Taraxer-14-en-3β-ol, an Anti-Inflammatory Compound from Sterculia foetida L.

Article abstract of DOI:10.1055/s-2004-815459

Taraxer-14-en-3β-ol (1) was shown to be the active ingredient in the leaves of Sterculia foetida L. The alcohol 1, its acetate and ketone showed anti-inflammatory activity against TPA induced mouse ear oedema with inhibition ratios of 60.0, 58.57 and 40.57 at 0.5 mg/ear, respectively. The percentage inhibition of inflammation increased with dose for each compound.

Full text of DOI:10.1055/s-2004-815459

Taraxer-14-en-3b-ol, an Anti-Inflam-
matory Compound from Sterculia
foetida L.
Table 1 Effect of compounds 1, 2 and 3 on TPA induced local inflam-
mation in Swiss Albino mice
Entry Treatment
Difference in ear
thickness
ꢀmm”10  SEM)
% inhibition of
inflammation
±
3
1
1
1
1
D. G. Naik , A. M. Mujumdar , R. J. Waghole , A. V. Misar ,
2
2
2
S. W. Annie Bligh , Alan Bashall , John Crowder
1
2
3
4
5
6
7
8
9
1
1
Control
70.00  3.34
±
Compound 1 0.25 mg/ear
Compound 1 0.5 mg/ear
Compound 1 1 mg/ear
Compound 2 0.25 mg/ear
Compound 2 0. 5 mg/ear
Compound 2 1 mg/ear
Compound 3 0.25 mg/ear
Compound 3 0.5 mg/ear
Compound 3 1 mg/ear
Indomethacin 0.5 mg/ear
36.80  2.80*
28.00  1.50*,#
25.70  2.10*
59.80  4.61
29.00  2.73*,#
17.00  3.74*
71.80  5.24
41.60  2.79*,#
36.40  2.36*
25.00  2.10*,#
53.36
57.06
62.82
17.08
59.72
76.39
±0.27
42.22
46.66
63.63
Abstract
Taraxer-14-en-3b-ol '1) was shown to be the active ingredient in
the leaves of Sterculia foetida L. The alcohol 1, its acetate and ke-
tone showed anti-inflammatory activity against TPA induced
mouse ear oedema with inhibition ratios of 60.0, 58.57 and
4
0.57 at 0.5 mg/ear, respectively. The percentage inhibition of in-
0
1
flammation increased with dose for each compound.
*
Significant as compared to control p < 0.001. Difference in ear thickness was converted into
percentage inflammation from which percentage inhibition was calculated.
Sterculia foetida L. leaf extract exhibited significant anti-inflam-
matory and CNS depressant activity [1]. The presence of taraxer-
ol, b-sitosterol, n-octacosanol and glucuronyl derivatives of pro-
cyanidin, scutellarein and luteolin is reported [1]. To locate the
hitherto unknown active ingredient, the extract was purified by
#
Inhibition ratio of compounds 1, 2, 3 and indomethacin at 0.5 mg/ear were 60.00, 58.57,
4
0.57 and 64.28 respectively. Inhibition ratio, IR = 100ꢀA - B)/A, where A = oedema in-
duced by TPA alone and B = oedema induced by TPA + sample.
column chromatography and isolated compounds were to be the least active, possibly due to the absence of free/protec-
screened. Local anti-inflammatory activity was determined ted hydroxyl group at C-3. The activity of alcohol 1 was superior
using the TPA-induced ear inflammation model in Swiss Albino to that of the acetate 2. This could be due to the presence of a free
mice. The results show dose-dependent and significant local hydroxy group at C-3. This trend is illustrated by the inhibition
anti-inflammatory activity of compound 1 against oedema pro- ratios at 0.5 mg/ear. The data also indicate the increased inhibi-
voked by local application of TPA. Comparison of the physical tion of inflammation with increase in dose in each case 'Table 1).
and spectral data of 1 with the literature confirmed it to be tara- However, it was slightly less in comparison with that of indome-
xer-14-en-3b-ol. Screening of its acetate 2 and ketone 3 'Fig.1) thacin. The phorbol ester provides a suitable model for evalua-
indicated their activities to be dose-dependent and the ketone tion of both topical and systemic anti-inflammatory agents. The
majority of its activities appear to involve or be dependent on
6
8
arachidonic acid release and metabolism and interaction with
protein kinase C [2].
Fig. 1 Chemical
structure of taraxer-
1
4-en-3b-ol and its
derivatives.
Materials and Methods
Melting points are uncorrected. IR spectra were recorded in CCl4
solutions on a Shimadzu IR 470 spectrophotometer. Optical rota-
tions were measured with a Perkin-Elmer spectropolarimeter.
1
NMR spectra were recorded on Bruker AM250 ' H, 250.13 MHz,
1
3
1
C, 62.9 MHz) and Bruker DRX500 spectrometers ' H, 500.13
MHz, 13C, 125.7 MHz) using TMS as an internal standard 'chemi-
cal shifts in d, ppm).
Leaves of Sterculia foetida L. were collected from Pune and were
authenticated by matching with the voucher specimen AHMA:
581 available with the Agharkar Herbarium at Maharashtra As-
sociation 'AHMA) at Agharkar Research Institute.
Affiliation: 1 Agharkar Research Institute, Pune, India ´ 2 Institute of Health Re-
search and Policy, London Metropolitan University, London, U.K.
Shade-dried leaves '1100 g) were extracted with EtOH '3 L). The
alcohol extract was evaporated under vacuum to yield total
crude extract as a dark viscous residue '35 g, 3.18%). Part of this
Correspondence: Dr. D. G. Naik ´ Chemistry Group ´ Agharkar Research Insti-
tute ´ Pune-411004 ´ India ´ Phone: +91-020-25653680 ´ Fax: +91-020-25651542 ´
E-mail: dgnpune@yahoo.co.in
'10 g) was adsorbed on silica gel '60±120 mesh, 15 g) and loaded
Received: July 23, 2003 ´ Accepted: November 8, 2003
on an MPLC column of TLC silica gel G '2.6”46 cm, 1:15 g). The
column was eluted using hexane '1 L), hexane/EtOAc '19:1, 1.8
L), hexane/EtOAc '9:1, 0.4 L), hexane/EtOAc '17:3, 0.4 L), hex-
Bibliography: Planta Med 2004; 70: 68±69 ´ ꢀ Georg Thieme Verlag Stuttgart ´
New York ´ ISSN 0032-0943 ´ DOI 10.1055/s-2004-815459

ane/EtOAc '1:1, 0.4 L), EtOAc '0.4 L), EtOH '0.4 L) at 4.8 mL/min, Acknowledgements
tR of 1: between 1±200 mL 2: between 200±400 mL. Similarly
eluted were fractions 3±24 with an elution volume 200 mL S. W. A. B. thanks the Royal Society for an Industry Fellowship
each. Fractions 6±10 eluted with hexane/EtOAc '19:1) were and the Royal Society of Chemistry Journal Grant for visiting In-
combined '0.450 g) and recrystallised with hexane yielding com- dia.
pound 1 '0.125 g). TLC single spot, '10% EtOAc in hexane, R :
f
2
0
0
[
1
.45); m.p. 278 8C; [a] : + 0.28 'CHCl ) lit.[3], m.p. 278±2808C,
D 3
2
0
±1
a] : + 28; IR 'CCl ): n = 3600,1540,1460,1380,1030,1000 cm ; References
H-NMR '250.133 Hz, deuterated acetone): proton at C-7 four
peaks 6.5916, 6.5790, 6.5615, 6.5473 of equal intensities, methyl
protons 2.1297, 1.9809, 1.9632, 1.9459, 1.9333, 1.8556, 1.8017 '7
sets of methyl protons); elemental analysis found: C 84.35; H
D 4
1
2
Mujumdar AM, Naik DG, Waghole RJ, Kulkarni DK, Kumbhojkar MS.
Pharmacological studies on Sterculia foetida leaves. Pharm Biol 2000;
3
8: 13±7
Young JM, De Young LM. Pharmacological methods in the control of
inflammation. In: Spector J, Back N, editors. New York: Alan R. Liss,
Inc, 1989: pp 215±31
1
1.96; calculated for C H O: C 84.44; H 11.74%.
30 50
3
4
Brooks CJW. Observations on taraxerol 'skimmiol). J Chem Soc 1955:
Monoacetate 2, prepared by treating taraxer-14-en-3b-ol '1, 150
mg), with acetic anhydride was obtained as a colourless solid
125 mg); m.p. 297±299 8C; [a]2 : + 11.738 'CHCl ), 'lit. [4] m.p.
028C); IR 'CCl ): n = 1720, 1440, 1360, 1240, 1030, 1000 cm ;
elemental analysis found: C 76.47; H 11.64; calculated for
C H O '2H O): C 76.25; H 11.20%.
1674±7
Paul BD, Rao GS. Kapadia GJ. Isolation of myricadiol, myricitrin, tara-
xerol and taraxerone from Myrica cerifera L. root bark. J Pharmaceuti-
cal Sci 1974; 63: 958±9
Bates RB, Jacobsen NE, Setzer WN, Stessman CC. NMR assignments
and conformation of taraxerenes. Magnetic Resonance in Chemistry
1998; 36: 539±41
De Young L, Kheifts J, Young J. Edema and cell in filtration in the phor-
bol treated mouse ear are temporally separate and can be differential-
ly modulated by pharmacological agents. Agents and Actions 1989;
0
'
3
D
3
±
1
4
5
6
3
2
52
2
2
Taraxer-14-en-3-one '3, 71 mg) was obtained by Joneꢁs oxidation
of 1 '150 mg); m.p. 235±237 8C; [a] : + 14.478 'CHCl ), 'lit. [5]
m.p. 238±2398C); IR 'CCl ): n = 1720, 1460, 1380, 1000 cm ;
2
0
D
3
2
6: 335±41
±
1
4
elemental analysis found: C 85.14; H 11.31; calculated for
C H O: C 84.91; H 11.32%.
3
0
48
Animal experiments were conducted as per guidelines suggested
by the Committee for the Purpose of Control and Supervision of
Experiments on Animals 'CPCSEA) under Ministry of Statistics
and Programme Implementation, Government of India.
Male Swiss Albino mice were obtained from the National Insti-
tute of Virology, Pune. They were inbred in the animal house fa-
cilities at Agharkar Research Institute, for several generations for
the last 19 years. They were housed in polypropylene cages in an
air-conditioned area at 25  28C with 10 to 14 h light and dark cy-
cle and were given Amrut brand balanced animal feed and water
ad-libitum. A group of at least six animals was used for individual
treatments.
6
9
Ear oedema was induced [6] on the right ear by topical applica-
tion of TPA '2.5 mg in 20 mL of acetone). The left ear 'control) re-
ceived the vehicle 'acetone). The compound was applied at 0.25,
0
.5 and 1 mg/ear, respectively, immediately after application of
TPA. Indomethacin in a dose of 0.5 mg/ear was used as a positive
control. The thickness of ear was measured before and at 4 h
after application of TPA using a micrometer 'Digitrix mark II, Ja-
pan).
The oedema was expressed as mean  SEM from these values and
these results were analysed by Studentꢁs t-test. Based on this the
percentage inhibition of inflammation and inhibition ratio at
0
.5 mg/ear were calculated to assess the anti-inflammatory ac-
tivity 'Table 1).
Letter¼ Planta Med 2004; 70: 68±69