ACTA BIOLOGICA CRACOVIENSIA

INTERACTION OF CAROTENOIDS WITH REACTIVE OXYGEN SPECIES
INVITED LECTURES
The quenching effect of singlet oxygen by
carotenoids and vegetables. Development
of singlet oxygen absorption capacity (SOAC)
assay method
Koichi Aizawa1 , Kazuo Mukai2 1 Research Institute, Kagome Co., Ltd., 17 Nishitomiyama,
Nasushiobara, Tochigi, 329-2762, Japan,
Koichi_Aizawa@kagome.co.jp
2 Department of Chemistry, Faculty of Science, Ehime University,
Bunkyo-cho 2-5, Matsuyama 790-8577, Japan
Lipid peroxyl radical (LOO • ) and singlet oxygen ( 1 O 2 ) are two wellknown
representative reactive oxygen species (ROS) generated in
biological systems. In recent years, the method to assess the total
oxygen radical absorption capacity (ORAC) of foods and plants
has been developed. On the other hand, the method to assess the
1 O2 -quenching activity of foods and plants which include
carotenoids and phenolic antioxidants has not been developed.
Thus, we developed the new, versatile method to assess singlet
oxygen absorption capacity. A kinetic study of the quenching
reaction of 1 O 2 with 8 kinds of carotenoids and some kinds of
vegetable extracts was performed in ethanol:chloroform:D 2 O
(50:50:1, v/v/v) solution at 35°C. The overall rate constants, k Q (=
k q + k r, physical quenching + chemical reaction), for the reaction
of carotenoids with 1 O 2 were measured, using the competition
reaction method, where 3-(1,4-epidioxy-4-methyl-1,4-dihydro-1naphthyl)
propionic acid (endoperoxide) was used as a singlet
oxygen generator, 2,5-diphenyl-3,4-benzofuran (DPBF) as an
UV-Vis absorption prove, and α-tocopherol as a standard compound.
The rate constants, k Q (S) and k Q (t 1/2 ), were determined
by analyzing the first-order rate constant (S) and the half-life (t 1/2 )
of the decay curve of DPBF with carotenoids, respectively, showing
good accordance with each other. Similar measurements were
performed for some extracts of vegetables rich in carotenoids.
Based on the results, a new assay method that can quantify the
singlet oxygen absorption capacity (SOAC) of foods and plants
including carotenoids and phenolic antioxidants was proposed.
REFERENCES
OUCHI A, AIZAWA K, IWASAKI Y, INAKUMA T, TERAO J, NAGAOKA S, MUKAI K.
2010. Kinetic study of the quenching reaction of singlet oxygen by
carotenoids and food extracts in solution. Development of a singlet
oxygen absorption capacity (SOAC) assay method. J. Agric.
Food Chem. 58: 9967-9978.
AIZAWA K, IWASAKI Y, OUCHI A, INAKUMA T, NAGAOKA S, TERAO J, MUKAI K.
2011. Development of singlet oxygen absorption capacity (SOAC)
assay method. 2. Measurements of the SOAC values for
carotenoids and food extracts. J. Agric. Food Chem. 59: 3717-
3729.
Reactivity of carotenoids and new putative
lycopene metabolites in a biomimetic
experimental model of oxidative stress
Pascale Goupy, Eric Reynaud, Michel Carail,
Olivier Dangles, Catherine Caris-Veyrat
UMR 408 Safety and Quality of Plant Products, INRA,
University of Avignon, Site Agroparc, F-84914 Avignon, France,
catherine.caris@avignon.inra.fr
Carotenoids, among which lycopene, are supposed to participate
in the prevention of degenerative diseases such as cancers and
cardiovascular diseases. Mechanisms underlying these effects are
Vol. 53, suppl. 1, 2011
17–22 July 2011, Krakow, Poland
not well known. Regulation of gene expression has been demonstrated
in in vitro studies. Antioxidant mechanisms could be
especially relevant prior to intestinal absorption, i.e. in the gastro-intestinal
(GI) tract where dietary antioxidants can accumulate
in large concentrations after a meal rich in plant products
and where different forms of oxidative stress can take place.
Carotenoids metabolites are of interest for their possible biological
activity which could be different from or even higher than
those of the parent carotenoid. Only few lycopene metabolites
were identified in vivo: 2,6-cyclolycopene-1,5-diol in humans [1],
apo-12'- and apo-8'-lycopenals in rats [2] and apo-10'-lycopenal in
ferrets [3]. Recently Kopec et al. [4] found for the first time a serie
of apo-lycopenals in the plasma of human subjects having consumed
tomato products. The same apo-lycopenals being present
in the tomato products, it is not known whether they were formed
in humans or if they were ingested and further absorbed.
We have synthesised three series of potential lycopene metabolites,
the apo-11-, apo-10'- and apo-14'-lycopenoids, each with four
different terminal chemical functions: aldehyde, carboxylic acid,
ester and alcohol. Our synthetic strategy was based on chemical
reactions classically used in carotenoid synthesis: the Horner-
Wadsworth-Emmons and Wittig condensations, together with
reduction, oxidation and saponification reactions for functional
group modifications. We determined the antioxidant activity of
carotenoids and putative metabolites of lycopene using a homemade
lipid peroxidation test mimicking oxidative stress in the GI
tract [5]. A mathematical treatment yielding useful kinetic parameters
was developed to achieve a quantitative comparison between
the investigated antioxidants and to establish structure-activity relationships.
The antioxidant activity of the apo-lycopenals increased
with increasing length of the conjugated double bond system, i.e. in
the order: apo-11-, apo-14'-, apo-12'-, apo-10'-, apo-8'-, apo-6'lycopenal.
For the apo-10'- and 14'-lycopenoids, the order of
increasing reactivity in relation with the terminal function was: OH
< COOEt ≤ CHO < COOH. Ionisation potentials for all investigated
apo-lycopenoids and energies of peroxyl radical addition were estimated
for data interpretation.
REFERENCES
KHACHIK F, STECK A, NIGGLI UA, PFANDER H. 1998. Partial synthesis and
structural elucidation of the oxidative metabolites of lycopene
identified in tomato paste, tomato juice, and human serum.
J. Agric. Food Chem. 46: 4874-4884.
GAJIC M, ZARIPHEH S, SUN FR, ERDMAN JW. 2006. Apo-8 '-lycopenal and
apo-12 '-lycopenal are metabolic products of lycopene in rat liver.
J. Nutr. 136: 1552-1557.
HU KQ, LIU C, ERNST H, KRINSKY NI, RUSSEL RM, WANG XD. 2006. The
biochemical characterization of ferret carotene-9',10'-monooxygenase
catalyzing cleavage of carotenoids in vitro and in vivo.
J. Biol. Chem. 281: 19327-19338.
KOPEC RE, RIEDL KM, HARRISON EH, CURLEY RW, HRUSZKEWYCZ DP,
CLINTON SK, SCHWARTZ SJ. 2010. Identification and quantification
of apo-lycopenals in fruits, vegetables, and human plasma.
J. Agric. Food Chem. 58: 3290-3296.
VULCAIN E, GOUPY P, CARIS-VEYRAT C, DANGLES O. 2005. Inhibition of the
metmyoglobin-induced peroxidation of linoleic acid by dietary
antioxidants: Action in the aqueous vs. lipid phase. Free Rad.
Res. 39: 547-563.
Novel functionality and molecular mechanism
of fucoxanthin
Kazuo Miyashita 1 , Masashi Hosokawa 2
1
Faculty of Fisheries Sciences, Hokkaido University, Hakodate,
041-8611, Japan, kmiya@fish.hokudai.ac.jp
2Faculty of Fisheries Sciences, Hokkaido University, Hakodate,
041-8611, Japan, hoso@fish.hokudai.ac.jp
We have found that brown seaweed carotenoid, fucoxanthin, is
regarded as playing an important role in the prevention of human
75