TY - JOUR
T1 - Photochemistry of the hemiketal form of anthocyanins and its potential role in plant protection from UV-B radiation
AU - Costa, Damien
AU - Galvão, Adelino M.
AU - di Paolo , Roberto E.
AU - Freitas, Adilson A.
AU - Lima, João Carlos dos Santos Silva E Pereira de
AU - Quina, Frank H.
AU - Maçanita, Antonio L.
N1 - Sem PDF
PY - 2015
Y1 - 2015
N2 - There is presently strong evidence that anthocyanins protect plant tissues from excessive solar radiation. In support of this, we have shown that the red flavylium form of anthocyanins (AH(+)) dissipates more than 99% of the absorbed radiation energy into heat through a series of ultra-fast excited-state processes, among which excited-state proton transfer to water plays the major role. In this work, it is shown for the first time that the less exuberant (colorless) hemiketal form of three common anthocyanins (pelargonin, cyanin, and malvin) is equally efficient at dissipating the absorbed (UV-B) radiation into heat by fast photo-tautomerization, which yields the cis-chalcone form in its ground state in a few picoseconds.
AB - There is presently strong evidence that anthocyanins protect plant tissues from excessive solar radiation. In support of this, we have shown that the red flavylium form of anthocyanins (AH(+)) dissipates more than 99% of the absorbed radiation energy into heat through a series of ultra-fast excited-state processes, among which excited-state proton transfer to water plays the major role. In this work, it is shown for the first time that the less exuberant (colorless) hemiketal form of three common anthocyanins (pelargonin, cyanin, and malvin) is equally efficient at dissipating the absorbed (UV-B) radiation into heat by fast photo-tautomerization, which yields the cis-chalcone form in its ground state in a few picoseconds.
KW - Photochemistry of anthocyanins
KW - Photo-tautomerization
KW - Conical intersection
KW - Quantum mechanics calculations
KW - Plant protection from UV radiation
U2 - 10.1016/j.tet.2014.06.092
DO - 10.1016/j.tet.2014.06.092
M3 - Article
SN - 0040-4020
VL - 71
SP - 3157
EP - 3162
JO - Tetrahedron
JF - Tetrahedron
IS - 20
ER -