Zeaxanthin + antheraxanthin

Some common carotenoids found in nature are all-frans-P-carotene, lycopene, a-car-otene, P-cryptoxanthin, canthaxanthin, zeaxanthin, antheraxanthin, violaxanthin, lutein, 9-cis-P-carotene, and 15,15- s-phytoene. 

D. Increased Conversion to Zeaxanthin + Antheraxanthin (Z+A) and Increased Allocation of Absorbed... 

FIGURE 1. The effect of irradiance on zeaxanthin formation in barley leaves values are expressed as a percentage of the total leaf xanthophyll contents. Samples were taken after 1 h irradiance. Violaxanthin + Antheraxanthin + Zeaxanthin (a) Violaxanthin (b) Zeaxanthin + Antheraxanthin (c). 

The photosynthetic pigments of higher plants comprise not only the chlorophylls (a and b) but also a range of carotenoids. The main ones of these are B-carotene (usually 25-30% of the total carotenoids) and the xanthophylls lutein (45-50%), violaxanthin (ca. 15%) and neoxanthin (ca. 15%), though small amounts of others, e.g. a-carotene, zeaxanthin, antheraxanthin, lutein-5,6-epoxide and a-cryptoxanthin, may also be detected. The... 

The 3-hydroxyl P-rings of zeaxanthin are further oxygenated by the introduction of 5,6-epoxy moieties by zeaxanthin epoxidase (ZEP). A mono-epoxidated intermediate, antheraxanthin is produced, followed by the di-epoxy xanthophyU, violaxanthin, as shown in Figure 5.3.3B. 

Physiologically, violaxanthin is an important component of the xanthophyU cycle a high light stress-induced de-epoxidation of the violaxanthin pool to the more photoprotective zeaxanthin is mediated by violaxanthin de-epoxidase (VDE). Violaxanthin and neoxanthin, an enzymatically (NXS)-produced structural isomer, are the precursors for the abscisic acid (ABA) biosynthetic pathway (Figure 5.3.1, Pathway 4 and Figure 5.3.2). In non-photosynthetic tissues, namely ripe bell peppers, antheraxanthin and violaxanthin are precursors to the red pigments, capsanthin and capsorubin, respectively (Figure 5.3.3B). 

Auroxanthin, antheraxanthin, violaxanthin, mutatoxanthin, lutein, zeaxanthin, a-cryptoxanthin or zeinoxanthin, P-cryptoxanthin, -carotene, a-carotene, P-carotene... 

Neoxanthin, violaxanthin, zeaxanthin, lutein, antheraxanthin, P-cryptoxanthin, lutein monoester, antheraxanthin monoester, P-cryptoxanthin monoester, lycopene, P-carotene, violaxanthin ester, lutein diester, P-cryptoxanthin ester, P-cryptoxanthin ester, zeaxanthin diester, zeaxanthin diester, zeaxanthin diester... 

Gilmore, A. and H. Yamamoto (1993). Linear models relating xanthophylls and lumen acidity to non-photochemical fluorescence quenching, evidence that antheraxanthin explains zeaxanthin-independent quenching. Photosynth Res 35 67-68. 

Fig. 2.3. Characteristic chromatogram of paprika paste. Detection at 450 nm. Peak identification 1 = Capsorubin 2 = 5,6-Diepikarpoxanthin 3 = Capsanthin-5,6-epoxide 4 = Capsanthin-3,6-epox-ide 5 = Violaxanthin 6 = Luteoxanthin 2 7 = Luteoxanthin 1 8 = Capsanthin 9 = Antheraxanthin 10 = Mutatoxanthin 11 = Cucurbitaxanthin A 12 = (9/9 Z)-Capsanthins 13 = (13/13 Z)-Capsanthins 14 = Zeaxanthin 15 = Nigroxanthin 16 = (9Z)-Zeaxanthin 17 = (13Z)-Zeaxanthin 18 = Cryptocapsin 19 = a-Cryptoxanthin 20 = /TCryptoxanthin 21 = (Z)-Cryptoxanthin 22 = /1-Carotene 23 = (Z)-jS-Carotene. Reprinted with permission from J. Deli et al. [27].

Fig. 2.34. Sample chromatogram of light-adapted Z. marina leaf sample. Peak identification 1 = neoxanthin, 2 = violaxanthin, 3 = antheraxanthin, 4 = lutein, 5 = zeaxanthin 6 = chlorophyll b, 1 = chlorophyll a, 8 = / -carotene. Reprinted with permisson from P. J. Ralph et al. [76].

Leaves were dark-adapted therefore, there is no detectable level of zeaxanthin. Concentrations are nmol pigment (mol chi a — b), the P value from one factor ANOVA is displayed below each column. V-A-Z = xanthophyll pool (violaxanthin, antheraxanthin, zeaxanthin) EPS = epoxidation state. Reprinted with permission from P. J. Ralph et al. [76]. 

Studies using HPLC (37 40, 41) would suggest there are fewer carotenoids in citrus than have been reported- The single most important one in the peel of oranges and tangerines is (3-citraurin, a reddish-orange carotenoid. Others include (3-cryptoxanthin, zeaxanthin, lutein, antheraxanthin, violaxanthin and to a lesser extent (3- carotene and -apo-8 -carotenal. The carotenes do not contribute very much to the color of the peel per se. 

A great variety of carotenoid compounds occur in photosynthetic bacteria and algae, whereas plants contain only a few carotenoids, i.e, (i-carotene (Figure 9.41), lutein, lycopene, violaxanhin, antheraxanthin, and zeaxanthin- Tomatoes, for example, are unique among plants in that they contain low levels of Ji-carotene but... 

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