization of monohydroxy xanthophyll separation, and finally with 30% acetone in petroleum ether for separation of di- and trihydroxy-carotenoids. ... 

The composition and amount of pigments in marine environments have also been vigorously investigated. Thus, on RP-HPLC method has been developed for the study of the effect of variable irradiance on the xanthophyll cycle of the seagrass Zostera marina. Extraction of pigments from seagrass was carried out by grinding the samples with acid-washed sand in the presence of 1 ml of 90 per cent acetone and the liquid phase was... 

Pigment levels given in mg/m2 leaf area and in mg/g dry weight (dw). Values measured are those from fully developed leaves in June, 2000. Pigment levels within one leaf usually vary by <3%, and pigment ratios vary by <1%. Abbreviations a + b total chlorophylls a and b x + c, xanthophylls and carotenes (total carotenoids). 

Immediately cork the tube filled with nitrogen and then add a drop or two of dichloromethane to dissolve the pigments for TLC analysis. Carry out the analysis without delay by spotting the mixture on a TLC plate about 1 cm from the bottom and 8 mm from the edge. Make one spot concentrated by repeatedly touching the plate, but ensure that the spot is as small as possible—less than 1.0 mm in diameter. The other spot can be of lower concentration. Develop the plate with 70 30 hexane acetone. With other plates try cyclohexane and toluene as eluents and also hexane/ethanol mixtures of various compositions. The container in which the chromatography is carried out should be lined with filter paper that is wet with the solvent so the atmosphere in the container will be saturated with solvent vapor. On completion of elution, mark the solvent front with a pencil and outline the colored spots. Examine the plate under the uv light. Are any new spots seen Report colors and i /values for all of your spots, and identify each as lycopene, carotene, chlorophyll, or xanthophyll. 

Low O2 generally delays or Inhibits the synthesis of lycopene, 11-carotene, and xanthophylls In tomato fruit (31.321. In sweet pepper, high COg delayed development of red color equally whether combined with 21% or 3% 02 (33). C2H4 Is known to accelerate the biosynthesis of carotenoids (34). 

Gabellini N, Bowyer JR, Hurt E, Melandri A and Hauska G (1982) A cytochrome b/c complex with ubiquinol-cytochrome C2 oxidoreductase activity from Rhodopseudo-monas sphaeroides. Eur J Biochem 126 105-111 Gilmore AM (1996) Mechanistic aspects of xanthophyll cycle-dependent photoprotection in higher plant chloroplasts and leaves. Physiol Plantarum 98 1-13 Giuliano G, Bartley GE and Scolnik PA (1993) Regulation of carotenoid biosynthesis during tomato development. Plant Cell 5 379-387... 

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