Lipase-catalyzed transesterification of trilinolein or trilinolenin with selected phenolic acids

Article abstract of DOI:10.1007/s11746-006-1181-3

The enzymatic transesterification of selected phenolic acids with TAG, including trilinolein (TLA) and trilinolenin (TLNA), was investigated in an organic solvent medium. Maximal bioconversion of 66% was obtained with a dihydrocaffeic acid (DHCA) to TLA ratio of 1:2 after 5 d of reaction. Similarly, the highest bioconversion of 62% was obtained with a DHCA to TLNA ratio of 1:2, but after 12 d of reaction. However, a ratio of 1:4 DHCA/TLA decreased the bioconversion to 53%. Transesterification reactions of ferulic acid with both TAG, using a ratio of 1:2, resulted in low bioconversion of 16 and 14% with TLA and TLNA, respectively. The overall results indicated that bioconversion of phenolic MAG was higher than that of phenolic DAG. The structures of mono- and dilinoleyl dihydrocaffeate as well as those of mono- and dilinolenyl dihydrocaffeate were confirmed by LC-MS analyses. The phenolic lipids demonstrated moderate radical-scavenging activity. Copyright

Full text of DOI:10.1007/s11746-006-1181-3

Lipase-Catalyzed Transesterification of Trilinolein
or Trilinolenin with Selected Phenolic Acids
Kebba Sabally, Salwa Karboune, Richard St-Louis, and Selim Kermasha*
Department of Food Science and Agricultural Chemistry, McGill University,
Ste-Anne de Bellevue, Québec, Canada H9X 3V9
ABSTRACT: The enzymatic transesterification of selected phe- for the production of biomolecules of high nutritional and func-
nolic acids with TAG, including trilinolein (TLA) and trilinolenin
(TLNA), was investigated in an organic solvent medium. Maximal
bioconversion of 66% was obtained with a dihydrocaffeic acid
(DHCA) to TLA ratio of 1:2 after 5 d of reaction. Similarly, the
highest bioconversion of 62% was obtained with a DHCA to
TLNA ratio of 1:2, but after 12 d of reaction. However, a ratio of
1:4 DHCA/TLA decreased the bioconversion to 53%. Transesteri-
fication reactions of ferulic acid with both TAG, using a ratio of
1:2, resulted in low bioconversion of 16 and 14% with TLA and
TLNA, respectively. The overall results indicated that bioconver-
sion of phenolic MAG was higher than that of phenolic DAG. The
structures of mono- and dilinoleyl dihydrocaffeate as well as
those of mono- and dilinolenyl dihydrocaffeate were confirmed
by LC-MS analyses. The phenolic lipids demonstrated moderate
radical-scavenging activity.
tional properties. The specific objective of the research was to
investigate the biosynthesis of phenolic lipids through the li-
pase-catalyzed transesterification reaction of selected phenolic
acids, including dihydrocaffeic acid (DHCA) and ferulic acid
(FA), with trilinolein (TLA) and trilinolenin (TLNA). The ef-
fects of reaction time and substrate molar ratio on the transes-
terification reactions were investigated. In addition, the struc-
tural characterization of end products was performed and the
radical-scavenging properties were determined.
MATERIALS AND METHODS
Materials. Immobilized lipase from Candida antarctica
(Novozym 435, CAL-B, with an activity of 10,000 propyl lau-
rate units/g solid enzyme) was obtained from Novozymes
(Bagsværd, Denmark). DHCA, FA, and 2,2-diphenyl-1-picryl-
hydrazyl radical (DPPH•) were purchased from Sigma Chemi-
cal Co. (St. Louis, MO). TLA, TLNA, and their FFA as well as
MAG and DAG were obtained from Nu-Chek-Prep (Elysian,
MN). Organic solvents of analytical and HPLC grades were
purchased from Fisher Scientific (Fair Lawn, NJ).
Paper no. J11214 in JAOCS 83, 101–107 (February 2006).
KEY WORDS: Lipase, organic solvent media, phenolic acids,
transesterification, trilinolein, trilinolenin.
The numerous health benefits of PUFA, such as linoleic (LA:
n-6) and linolenic (LNA: n-3) acids, and their TAG have re-
sulted in a growing interest in their use as functional foods and
nutraceutical supplements. Although LA and LNA are impli-
cated in vital biological processes, such as the prevention of
cardiovascular diseases (1), they are susceptible to rapid oxida-
tion (2), which could result in lowering their quality and nutri-
tional value.
Most phenolic acids are known to be potent antioxidants (3)
and are also reported to provide protective effects as anti-
inflammatory, anticarcinogenic, and antimutagenic compounds
(4,5). Phenolic acids are, however, less effective as antioxidants
in fats and oils as a result of their low solubility in hydrophobic
media (6).
The incorporation of phenolic acids in TAG may result in
novel structured phenolic lipids, with combined potential
health benefits and functional properties. Only a few reports
have appeared in the literature regarding the biosynthesis of
structured TAG containing a phenolic acid moiety (7,8).
The present work is part of on-going research in our labora-
tory (8–10) aimed at the development of a biosynthetic process
Transesterification reactions of phenolic acids with trilin-
olein and trilinolenin. Lipase-catalyzed transesterification re-
actions were carried out in 50-mL Erlenmeyer flasks, using the
method developed previously in our laboratory (10). The trans-
esterification reaction of DHCA with TLA, at a final concen-
tration of 5 mM, was carried out in 9 mL of a homogeneous or-
ganic solvent mixture of hexane and 2-butanone (75:25,
vol/vol). Stock solutions of DHCA and TLA were prepared,
prior to their addition into the reaction flask, in 2-butanone and
hexane, respectively. The enzymatic reaction was initiated by
the addition of 25 mg of the solid enzyme. Control experi-
ments, without enzyme, were carried out in tandem in these tri-
als. The enzymatic mixtures were incubated at 55°C in an or-
bital shaker (New Brunswick Scientific Co., Inc., Edison, NJ),
with continuous shaking (150 rpm). All the assays were run in
duplicate. The enzymatic reaction was halted by termination of
contact with the immobilized lipase by decantation of the
organic solvent off of the immobilized lipase. The effect of dif-
ferent molar ratios of DHCA to TLA (1:1, 1:2, 1:4, and 2:1) on
the transesterification reactions was investigated. In addition,
the transesterification reaction of DHCA and FA with TLA or
TLNA, respectively, was carried out with a substrate molar
ratio of 1:2.
*To whom correspondence should be addressed at Dept. of Food Science
and Agricultural Chemistry, McGill University, 21,111 Lakeshore, Ste-Anne
de Bellevue, Québec, Canada H9X 3V9. E-mail: selim.kermasha@mcgill.ca
Copyright © 2006 by AOCS Press
101
JAOCS, Vol. 83, no. 2 (2006)

102
K. SABALLY ET AL.
Characterization of enzymatic reaction components. The mass spectrometry (APCI-MS). The APCI-MS system (Ther-
transesterification reaction was monitored by HPLC analysis, moFinnigan, San Jose, CA) was equipped with the Zorbax SB-
according to the modified method of Andrikopoulos et al. (11). C18 reversed-phase column (Agilent) as well as a Surveyor liq-
Samples of reaction mixtures were dried at room temperature uid chromatography pump, an autosampler, and an Xcalibur®
under vacuum, using an Automatic Environmental Speed Vac system control software (version 1.3) for data acquisition and
System (Savant Instruments Inc., Holbrook, NY). The dried processing. The mass spectrometer was operated in positive ion
samples were dissolved in 4.5 mL of isopropanol prior to mode with a collision energy source of 15 V. The ion spray and
HPLC analysis. The separation of reaction components was capillary voltage were set at 4.0 kV and 15.6 V, respectively.
performed on a Zorbax SB-C18 reversed-phase column (250 ×
Determination of radical-scavenging activity of phenolic
4.6 mm, 5 µm; Agilent, Wilmington, DE) using a Beckman lipids. The scavenging activity of phenolic lipids on the free
Gold system (Model 126; Beckman Instruments Inc., San radical DPPH• was determined according to a modification of
Ramon, CA) equipped with an autosampler (Model 507), a UV the method of Silva et al. (5). In a 1-mL spectrophotometric
diode-array detector (Model 168), and computerized data han- cuvette, the sample was mixed with 10−4 M ethanolic DPPH•
dling and integration analysis. Elution of the 20-µL injected solution. DPPH• reduction was monitored spectrometrically at
sample was carried out with a gradient system using an aceto- 517 nm against a blank assay without DPPH•, over a 20 min
nitrile/methanol mixture (7:5, vol/vol) as solvent A and iso- incubation period, using a Beckman spectrophotometer (Model
propanol as solvent B; the elution was initiated by a flow of 650; Beckman Instruments, Inc., Fullerton, CA). Control reac-
100% solvent A for 10 min, followed by a 20-min linear gradi- tions, containing only DPPH•, were carried out in tandem with
ent to 100% solvent B, which was maintained for an additional these trials. All assays were carried out in duplicate. The per-
5 min. The flow rate was 1 mL/min, and detection was per- centage of residual DPPH•, at any given time (min), was deter-
formed at 215 and 280 nm. The bioconversion was calculated mined as the absorbance of DPPH• divided by that of the con-
on the basis of the total peak area of phenolic lipids, monitored trol trial multiplied by 100.
at 280 nm, at a defined reaction time divided by the area of phe-
nolic acid of the blank, multiplied by 100. The enzymatic ac-
tivity was calculated from the slope, obtained by polynomial
RESULTS AND DISCUSSION
regression of the initial part of the plot of residual phenolic acid The mixture of hexane/2-butanone (75:25, vol/vol), which was
concentration vs. reaction time. The unit of enzymatic activity determined to be an appropriate organic solvent reaction
was defined as µmol of esterified phenolic acid per g of solid medium for the lipase-catalyzed biosynthesis of phenolic lipids
immobilized lipase per min.
The characterization of reaction components of the lipase- phenolic acids with TLA and TLNA (Scheme 1).
catalyzed transesterification reactions was also performed by Effect of substrate molar ratios on the transesterification re-
(10), was used for the transesterification reactions of selected
HPLC interfaced to atmospheric pressure chemical ionization- action. The effect of different substrate molar ratios on the time
SCHEME 1
JAOCS, Vol. 83, no. 2 (2006)

LIPASE-CATALYZED TRANSESTERIFICATION OF TRILINOLEIN AND TRILINOLENIN
103
FIG. 1. Effect of dihydrocaffeic acid (DHCA) and trilinolein (TLA) ratios of 2:1 (G), 1:1 (G), 1:2
(I), and 1:4 (I) on the bioconversion (A), and on the enzymatic activity (B) of lipase-catalyzed
reaction in a mixture of hexane/2-butanone (75:25, vol/vol).
course of the transesterification reaction of DHCA with TLA is
HPLC and LC-MS characterization of enzymatic reaction
shown in Figure 1. Decreasing the molar ratio of DHCA to components. Figure 2 shows a typical HPLC chromatogram of
TLA from 1:1 to 1:4 resulted in a concomitant increase in en- reaction components of lipase-catalyzed transesterification re-
zymatic activity (Fig. 1B). When using a 1:2 ratio of DHCA to actions of DHCA with TLA and TLNA, monitored at 215 and
TLA, the highest bioconversion of phenolic lipids of 66% (Fig. 280 nm. Figures 2A and 2B demonstrate the analysis of the re-
1A) was obtained after 5 d of reaction, with an enzymatic ac- action components of the transesterification reactions of DHCA
tivity of 0.50 µmol esterified phenolic acid/g solid enzyme/min with TLA. Peak #1, which absorbed at both wavelengths (215
(Fig. 1B). Although the highest enzymatic activity of 0.61 and 280 nm), and peak #7, absorbing only at 215 nm, were
µmol esterified phenolic acid/g solid enzyme/min was obtained characterized as the substrates DHCA and TLA, respectively,
with the DHCA to TLA ratio of 1:4 (Fig. 1B), the bioconver- with reference to standards. Peaks #2 and 5 were characterized
sion of 53% was lower than that (66%) obtained with the ratio as the two main end products of the transesterification reactions
of 1:2 (Fig. 1A). The limited increase in the bioconversion with of DHCA with TLA; they absorbed at both 215 and 280 nm,
a DHCA to TLA ratio of 1:4 may be due to the reaction having with a UV-spectral scanning close to that of DHCA. However,
reached its equilibrium and/or to enzyme denaturation (12). the hydrolytic by-products of TLA were demonstrated as peaks
The results (Fig. 1A) also show that there was a decrease in the #3 and 6 for mono- and dilinolein, respectively. Peak #4, which
bioconversion of phenolic lipids after its maximum just before also absorbed at both wavelengths, could be a side-reaction
the reaction reached equilibrium; this phenomenon may be due product. Figures 2A′ and 2B′ represent the analysis of reaction
to a shift in the thermodynamic reaction toward hydrolysis of components of the transesterification reactions of DHCA with
phenolic lipids as a result of the increase in the concentration TLNA. Similarly, peaks #1′ and 7′ represent the substrates
of the polar hydrolytic products (8).
DHCA and TLNA, respectively; the main phenolic lipid prod-
Figure 1 also shows that the presence of an excess of phe- ucts were characterized as peaks #2′ and 5′. The hydrolytic
nolic acid substrate, at the DHCA to TLA ratio of 2:1, resulted products of TLNA were represented by peaks #3′ and 6′ for
in a much lower enzymatic activity (0.14 µmol esterified phe- mono- and dilinolenin, respectively. Peak #8′ could be a possi-
nolic acid/g solid enzyme/min) and bioconversion (15%). The ble oxidation product of TLNA, since TLNA is a more unsatu-
inhibitory effect of an excess of DHCA could be due to an in- rated lipid and hence is more prone to oxidation than TLA.
crease in its concentration in the enzyme microenvironment,
Further analysis of potential end products of the lipase-cat-
which may result in high interaction between the substrate and alyzed transesterification reactions of DHCA with TLA and
the enzyme. Yesiloglu (13) reported that a high ethanol con- TLNA was performed by APCI-MS (Fig. 3).The fragmenta-
centration in the ethanolysis of sunflower oil resulted in low li- tion pattern of peak #2 (Fig. 2A) showed abundant fragmented
pase activity and yield.
ions with m/z of 337 and 501 as well as a molecular ion of m/z
JAOCS, Vol. 83, no. 2 (2006)

104
K. SABALLY ET AL.
FIG. 2. HPLC chromatograms of the samples of the enzymatic transesterification reactions of
DHCA with TLA (A and B) and trilinolenin (TLNA) (A′ and B′) monitored at 280 and 215 nm.
Peak numbers were identified as follows: dihydrocaffeic acid, #1 and 1′; TLA, #7; TLNA, #7’;
phenolic MAG, #2 and 2’; phenolic DAG, #5 and 5’; MAG, #3 and 3’; DAG, #6 and 6’; side
reaction product, #4; and TLNA oxidation product, #8′.
518 corresponding to monolinoleyl dihydrocaffeate with a rate of hydrolysis reaching 75 and 90% after 6 and 8 d, respec-
M.W. of 518 g/mol (Fig. 3A). Fragmentation of peak #2′ (Fig. tively. In parallel, the biosynthesis of total dihydrocaffeoylated
2A′) resulted in ion fragments of m/z 335 and 500 with a mo- linoleyl lipids increased steadily, reaching a maximal biocon-
lecular ion of m/z 517, characteristic of monolinolenyl dihy- version of 66% after 5 d of reaction before its decrease to 38%
drocaffeate with a M.W. of 517 g/mol (Fig. 3A′). Similarly, after 8 d. The decrease in bioconversion of dihydrocaffeoylated
APCI-MS analysis of peak #5 (Fig. 2A) produced ions of m/z linoleyl lipids, with a concomitant maximal hydrolysis of TLA,
379 and 660, which correspond to the structural pattern charac- could confirm the shift of the equilibrium reaction toward hy-
teristic of dilinoleyl dihydrocaffeate with a M.W. of 782 g/mol drolysis rather than biosynthesis. The results (Fig. 4A) also in-
(Fig. 3B). The ions with m/z 596 and 500 as well as the molec- dicate that the bioconversion of mono- and dilinoleyl dihydro-
ular ion with m/z 782 (Fig. 3B′), obtained from ion fragmenta- caffeate showed similar trends over the time course of the re-
tion of peak #5′ (Fig. 2A′), indicate the formation of dilinolenyl action; however, the extent of bioconversion was higher for
dihydrocaffeate with a M.W. of 781 g/mol.
monolinoleyl dihydrocaffeate than for dilinoleyl dihydrocaf-
Effect of substrate type on the transesterification reaction. feate, with a maximum value of 48 and 22%, respectively, after
Figure 4 shows the progress curves of the hydrolysis products 5 d of reaction.
as well as those of phenolic lipids over a 13-d period of lipase-
Figure 4B shows a rapid initial hydrolysis of TLNA (55%)
catalyzed transesterification reactions of DHCA with TLA or within the first 2 d, followed by a steady increase to reach 70%
TLNA, using a molar ratio of 1:2. The results (Fig. 4A) show after 4 d of reaction; this maximum hydrolysis degree of TLNA
that the hydrolysis of TLA (50%) was rapidly achieved within was lower than that of TLA (90%). The results also indicate a
the first 2 d of the reaction, which was followed by a slower rapid production of dihydrocaffeoylated linolenyl lipids (35%)
JAOCS, Vol. 83, no. 2 (2006)

LIPASE-CATALYZED TRANSESTERIFICATION OF TRILINOLEIN AND TRILINOLENIN
105
FIG. 3. Atmospheric pressure chemical ionization MS analysis of monolinoleyl dihydrocaf-
feate (A), dilinoleyl dihydrocaffeate (B), monolinolenyl dihydrocaffeate (A’), and dilinolenyl di-
hydrocaffeate (B′).
FIG. 4. Progress curves of the biosynthesis of phenolic MAG (I), phenolic DAG (I), and total
phenolic lipids (L) as well as the hydrolysis of TAG (L) during the lipase-catalyzed transester-
ification of dihydrocaffeic acid with TLA (A) and TLNA (B).
JAOCS, Vol. 83, no. 2 (2006)

106
K. SABALLY ET AL.
TABLE 1
Effects of Nature of Phenolic Acids and TAG on the Enzyme Activity and Bioconversion of Lipase-Catalyzed
Transesterification in Hexane/2-Butanone Mixture (75:25, vol/vol)
Trilinolein
Trilinolenin
Phenolic acid
Enzyme activitya
Bioconversionb
Enzyme activitya
Bioconversionb
Dihydrocaffeic acid
Ferulic acid
0.50
0.04
66.0 (2.7)c
0.52
0.03
62.0 (1.9)c
15.6 (3.7)c
14.0 (5.8)c
aEnzymatic activity was defined as µmol esterified phenolic acid/g solid enzyme/min reaction time.
bBioconversion (%) was calculated on the basis of the total peak area of phenolic lipids, monitored at 280 nm, divided by
the area of phenolic acid of the blank, multiplied by 100.
cRelative SD was calculated from the SD of duplicate samples divided by their mean, multiplied by 100.
during the first day of reaction, followed by a steady increase
in the yield reaching its maximum of 62% after 12 d. The
biosynthesis of dihydrocaffeoylated linolenyl lipids did not
show, over the time course of reaction, the same pattern as that
of dihydrocaffeoylated linoleyl lipids (Fig. 4A); these findings
may be explained by the limited increase in the hydrolysis
products of TLNA after 4 d of reaction, which could favor the
reverse biosynthesis reaction. In addition, the results (Fig. 4B)
show that the bioconversion of monolinolenyl dihydrocaffeate
(46%) was higher than that of dilinolenyl dihydrocaffeate
(16%). The overall results (Fig. 4, Table 1) show that the enzy-
matic activity (0.50–0.52 mmol esterified phenolic acid/g solid
enzyme/min) and the maximum bioconversion of phenolic
lipids (62–66%) were similar for both transesterification reac-
tions of DHCA with TLA and TLNA.
In using the same reaction conditions, the enzymatic activ-
ity and bioconversion for the transesterification reactions of FA
with TLA and TLNA were lower than those obtained with
FIG. 5. Time course for diphenylpicrylhydrazyl radical (DPPH•) scav-
DHCA (Table 1). The highest total bioconversion of feruloyl- enging by dihydrocaffeic acid (G) and α-tocopherol (G) as well as dihy-
drocaffeoylated linoleyl (I) and linolenyl (I) lipids, using DPPH• (L)
as a control trial.
ated linoleyl and linolenyl lipids was only 16 and 14%, respec-
tively. The affinity of Novozym 435 is therefore greater for
DHCA than for FA. The presence of both the methoxyl sub-
linolenyl alcohols affected its radical-scavenging activity; how-
ever, the radical-scavenging activity of linoleyl and linolenyl
dihydrocaffeate was higher than that of dihydrocaffeoylated
lipids, indicating that the size and nature of the attached lipid
has a significant effect on the antioxidant efficacy of phenolic
lipids. The fatty alcohols, being less bulky than TAG, could
have conferred less constraint on changes or rotation around
the single bond on the side chain of DHCA.
stituent and the double bond on the side chain of the aromatic
ring of FA could explain why its affinity is lowest for the trans-
esterification reactions with TAG (7,14,15).
Free radical-scavenging activity of DHCA and its acylglyc-
erol esters. The ability of dihydrocaffeoylated lipids to scav-
enge the stable free radical DPPH• was investigated (Fig.
5).The steady state of the radical scavenging reaction was
reached within 20 min. The radical-scavenging activity was 84,
42, 16, and 16% for DHCA, for α-tocopherol, and for the dihy-
drocaffeoylated linoleyl and linolenyl lipids, respectively.
These findings indicate that the structured phenolic lipids,
formed by the transesterification reactions of DHCA with se-
lected TAG, have certain antioxidant potency. The decrease in
the antiradical effect of DHCA following the esterification of
its carboxyl group could be due to its conformational changes
(5). DHCA has a single bond on its side chain, which allows
its rotation around this bond; however, this rotation may have
been restricted to a certain degree by the attachment of a lipid
moiety on the carbonyl group of the DHCA. Similarly, Sabally
et al. (10,16) reported that the structural modification of the
carboxyl group of DHCA by esterification with linoleyl or
ACKNOWLEDGMENTS
This research work was supported by the Ministère de l’Agriculture,
des Pêcheries et de l’Alimentation du Québec (CORPAQ). The
Canadian Commonwealth Scholarship Program awarded the Ph.D.
graduate student fellowship.
REFERENECES
1. Kris-Etherton, P.M., W.S. Harris, and L.J. Appel, Fish Con-
sumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular
Disease, Circulation 106:2747–2757 (2002).
2. Ito, N., M. Hirose, S. Fukushima, H. Tsuda, H.T. Shirai, and M.
JAOCS, Vol. 83, no. 2 (2006)

LIPASE-CATALYZED TRANSESTERIFICATION OF TRILINOLEIN AND TRILINOLENIN
107
Tatematsu, Studies on Antioxidants: Their Carcinogenic and
Modifying Effects on Chemical Carcinogenesis, Food Chem.
Toxicol. 24:1071–1082 (1986).
pase-Catalyzed Esterification of Cinnamic Acid and Oleyl Al-
cohol in Organic Solvent Media, J. Chem. Technol. Biotechnol.
80:462–468 (2005).
3. Castelluccio, C., G.P. Bolwell, C. Gerrish, and C. Rice-Evans, 10. Sabally, K., S. Karboune, F.K. Yebaoh, and S. Kermasha, En-
Differential Distribution of Ferulic Acid to the Major Plasma
Constituents in Relation to Its Potential as an Antioxidant,
Biochem. J. 316:691–694 (1996).
zymatic Esterification of Dihydrocaffeic Acid with Linoleyl Al-
cohol in Organic Solvent Media, Biocatal. Biotransform.
23:37–44 (2005).
4. Ho, C.-T., Phenolic Compounds in Food. An Overview, in Phe- 11. Andrikopoulos, N.K., H. Brueschweiler, H. Felber, and C.
nolic Compounds in Food and Their Effects on Health I. Analy-
Taeschler, HPLC Analysis of Phenolic Antioxidants, Tocopher-
sis Occurrence & Chemistry, edited by C.-T. Ho, C.Y. Lee, and
ols and Triglycerides, J. Am. Oil Chem. Soc. 68:359–364 (1991).
M.-T. Huang. ACS Symposium Series 506, American Chemical 12. Hadzir, N.M., M. Basri, M.B.A. Rahman, C.N.A. Razak,
Society, Washington, DC, 1992, pp. 2–7.
5. Silva, F.A.M., F. Borges, C. Guimarã, J.L.F.C. Lima, C. Matus,
and S. Reis, Phenolic Antioxidants and Derivatives: Studies on
R.N.Z.A. Rahman, and A.B. Salleh, Enzymatic Alcoholysis of
Triolein to Produce Wax Ester, J. Chem. Technol. Biotechnol.
76:511–515 (2001).
the Relationship Among Structure, Radical Scavenging Activity 13. Yesiloglu, Y., Immobilized Lipase-Catalyzed Ethanolysis of
and Physicochemical Parameters, J. Agric. Food Chem.
48:2122–2126 (2000).
6. Stamatis, H., V. Sereti, and F.N. Kolisis, Enzymatic Synthesis
of Hydrophilic and Hydrophobic Derivatives of Natural Pheno-
lic Acids in Organic Media, J. Mol. Catal. B: Enzym.
11:323–328 (2001).
7. Compton, D.L., J.A. Laszlo, and M.A. Berhow, Lipase-Cat-
alyzed Synthesis of Ferulate Esters, J. Am. Oil Chem. Soc.
77:513–519 (2000).
8. Karboune, S., M. Safari, B.-M. Lue, F.K. Yebaoh, and S. Ker-
masha, Lipase-Catalyzed Biosynthesis of Cinnamoylated Lipids
in a Selected Organic Solvent Medium, J. Biotechnol.
119:281–290 (2005).
Sunflower Oil, J. Am. Oil Chem. Soc. 81:157–160 (2004).
14. Guyot, B., B. Bosquette, M. Pina, and J. Graille, Esterification
of Phenolic Acids from Green Coffee with an Immobilized Li-
pase from Candida antarctica in Solvent-Free Medium,
Biotechnol. Lett. 19:529–532 (1997).
15. Stamatis, H., V. Sereti, and F.N. Kolisis, Studies on the Enzy-
matic Synthesis of Lipophilic Derivatives of Natural Antioxi-
dants, J. Am. Oil Chem. Soc. 76:1505–1510 (1999).
16. Sabally, K., S. Karboune, F.K. Yebaoh, and S. Kermasha, Li-
pase-Catalyzed Esterification of Linolenyl Alcohol with Se-
lected Phenolic Acids in Organic Solvent Media, Appl. Biochem.
Biotechnol. 127:17–28 (2005).
9. Lue, B.-M., S. Karboune, F.K. Yebaoh, and S. Kermasha, Li-
[Received August 17, 2005; accepted November 17, 2005]
JAOCS, Vol. 83, no. 2 (2006)