Synthesis and activity on free radical processes and inflammation of 9,10-dihydro-5,8-dimethoxy-triptycene-quinones

Article abstract of DOI:10.1016/S0223-5234(03)00078-3

Three triptycene quinones bearing methoxy groups were prepared following a Diels-Alder methodology and were evaluated for antioxidant and anti-inflammatory activity bearing in mind their structural features that could justify intervention with free radical processes. Improved synthetic pathways were achieved for target molecules 9,10-dihydro-5,8-dimethoxy-9,10-[o]benzenoanthracene-1,4-dione (4), 9,10-dihydro-2-hydroxy-5,8-dimethoxy-9,10-[o]benzenoanthracene-1,4-dione (6), and 9,10-dihydro-2,5,8-trimethoxy-9,10-[o]benzenoanthracene-1,4-dione (9). Under our experimental conditions these compounds showed very significant antioxidant activity offering protection against lipid peroxidation of rat hepatic microsomal fraction while inhibiting the reaction completely at very low concentrations (12.5-80 μM). Moreover, compound 6 that was examined, inhibited by 44% (at 120 μM) lipoxygenase acitvity while the anti-inflammatory activity of the compounds, as assessed by the reduction of the mouse paw edema induced by Freund's complete adjuvant, was significant and comparable to that of indomethacin.

Full text of DOI:10.1016/S0223-5234(03)00078-3

European Journal of Medicinal Chemistry 38 (2003) 621Á626
/
www.elsevier.com/locate/ejmech
Short communication
Synthesis and activity on free radical processes and inflammation of
9,10-dihydro-5,8-dimethoxy-triptycene-quinones
Nikoletta J. Xanthopoulou a, Angeliki P. Kourounakis b,*, Spyros Spyroudis a,
Panos N. Kourounakis b
a Chemistry Department, Laboratory of Organic Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
b Department of Pharmaceutical Chemistry, School of Pharmacy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Received 13 December 2002; received in revised form 6 March 2003; accepted 6 March 2003
Abstract
Three triptycene quinones bearing methoxy groups were prepared following a DielsÁAlder methodology and were evaluated for
/
antioxidant and anti-inflammatory activity bearing in mind their structural features that could justify intervention with free radical
processes. Improved synthetic pathways were achieved for target molecules 9,10-dihydro-5,8-dimethoxy-9,10-[o]benzenoanthra-
cene-1,4-dione (4), 9,10-dihydro-2-hydroxy-5,8-dimethoxy-9,10-[o]benzenoanthracene-1,4-dione (6), and 9,10-dihydro-2,5,8-tri-
methoxy-9,10-[o]benzenoanthracene-1,4-dione (9). Under our experimental conditions these compounds showed very significant
antioxidant activity offering protection against lipid peroxidation of rat hepatic microsomal fraction while inhibiting the reaction
completely at very low concentrations (12.5Á80 mM). Moreover, compound 6 that was examined, inhibited by 44% (at 120 mM)
/
lipoxygenase acitvity while the anti-inflammatory activity of the compounds, as assessed by the reduction of the mouse paw edema
induced by Freund’s complete adjuvant, was significant and comparable to that of indomethacin.
´
# 2003 Editions scientifiques et me´dicales Elsevier SAS. All rights reserved.
Keywords: Antioxidant; Anti-inflammatory; Triptycene; Quinone
1. Introduction
investigate structureÁactivity relationships. Our goal
/
was to improve the synthetic procedures and yields,
and explore their antioxidant and anti-inflammatory
properties knowing the relationship between these two
activities in many compounds.
Triptycene quinones combining the rigid structure of
triptycene with the redox properties of the quinone ring,
find many applications in organic chemistry [1]. Some
triptycene quinone derivatives bearing methoxy groups
exhibit potent anticancer and antimalarial activities
[2,3]. Since their structure may justify a possible inter-
vention in free radical processes, we attempted to
explore better the chemistry and other biological activ-
ities of such derivatives. Three target molecules, namely
9,10-dihydro-5,8-dimethoxy-9,10-[o]benzenoanthra-
2. Chemistry
The starting material, 1,4-dimethoxyanthracene (1)
was prepared from commercially available quinizarin
cene-1,4-dione
(4),
9,10-dihydro-2-hydroxy-5,8-di-
[4].
thracene-1,4-dione (4) was prepared by modification of
a method from literature [5]. DielsÁAlder reaction of
1,4-dimethoxyanthracene with p-benzoquinone af-
forded the dihydro DielsÁAlder adduct 2 (68% yield).
9,10-Dihydro-5,8-dimethoxy-9,10-[o]benzenoan-
methoxy-9,10-[o]benzenoanthracene-1,4-dione (6), and
9,10-dihydro-2,5,8-trimethoxy-9,10-[o]benzenoanthra-
cene-1,4-dione (9) (Fig. 1) were synthesized in order to
/
/
The latter was almost quantitatively acid-isomerized to
the corresponding hydroquinone 3, which was effec-
tively oxidized to quinone 4, under mild conditions with
(diacetoxyiodo)benzene, PhI(OAc)2 (Fig. 2).
* Corresponding author: Present address. Department of Medicinal
Chemistry, School of Pharmacy, Aristotle University of Thessaloniki,
54006 Thessaloniki, Greece.
E-mail address: angeliki@pharm.auth.gr (A.P. Kourounakis).
´
0223-5234/03/$ - see front matter # 2003 Editions scientifiques et me´dicales Elsevier SAS. All rights reserved.
doi:10.1016/S0223-5234(03)00078-3

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Fig. 1. Structures of the quinones tested for antioxidant and anti-inflammatory properties (compounds 4, 6, 9).
Quinone 4 was one of the three target quinones tested
converted to 9,10-dihydro-1,2,4-tris-acetoxy-5,8-di-
methoxy-9,10-[o]benzenoanthracene (5) through a typi-
for their antioxidant and anti-inflammatory properties,
but also served as a starting material for the preparation
of 9,10-dihydro-2-hydroxy-5,8-dimethoxy-9,10-[o]ben-
zenoanthracene-1,4-dione (6), considering our interest
in hydroxyquinones in general [1,6] and triptycene
hydroxyquinones more specifically [1]. Quinone 4 was
cal ThieleÁWinter acetoxylation reaction and the latter
/
was hydrolyzed and oxidized in one step under alkaline
conditions to the desired hydroxyquinone 6 in very good
overall yield.
9,10-Dihydro-2,5,8-trimethoxy-9,10-[o]benzenoan-
thracene-1,4-dione (9) was prepared in very good yield
directly from the reaction of 1,4-dimethoxyanthracene
(1) and 2-methoxy-p-benzoquinone (8), combining three
steps (DielsÁAlder reaction, isomerization and oxida-
/
tion of the intermediate hydroquinone) in one. This
methodology is shorter and more effective compared to
alternative procedures published lately [3]. Quinone 8
was prepared by oxidation of the corresponding hydro-
quinone 7 under mild conditions, using PhI(OAc)2 as
the oxidant of choice (Fig. 2).
3. Pharmacology
Target compounds (4, 6 and 9) were evaluated for
their antioxidant and anti-inflammatory activity using
standard and known protocols [7Á10]. All examined
/
compounds offered very significant protection against in
vitro lipid peroxidation, while for in vivo anti-inflam-
matory activity the effect of the examined compounds
was evaluated on the mouse paw edema assay using
FCA (Freund’s complete adjuvant) as a flogistic agent.
We further investigated the effect of one of the
compounds 6 on lipoxygenase activity.
4. Results
All examined compounds (4, 6 and 9) (Fig. 1) offered
very significant protection against lipid peroxidation of
rat hepatic microsomal fraction: they inhibited the
reaction completely (100%) at a concentration ranging
from 12.5 to 80 mM. The time course of lipid peroxida-
tion as affected by various concentrations of the test
compounds is shown in Fig. 3. From these results IC50
values, after 45 min of incubation, were 9, 54 and 11 mM
Fig. 2. Synthetic scheme for the preparation of 9,10-dihydro-5,8-
dimethoxy-9,10-[o]benzenoanthracene-1,4-dione (compound 4), 9,10-
dihydro-5,8-dimethoxy-2-hydroxy-9,10-[o]benzenoanthracene-1,4-
dione (compound 6) and 9,10-dihydro-2,5,8-trimethoxy-9,10-[o]benze-
noanthracene-1,4-dione (compound 9).
for 4, 6 and 9, respectively.
D-a-Tocopherol acetate,
used as a reference compound, was found to inhibit lipid
peroxidation by 100 and 10% at 1 and 0.5 mM,

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623
Fig. 3. Time course of lipid peroxidation as affected by various
concentrations of compounds 4, 6 and 9. Activity of the compounds is
expressed as the concentration of compounds that inhibited lipid
peroxidation by 50% after 45 min of incubation (IC50 values). Results
are expressed as a mean (9SEM) of two independent experiments.
/
respectively, under the same experimental conditions. In
the anti-inflammatory assay the examined compounds
demonstrated significant reduction of the paw edema
produced by FCA. Compound 4, at a concentration of
0.15 and 0.3 mmol kgꢀ1, presented a 50 and 65%
inhibition of paw edema, respectively. Compound 9 at
0.15 and 0.3 mmol kgꢀ1, inhibited paw edema by 63 and
75%, while compound 6 at the same concentrations
inhibited paw edema by 40 and 60%, respectively (Fig.
4). Under the same experimental conditions, indometha-
cin (110 mmol kgꢀ1) exhibited a 67% paw edema
inhibition. The effect of compound 6 on lipoxygenase
activity at 120 and 60 mM is shown in Fig. 5. It
demonstrated a 44 and 23% inhibition of this enzyme,
respectively. The other two compounds could not be
evaluated in this assay since they showed insufficient
solubility in 60% ethanol in water (see methods).
Fig. 4. Effect of 4, 6 and 9 on the hind paw edema induced by FCA in
Balb/C mice. Values are means (9SEM) of two independent experi-
ments (nꢁ6).
/
/
Fig. 5. Effect of 6 on lipoxygenase activity. Values are the mean (9
/
SEM) of two independent experiments.

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5. Discussion
Further, it offers a possible mechanism of action for the
in vivo anti-inflammatory activity of the compounds.
In conclusion, improved synthetic pathways were
achieved for compounds 4, 6 and 9. In addition, under
our experimental conditions these compounds showed
very significant antioxidant and anti-inflammatory ac-
tivity confirming also a relationship between these two
activities.
Regarding the synthesis of the tested quinones 4, 6, 9,
the described methods of preparation offer an easy route
to this type of compounds, namely triptycene quinones
with methoxy groups.
We examined the protection offered by the three
triptyceneÁ
tion using a standard technique [8Á
compounds in low concentrations (6Á
very efficiently hepatic microsomal membranes from
peroxidation. The most active were 4 (IC50ꢁ9 mM) and
9 (IC50ꢁ11 mM) followed by 6 (IC50ꢁ54 mM). This
/
quinone derivatives against lipid peroxida-
10]. The examined
40 mM) protected
/
/
6. Experimental
/
/
/
6.1. Materials
protective action could be mainly attributed to the
quinonoid structure common to all tested compounds
and could be explained by the abstraction of hydrogen
atoms by reaction with ROS [7,11]. Furthermore, the
triple allylic hydrogen of these compounds may antag-
onise those of polyunsaturated fatty acids for ROS.
Since lipophilicity has usually a positive influence on
antioxidant activity [12,13] we calculated the lipophili-
city of the three derivatives to find that compound 4 has
a slightly higher lipophilicity (clog P 3.282 compared to
clog P 3.035 for compound 6 and to clog P 3.044 for
compound 9). Nevertheless, no correlation between
lipophilicity and antioxidant activity could be deduced
since compounds 4 and 9 were more or less equipotent.
We also examined the effect of the test compounds on
inflammation in an attempt to evaluate their anti-
inflammatory actions in conjunction with their antiox-
idant activity. It is well known that in inflammation
oxidative stress plays an important role, both humorally
and cellularly, via the action of COX enzymes, lipox-
ygenase and leukocytes. The anti-inflammatory activity
of the compounds was assessed as reduction of the
mouse paw edema induced by the FCA, a phlogistic
producing an experimental arthritis model quite similar
to human rheumatoid arthritis [14]. All examined
compounds were quite active anti-inflammatory agents.
This also suggests the participation of oxidative pro-
cesses in inflammation as well as the importance of
antioxidant therapy for these conditions.
2-Thiobarbituric acid was purchased from Sigma
Chemical Co. (St. Louis, MO, USA). All other chemi-
cals were of the highest commercially available purity.
6.2. Chemistry
Melting points were determined on a Stuart Scientific
Melting Point Apparatus SMP3 (230 V) and are
uncorrected. 1H-NMR spectra were recorded with a
Bruker AM 300 (300 and 75 MHz for 1H and 13C,
respectively) in ca. 5% solution of CDCl3 using Me4Si as
the internal standard. Mass spectra were recorded with a
spectrometer VG-250 in 70 eV, ESI. Elemental analyses
were carried out in a PerkinÁElmer 2400-II elemental
/
analyst. Chromatography columns were filled with silica
gel No. 60 of Merck A.G. Industry.
6.2.1. 1,4-Dimethoxyanthracene (1)
1,4-Dimethoxyanthracene was prepared from quini-
zarin, in three steps (methylation and two subsequent
reductions with NaBH4) following a procedure from
literature [4].
6.2.2. 5,8-Dimethoxy-4a,9,9a,10-tetrahydro-9,10-
[o]benzenoanthracene-1,4-dione (2)
To a solution of 1,4-dimethoxy-anthracene (1.95 g,
9.5 mmol) in CH3CN (40 mL) 1,4-benzoquinone was
added (4.2 g, 38.8 mmol) and the mixture was refluxed
It is known that the 5-lipoxygenase pathway is the
source of a potent group of inflammatory mediators, the
leukotrienes, implicated in neutrophil activation, which
is associated with the induction of inflammation. Several
nonsteroidal anti-inflammatory drugs are moderate
lipoxygenase inhibitors, most of them having the ability
to participate in redox processes. The synthesised
compounds intervene in such reactions, since they
inhibit lipid peroxidation, thus, their effect on lipox-
ygenase activity is of interest for investigation. Com-
pound 6 that was examined offered significant inhibition
of this enzyme at a concentration of 120 mM which also
confirms the above mentioned relation between lipox-
ygenase inhibition and inhibition of lipid peroxidation.
for 10 h. After cooling, the yellowÁgreen precipitate
/
formed was filtered and dried in a desiccator for 24 h to
1
afford 2 (2.23 g, 68%) m.p. 220 8C (dec.). H-NMR: d
2.17 (s, 2H), 3.80 (s, 6H), 6.54 (s, 2H), 6.58 (s, 2H),
7.00Á
/
7.11 (m, 2H), 7.42Á/7.51 (m, 2H). MS (70 eV); m/z
(%): 347 (100) [Mꢂ
/
1], 239 (77), 224 (70), 208 (31), 180
(48), 152 (68). C22H18O4 (346.38) Anal. Calc.: C, 76.28;
H, 5.24; Found: C, 76.01; H, 5.50%.
6.2.3. 9,10-Dihydro-1,4-dihydroxy-5,8-dimethoxy-9,10-
[o]benzenoanthracene (3)
A suspension of 5,8-dimethoxy-4a,9,9a,10-tetrahydro-
9,10-[o]benzenoanthracene-1,4-dione (2) (0.75 g, 2.16
mmol) in CH3COOH (50 mL) was refluxed until the

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/626
625
solid was completely dissolved (20Á
/
30 min). Twenty
v) (0.8 mL, 0.256 g, 6.4 mmol) was added with stirring at
r.t. The yellow solution turned to green and then purple.
Stirring was continued for 30 min and then the solution
was acidified with hydrochloric acid (20% v/v) (pH 2)
(color changed to orange). The solution was poured
onto water (20 mL) and the orange precipitate formed
was filtered, washed with water, and dried in a vacuum
desiccator for 24 h to afford 0.13 g of orange crystals
drops of hydrobromic acid (48% solution) were added
and the resulting mixture was poured into water (10
mL). The white precipitate formed was filtered and dried
in a desiccator for 24 h to yield 3 (0.74 g, 98%): m.p. ꢀ
200 8C (dec.). 1H-NMR: (CDCl3ꢂ
DMSO-d6) d 3.80 (s,
6H), 6.27 (s, 2H), 6.34 (s, 2H), 6.55 (s, 2H), 6.96Á7.01
(m, 2H), 7.35Á7.42 (m, 2H). MS (70 eV); m/z (%): 348
(100) [Mꢂ2], 330 (36), 316 (94), 298 (34), 284. C22H18O4
/
/
/
/
/
(yield 92%), m.p.: 174Á
3.79 (s, 3H), 5.90 (s, 1H), 6.20 (s, 1H), 6.23 (s, 1H), 6.54
(s, 2H), 7.01Á7.19 (m, 2H), 7.30Á
7.50 (m, 2H). 13C-
/
178 8C. 1H-NMR: d 3.78 (s, 3H),
(346.38) Anal. Calc.: C, 76.28; H, 5.24; Found: C, 76.68;
H, 4.99%.
/
/
NMR: d 41.54, 41.80, 56.32, 56.39, 106.05, 109.51,
124.36, 124.78, 125.42, 126.88, 130.21, 144.02, 183.01
6.2.4. 9,10-Dihydro-5,8-dimethoxy-9,10-
[o]benzenoanthracene-1,4-dione (4)
(CÄ
/
O), 183.98 (CÄ
/
O). MS (70 eV); m/z (%): 361 (100)
To a solution of 9,10-dihydro-1,4-dihydroxy-5,8-di-
methoxy-9,10-[o]benzenoanthracene (3) (0.243 g, 0.70
mmol) in CH2Cl2 (8 mL) a solution of (diacetoxyio-
do)benzene (0.237 g, 0.73 mmol) in CH2Cl2 (8 mL) was
added with stirring at room temperature (r.t.). Stirring
was continued for 1 h. The solution was concentrated to
dryness and purified by column chromatography (silica
[Mꢂ
/
1], 291 (35), 263 (57), 239 (34), 224. C22H16O5
(360.37) Anal. Calc.: C, 73.32; H, 4.47; Found: C, 73.65;
H, 4.23%.
6.2.7. 2-Methoxy-p-benzoquinone (8)
To a solution of commercially available 1,4-dihy-
droxy-2-methoxy-benzene (7) (2.5 g, 17.8 mmol) in
CH3OH (45 mL) a solution of (diacetoxyiodo)benzene
(5.9 g, 18.3 mmol) in CH3OH (45 mL) was added with
stirring at r.t. Stirring continued for 1 h. The solution
was concentrated to dryness and purified by column
chromatography (silica gel) using a mixture of petro-
gel) using a mixture of petroleum etherÁ
(5:1) as eluant to afford 0.21 g of 4 (yield 88%), m.p.:
271Á
272 8C. 1H-NMR: d 3.81 (s, 6H), 6.24 (s, 2H), 6.55
(s, 2H), 6.59 (s, 2H), 7.00Á7.05 (m, 2H), 7.42Á7.50 (m,
2H). 13C-NMR: d 41.25, 56.27, 109.34, 124.47, 125.23,
/
ethyl acetate
/
/
/
133.41, 135.23, 144.09, 149.48, 152.74, 183.50 (CÄ
/
O).
leum etherÁ
of 8 (yield 87%), m.p.: 145Á
2H), 5.95 (s, 1H), 3.84 (s, 3H). 13C-NMR: d 56.2, 107.5,
111.6, 134.2, 137.1, 181.6 (CÄO), 187.4 (CÄO).
/
ethyl acetate (2:1) as eluant to afford 2.14 g
MS (70 eV); m/z (%): 344 (100) [Mꢂ], 330 (40), 286 (25),
176. C22H16O4 (344.37) Anal. Calc.: C, 76.73; H, 4.68;
Found: C, 76.41; H, 4.67%.
/
146 8C. 1H-NMR: d 6.72 (s,
/
/
6.2.5. 9,10-Dihydro-5,8-dimethoxy-1,2,4-tris-acetoxy-
9,10-[o]benzenoanthracene (5)
6.2.8. 9,10-Dihydro-2,5,8-trimethoxy-9,10-
[o]benzenoanthracene-1,4-dione (9)
To
a
solution 9,10-dihydro-5,8-dimethoxy-9,10-
A mixture of 2-methoxy-p-benzoquinone (8) (0.77 g,
5.6 mmol) and 1,4-dimethoxyanthracene (1) (0.5 g, 2.10
mmol) in glacial acetic acid (15 mL) was refluxed for 4 h.
After cooling, the solution was poured onto water (15
mL) and the solid was filtered, washed with a small
amount of water and purified by column chromatogra-
[o]benzenoanthracene-1,4-dione (4) (0.66 g, 1.91 mmol)
in acetic anhydride (33 mL), a catalytic amount of
sulphuric acid was added (0.63 g, 0.33 mL, 6.34 mmol)
with stirring at r.t. for 1 h. The mixture was poured into
ice water (100 mL) and stirring was continued for
another half an hour until the product was crystallized.
The solid was filtered, washed with water, and dried in a
vacuum desiccator overnight to give 0.91 g of 4 (yield
1
98%), m.p.: 117Á
(s, 3H), 2.43 (s, 3H), 3.76 (s, 3H), 3.77 (s, 3H), 5.87 (s,
1H), 5.89 (s, 1H), 6.49 (s, 2H), 6.71 (s, 1H), 6.99Á7.02
(m, 2H), 7.30Á7.40 (m, 2H). MS (70 eV); m/z (%): 490
(7) [Mꢂ2], 432 (10), 348 (20), 316 (8), 244 (10), 205 (12),
phy (silica gel) using a mixture of petroleum etherÁ
/ethyl
acetate (2:1) as eluant to afford 0.69 g of product 9 (yield
1
88%), m.p.: 108Á
(s, 6H), 5.72 (s, 1H), 6.23 (s, 1H), 6.25 (s, 1H), 6.53 (s,
2H), 6.97Á7.01 (dd, 2H, Jꢁ5.5, 3 Hz), 7.40Á7.45 (dd,
2H, Jꢁ
5.5, 3 Hz). 13C-NMR: d 42.34, 42.32, 53.42,
/
110 8C. H-NMR: d 3.74 (s, 3H), 3.79
/
120 8C. H-NMR: d 2.27 (s, 3H), 2.41
/
/
/
/
/
/
55.28, 55.37, 104.43, 106.59, 108.20, 124.02, 124. 2,
126.14, 126.23, 133.3, 133.5, 144.0, 144.2, 149.6, 149.7,
/
180 (25), 150 (20), 135 (22), 122 (46), 111 (66), 91 (80), 81
(100). C28H24O8 (488.49) Anal. Calc.: C, 68.85; H, 4.95;
Found: C, 68.62; H, 4.74%.
150.8, 153.64, 158.28, 178.23 (CÄ
/
O), 183.41 (CÄ
/
O). MS
(70 eV); m/z (%): 374 (100) [Mꢂ], 360 (30), 344 (30), 316
(21). C23H18O5 (374.40) Anal. Calc.: C, 73.78; H, 4.84;
Found: C, 73.57; H, 4.99%.
6.2.6. 9,10-Dihydro-2-hydroxy-5,8-dimethoxy-9,10-
[o]benzenoanthracene-1,4-dione (6)
6.3. In-vitro lipid peroxidation
To a solution of 9,10-dihydro-5,8-dimethoxy-1,2,4-
tris-acetoxy-9,10-[o]benzenoanthracene (5) (0.19 g, 0.39
mmol) in methanol (8 mL), a solution of NaOH (32% w/
Hepatic microsomal fraction from untreated female
Fischer-344 rats (180Á220 g), was prepared as described
/

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/
[8]. The incubation mixture contained heat inactivated
(90 8C for 90 s) hepatic microsomes corresponding to 2.5
mg protein/mL (final concentration) or 4 mM fatty acid
residues [9], ascorbic acid (0.2 mmol Lꢀ1) and various
the method is checked by examining the activity of
nordihydroguaiaretic acid (10 mM), used here as a
reference under exactly the same experimental condi-
tions.
concentrations (1Á
0.05 mmol Lꢀ1) of the test com-
/
pounds dissolved in DMSO. The reaction was started by
the addition of a freshly prepared FeSO4 solution (10
mmol Lꢀ1), the mixture was incubated at 37 8C for 45
min. Lipid peroxidation was assessed spectrophotome-
trically (535 against 600 nm) determining the TBA
reactive material [10]. Under the above experimental
conditions, all compounds, as well as DMSO, were
tested and found not to interfere with the assay. Each
experiment was performed at least in triplicate.
6.6. cLog P
Hydrophobicity, expressed as clog P values, of com-
pounds was calculated with the programme CLOGP,
v4.62, Daylight Chemical Information Systems Inc.
References
6.4. Effect of the test compounds on FCA induced
inflammation
[1] S. Spyroudis, N. Xanthopoulou, Org. Chem. 67 (2002) 4612Á
(and references cited therein).
[2] E.M. Perchellet, M.J. Magill, X. Huang, C.E. Brantis, D.H. Hua,
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E.M. Perchellet, B.J. Sperfslage, J.P. Perchellet, S. Jiang, D.E.
/
4614
/
Edema was induced by i.d. injection of FCA
(Freund’s Complete Adjuvant, 0.05 mL/paw) into the
right hind paw of male Balb/C mice (20Á30 g) (the left
/
Kyle, P.K. Chiang, J. Org. Chem. 7 (2002) 2907Á
[4] T.R. Criswell, B.H. Klanderman, J. Org. Chem. 39 (1974) 770Á
774.
[5] H. Iwamura, K. Makino, J.C.S. Chem. Comm. (1978) 720Á
[6] S. Spyroudis, Molecules 5 (2000) 1291Á1330.
/
2912.
paw serving as control) [14]. Groups of six animals were
used and the test compounds (suspended in water with
few drops of Tween-80) were given i.p. (0.15 or 0.3
mmol kgꢀ1) 15 min prior to the FCA injection. Mice
were euthanised 3 h later and the produced edema was
estimated as paw weight increase 3 h after the FCA
administration [15]. Indomethacin a known anti-inflam-
matory drug was used as reference in addition to the
absolute control. Statistical analysis was performed with
the student’s t-test and differences between treated and
/
/
721.
/
[7] A.P. Kourounakis, A. Gavalas, A.N. Assimopoulou, V.P. Papa-
georgiou, P.N. Kourounakis, Arch. Pharm. (Weinheim) 335 (6)
(2002) 262Á
[8] E. Rekka, J. Kolstee, H. Timmerman, A. Bast, Eur. J. Med.
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[10] E.A. Rekka, A.P. Kourounakis, P.N. Kourounakis, Res. Comm.
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[11] D.Y. Gao, M. Kakuma, S. Oka, K. Sugino, H. Sakurai, Bioorg.
Med. Chem. 8 (11) (2000) 2561Á2569.
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Med. Chem. 34 (1991) 267Á276.
[13] L. Fraisse, J.B. Verhac, B. Roche, M.C. Rascle, A. Rabion, J.L.
Seris, J. Med. Chem. 36 (1993) 1465Á1473.
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[15] L. Hadjipetrou-Kourounakis, E. Rekka, A. Kourounakis, Ann.
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[16] I.B. Taraporewala, J.M. Kauffman, J. Pharma. Sci. 79 (1990)
173Á178.
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266.
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non-treated groups were significant at P B
/0.0001.
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/
6.5. Effect on lipoxygenase activity
/
The reaction mixture contains (final concentrations)
the test compound, dissolved in 60% ethanol (120 or 60
mM), or the solvent, soybean lipoxygenase, dissolved in
2% ethanol in 0.9% NaCl solution (250 u mLꢀ1) and
/
/
sodium linoleate (100 mM), in TrisÁ
The reaction is monitored for 6Á7 min at 28 8C, by
recording absorbance at 234 nm [16]. The reliability of
/HCl buffer, pH 9.0.
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/