25th International Meeting on Organic Geochemistry IMOG 2011

P-415
Stable carbon isotope compositions of lignin phenols and cutin
acids among C3, C4 and CAM plants
Kazuhiko Sonoda, Masashiro Takahashi, Shuichi Yamamoto
Faculty of Engineering, Soka University, Tokyo, Japan (corresponding author:e09d5702@soka.ac.jp)
Compound-specific stable isotope analysis (CSIA) by
gas chromatography/combustion/isotope ratio mass
spectrometry (GC/C/IRMS) yields the isotopic
composition of individual compounds in natural samples,
and has been employed as a powerful tool for tracing the
source and delivery of biomarkers in geographical
samples and for reconstructing the paleoenvironment
[1,2].
An analysis of the carbon isotopic compositions
(� 13 C, ‰) of lignin phenols and cutin acids enables a
quantitative assessment of the properties of plant matter
input into geochemical samples. We have achieved the
CSIA of lignin phenols and cutin acids based on off-line
degradation and derivatization by the TMAH
(tetramethylammonium hydroxide) method, semipurification
using high-performance liquid
chromatography (HPLC), and CSIA by GC/C/IRMS [3]. In
this study, we report the measurement of the carbon
isotope compositions of lignin phenols and cutin acids
among C3, C4 and CAM plants using the method.
Fifteen terrestrial plant leaves including two C3 herbs,
five C3 woody plants, five C4 plants and three CAM
plants were used in this study. These plants were
analyzed off-line using the TMAH thermochemolysis
method. Semi-purification, isotope analysis and correction
methods of � 13 C values for lignin phenols and cutin acids
used have been reported [3]. � 13 C values of bulk tissues
from these plants were determined by elemental
analysis/isotope ratio mass spectrometry (EA/IRMS),
GC/C/IRMS.
Table 1 shows � 13 C values of bulk tissue, lignin phenols
and cutin acids in C3, C4 and CAM plants. In all plants,
lignin phenols (Va, Sa, Vc) and cutin acids are depleted in
� 13 C values (3.5 to 15.7‰) relative to bulk tissue. In
addition, the magnitude of 13 C-depletion of lignin phenols
and cutin acids are distinctive depending on plant classes.
For example, C4 plant lignin phenols are less depleted in
Va (9.7‰), Sa (9.4‰) and Vc (4.0‰) relative to bulk
tissue, respectively, while C3 woody plant lignin phenols
are more depleted in Va (9.8‰), Sa (15.7‰) and Vc
(7.2‰). However, � 13 C values of Pc are rarely different
from bulk tissue in all plants. On the other hand, � 13 C
values of cutin acids from all plants are depleted in Cutin
A (up to 9.8‰) and Cutin C (up to 10.3‰) relative to bulk
tissue.
The above results are compatible with observations of
C3, C4 and CAM plants. Different 13 C-depletions among
lignin phenols and cutin acids were observed in all plants,
where the fractionation trends were consistent with
different isotopic fractionations among photosynthesis,
and different growing rates of perennial or yearly plants.
Table 1. Carbon isotopic composition (‰, av. ± s.d.)
of bulk tissue, lignin phenols and cutin acid from C3, C4
and CAM plants.
C3 herbaceous
plant (n=2)
C3 woody plant
(n=5)
C4 plant (n=5) CAM plant (n=3)
� 13 Cbulk -25.6 ± 0.2 -28.9 ± 1.1 -12.2 ± 0.7 -20.2 ± 4.8
Lignin phenols
Va -33.8 ± 0.2 -38.7 ± 1.5 -21.9 ± 3.1 -30.6 ± 2.3
Sa -37.0 ± 1.2 -44.5 ± 1.8 -21.6 ± 1.0 -33.8 ± 0.1
Pc -25.0 ± 0.4 -27.9 ± 1.7 -11.4 ± 0.9 -21.6 ± 3.8
Vc -29.1 ± 0.3 -36.1 ± 0.9 -16.2 ± 1.3 -27.0 ± 2.1
Cutin acids
Cutin A -37.4 ± 0.7 -38.7 ± 1.5 -23.2 ± 0.7 -31.8 ± 3.6
Cutin C -38.8 ± 0.9 -39.2 ± 1.9 -22.8 ± 0.7 -32.1 ± 3.2
Va: 4-hydroxy-3-methoxybenzoic acid, Sa: 4-hydroxy-3,5dimethoxybenzoic
acid, Pc: p-Coumaric acid, Vc: Ferulic
acid, Cutin A: 8,16-/9,16-/10,16-dihydroxy C16 acid, Cutin
C: 9,10,18-trihydroxy C18 acid
References
[1] Chikaraishi, Y. (2007) Res. Org. Geochem. 22, 1-18.
[2] Chikaraishi, Y. and Oba, Y. (2008) Res. Org.
Geochem. 23/24, 99-122
[3] Sonoda, K., et al. (2010) Res. Org. Geochem 26, 115-
122.
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