Lutein chloroplasts

Typically several different carotenoids occur in plant tissues containing this class of pigments. Carotenoids are accumulated in chloroplasts of all green plants as mixtures of a- and P-carotene, P-cryptoxanthin, lutein, zeaxanthin, violaxanthin, and neoxanthin. These pigments are found as complexes formed by noncovalent bonding with proteins. In green leaves, carotenoids are free, nonesterified, and their compositions depend on the plant and developmental conditions. In reproductive... 

Aman, R., A. Schieber, and R. Carle. 2005a. Effects of heating and illumination on trans-cis isomerization and degradation of (3-carotene and lutein in isolated spinach chloroplasts. J. Agric. Food Chem. 53 9512-9518. 

Higher plant chloroplasts typically accumulate lutein, )3-carotene, violaxanthin, and neoxanthin (in order of abundance) as their major carotenoids. In general, carotenoid levels are directly proportional to the amount of chlorophyll in photosynthetic tissues, with lutein and neoxanthin being correlated with Chi b levels and j3-carotene with Chi a (Juhler et al.,... 

The carotenoid composition and distribution from thylakoid and PSII particles was also influenced by a limited Cu supply. Total carotenoid content was lower in whole thylakoids and PSII particles isolated from Cu-depleted plants. In Cu-depleted pea plants we obtained higher levels of violaxanthin and neoxanthin and lower lutein and B-carotene contents. This effect could be associated with modifications of xanthophyll cycle and it could influence the pigment composition of chlorophyll-carotenoid complexes from chloroplasts. 

As mentioned above, the leaves of all green plants contain the same major carotenoids -carotene (1), lutein (2), viola-xanthin (3), and neoxanthin (4). Smaller amounts of other compounds are often present. These compounds are located in the chloroplast grana as chromoproteins (Britton, 1983 Britton et al., 1982). 

Land plants including moss, fern, gymnosperm, and angiosperm majorly contain the carotenoids, (3-carotene 13, violaxanthin 16,9 -cis neoxanthin 19, and lutein 11 in chloroplasts for photosynthesis. Some unique carotenoids are found in specific organs, such as petals, fruits, and roots these carotenoids are not involved in photosynthesis. 

Figure 18.1 Chloroplast pigments separated from 3-5 pi of leaf extract by thin-layer chromatography on silica gel sheets. N = Neoxanthin V = viola-xanthin L = lutein b = chlorophyll b a = chlorophyll a C = carotene F = solvent front X = origin Y = yellow 0 = orange G = green III = blue-green over HCI vapors, = blue over HCI vapors Ac = acetone 10 = isooctane DE = diethyl ether. [Reprinted with permission of the Journal of Chemical Education, Washington, DC, from Strain and Sherma (1969).]...

Stability studies showed that the pigments degraded less on the Cig layers than on silica gel, and also when plates were wrapped in aluminum foil after development. Quantification of P-carotene, chlorophylls a and b, and lutein in the spinach leaves was done by scanning densitometry on the Cig layer at then-wavelengths of maximum absorption. This article also provided extensive tabular data on the separation of chloroplast pigments in various chromatographic systems. 

Fruits with low content of carotenoids (occurring mostly in chloroplasts) such as P-carotene, lutein, violaxanthin, neoxanthin (e. g., pineapples, bananas, figs and grapes). 

Juhler, R.K. and Cox, R.P., High-performance liquid chromatographic determination of chloroplast pigments with optimized separation of lutein and zeaxanthin, J. Chromatograph., 508, 232, 1990. 

The same four major carotenoids, )8-carotene, lutein, violaxanthin, and neoxanthin (5, 6 -epoxy-6,7-didehydro-5,6,5, 6 -tetrahydro-)8,)8-carotene-3,5,3 -triol), accumulate in the chloroplasts of all green leaves (Figure 4.1), with minor amounts of a-carotene (j8,e-carotene), zeaxanthin (/3,/3-carotene-3,3 -diol), antheraxanthin (5,6-epoxy-5,6-dihydro-/3,/3-carotene-3,3 -diol) and lutein 5,6-epoxide (3,3 -dihydroxy-5,6-epoxy-ar-carotene). Although quantitative differences between species are found, the carotenes account for about 25% of total leaf carotenoids, while lutein, the main xanthophyll, is about 45% of the total. The xanthophylls are unesterified except in senescing leaves. The distribution of carotenoids in flowers, fruits, and roots of plants can be found in several comprehensive reviews and will not be discussed here. 

In photosynthetically active chloroplasts, the carotenoids are found as part of photosynthetic pigment-protein complexes (PPCs) in the thylakoid membranes. The core complex, CCI, contains one /3-carotene molecule per 40 chlorophyll a, whereas the light-harvesting complex LHCI is associated with lutein, violaxanthin, and neoxanthin. /3-Carotene is also located in CCII, ° while LHCII contains xanthophylls." The separation, identification, and nomenclature of the PPCs has been discussed in detail in several recent reviews. ... 

Not only/3-carotene but alsooC -carotene, lutein, violaxanthin, neoxanthin and presumably other carotenoids may form LVM s. It seems likely that the LWAFs of pigments are formed mainly under appropriate conditions in artificial systems. However, the possibility cannot be excluded that under suitable conditions they may also be encountered in chloroplasts. For example, when using DEAEcc we were able to isolate the /3-carotene LWAF only from winter spinach (Wipckowski et al., 1981). So it seems likely that it occurred in the chloroplasts prior to treatment with Triton X-100. 

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