Mycosporine‐Like Amino Acids (MAAs) in Biological Photosystems

Abstract

International audienc

Mycosporine-Like Compounds in Chlorolichens: Isolation from Dermatocarpon luridum and Dermatocarpon miniatum, and their Photoprotective Properties

“…Such UV-absorbing compounds are distributed in taxonomically diverse organisms of terrestrial, marine, or freshwater origin [9]. More recently, the distribution of mycosporinelike compounds has been reported in cyanolichens (symbiotic organisms resulting from an association between a fungus and a cyanobacterium) [10,11]. Although chlorolichens correspond to 90 % of lichen species, mycosporine-like compounds have not yet been described in chlorolichens in which cyanobacteria are replaced by green algae.…”

Chemical constituents of the lichen Dermatocarpon luridum and pKa value of isolated mycosporine

“…(1) 3 10 pH HO (5) 10 pKa Ka (6) where Ka is the acid dissociation constant of the conjugate acid BH + ; A i is the measured absorbance at pH i and at the wavelength BH+ and B are the molar extinction coefficients at the wavelength of each form: conjugated acid BH + and base B respectively; C 0 is the total concentration of mycosporine in mol/L. From Eq.…”

“…Mycosporines are small watersoluble molecules absorbing UV radiations in the wavelength range 310-320 nm, based on their common aminocyclohexenone ring linked with an amino acid or an amino alcohol. To date, more than 40 mycosporines and derivatives have been described, some bearing functional groups or being covalently linked with saccharidic units [5]. The dissociation constants of many mycosporines are not available at all.…”

Análise do desempenho fisiológico e da composição química de Pterocladiella capillacea (Rhodophyta, Gelidiales) submetida a diferentes irradiâncias

“…400-700 nm) e radiação UV-A ou UV-B (Carreto & Carignan, 2011). Dessa forma, geralmente é observada uma correlação positiva entre radiação e produção de MAAs Carreto & Caignan, 2011;Barre et al, 2014), com possibilidade de indução de MAAs em períodos curtos de tempo.…”

“…Em macroalgas vermelhas, os MAAs são em geral a proteção mais eficaz contra os efeitos combinados de temperatura, irradiância e estresse oxidativo por serem eficientes antioxidantes e dissipadores de calor, além de contribuir para o equilíbrio osmótico sob estresse iônico (De La Coba et al, 2009;Yoshiki et al, 2009;Yuan et al, 2009;Barre et al, 2014).…”