Curcumin glucuronides: Assessing the proliferative activity against human cell lines

Article abstract of DOI:10.1016/j.bmc.2013.11.006

A gram scale synthesis of the glucuronide metabolites of curcumin were completed in four steps. The newly synthesized curcumin glucuronide compounds 2 and 3 along with curcumin 1 were tested and their anti-proliferative effects against KBM-5, Jurkat cell, U266, and A549 cell lines were reported. Biological data revealed that as much as 1 μM curcumin 1 exhibited anticancer activity and almost 100% cell kill was noted at 10 μM on two out of four cell lines; while curcumin mono-glucuronide 2 as well as di-glucuronide 3 displayed no suppression of cell proliferation.

Full text of DOI:10.1016/j.bmc.2013.11.006

Bioorganic & Medicinal Chemistry 22 (2014) 435–439
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Curcumin glucuronides: Assessing the proliferative activity against
human cell lines
Ashutosh Pal, Bokyung Sung, Basvoju A. Bhanu Prasad, Paul T. Schuber Jr., Sahdeo Prasad,
⇑
Bharat B. Aggarwal, William G. Bornmann
Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 31 May 2013
Revised 28 October 2013
Accepted 5 November 2013
Available online 12 November 2013
A gram scale synthesis of the glucuronide metabolites of curcumin were completed in four steps. The
newly synthesized curcumin glucuronide compounds 2 and 3 along with curcumin 1 were tested and
their anti-proliferative effects against KBM-5, Jurkat cell, U266, and A549 cell lines were reported. Biolog-
ical data revealed that as much as 1
was noted at 10 M on two out of four cell lines; while curcumin mono-glucuronide 2 as well as di-glu-
curonide 3 displayed no suppression of cell proliferation.
lM curcumin 1 exhibited anticancer activity and almost 100% cell kill
l
Keywords:
Curcumin
Ó 2013 Published by Elsevier Ltd.
Curcumin mono-glucuronide
Curcumin di-glucuronides
1. Introduction
exhibit any biological activity. In an effort to address this central
question, curcumin glucuronides were synthesized and its potency
against human cell lines was compared to the inhibitory activities
with that of curcumin thereby providing irrefutable evidence dem-
onstrating complete biological inactivity.
While the chemistry and biology of glucuronides is well known
and plays a central role in detoxification pathway,20 the synthesis
of curcumin glucuronides have been largely overlooked with only
one briefly description in the literature via enzymatic synthesis
with no chemical characterization.21 Thus, to date no chemical
synthesis of curcumin glucuronides has not yet been reported
nor the products chemically characterized. Herein we report an
efficient synthesis of curcumin glucuronides starting from vanillin
(Fig. 1).
Curcumin
1 (1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-hept-
adiene-3,5-dione/diferuloyl methane), the main yellow pigment
of the Curcuma longa L, has been reported to have antioxidant, anti-
proliferative and various biological properties.1–13 Curcumin has
also been reported to decrease total cholesterol and LDL choles-
terol level in serum and to increase the beneficial HDL cholesterol
level.14 It has been claimed that curcumin inhibits HIV-I integrase
protein, thus potentially preventing HIV-I from infecting CD-4 and
CD-8 cell.15 Curcumin is a non-nutritive, non-toxic compound in
turmeric, a spice that has been used for centuries in India and else-
where as a herbal medicinal treatment for wounds, jaundice, and
rheumatoid arthritis.16 It exerts cancer chemo-preventive efficacy
in a wide variety of rodent models of carcinogenesis.17 In common
with several other diet-derivative polyphenols, curcumin has very
poor bioavailability,13 cellular uptake is slow and it gets metabo-
lized fast, once inside the cell, requiring repeated oral doses in
order to achieve significant concentration inside the cells for ther-
apeutic activity. This poor bioavailability is attributed to one of the
major metabolites, curcumin glucuronide, that is accumulated in
the intestine18 when curcumin is administered orally.19 Interest-
ingly enough, in the miliéu intérieur of studies done on curcumin,
the critical central question which has remained unanswered or
even addressed, is that of whether or not curcumin glucuronides
2. Results and discussion
The syntheses of curcumin derivatives are shown in Schemes
1–3. Conversion of vanillin to its corresponding b-
was performed with acetobromo- -glucuronic acid methyl ester
and silver oxide in quinoline to give the key aldehyde b- -gluco-
D-glucuronide
a-D
D
pyranosiduronic acid derivative 6 in 70% yield. Keto-enol com-
pounds (7 and 9) were synthesized from the corresponding
aldehydes with two equivalents of acetylacetone-boron complex
in presence of n-butylamine (Scheme 1).22 A preliminary purifica-
tion by flash column over silica gel followed by recrystallization
from ethanol and water gave products that were visualized by
fluorescence and UV illumination. Compound 8 was synthesized
⇑
Corresponding author. Tel.: +1 713 563 0081; fax: +1 713 563 1878.
E-mail address: wbornmann@mdanderson.org (W.G. Bornmann).
0968-0896/$ - see front matter Ó 2013 Published by Elsevier Ltd.
http://dx.doi.org/10.1016/j.bmc.2013.11.006

436
A. Pal et al. / Bioorg. Med. Chem. 22 (2014) 435–439
O
OH
O
OH
H3CO
OCOMe
CHO
OCH3
OH
H3CO
HO
H3CO
OCOMe
O
MeOCO
MeOCO
O
4
MeOCO
MeOCO
a
b
O
1
curcumin
8
O
O
OH
COOMe
6
OCH3
OH
H3CO
OH
9
COOMe
HO
O
6
O
b
HO
2
curcumin mono-glucuronide
COOH
O
OH
O
OH
OCH3
OCOMe
OCOMe
H3CO
OCOMe
O
OCH3
OH
O
H3CO
OH
O
MeOCO
MeOCO
OH
OH
HO
HO
O
10
O
O
OCOMe
COOMe
O
O
COOMe
COOH
COOH
3
curcumin di-glucuronide
c
Figure 1. Chemical structures of curcumin, curcumin monoglucuronide and
curcumin diglucuronide.
O
3
OH
OCH3
OH
O
H3CO
OH
H3CO
OCOMe
O
CHO
OH
OH
HO
HO
O
OCOMe
Br
O
O
H3CO
HO
CHO
MeOCO
MeOCO
MeCOO
MeCOO
a
COOH
COOH
+
O
COOMe
5
O
COOMe
Scheme 2. Reagents and condition: (a) 2,4-pentanedione, B2O3, (n-BuO)3B, EtOAc,
85 °C, 30 min, n-BuNH2, 105 °C, 30 min, 1 N HCl, 50%; (b) B2O3, (n-BuO)3B, ethyl
acetate, 85 °C, 30 min, piperidine, 85 °C, 30 min, 0.5 N HCl, 50 °C, 30 min, 55% (c)
MeOH, 1 N NaOH, 50 °C, 1 h, 50% formic acid, 75%.
4
6
O
7
OH
H3CO
HO
H3CO
HO
CHO
b
c
O
OH
H3CO
OCOMe
O
CHO
OCH3
OH
H3CO
OCOMe
O
H3CO
HO
CHO
MeOCO
MeOCO
a
MeOCO
MeOCO
d
1
+ 8 + 10
+
O
2
O
COOMe
6
8
COOMe
4
Scheme 1. Reagents and conditions: (a) Ag2O, quinoline, 0 °C to rt, 1.5 h, 70%; (b)
2,4-pentanedione, B2O3, (n-BuO)3B, EtOAc, 85 °C, 30 min, n-BuNH2, 105 °C, 30 min,
1 N HCl, 50%; (c) B2O3, (n-BuO)3B, EtOAc, 85 °C, 30 min, piperidine, 85 °C, 30 min,
0.5 N HCl, 50 °C, 30 min, 55%; (d) MeOH, 1 N NaOH, 50 °C, 1 h, 50% formic acid, 70%.
Scheme 3. Reagents and conditions: (a) 2,4-pentanedione, B2O3, (n-BuO)3B, EtOAc,
85 °C, 30 min, n-BuNH2, 105 °C, 30 min, 1 N HCl, 25%.
8 (25%) and 10 (<5%) along with the curcumin 1 (10%) as yellow
products.
by coupling keto-enol compound 7 and the vanillin-boron complex
in the presence of piperidine which was found to give better yields
than when n-butylamine was used Subsequent hydrolysis of acetyl
and ester groups at the glucuronide moiety 8 was achieved by
treatment with aqueous 1 N NaOH in methanol (1:1) followed by
acidification with 50% formic acid in ice water to give curcumin
mono-glucuronide 2 in 70% yield.
Similarly compound 9 was converted to the curcumin di-
glucuronide 10 starting with the treatment of aldehyde 6 using
piperidine as condensation reagent as shown in Scheme 2. Com-
pound 8 was also synthesized from the keto-enol compound 9
using vanillin 4 as the aldehyde substrate for the condensation
reaction. Hydrolysis of methyl ester and removal of acetyl groups
was done using the same method described in Scheme 1 affording
curcumin di-glucuronide 3 as a yellow solid. In Scheme 3, an
equivalent molar mixture of 6 and vanillin 4 was reacted with
the acetylacetone-boron complex in the same manner as described
in Scheme 1 as well as in Scheme 2.23 After treatment of the reac-
tion mixture with 1 N HCl and work up, the crude mixture was
purified by silica gel flash chromatography to give the compounds
Curcumin and curcumin glucuronides were evaluated for their
ability to suppress the transcription factor, NF-jB in human leuke-
mic KBM-5 cells as they expressed TNF receptors and were re-
sponse to TNF activation. The KBM-5 cells were pre-incubated for
4 h with curcumin 1 and curcumin glucuronides (compound 2
and 3) and were treated 0.1 nM TNF for 30 min. The nuclear
extracts were prepared and assayed for the NF-
electrophoretic mobility shift assay (EMSA). Curcumin inhibited
TNF-induced NF- B activation at 25 M concentration; however
jB activation by
j
l
curcumin glucuronides had no effects on NF-
jB suppression
(Fig. 2).
Because NF-jB activation is known to regulate proliferation of
tumor cells, we examined the effect of curcumin 1, and compounds
2 and 3 on proliferation of tumor cell lines. The effect of curcumin 1
and compounds 2 and 3 were compared at equimolar concentra-
tions. The anti-proliferative effects (cytotoxicities) against different
cell lines are shown in Figure 3.
In all four KBM-5, Jurkat, U266 and A549 cells, curcumin 1
showed anti-proliferative effects with IC50 values of 3.84, 4.29,
7.57 and 17.3 lM respectively. In contrast to curcumin 1,

A. Pal et al. / Bioorg. Med. Chem. 22 (2014) 435–439
437
Figure 2. Evaluation of curcumin 1 and its glucuronide derivatives 2 and 3 on TNF-induced NF-jB DNA binding in KBM-5 human myeloid cells. Cells were pretreated with
curcumins for 4 h, then, stimulated with TNF (0.1 nmol/L) for 30 min, and analyzed for NF- B DNA binding by EMSA.
j
Figure 3. Evaluation of curcumin 1 and its glucuronide derivatives 2 and 3 on cell proliferation. Five thousand KBM-5 (A) Jurkat (B) U266 (C) and A549 (D) cells per well were
seeded in triplicate onto 96-well plates; treated with the each compound at 1, 5, 10, 25, 50, 100 or 200 M. After 72 the cell viability was measured by the MTT method and
presented as % cell viability. The data were expressed as the means SD of triplicate samples. ⁄P <0.05 and ⁄⁄P <0.01 versus untreated cells.
l
compounds 2 and 3 have no suppression against cell proliferation
4. Experimental
and IC50’s were more than 200 lM concentrations (Fig. 3).
4.1. Reagents, instrumentation and cell lines
3. Conclusion
All reagents and solvents were purchased from Aldrich Chemi-
cal Co. (Milwaukee, WI), and used without further purification.
Melting points were measured in open capillary tubes on a Hoover
capillary apparatus and are uncorrected. 1H NMR and 13C NMR
spectra were recorded on an IBM-Bruker Avance 300 (300 MHz
for 1H NMR and 75.48 MHz for 13C NMR), and IBM-Bruker Avance
500 (500 MHz for 1H NMR and 125.76 MHz for 13C NMR), spec-
trometers. Chemical shifts (d) are determined relative to CDCl3
(referenced to 7.27 ppm (d) for 1H NMR and 77.0 ppm for 13C
NMR) or DMSO-d6 (referenced to 2.49 ppm (d) for 1H NMR and
39.5 ppm for 13C NMR). Proton–proton coupling constants (J) are
given in Hertz and spectral splitting patterns are designated as sin-
glet (s), doublet (d), triplet (t), quadruplet (q), multiplet or over-
lapped (m), and broad (br). Low resolution mass spectra (ion
spray, a variation of electrospray) were acquired on a Perkin–Elmer
Curcumin mono-glucuronide 2 and curcumin-di-glucuronide 3
were synthesized in four steps with overall yields of 61% and
62% respectively. It was also shown that both the acetylated
compounds 8 and 10 along with curcumin 1 can be synthesized
in one-pot condensation of 6 and 4 in presence of acetylacetone-
B2O3 complex. The newly synthesized curcumin glucuronide
compounds 2 and 3 along with curcumin 1 were tested and their
anti-proliferative effects against KBM-5, Jurkat, U266 and A549 cell
lines were reported. The biological data revealed that curcumin
glucuronides showed very little anti-proliferative activity and no
effect on NF-
effects at 25
j
B; while, curcumin displayed NF-
jB inhibitory
l
M. Thus, confirming that curcumin mono-glucuro-
nide 2 and curcumin-di-glucuronide 3 are non-toxic and non-
antiinflammatory.

438
A. Pal et al. / Bioorg. Med. Chem. 22 (2014) 435–439
Sciex API 100 spectrometer or Applied Biosystems Q-trap 2000 LC-
MS-MS.
145.1 °C; 1H NMR (CDCl3) d 15.5 (br, 1H), 7.52 (d, J = 0.6 Hz, 1H),
7.08 (d, J = 8.4 Hz, 1H), 7.01 (s, 1H), 6.92 (d, J = 8.4 Hz, 1H), 6.32
(d, J = 15.6 Hz, 1H), 5.90 (br, 1H), 5.63 (s, 1H), 3.93 (s, 3H); 13C
NMR (CDCl3) d 196.9, 178.0, 147.8, 146.8, 140.1, 127.7, 122.7,
120.4, 114.8, 109.6, 100.7, 56.0, 26.8; IR (neat) 1752.87, 1686.3,
1594.47 cm-1; HRMS (C13H14O4) calcd 234.08 found 235.2 (M+H).
Flash chromatography was performed using Merk silica gel 60
(mesh size 230–400 ASTM) or using an Isco (Lincon, NE)
combiFlash Companion or SQ16x flash chromatography system
with RediSep columns (normal phase silica gel (mesh size 230–
400ASTM) and Fisher Optima TM grade solvents. Thin-layer
chromatography (TLC) was performed on E. Merk (Darmstadt, Ger-
many) silica gel F-254 aluminum-backed plates with visualization
under UV (254 nm) and by staining with potassium permanganate
or ceric ammonium molybdate. Penicillin, streptomycin, RPMI
1640 medium, Dulbecco’s modified eagles medium and Iscove’s
modified Dulbecco’s medium, and fetal bovine serum were ob-
tained from Invitrogen. Bacteria-derived human recombinant tu-
4.1.3. Curcumin b-D-glucopyranosiduronic acid 2,3,4-tri-O-
acetyl, methyl ester (8)
Compound 7 (1.35 g, 5.7 mmol) and B2O3 (600 mg, 8.6 mmol)
were dissolved in ethyl acetate (15 mL) at 85 °C. To this mixture
was added an ethyl acetate solution (30 mL) of 6 (1.6 g, 3.4 mmol)
and (n-BuO)3B (2.28 mL, 8.49 mmol). After stirring for 1 h, the mix-
ture was treated with piperidine (200 lL, mmol) at 85 °C for
mor necrosis factor (TNF), purified to homogeneity with
a
30 min, and then with 0.5 N HCl (20 mL) at 50 °C for 30 min. Reac-
tion mixture was cooled and then extracted with ethyl acetate,
washed with water and dried over Na2SO4. Flash chromatography
over silica gel (1:2 to 1:9 hexanes/EtOAc) gave 8 as yellow foam
specific activity of 5 ꢀ 107 units/mg, and was kindly provided by
Genentech (South San Francisco, CA).
The KBM-5 (human chronic myeloid leukemia) cell lines were
obtained from Dr. Nicholas J. Donato (University of Michigan Com-
prehensive Cancer Center), Jurkat (human T cell leukemia), U266
(multiple myeloma) and A549 (lung adenocarcinoma) cells were
obtained from American Type Culture Collection (Manassas, VA).
The Jurkat and U266 cells were cultured in RPMI 1640 medium,
A549 cells were cultured in Dulbecco’s modified eagles medium
with 10% fetal bovine serum. KBM-5 cells were cultured in Iscove’s
modified Dulbecco’s medium with 15% fetal bovine serum. All cul-
ture media were supplemented with 100 units/mL penicillin and
(2.17 g, 55%). IR (neat) 1755.68, 1626.44, 1586.48, 1509.51 cm-1
;
1H NMR (CDCl3) d 7.59 (d, J = 15.6 Hz, 1H), 7.56 (d, J = 15.6 Hz,
1H), 7.10 (m, 5H), 6.92 (d, J = 7.8 Hz, 1H), 6.49 (d, J = 16.2 Hz, 1H),
6.48 (d, J = 16.2 Hz, 1H), 5.81 (s, 1H), 5.34 (m, 3H), 5.10 (d,
J = 7.2 Hz, 1H), 3.94 (s, 3H), 3.86 (s, 3H), 3.74 (s, 3H), 2.08 (s, 3H),
2.05 (s, 3H), 2.04 (s, 3H); 13C NMR (CDCl3) d 184.2, 182.2, 170.1,
169.4, 169.3, 166.9, 150.8, 148.0, 147.3, 147.3, 146.8, 141.0, 139.5,
131.9, 127.6, 123.6, 122.9, 121.7, 121.6, 120.2, 114.9, 111.7,
109.7, 101.4, 100.3, 72.7, 71.8, 71.1, 69.2, 56.1, 55.9, 52.9, 20.6,
20.6, 20.5; HRMS (C34H36O15) calcd 684.2054 found 685.5 (M+H).
100
lg/mL streptomycin.
4.1.1. b-
D
-Glucopyranosiduronic acid, 4-formy-2-
4.1.4. b-D-Mono-glucuronidecurcumin (2)
methoxyphenyl, methyl ester, triacetate (6)
To a cooled (ice-water bath) solution of the glucuronate ester
(500 mg, 0.74 mmol) in methanol (14 mL) was added aqueous
1 N NaOH solution (14 mL) drop wise. The resulting solution was
then stirred for 3 h at 0 °C and then pH of the solution was adjusted
to 3–4 by adding 50% aqueous formic acid. The yellow solid was fil-
tered, collected and purified by reversed phase chromatography
using water and methyl alcohol as eluent (gradient 20–80,
50 min) to give 2 as yellow solid (0.28 g, 70%); IR (Neat): 3400,
Vanillin 4 (0.5 g, 3.3 mmol) and acetobromo-a-D-glucuronic
acid methyl ester 5 (2.3 g, 5.9 mmol) were dissolved in distilled
quinoline (20 mL) and silver oxide (0.8 g, 4 mmol) was added in
portions at 0 °C. The reaction mixture was stirred in the dark at
0 °C for 30 min and at room temperature for 90 min. After the addi-
tion of acetic acid (40 mL), the mixture was poured into water
(400 mL) and passed through Celite pad and the filtrate was ex-
tracted with ethyl acetate (2 ꢀ 200 mL), washed with brine and
then dried. Purification by flash chromatography using dry-packed
silica gel and elution with hexane–EtOAC (70:30, first 25 min, and
then 20:80 for 40 min) gave 6 (1.08 g, 70%) as a white solid: mp
100–102 °C. 1H NMR (500 MHz CDCl3) d 9.90 (s, 1H), 7.44 (s, 1H),
7.43 (d, J = 7.8 Hz, 1H), 7.25 (d, J = 7.8 Hz, 1H), 5.35 (m, 3H), 5.19
(d, J = 6.6 Hz, 1H), 4.17 (d, J = 9 Hz, 1H), 3.89 (s, 3H), 3.73 (s, 3H),
2.08 (s, 3 H), 2.06 (s, 3H), 2.05 (s, 3H); 13C NMR (125 MHz CDCl3)
188.5, 167.7, 166.9, 166.7, 164.4, 148.6, 148.3, 130.6, 123.1,
116.4, 108.2, 97.2, 70.3, 69.1, 68.4, 66.6, 53.6, 50.4, 18.2, 18.2,
1624.4, 1585.9 cm-1 1H NMR (DMSO-d6) d 7.56 (d, J = 7.2 Hz,
;
1H), 7.56 (d, J = 6.6 Hz, 1H), 7.37 (s, 1H), 7.31 (s, 3H), 7.23 (d,
J = 8.4 Hz, 1H), 7.14 (d, J = 9.6 Hz), 7.12 (d, J = 8.4 Hz, 1H), 6.84
(m, 2H), 6.75 (d, J = 15.6 Hz, 1H), 6.08 (s, 1H), 5.21 (br, 1H), 5.10
(br, 1H), 4.95 (d, J = 7.2 Hz, 1H), 3.84 (s, 3H), 3.83 (s, 3H), 3.4–
3.12 (m, 4H); 13C NMR (DMSO-d6) d 184.3, 182.9, 172.2, 166.2,
150.2, 149.7, 149.2, 148.5, 141.3, 140.3, 129.1, 126.6, 123.7,
122.9, 121.6, 116.2, 115.8, 111.8, 111.8, 101.5, 100.2, 77.4, 74.1,
73.5, 72.5, 56.3, 56.2; HRMS (C27H28O12) calcd 544.1581 found
545.5 (M+H) and 567.4 (M+Na).
18.1; IR (neat) 1752.87, 1686.3, 1594.47 cm-1; HRMS (C21H24O12
calcd 468.12 found 486.4 (M+NH4).
)
4.1.5. 1-[4-(2,3,4-Tri-O-acetyl, methyl ester, b-D-glucuronides of-
3-methoxyphenyl)-5-hydroxy-1,4-hexadien-3-one (9)
4.1.2. 5-Hydroxy-1-(4-hydroxy-3-methoxyphenyl)-1,4-
hexadien-3-one (7)
1H NMR (CDCl3) d 7.58 (d, J = 15.6 Hz, 1H), 7.11 (m, 3H), 6.52 (d,
J = 15.6 Hz, 1H), 5.33 (m, 3H), 5.1 (d, J = 7.2 Hz, 1H) 3.87 (s, 3H),
2.08 (s, 3H), 2.06 (s, 3H), 2.04 (s, 3H); 13C NMR (CDCl3) d 197.7,
190.9, 176.9, 170.1, 169.4, 169.2, 166.9, 150.9, 147.4, 139.1,
131.8, 125.5, 122.2, 121.3, 120.2, 111.6, 111.8, 101.1, 100.3, 72.7,
71.8, 69.2, 60.4, 56.1, 52.9, 20.6, 20.5; HRMS (C26H30O13) calcd
550.16 found 551.5(M+4H) and 568.5(M+NH4).
2,4-Pentanedione (3.3 mL, 32.07 mmol) and B2O3 (2 g,
28.7 mmol) were dissolved in ethyl acetate (30 mL), and the solu-
tion was stirred at 80 °C for 30 min. To this mixture was added an
ethyl acetate solution of (40 mL) of the vanillin 4 (2.2 g, 14.4 mmol)
and (n-BuO)3 (1.6 mL, 5.96 mmol). After stirring for 30 min at
85 °C, n-butylamine (0.5 mL, 5.04 mmol) was added drop wise to
the mixtures, which was allowed to stir at 105 °C for 1.5 h. Then
the reaction mixture was treated with 1 N HCl (10 mL) at 50 °C
and stirred at the same temperature for 1 h. Reaction mixture
was cooled and then extracted with ethyl acetate, washed with
water and dried over Na2SO4. Flash chromatography over silica
gel (2:1, hexanes/EtOAc) followed by recrystallization from ethanol
and water, gave the 7 as yellow crystals (1.69 g, 50%): mp 143.1–
4.1.6. Bis-[2,3,4-tri-O-acetyl, b-
D
-glucopyranosiduronic acid
1H NMR (CDCl3) d 7.58 (d,
methyl ester]-curcumin (10)
IR (Neat): 2255, 1756, 1629 cm-1
;
J = 15.6 Hz, 2H), 7.10 (m, 6H), 7.31 (s, 3H), 6.53 (d, J = 15.6 Hz,
2H), 5.83 (br, 1H), 5.33 (m, 6H), 5.10 (d, J = 7.2 Hz, 2H), 3.86 (s,
6H), 3.74 (s, 6H), 2.08 (s, 6H), 2.06 (s, 6H), 2.04 (s, 6H); 13C NMR
(CDCl3) d 183.1, 170.1, 169.3, 169.2, 166.9, 150.9, 147.5, 140.0,

A. Pal et al. / Bioorg. Med. Chem. 22 (2014) 435–439
439
131.8, 123.6, 121.7, 120.2, 111.8, 100.3, 100.1, 72.7, 71.8, 71.1, 69.2,
56.2, 52.9, 20.6, 20.5; HRMS (C47H52O24) calcd 1000.9014 found
1001.9 (M+H) and 1018.1 (M+NH4).
University of Texas M.D. Anderson Cancer Center. We dearly thank
Asha Nadipuram, Zhenghong Peng, Yunming Ying and David Max-
well for their assistance and encouragement.
4.1.7. b-
D-Di-glucuronidecurcumin (3)
Supplementary data
IR (Neat): 2816, 2777, 2682, 1614 cm-1
;
1H NMR (DMSO-d6) d
7.52 (d, J = 15.6 Hz, 2H), 7.30 (s, 2H), 7.22 (d, J = 8.4 Hz, 2H), 7.10
(d, J = 8.4 Hz, 2H), 6.79 (d, J = 16.2 Hz, 2H), 5 (d, J = 6.6 Hz, 2H),
3.80 (s, 6H), 3.64 (d, J = 9.0 Hz, 2H), 3.34 (m, 6H); 13C NMR
(DMSO-d6) d 183.9, 173.3, 150.1, 149.1, 141.5, 130.2, 123.8,
123.7, 117.1, 116.5, 112.3, 100.7, 76.8, 76.2, 73.8, 72.6, 56.9; HRMS
(C33H36O18) calcd 720.6281 found 721.6 (M+H) and 743.4 (M+Na).
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.bmc.2013.11.006.
These data include MOL files and InChiKeys of the most important
compounds described in this article.
References and notes
4.2. Preparation of nuclear extracts and electrophoretic
mobility shift assays for NF-jB
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4.2.2. Statistical analysis
All data values were presented as mean SD. Statistical com-
parisons were measured using Student’s t-test. Differences were
considered significant at a P <0.05.
Acknowledgments
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This work was carried out with the startup funds to William G.
Bornmann and collaboration with Bharat B. Aggarwal from the