/WHO, 2002 ; Murkovic and Neunteufl, 2002 ). In vegetables, common provitamin A carotenoids include β-carotene, α-carotene, and β-cryptoxanthin ( ODS/NIH, 2006 ). Other common carotenoids such as lycopene, lutein, and zeaxanthin do not have vitamin A
% MeOH, 90% MTBE, and 4% water over 60 min; and 3) zeaxanthin (ZEA) was assayed by the gradient elution schedule of Rouseff et al. (1996) : the composition altered from 90% MeOH, 5% MTBE, and 5% water through a linear gradient to 95% MeOH and 5% MTBE
. HPLC allowed for the comparison of the carotenoid pigments lutein, capsanthin, and zeaxanthin among the four tissue categories. Lutein concentration was observed to follow general trend 2. Its concentration in symptomatic tissue (iv) was significantly
). Carotenoid formation is highly conserved throughout all plant species with six primary functioning carotenoids (antheraxanthin, β-carotene, lutein, neoxanthin, violaxanthin, and zeaxanthin) normally present in leafy tissues ( Sandmann, 2001 ). Carotenoid
on chromatogram. Peak identification was based on comparison of retention time and spectral characteristics of compound from the samples with those of available standards such as β-carotene, zeaxanthin (Sigma-Aldrich, Budapest, Hungary), or
( Leonelli et al., 2017 ). Plants with light-induced zeaxanthin (Z) establish larger NPQ and Z formation shapes the photosynthetic membrane into a responsive state against high-light exposure by enhancing the rate of NPQ formation ( Ruban, 2016 ). The NPQ
-carotene, lutein, zeaxanthin, violaxanthin, capsanthin, and capsorubin were purchased from Fujifilm Wako Pure Chemical (Osaka, Japan). These standard samples and the extracted compounds were analyzed by HPLC under the same conditions as described previously, and
photodamage ( Christie, 2007 ; Fraikin et al., 2013 ). The xanthophyll cycle pigments (zeaxanthin, antheraxanthin, violaxanthin) in plants are vital for energy dissipation of excess absorbed radiant light energy. Under high-light stress, violaxanthin is
= zeaxanthin epoxidase; VDE = violaxanthin de-epoxidase; NSY = neoxanthin synthase; NCED = nine- cis -epoxycarotenoid dioxygenase; ABA = abscisic acid. Lycopene accumulates in only a few species of citrus fruits, such as grapefruit ( C. paradisi ) and pummelo
lutein (3R,3′R,6′β,ɛ−carotene-3,3′diol), an oxygenated xanthophyll, and β-carotene (β,β−carotene), a hydrocarbon carotene. β-carotene and also zeaxanthin, antheraxanthin, violaxanthin, and neoxanthin are a group of carotenoids that contain two β