Deuterated Curcuminoids: Synthesis, Structures, Computational/Docking and Comparative Cell Viability Assays against Colorectal Cancer

Article abstract of DOI:10.1002/cmdc.201900179

A series of deuterated curcuminoids (CUR) were synthesized, bearing two to six OCD₃ groups, in some cases in combination with methoxy groups, and in others together with fluorine or chlorine atoms. A model ring-deuterated hexamethoxy-CUR–BF₂ and its corresponding CUR compound were also synthesized from a 2,4,6-trimethoxybenzaldehyde-3,5-d₂ precursor. As with their protio analogues, the deuterated compounds were found to remain exclusively in the enolic form. The antiproliferative activities of these compounds were studied by in vitro bioassays against a panel of 60 cancer cell lines, and more specifically in human colorectal cancer (CRC) cells (HCT116, HT29, DLD-1, RKO, SW837, and Caco2) and in normal colon cells (CCD841CoN). The deuterated CUR–BF₂ adducts exhibited better overall growth inhibition by NCI-60 assay, while for other CUR–BF₂ adducts the non-deuterated analogues were more cytotoxic. Results of the more focused comparative cell viability assays followed the same trend, but with some variation depending on cell lines. The CUR–BF₂ adducts exhibited significantly higher cytotoxicity than CURs. Structural studies (X-ray and DFT) and computational molecular docking calculations comparing their inhibitory efficacy with those of known anticancer agents used in chemotherapy are also reported.

Full text of DOI:10.1002/cmdc.201900179

Accepted Article
Title: Deuterated Curcuminoids: Synthesis, Structures, Computational/
Docking and Comparative Cell Viability Assay against Colorectal
Cancer
Authors: Kenneth K. Laali, Angela Zwarycz, Scott Bunge, Gabriela
Borosky, Manabu Nukaya, and Gregory Kennedy
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: ChemMedChem 10.1002/cmdc.201900179
Link to VoR: http://dx.doi.org/10.1002/cmdc.201900179
A Journal of
www.chemmedchem.org

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
Deuterated Curcuminoids: Synthesis, Structures,
Computational/Docking and Comparative Cell Viability Assay
against Colorectal Cancer
Kenneth K. Laali,*[a] Angela T. Zwarycz,[a] Scott D. Bunge[b], Gabriela L. Borosky,[c] Manabu Nukaya,[d]
and Gregory D. Kennedy[d]
[a]
Prof. Kenneth K. Laali and Angela T. Zwarycz. Department of Chemistry, University of North Florida, 1 UNF Drive, Jacksonville, Florida 32224, USA
kenneth.laali@unf.edu
[b]
[c]
Prof. Scott D. Bunge. Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
Dr. Gabriela L. Borosky. INFIQC, CONICET and Departamento de Química Teórica y Computacional, Facultad de Ciencias Químicas, Universidad
Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
[d]
Dr. Manabu Nukaya and Prof. Gregory D. Kennedy. Department of Surgery, University of Alabama-Birmingham School of Medicine, Birmingham, AL
35294-0016, USA.
parent curcumin,[6] we synthesized two libraries of deuterated
CUR-BF2 and CUR compounds, one bearing OCD3 groups, and
the other bearing fluorines and OCD3 groups (see Figures 2-3),
as models that may exhibit improved metabolic stability via a
secondary / remote deuterium isotope effect stemming from the
demethylation pathway. The ring-deuterated hexamethoxy-CUR-
BF2 and CUR compounds were also synthesized for comparison
with their non-deuterated analogs. Herein we report their
synthesis, structural studies (by X-ray analysis and DFT),
computational / docking, and comparative in-vitro bioassay via
NCI-60 assay, and more specifically against human colorectal
cancer CRC cells (HCT116, HT29, DLD-1, RKO, SW837, and
Caco2) in comparison to normal colon cells (CCD841CoN).
Abstract: A series of deuterated curcuminoids were synthesized,
bearing two to six OCD3 groups, in some cases in combination with
OCH3 groups, and in others together with fluorines. A model ring
deuterated hexamethoxy-CUR-BF2 and its corresponding CUR
compound
were
also
synthesized
form
a
2,4,6-
trimethoxybenzaldehyde-3,5-d2 precursor. As with their protio-
analogues, the deuterated compounds remained exclusively in the
keto-enolic form. The anti-proliferative activity of these compounds
were studied by in-vitro bioassay against a panel of 60 cancer cell
lines, and more specifically in human colorectal cancer (CRC) cells
(HCT116, HT29, DLD-1, RKO, SW837, and Caco2) and in normal
colon cells (CCD841CoN). The deuterated CUR-BF2 adducts
exhibited better overall growth inhibition by NCI-60 assay, while for
other CUR-BF2 adducts the non-deuterated analogues were more
cytotoxic. More focused comparative cell viability assay followed the
same trend but with some variation depending on cell lines. The CUR-
BF2 adducts exhibited significantly higher cytotoxicity compared to
CURs. Structural studies (X-ray and DFT), and computational
molecular docking calculations comparing their inhibitory efficacy with
those of known anti-cancer agents used in chemotherapy are also
reported.
Results and Discussion
Synthesis of deuterated CUR-BF2 adducts and CURs
Variously substituted deuterated benzaldehydes were
prepared from the corresponding hydroxyl derivatives by reaction
with appropriate equivalents of CD3I in DMF solvent. The
resulting deuterated analogues were subjected to the reaction
sequence adopted from our earlier work,[8-10] as outlined in
Scheme 1, to prepare the corresponding CUR-BF2 compounds.
Thermally induced decomplexation in pressure flask or under
reflux furnished the respective CUR compounds. The
hexamethoxy-d4-CUR-BF2 16a and its corresponding CUR
compound 16 were similarly synthesized (Scheme 1 and Figure
4) starting from the corresponding ring di-deuterated 2,4,6-
trimethoxy-benzaldehyde, prepared by the H / D exchange
method.[11]
Introduction
Curcumin is a non-toxic phenolic natural product extracted
from turmeric, and is widely used as dietary supplement and
therapeutic agent in Asian and Chinese medicines. Despite
proven anti-inflammatory, anti-bacterial, and anti-mutagenic
efficacy, its unfavorable bio-physicochemical features, in
particular poor solubility, low bioavailability, rapid metabolism,
have prevented the development of a curcumin-based anticancer
drug. Added to these drawbacks is curcumin’s complex biological
profile, because it influences multiple signaling molecules, making
it challenging to identify its pharmacophore. [1-5]
Curcumin is metabolized in vivo by reduction to form
dihydro-, tetrahydro- and hexahydro-derivatives, as well as by
conjugation to form glucuronide, sulfate, and a GS-adduct via
Michael addition. In addition to these well-known pathways,
metabolic products formed via demethylation were recently
discovered in human intestinal microbiota.[6]
Structural Studies
NMR spectra of all synthesized compounds confirm their
keto-enolic conformation similar to their protio-analogues (see
supporting information). Additionally, single crystals of adducts 1
and
3
suitable for X-ray analysis were grown from
dichloromethane at room temperature. The structure of CUR-BF2
There is significant interest in the deuterated analogs of
drugs with the goal to improve the pharmacokinetic and
toxicological profile of active pharmaceuticals.[7] The success of
this approach depends on whether or not the H / D exchange is
at or near the site that is part of the slow step (rate determining)
in the metabolic transformations.
In continuation of our previous studies on novel
curcuminoids and CUR-BF2 adducts [8-10], and with the recent
discovery of demethylation as an additional metabolic pathway in
Figure 1. Parent curcumin - exclusive presence of the enol tautomer
1
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
Scheme 1. Synthesis of deuterated CUR-BF2 and CUR compounds
Figure 3. The “heavy” and “light” pairs of fluoromethoxy-CUR-BF2 and CUR
compounds
Figure 4. Ring deuterated CUR-BF2 and CUR
Figure 2. “Heavy” and “light” pairs of CUR-BF2 and CUR compounds
adduct 1 bearing six OCD3 substituents is shown in Figure 5.
Compound 1 crystallizes in the triclinic space group Pī. The
asymmetric unit corresponds to one molecule with a total of two
molecules in each cell. A packing diagram is shown (Supporting
Information (SI) Figure S1). Each molecule interacts with an
adjacent molecule via three H – F contacts (2.7076(3) Å,
Figure 5. Thermal ellipsoid plot of CUR-BF2 adduct 1 (ellipsoids are drawn at
50 % probability)
2
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
compared with those of known inhibitors used in anticancer
therapies (Table 1). The studied curcuminoids afforded good
binding energies that were similar or even better than those of
usually employed chemotherapeutic inhibitors. The fluorinated
derivatives gave in general more favorable docking energies. It is
interesting to note their particularly high affinity with proteins
involved in CRC (HER2, HER1, hTS), as well as their docking
energies similar to that of Regorafenib, a multi-kinase inhibitor
approved by FDA in 2012 for treatment of CRC.[23] The most
stable binding poses of 9a as model compound in the active sites
of HER1 and hTS are shown in Figure 7. The interactions
between the ligand atoms and the residues of both proteins are
hydrophobic contacts, which are illustrated as red radial lines. The
corresponding 3D representations are depicted in Figure 8.
Table
1
Binding affinities for selected curcuminoids and known
chemotherapeutic drugs.
Figure 6. Optimized structures of deuterated CUR-BF2 compounds 1 and 3.
Protein
Binding energy (kcal / mol)
Known inhibitors
1a
3a
9a
11a
13a
2.8220(3) Å and 2.8252(5) Å). The crystal for adduct 3 diffracted
poorly and only the unit cell parameters (Table S1) and atom
connectivity could be obtained (Figure S2).
Geometries of compounds 1 and 3 were optimized by
density functional theory (DFT) computations at the B3LYP / 6-
31G* level. Structures are shown in Figure 6 (deuterium atoms
are displayed in blue).
HER2
SYR127063: -11.4
Lapatinib: -10.7
Afatinib: -9.4
-8.4
-8.0
-9.6
-10.0
-10.0
HER1
Gefitinib: -7.3
Erlotinib: -6.3
-7.2
-7.3
-8.1
-9.9
-7.8
-7.8
VEGFR2
Axitinib: -9.2
Sorafenib: -10.8
Lenvatinib: -8.9
-8.2
-8.3
-10.0
-10.2
Computational docking
Molecular docking calculations for model compounds were
performed with the aim to elucidate the factors determining the
biological activity of the studied curcuminoids. The proteins
selected for these docking studies participate in diverse
oncogenic processes, described as follow. From the tyrosine
kinase receptors in the epidermal growth factor receptor (EGFR)
family, HER2 has an important role in the evolution of several
human cancers.[12] As overexpression of HER2 occurs in breast,
prostate, gastric/gastroesophageal, ovarian, endometrial, bladder,
lung, colon, and head and neck cancers, it is a target for therapies
pointing to inhibition of this protein to decrease tumor growth.[12]
Mutated and overactive HER1 is linked to the initiation of a
cascade of signaling pathways resulting in tumor growth and
progression.[13] This enzyme is overexpressed in many human
epithelial malignancies including non-small cell lung cancer
(NSCLC), pancreatic and hepatocellular carcinoma, and
colorectal, breast, ovarian, endometrial, and renal cancer. HER1
inhibition results in reduced tumor cell migration and invasiveness,
and induction of apoptosis.[14] Vascular endothelial growth factor
receptor (VEGFR) tyrosine kinases are clinically confirmed
targets of inhibitors applied in renal cell carcinoma therapy.[15]
Inhibition of the tumor cell proteasome has been suggested as the
mechanism by which curcumin prevents the proliferation of acute
promyelocytic leukemia (APL) cells.[16] Treatment with
proteasome inhibitors decreases proliferation and induces
apoptosis and sensitization of diverse tumor cells to
Regorafenib: -10.8
Vemurafenib: -9.3
Dabrafenib: -12.9
BRAF
-9.1
-8.3
-8.5
-7.9
-9.1
-9.2
-9.3
Proteasome
Bortezomib: -7.8
Ixazomib: -7.8
-9.2
-9.0
-9.4
Carfilzomib: -8.5
Navitoclax: -8.3
Venetoclax: -8.2
Bcl-2
hTS
-6.7
-6.7
-7.5
-7.6
-7.7
Raltitrexed: -8.0
-8.0
-8.0
-8.7
-8.6
-8.7
FdUMP; -7.7
Leu788
Tyr135
Glu87
Ala743
Lys745
Trp109
Asn226
His196
Thr790
Leu844
Ile108
Thr854
Phe225
chemotherapeutic
drugs
and
irradiation.[17]
Moreover,
Gly796
Leu221
proteasome inhibition has been proposed as one of the
mechanisms for the therapeutic role of curcumin in human colon
cancer.[18] As oncogenic activation of BRAF stimulates cancer cell
growth, selective inhibition of this protein significantly improved
treatment of metastatic melanoma.[19] The connection of proteins
in the Bcl-2 family (key regulators of normal apoptosis) with tumor
initiation, disease progression, and drug resistance makes them
important targets for antitumor therapy.[20] Bcl-2 is overexpressed
in acute and chronic leukemias and plays a critical role in the
survival of multiple lymphoid malignancies.[20] Inhibitors of human
thymidylate synthase (hTS) are effective therapeutic agents in the
chemotherapy of colorectal cancer (CRC) and NSCLC.[21,22]
Binding energies for derivatives 1a, 3a, 9a, 11a, and 13a
were determined in the active site of various proteins involved in
carcinogenic pathways. Computed binding affinities were
Met793
Leu718
Leu792
Lys77
Lys728
Arg78
Pro794
a
b
Figure 7. Most favorable binding mode of 9a in the active site of (a) hTS, and
(b) HER1
3
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
A remarkable finding is the significantly enhanced anti-
cancer activity (decrease in cell viability) in CRC cell lines treated
with CUR-BF2 compound 11 versus 11a (Figures 9 and S3). To
shed light on possible factors that may control the different
a
b
Figure 8. 3D representation of the most favorable binding mode of 9a in the
active site of (a) hTS, and (b) HER1
It has been reported that inhibition of proteasome activity by
curcumin in human colon cancer HCT-116 and SW480 cell lines
leads to accumulation of ubiquitinated proteins and several
proteasome target proteins, with subsequent induction of
apoptosis, and decreased tumor growth.[18] The study suggests
the potential use of curcumin for treatment of both early-stage and
late-stage / refractory colon cancer.[18] In this regard, favorable
binding affinities in proteasome computed for the curcuminoids in
the present study appear relevant and are promising.
In-Vitro Bioassay Study
The majority of the deuterated and non-deuterated CUR-
BF2 and CUR compounds synthesized in the present study were
initially tested for their anti-proliferative activity by the NCI-60
assay under standard 10-5 molar concentration. Interestingly, four
synthetic CUR compounds (1a, 7a, 9a, and 11) exhibited potent
anti-proliferative activity in all cell lines, except in non-small cell
lung cancer and CNS cancer cells (Mean growth percentage; 1a
(32.63%), 7a (30.49%), 9a (35.39%), 11 (39.00%) (Table S2).
These compounds were subsequently selected by NCI for 5-dose
assay (see data output in SI file). Four out of six deuterated CUR-
BF2 adducts (1, 5, 7, 9) exhibited considerably lower anti-
proliferative activity compared to their corresponding non-
deuterated analogues (1a, 5a, 7a, 9a) in most cancer cell lines.
By contrast, deuterated CUR-BF2 adducts 3 and 11 exhibited
better overall growth inhibition relative to their non-deuterated
counterparts (3a, 11a) (Table S2). Subsequent studies focused
more specifically on comparative bioassay against human
colorectal cancer (CRC) cells (HCT116, HT29, DLD-1, RKO,
SW837, Caco2) and normal colon cells (CCD841CoN). The CUR-
BF2 compounds 1a, 7a, 9a, and 11 displayed notable cell growth
inhibition (decrease in cell viability) in CRC cell lines as well as in
normal colon cells. Comparing the anti-cancer activity between
the CUR-BF2 adducts and the corresponding CUR derivatives
(e.g., 1 vs. 2, 1a vs. 2a), clearly shows that BF2 complexation
remarkably enhances the anti-cancer potency of the CUR
compounds (Figure 9, A through C).
Figure 9. The deuterated and non-deuterated CUR–BF2 adducts showed
significantly higher anticancer activity than the corresponding CUR compounds
in CRC cells: (A) HCT116, (B) HT29 and (C) DLD-1. CRC cells were treated
with DMSO or CUR compounds (10 M) for 72 h. Error bars represent ± SEM
of two independent experiments performed in triplicates or quadruplicates. (gray
bar: deuterated compound, black bar: non-deuterated compound).
Given recent reports on the efficacy of some curcumin-BF2
adducts for two-photon imaging and as crosslinking inhibitors for
amyloid beta species in Alzheimer’s disease (AD),[24,25] it is likely
that CUR-BF2 compounds could also serve as chemotherapeutic
agents for colorectal cancer.
Although substitution of OMe for OCD3 did not noticeably
improve the anti-cancer capability of most CUR compounds,
deuterated analogues 8, 11, and 13 exhibited increased anti-
cancer effect in CRC cell lines compared to their non-deuterated
counterparts (Figures 9 and S3).
Focusing on apoptosis, the caspase 3 / 7 activity (activation
of caspase 3 and 7 is an essential event during cell apoptosis)
induced by these curcuminoids were measured, since cell
apoptosis are the representative anti-cancer pathways induced by
CUR compounds.[5] The data (Figure 10) shows that CUR-BF2
adducts 1 / 1a, 5 / 5a, and 7 / 7a significantly enhanced apoptosis
activity in HCT116 CRC cells.
Figure 10. Apoptosis (Caspase 3 / 7) activity comparison: HCT116 cells were
treated with DMSO or CUR compounds (10 M) for 24 h. Error bars represent
± SEM of two independent experiments performed in triplicates. (gray bar:
deuterated compound, black bar: non-deuterated compound).
4
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
Table 2 The IC50 of deuterated and non-deuterated CUR–BF2 adducts in
human CRC cells.
than that in non-deuterated compound 11a toward CRC cells
(HCT116, DLD-1, RKO) (Figure 11B).
Recent studies have determined that generation of reactive
oxygen species (ROS) and G1 phase cell cycle arrest are also
involved in the anticancer mechanisms of curcumin and curcumin
analogs.[29-31] The difference likely stems from difference in the
relative ability of 11 and 11a to induce ROS-mediated cell growth
inhibition and G1 phase cell cycle arrest as well as apoptosis in
CRC cells.
IC50 (M)
Cell line
HCT116
HT29
DLD-1
RKO
11
11a
20.8
13.9
9.1
110.6*
93.9*
49.9*
31.5*
8.0
*significantly different relative to compound 11-treated cells (P<0.05)
Collectively, these results suggest that the anti-cancer
activity (growth inhibition and apoptosis) are mainly influenced by
the chemical structure and complexation with BF2 rather than by
H / D exchange in an in vitro setting, although it has been
predicted that the deuteration might improve the anti-cancer
properties of CUR compounds by altering their pharmacokinetics
and drug metabolism (e.g., half-life extension). Given their
complex metabolism, future studies should focus on animal
models to evaluate the effect of “deuterium switching” in
curcuminoids.
Conclusions
In the present study a series of deuterated CUR-BF2 and
CUR compounds were synthesized and characterized.
Computational docking studies showed highly favorable
interactions with several key proteins involved in carcinogenesis
mechanism, that were comparable to and in some cases
exceeded
known
chemotherapeutic
drugs.
Synthetic
curcuminoids 1a, 7a, 9a, and 11 exhibited potent anti-proliferative
activity by NCI-60 assay. Focusing more specifically on CRC
cells, CUR-BF2 adducts 1 / 1a, 5 / 5a, and 7 / 7a significantly
enhanced apoptosis activity in HCT116. Whereas cell viability and
apoptosis activity of the deuterated and non-deuterated pairs
were similar in most cases, the deuterated analog 11 exhibited
notably enhanced apoptosis activity with 4-7 times lower IC50s in
CRC cells. It appears that under in-vitro setting, structural effects
and in particular complexation to BF2 are major contributors to
cytotoxicity rather than D to H switching. Given the complexity of
metabolic pathways in curcuminoids, future work should logically
focus on comparative animal study to better gauge the role of
deuterium.
Figure 11. Cytotoxicity and apoptosis (Caspase 3 / 7) activity comparison: CRC
cells (HCT116, HT29, DLD-1, RKO) were treated with CUR compound 11 or
11a (20 M) for 24 h. Error bars represent ± SEM of two independent
experiments performed in triplicates. *significantly different relative to
compound 11-treated cells (p<0.05). (gray bar: deuterated compound 11, black
bar: non-deuterated compound 11a).
Experimental Section
General: The substituted benzaldehydes, MeI and MeI-d3 were
all high purity commercially available samples and were used
without further purification. NMR spectra were recorded on a 500
MHz instrument using CDCl3, DMSO-d6 or acetone-d6 as solvent.
19F NMR were referenced relative to external CFCl3. HRMS
analyses were performed on a Finnigan Quantum ultra-AM in
electrospray mode using methanol as solvent. FT-IR spectra were
recorded in ATR mode (as thin films formed via DCM
evaporation). Melting points were measured in open capillaries
and are not corrected.
responses of these compounds to CRC cells, their IC50 (50%
inhibitory concentration of cell growth) values were measured in
HCT116, HT29, DLD-1, and RKO cells and compared (Table 2).
The IC50 values for the deuterated CUR-BF2 compound 11 were
approximately 4-7 times lower in these cell lines, with RKO cells
exhibiting the highest sensitivity (IC50: RKO < DLD-1 < HT29 <
HCT116). In RKO cells, the cytotoxicity and caspase 3 / 7 activity
(apoptosis activity) were also highly enhanced upon treatment
with 11 and 11a compared to other cell lines (Figure 11A-B).
Several studies have demonstrated that the epigenetic
mutation and modulation on CRC-related genes (i.e., TP53,
BRAF, KRAS, PTEN, PIK3CA) impact the sensitivity to curcumin
and curcumin analogs in CRC cells.[26-28] Therefore, the
comprehensive comparison of CRC-related gene mutations and
modifications in CRC cell lines would reveal the factors that
determine the different sensitivity of the fluorinated CUR-BF2
compounds 11 and 11a.
General procedure for methylation of Substituted
monohydroxy-benzaldehydes: Substituted benzaldehyde (1
equiv.) was added to a suspension of potassium carbonate (3.62
mmol) in 10-15 mL of DMF in a round bottom flask with efficient
magnetic stirring. Iodomethane or iodomethane-d3 (1.5 equiv.)
was then added immediately, and the reaction mixture was
flushed with nitrogen and left under stirring overnight. Upon
completion (TLC analysis) the reaction mixture was transferred to
a beaker and enough DI water was added to dissolve the
remaining potassium carbonate, then DCM was added to extract
the aldehyde (3 x 10 mL). The organic layer was washed with DI
water (3 x 100 mL) to remove most of the remaining DMF. The
organic layer was dried over sodium sulfate, filtered, and the
solvent evaporated to give the product.
Surprisingly, although the enhanced levels of cytotoxicity
between 11 and 11a in CRC cells (HCT116, HT29, DLD-1) were
similar (Figure 11A), the apoptotic activity of the deuterated
counterpart (compound 11) was slightly, but significantly, higher
5
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
Methylation of 2,3-dihydroxybenzaldehyde and 3,4-
dihydroxybenzaldehyde: The procedure described above was
employed but with double quantity of MeI or CD3I, and potassium
carbonate.
Curcuminoid-BF2 adduct
1
(via 2,3,4-Trimethoxy-d9-
o
benzaldehyde): Yield 81%, red solid, mp 178-179 C, Rf 0.09
1
(40% EtOAc in hexane). H NMR (acetone-d6, 500 MHz): δ 8.20
(d, J = 16.0 Hz, 2H), 7.60 (d, J = 9.0 Hz, 2H), 7.05 (d, J = 15.5 Hz,
2H), 6.94 (d, J = 8.5 Hz, 2H), 6.46 (s, 1H). 13C NMR (acetone-d6,
125 MHz): δ 180.1, 157.6, 154.2, 142.3, 141.3, 124.7, 120.9,
119.7, 108.3, 101.7. 19F NMR (acetone-d6, 470 MHz): δ -140.8 (s,
11B-F), -140.8 (s, 10B-F). IR (cm-1): 2361, 2342, 2230, 2072, 1701,
1605, 1587, 1487, 1441, 1395, 1285, 1152, 1098, 1051.
General procedure for the synthesis of the CUR-BF2
Adducts[8,9]. To a two-necked round bottom flask, 2.2 equiv. of
aldehyde and 1.0 equiv. of acetyl acetone-BF2 complex were
introduced, and dissolved in minimal amount of ethyl acetate, and
the flask was flushed with nitrogen. N-butylamine (0.22 equiv.)
was then added dropwise to the reaction mixture via syringe, and
the reaction was allowed to continue overnight under stirring,
whereupon a solid precipitated out of solution. Completion of the
reaction was confirmed by TLC. The reaction mixture was cooled,
filtered through a Buchner funnel, and the solid was washed with
cold ethyl acetate and diethyl ether, and dried under vacuum.
(1E,4E,6E)-5-Hydroxy-1,7-bis(2,3,4-trimethoxy-d9-
phenyl)hepta-1,4,6-trien-3-one 2: Yield 88%, orange solid, mp
115-116 °C, Rf 0.40 (40% EtOAc in hexane). H NMR (CDCl3,
500 MHz): δ 7.85 (d, J = 16.0 Hz, 2H), 7.30 (d, J = 8.5 Hz, 2H),
6.70 (d, J = 9.0 Hz, 2H), 6.64 (d, J = 16.0 Hz, 2H), 5.83 (s, 1H).
13C NMR (CDCl3, 125 MHz): δ 183.6, 155.4, 153.3, 142.4, 135.3,
123.4, 123.2, 122.1, 107.6, 101.3, 60.6 (m, CD3), 60.0 (m, CD3),
55.3 (m, CD3), HRMS (ESI): m/z [M+H]+ calcd for C23H11O8D18:
475.29922 found:475.3091. IR (cm-1): 2359, 2226, 2070, 1616,
1487, 1435, 1296, 1186, 1136, 1092, 980, 907.
1
General procedure for decomplexation of the CUR-BF2
adducts
a) Using pressure flask - 100-200 mg of CUR-BF2 was added to
a pressure flask along with 3.0 equivalents of sodium oxalate and
20 mL of an 8:2 methanol/water mixture. The flask was tightly
closed with the screw cap covered with Teflon tape, and the flask
was carefully immersed into a pre-heated silicon oil bath at 150-
160°C and allowed to stir until a distinct color change occurred
(usually within an hour). The reaction mixture was allowed to cool
to room temperature and the content was transferred to an
appropriate size round bottom flask. The solvent mixture was
evaporated and the solid was filtered with a Buchner funnel,
washed with a copious amount of deionized (DI) water, and dried
under vacuum. Completion of reaction was confirmed by TLC and
by 19F NMR (no fluorine signal).
Curcuminoid-BF2 adduct 3 (via 3,5-Dimethoxy-4-methoxy-d3-
benzaldehyde): Yield 44%, red solid, mp 262-264oC, Rf 0.73
1
(40% EtOAc in hexane). H NMR (acetone-d6, 500 MHz): δ 7.98
(d, J = 16.0 Hz, 2H), 7.21 (s, 4H), 7.08 (d, J = 15.5 Hz, 2H), 6.45
(s, 1H), 3.92 (s, 12H, OMe). 13C NMR (acetone-d6, 125 MHz): δ
180.0, 153.6, 147.6, 141.5, 130.0, 121.1, 107.8, 102.2, 56.6. 19F
NMR (acetone-d6, 470 MHz): δ -135.5 (s, 11B-F), -135.6 (s, 10B-
F). IR (cm-1): 1622, 1582, 1564, 1499, 1470, 1456, 1418, 1398,
1341, 1323, 1304, 1273, 1240, 1177, 1159, 1125, 1090.
(1E,4E,6E)-5-Hydroxy-1,7-bis(3,5-dimethoxy-4-methoxy-d3-
phenyl)hepta-1,4,6-trien-3-one 4: Yield 89%, orange solid, mp
1
180-183°C, Rf 0.82 (40% EtOAc in hexane). H NMR (acetone-
d6, 500 MHz): δ 7.63 (d, J = 15.5 Hz, 2H), 7.06 (s, 4H), 6.84 (d, J
= 15.5 Hz, 2H), 6.06 (s, 1H), 3.91 (s, 12H, OMe). 13C NMR
(acetone-d6, 125 MHz): δ 183.6, 153.8, 140.5, 140.4, 130.6,
123.5, 105.8, 101.2, 58.9 (m, OCD3), 55.6 (OMe). HRMS (ESI):
m/z [M+H]+ calcd for C25H23O8D6: 463.22390; found: 463.20963.
IR (cm-1): 3003-2839, 2071, 1628, 1576, 1497, 1454, 1416, 1339,
1265, 1238, 1123, 1090.
b) Under Reflux – The same procedure as above was followed,
but instead of using a pressure flask the decomplexation was
affected by heating under reflux. The reaction was monitored by
TLC and additional sodium oxalate and solvent were added as
needed. Upon completion (TLC monitoring) the same isolation
steps (as in a) were followed.
Synthesis of 2,4,6-Trimethoxy-3,5-d2-benzaldehyde. This
compound was prepared according to the method of Werner et.
al.[11] by reacting the “light” aldehyde with D2O/B(C6F5)3. Briefly,
2,4,6-Trimethoxy-benzaldehyde was reacted with D2O (97 equiv.)
and B(C6F5)3 (0.10 equiv.) in CDCl3 in a pressure tube kept at 100
°C for 72 hours. The solvent was then evaporated and the product
was purified by flash chromatography with ethyl acetate. The %
deuteration was determined as 94% by 1H NMR. Attempts to
prepare the ring deuterated analog of 3,4,5-benzaldehye using
this procedure was unsuccessful even after prolonged reaction
times, increasing temperature, or by using additional B(C6F5)3.
This finding reinforces the suggested H/D mechanism,[11] because
in this case the OMe groups cannot help stabilize the benzenium
ion of ipso attack leading to H / D exchange. Using a procedure
similar to that reported previously,[8,9] the ring deuterated
hexamethoxy-CUR-BF2 adduct 15 was prepared by reacting the
3,5-d2-aldehyde (2.2 equiv.) with acetylacetone-BF2 complex (1
equiv.) and n-BuNH2 (0.22 equiv.) in ethyl acetate under nitrogen.
Upon completion (monitored by TLC) the product was vacuum
filtered, washed with ethyl acetate, and dried under vacuum. The
corresponding deuterated curcuminoid 16 was prepared as
previously described for 16a,[9] by addition of Na2C2O4 (4 eq) in
8:2 methanol/water in a Monowave reactor.[32] The temperature
was set to 140 °C and held for 10 minutes. Upon completion, the
product was vacuum filtered, rinsed with DI water and dried under
high vacuum.
Curcuminoid-BF2
adduct
5
(via
2,3-dimethoxy-d6-
benzaldehyde): Yield 77%, yellow solid, mp 180-181 oC, Rf 0.40
(40% EtOAc in hexane). 1H NMR (DMSO-d6, 500 MHz): δ 8.17 (d,
J = 16.0 Hz, 2H), 7.48 (dd, J = 8.0 and 1.5 Hz, 2H), 7.25 (d, J =
16.5 Hz, 2H), 7.23 (dd, J = 5.5 and 1.5 Hz, 2H), 7.18 (t, J = 8.0
Hz, 2H), 6.72 (s, 1H). 13C NMR (DMSO-d6, 125 MHz): δ 180.6,
153.3, 149.3, 141.3, 127.9, 125.0, 122.9, 120.2, 117.0, 103.1. 19
F
NMR (DMSO-d6, 470 MHz): δ -137.0 (s, 11B-F), -137.1 (s, 10B-F).
IR (cm-1): 2251-2195, 2075, 1616, 1576, 1549, 1520, 1456, 1402,
1325, 1277, 1219, 1188, 1165, 1107, 1088, 1049, 1003.
Curcuminoid-BF2
adduct
5a
(via
2,3-
dimethoxybenzaldehyde): Yield 70%, yellow solid, mp 184-185
oC, Rf 0.43 (40% EtOAc in hexane). H NMR (acetone-d6, 500
1
MHz): δ 8.33 (d, J = 15.5 Hz, 2H), 7.44 (dd, J = 8.0 and 1.5 Hz,
2H), 7.22 (dd, J = 7.7 and 2.0 Hz, 2H), 7.17 (t, J = 8.0 Hz, 2H),
7.16 (d, J = 15.5 Hz, 2H), 6.61 (s, 1H), 3.94 (s, 6H), 3.92 (s, 6H).
13C NMR (acetone-d6, 125 MHz): δ 186.1, 158.5, 154.7, 146.4,
133.1, 129.6, 127.5, 125.0, 121.3, 107.5, 65.9 (OMe), 60.6 (OMe).
19F NMR (acetone-d6, 470 MHz): δ -140.0 (s, 11B-F), -140.1 (s,
10B-F). IR (cm-1): 2953, 2837, 1616, 1578, 1557, 1520, 1464,
1427, 1402, 1325, 1265, 1165, 1053.
(1E,4E,6E)-5-Hydroxy-1,7-bis(2,3-dimethoxy-d6-
phenyl)hepta-1,4,6-trien-3-one 6: Yield 82%, yellow solid, mp
119-120 °C, Rf 0.37 (20% EtOAc in hexane). H NMR (CDCl3,
1
6
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
500 MHz): δ 7.98 (d, J = 16.5 Hz, 2H), 7.20 (dd, J = 8.2 and 1.5
Hz, 2H), 7.08 (t, J = 8.0 Hz, 2H), 6.94 (dd, J = 8.0 and 1.5 Hz, 2H),
6.71 (d, J = 16.0 Hz, 2H), 5.90 (s, 1H). 13C NMR (CDCl3, 125
MHz): δ 183.6, 153.2, 148.5, 135.2, 129.2, 125.6, 124.1, 119.2,
113.7, 101.6, 60.5 (m, CD3), 55.2 (m, CD3). HRMS (ESI): m/z
[M+H]+ calcd for C23H13O6D12: 409.24043 found: 409.2513; IR
(cm-1): 3064-2916, 2222, 2069, 1622, 1574, 1454, 139, 1277,
1217, 1179, 1138, 1107, 1092, 1047.
F), -137.2 (s, 10B-F). IR (cm-1): 2953-2853, 1607, 1557, 1495,
1462, 1433, 1398, 1377, 1302, 1263, 1207, 1152, 1069.
(1E,4E,6E)-5-Hydroxy-1,7-bis(5-fluoro-2-methoxy-d3-
phenyl)hepta-1,4,6-trien-3-one 10: Yield 99%, yellow solid, mp
162-165°C, Rf 0.79 (40% EtOAc in hexane). 1H NMR (CDCl3, 500
MHz): δ 7.95 (d, J = 16.0 Hz, 2H), 7.26 (dd, J = 9.0 and 3.0 Hz,
2H), 7.05 (m, 2H), 6.86 (dd, J = 9.2 and 4.5 Hz, 2H), 6.67 (d, J =
15.5 Hz, 1H), 5.88 (s, 1H). 13C NMR (CDCl3, 125 MHz): δ 183.4,
156.9 (1JCF = 238.5 Hz), 154.6, 134.6 (d, J = 1.9 Hz), 125.6, 125.2
(d, J = 7.7 Hz), 117.4 (d, J = 22.9), 114.2 (d, J = 22.9 Hz), 112.2
(d, J = 8.7 Hz), 101.9. 19F NMR (CDCl3, 470 MHz): δ -123.6 (m).
HRMS (ESI): m/z [M+H]+ calcd for C21H13F2O4D6: 379.16280;
found: 379.16049. IR (cm-1): 2953-2853, 1624, 1557, 1487, 1429,
1300, 1273, 1198, 1155, 1107, 970.
(1E,4E,6E)-5-Hydroxy-1,7-bis(2,3-dimethoxyphenyl)hepta-
1,4,6-trien-3-one 6a: Yield 95%, yellow solid, mp 118-119 °C, Rf
0.34 (20% EtOAc in hexane). 1H NMR (CDCl3, 500 MHz): δ 7.97
(d, J = 16.5 Hz, 2H), 7.21 (dd, J = 8.0 and 1.5 Hz, 2H), 7.08 (t, J
= 8.0 Hz, 2H), 6.95 (dd, J = 8.0 and 1.5 Hz, 2H), 6.71 (d, J = 15.5
Hz, 2H), 5.90 (s, 1H), 3.90 (s, 6H), 3.90 (s, 6H) . 13C NMR (CDCl3,
125 MHz): δ 183.6, 153.2, 148.6, 135.2, 129.2, 125.6, 124.2,
119.2, 113.8, 101.6, 61.4 (OMe), 55.9 (OMe). HRMS (ESI): m/z
[M+H]+ calcd for C23H25O6: 397.16511 found:397.1725 . IR (cm-1):
2955, 2914, 2361, 2341, 1719, 1622, 1578, 1458, 1377, 1265,
1219, 1134, 1069, 1003.
(1E,4E,6E)-5-Hydroxy-1,7-bis(5-fluoro-2-
methoxyphenyl)hepta-1,4,6-trien-3-one 10a: Yield 87%, yellow
1
solid, mp 161-164°C, Rf 0.79 (40% EtOAc in hexane). H NMR
(CDCl3, 500 MHz): δ 7.95 (d, J = 16.0 Hz, 2H), 7.26 (dd, J = 9.5
and 3.0 Hz, 2H), 7.05 (pseudo-dt, J = 8.5 and 3.0 Hz, 2H), 6.87
(dd, J = 8.7 and 4.5 Hz, 2H), 6.67 (d, J = 16.0 Hz, 1H), 5.88 (s,
1H), 3.89 (s, 6H, OMe). 13C NMR (CDCl3, 125 MHz): δ 183.4,
157.0 (1JCF = 239.4 Hz), 154.6 (d, J = 1.9 Hz), 134.6 (d, J = 1.9
Hz), 125.6, 125.2 (d, J = 7.5 Hz), 117.4 (d, J = 23.9), 114.2 (d, J
= 22.9 Hz), 112.3 (d, J = 7.7 Hz), 101.9, 56.1 (OMe). 19F NMR
(CDCl3, 470 MHz): δ -123.9. HRMS (ESI): m/z [M+H]+ calcd for
C21H19F2O4: 373.12514; found: 373.12372. IR (cm-1): 3076-2908,
1626, 1553, 1487, 1427, 1300, 1275, 1233, 1204, 1177, 1153,
1103, 1026.
Curcuminoid-BF2
benzaldehyde): Yield 60%, dark-purple solid, mp 224-227C, Rf
0.15 (40% EtOAc in hexane). H NMR (DMSO-d6, 500 MHz): δ
7.96 (d, J = 15.5 Hz, 2H), 7.48, (d, J = 2.0 Hz, 2H), 7.45 (dd, J =
8.2 and 2.5 Hz, 2H), 7.09 (d, J = 15.5 Hz, 2H), 7.07 (d, J = 8.5 Hz,
2H), 6.50 (s, 1H). 13C NMR (DMSO-d6, 125 MHz): δ 179.5, 153.0,
149.6, 147.3, 127.5, 125.6, 119.3, 112.3, 111.7, 101.8, 55.4 (m,
OCD3). 19F NMR (DMSO-d6, 470 MHz): δ -137.9 (s, 11B-F), -138.0
(s, 10B-F). IR (cm-1): 2955-2852, 2072, 1611, 1576, 1539, 1504,
1435, 1389, 1341, 1279, 1142, 1099, 1053.
adduct
7
(via
3,4-dimethoxy-d6-
1
Curcuminoid-BF2 adduct 11 (via 4-fluoro-2-methoxy-d3-
benzaldehyde): Yield 68%, orange solid, mp 269-270oC, Rf 0.66
(40% EtOAc in hexane). 1H NMR (DMSO-d6, 500 MHz): δ 8.13 (d,
J = 16.0 Hz, 2H), 7.93 (dd, J = 9.0 and 7.0 Hz, 2H), 7.20 (d, J =
16.0 Hz, 2H), 7.09 (dd, J = 11.0 and 2.5 Hz, 2H), 6.93 (dt, J = 8.5
and 2.5 Hz, 2H), 6.58 (s, 1H). 13C NMR (DMSO-d6, 125 MHz): δ
180.2, 166.1 (d,1JCF = 251.8 Hz), 161.2 (d, J = 10.6 Hz), 140.7,
132.2 (d, J = 11.4 Hz), 121.4, 119.6 (d, J = 2.8 Hz), 108.7 (d, J =
21.9 Hz), 102.8, 101.0 (d, J = 26.6 Hz), 56.0 (m, OCD3). 19F NMR
(DMSO-d6, 470 MHz): δ -103.3 (m, 2F), -137.4 (s, 11B-F), -137.5
(s, 10B-F). IR (cm-1): 1599, 1541, 1435, 1404, 1296, 1277, 1263,
1159, 1111, 1092, 1011.
(1E,4E,6E)-5-Hydroxy-1,7-bis(3,4-dimethoxy-d6-
phenyl)hepta-1,4,6-trien-3-one 8: Yield 97%, orange solid, mp
1
128-129°C, Rf 0.36 (40% EtOAc in hexane). H NMR (acetone-
d6, 500 MHz): δ 7.63 (d, J = 15.5 Hz, 2H), 7.34 (d, J = 2.0 Hz, 2H),
7.25 (dd, J = 8.5 and 2.0 Hz, 2H), 7.02 (d, J = 8.5 Hz, 2H), 6.76
(d, J = 15.5 Hz, 2H), 6.01 (s, 1H). 13C NMR (acetone-d6, 125
MHz): δ 183.6, 151.6, 149.8, 140.3, 128.0, 122.7, 121.0, 111.6,
110.4, 100.9, 54.4 (m, OCD3). HRMS (ESI): m/z [M+H]+ calcd for
C23H13O6D12: 409.24043; found: 409.23203. IR (cm-1): 3048,
2070, 1622, 1580, 1505, 1431, 1341, 1306, 1277, 1234, 1175,
1138, 1101, 1015.
Curcuminoid-BF2 adduct
9
(via 5-fluoro-2-methoxy-d3-
Curcuminoid-BF2
adduct
11a
(via
4-fluoro-2-
benzaldehyde): Yield 81%, orange solid, mp 262-263oC, Rf 0.67
methoxybenzaldehyde): Yield 84%, orange solid, mp 269-
270oC, Rf 0.64 (40% EtOAc in hexane). 1H NMR (DMSO-d6, 500
MHz): δ 8.12 (d, J = 15.5 Hz, 2H), 7.92 (dd, J = 8.7 and 7.0 Hz,
2H), 7.19 (d, J = 15.5 Hz, 2H), 7.09 (dd, J = 11.0 and 2.5 Hz, 2H),
6.93 (pseudo-dt, J = 8.5 and 2.0 Hz, 2H), 6.57 (s, 1H), 3.95 (s,
6H). 13C NMR (DMSO-d6, 125 MHz): δ 180.2, 166.1 (1JCF = 251.8
Hz), 161.2 (d, J = 10.6 Hz), 140.7, 132.2 (d, J = 11.4 Hz), 121.4,
119.6 (d, J = 2.9 Hz), 108.7 (d, J = 23.0 Hz), 102.8, 101.0 (d, J =
26.6 Hz), 57.0(OMe). 19F NMR (DMSO-d6, 470 MHz): δ -103.3 (m,
2F), 137.4 (s, 11B-F), -137.5 (s, 10B-F). IR (cm-1):1599, 1541, 1456,
1404, 1273, 1157, 1067, 1011.
1
(40% EtOAc in hexane). H NMR (DMSO-d6, 500 MHz): δ 8.16
(dd, J = 16.0 and 1.0 Hz, 2H), 7.77 (dd, J = 9.2 and 3.5 Hz, 2H),
7.38 (m, 2H), 7.31 (d, J = 16.0 Hz, 2H), 7.16 (dd, J = 9.2 and 4.0
Hz, 2H), 6.57 (s, 1H). 13C NMR (DMSO-d6, 125 MHz): δ 180.5,
156.8 (1JCF = 232.7 Hz), 155.8, 140.3 (d, J = 3.1 Hz), 123.8 (d, J
= 7.7 Hz), 123.1, 120.7 (d, J = 22.9 Hz), 115.3 (d, J = 23.9 Hz),
114.2 (d, J = 8.7 Hz), 103.4, 56.1 (m, OCD3). 19F NMR (DMSO-
d6, 470 MHz): δ -123.1 (m, 2F), -137.1 (s, 11B-F), -137.2 (s, 10B-
F). IR (cm-1):1607, 1553, 1485, 1435, 1396, 1304, 1273, 1206,
1155, 1109, 1070.
Curcuminoid-BF2
adduct
9a
(via
5-fluoro-2-
(1E,4E,6E)-5-Hydroxy-1,7-bis(4-fluoro-2-
methoxybenzaldehye): Yield 93%, orange solid, mp
methoxy(d3)phenyl)hepta-1,4,6-trien-3-one 12: Yield 86%,
yellow solid, mp 214-215°C, Rf 0.82 (40% EtOAc in hexane). H
1
1
decomposes ~260oC, Rf 0.64 (40% EtOAc in hexane). H NMR
(DMSO-d6, 500 MHz): δ 8.16 (d, J = 16.5 Hz, 2H), 7.77 (dd, J =
9.2 and 3.0 Hz, 2H), 7.38 (pseudo-dt, J = 8.7 and 3.0 Hz, 2H),
7.31 (d, J = 15.5 Hz, 2H), 7.17 (dd, J = 9.0 and 4.5 Hz, 2H), 6.57
(s, 1H), 3.92 (s, 6H, OMe). 13C NMR (DMSO-d6, 125 MHz): δ
180.5, 156.8 (1JCF = 233.7 Hz), 155.8 (d, J = 2.9 Hz), 140.3 (d, J
= 1.9 Hz), 123.8 (d, J = 8.5 Hz), 123.1, 120.7 (d, J = 23.9 Hz),
115.3 (d, J = 23.9 Hz), 114.2 (d, J = 8.5 Hz), 103.4, 57.0 (OMe).
19F NMR (DMSO-d6, 470 MHz): δ -123.1 (m, 2F), -137.1 (s, 11B-
NMR (acetone-d6, 500 MHz): δ 7.93 (d, J = 16.5 Hz, 2H), 7.76
(dd, J = 8.2 and 6.5 Hz, 2H), 6.93 (dd, J = 11.2 and 2.0 Hz, 1H),
6.89 (d, J = 16.0 Hz, 1H), 6.80 (dt, J = 8.0 and 2.5, 2H), 6.03 (s,
1H). 13C NMR (DMSO-d6, 125 MHz): δ 183.8, 164.9 (d, 1JCF = 249
Hz), 160.0 (d, J = 10.4 Hz), 134.4, 130.6 (d, J = 11.4 Hz), 124.5,
120.1 (d, J = 2.9 Hz), 108.1 (d, J = 21.9 Hz), 102.4, 100.6 (d, J =
25.8 Hz). 19F NMR (CDCl3, 470 MHz): δ -108.7. HRMS (ESI): m/z
7
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
[M+H]+ calcd for C21H13F2O4D6: 379.16280; found: 379.15240. IR
Curcuminoid-BF2 adduct 15 (via 5-chloro-2-methoxy-d3-
benzaldehyde): Yield 69%, orange solid, mp 274-275oC, Rf 0.86
(40% EtOAc in hexane). 1H NMR (DMSO-d6, 500 MHz): δ 8.14 (d,
J = 16.0 Hz, 2H), 7.98 (d, J = 2.5 Hz, 2H), 7.56 (dd, J = 9.2 and
2.5 Hz, 2H), 7.36 (d, J = 16.0 Hz, 2H), 7.19 (d, J = 9.0 Hz, 2H),
6.58 (s, 1H). 13C NMR (DMSO-d6, 125 MHz): δ 180.5, 158.1,
140.0, 133.5, 128.8, 125.5, 124.4, 123.2, 114.6, 103.5. 19F NMR
(DMSO-d6, 470 MHz): δ -137.0 (s, 11B-F), -137.1 (s, 10B-F). IR
(cm-1): 1614, 1572, 1553, 1516, 1481, 1404, 1304, 1285, 1256,
1161, 1099, 1015.
(cm-1): 1620, 1497, 1429, 1277, 1163, 1136, 1111, 1096, 1016.
(1E,4E,6E)-5-Hydroxy-1,7-bis(4-fluoro-2-
methoxyphenyl)hepta-1,4,6-trien-3-one 12a: Yield 97%, yellow
1
solid, mp 216-218°C, Rf 0.81 (40% EtOAc in hexane). H NMR
(acetone-d6, 500 MHz): δ 7.93 (d, J = 16.5 Hz, 2H), 7.76 (dd, J =
8.7 and 6.5 Hz, 2H), 6.94 (dd, J = 11.0 and 2.5 Hz, 1H), 6.89 (d,
J = 16.0 Hz, 1H), 6.80 (pseudo-dt, J = 8.0 and 2.5, 2H), 6.04 (s,
1H), 4.00 (s, 6H). 13C NMR (DMSO-d6, 125 MHz): δ 183.8, 164.9
(1JCF = 250 Hz), 160.0 (d, J = 10.6 Hz), 134.4, 130.5 (d, J = 10.4
Hz), 124.5, 120.1 (d, J = 2.8 Hz), 108.1 (d, J = 21.9 Hz), 102.4,
100.6 (d, J = 25.8 Hz), 56.8 (OMe). 19F NMR (CDCl3, 470 MHz): δ
-108.7. HRMS (ESI): m/z [M+H]+ calcd for C21H19F2O4:
373.12514; found: 373.11947. IR (cm-1): 1620, 1603, 1499, 1450,
1414, 1319, 275, 1137, 1032.
Curcuminoid-BF2
adduct
15a
(via
5-chloro-2-
methoxybenzaldehye): Yield 68%, orange solid, mp 271-273oC,
1
Rf 0.61 (40% EtOAc in hexane). H NMR (DMSO-d6, 500 MHz):
δ 8.13 (d, J = 16.0 Hz, 2H), 7.97 (d, J = 3.0 Hz, 2H), 7.55 (dd, J =
9.2 and 3.0 Hz, 2H), 7.36 (d, J = 15.5 Hz, 2H), 7.19 (d, J = 9.0 Hz,
2H), 6.58 (s, 1H), 3.93 (s, 6H, OMe). 13C NMR (DMSO-d6, 125
MHz): δ 180.5, 158.1, 140.0, 133.5, 128.8, 125.5, 124.4, 123.2,
114.6, 103.5, 56.8 (OMe). 19F NMR (DMSO-d6, 470 MHz): δ -
137.0 (s, 11B-F), -137.1 (s, 10B-F). IR (cm-1): 1612, 1572, 1553,
1516, 1485, 1304, 1256, 1161, 1070.
Curcuminoid-BF2 adduct 13 (via 3-fluoro-2-methoxy-d3-
benzaldehyde): Yield 68%, orange solid, mp 238-240oC, Rf 0.55
(40% EtOAc in hexane). 1H NMR (DMSO-d6, 500 MHz): δ 8.14 (d,
J = 15.5 Hz, 2H), 7.74 (d, J = 8.0 Hz, 2H), 7.46 (m, 2H), 7.32 (d,
J = 16.0 Hz, 2H), 7.22 (m, 2H), 6.77 (s, 1H). 13C NMR (DMSO-d6,
125 MHz): δ 180.8, 155.4 (d, 1JCF = 246.0 Hz), 147.4 (d, J = 11.4
Hz), 140.2 (d, J = 3.8 Hz), 128.8 (d, J = 2.9 Hz), 125.0 (d, J = 2.9
Hz), 124.7 (d, J = 8.5 Hz), 123.8, 120.9 (d, J = 20.1 Hz), 103.5.
19F NMR (DMSO-d6, 470 MHz): δ -129.7 (m, 2F), -136.7 (s, 11B-
F), -136.8 (s, 10B-F). IR (cm-1): 2359, 2341, 1622, 1557, 1464,
1406, 1275, 1217, 1179, 1134, 1074, 1020
Curcuminoid-BF2 adduct 16 (via 2,4,6-Trimethoxy-3,5-d2-
benzaldehyde): Yield 68%, dark purple solid, mp 298oC, Rf 0.20
(40% EtOAc in hexane). 1H NMR (DMSO-d6, 500 MHz): δ 8.21 (d,
J = 16.0 Hz, 2H), 7.14 (d, J = 15.5 Hz, 2H), 6.39 (s, 1H), 6.33 (s,
0.20H), 3.92 (s, 12H), 3.88 (s, 6H). 13C NMR (DMSO-d6, 125
MHz): δ 179.3, 165.4, 162.5, 136.9, 119.7, 105.8, 102.7, 91.5 (m,
C-D), 56.7, 56.3. 19F NMR (DMSO-d6, 470 MHz): δ -138.2 (s, 11B-
F), -138.3 (s, 10B-F).
Curcuminoid-BF2
adduct
13a
(via
3-fluoro-2-
methoxybenzaldehye): Yield 66%, orange solid, mp 230-232oC,
(1E,4E,6E)-5-Hydroxy-1,7-bis(2,3,4-trimethoxy-3,5-d2-
phenyl)hepta-1,4,6-trien-3-one 16a: Yield 82%, red-orange
solid, mp 195oC, Rf 0.44 (40% EtOAc in hexane). 1H NMR
(CDCl3, 500 MHz): δ 8.06 (d, J = 16.0 Hz, 2H), 7.01 (d, J = 16.0
Hz, 2H), 6.13 (s, 0.48 H), 5.79 (s, 1H), 3.89 (s, 12H), 3.85 (s,
6H). 13C NMR (CDCl3, 125 MHz): δ 184.6, 162.5, 161.2, 131.0,
124.4, 106.7, 101.5, 90.5, 90.1 (m, CD), 55.7, 55.4.
1
Rf 0.64 (40% EtOAc in hexane). H NMR (DMSO-d6, 500 MHz):
δ 8.13 (d, J = 16.0 Hz, 2H), 7.74 (d, J = 8.5 Hz, 2H), 7.46 (m, 2H),
7.32 (d, J = 15.5 Hz, 2H), 7.22 (m, 2H), 6.77 (s, 1H), 3.99 (d, J =
2.0 Hz, 6H). 13C NMR (DMSO-d6, 125 MHz): δ 180.8, 155.5
(d,1JCF = 246.0 Hz), 147.4 (d, J = 11.6 Hz), 140.2 (d, J = 3.9 Hz),
128.9 (d, J = 2.9 Hz), 125.0 (d, J = 2.9 Hz), 124.8 (d, J = 7.7 Hz),
123.8, 120.9 (d, J = 19.0 Hz), 103.5, 62.5 (d, 5JCF = 6.8 Hz, OMe).
19F NMR (DMSO-d6, 470 MHz): δ -129.7 (m, 2F), -136.7 (s, 11B-
F), -136.8 (s, 10B-F). IR (cm-1): 2953-2845, 1620, 1549, 1476,
1273, 1161, 1057.
2,3,4-Trimethoxy-d9-benzaldehyde: Yield 23%, Rf 0.69 (40%
EtOAc in hexane). 1H NMR (CDCl3, 500 MHz): δ 10.21 (s, 1H),
7.57 (d, J = 9.0 Hz, 1H), 6.72 (dd, J = 1.0 and 8.5 Hz, 1H). 13
C
NMR (CDCl3, 125 MHz): δ 188.8, 159.3, 156.9, 141.5, 124.2,
123.3, 107.3, 61.4 (m, J = 21.9 Hz; CD3), 60.1 (m, J = 21.9 Hz,
CD3), 55.2 (m, J = 22.0 Hz, CD3).
(1E,4E,6E)-5-Hydroxy-1,7-bis(3-fluoro-2-
methoxy(d3)phenyl)hepta-1,4,6-trien-3-one 14: Yield 98%,
yellow solid, mp 82-84°C, Rf 0.81 (40% EtOAc in hexane). H
1
NMR (CDCl3, 500 MHz): δ 7.93 (d, J = 16.0 Hz, 2H), 7.35 (d, J =
7.5 Hz, 2H), 7.12 (m, 2H), 7.04 (m, 2H), 6.72 (d, J = 16.0 Hz, 2H),
5.89 (s, 1H). 13C NMR (CDCl3, 125 MHz): δ 183.4, 155.7 (d, 1JCF
= 248.0 Hz), 146.7 (d, J = 11.4 Hz), 134.5 (d, J = 3.8 Hz), 129.8
(d, J = 2.9 Hz), 126.1, 123.5 (d, J = 8.7 Hz), 123.1 (d, J = 2.9 Hz),
118.2 (d, J = 20.0 Hz), 102.0. 19F NMR (CDCl3, 470 MHz): δ -130.1
(m). HRMS (ESI): m/z [M+H]+ calcd for C21H13F2O4D6: 379.16280;
found: 379.15662. IR (cm-1): 3080, 2955-2852, 1626, 1457, 1275,
1211, 1138, 1094.
3,5-Dimethoxy-4-methoxy-d3-benzaldehyde: Yield 63%, light
1
yellow solid, Rf 0.88 (40% EtOAc in hexane). H NMR (CDCl3,
500 MHz): δ 9.88 (s, 1H), 7.15 (s, 2H), 3.95 (s, 6H). 13C NMR
(CDCl3, 125 MHz): δ 191.1, 153.6, 143.6, 131.7, 106.7, 56.3.
3,4-Dimethoxy-d6-benzaldehyde: Yield 56%, Rf 0.48 (40%
EtOAc in hexane). 1H NMR (CDCl3, 500 MHz): δ 9.85 (s, 1H), 7.46
(dd, J = 2.0 and 8.0 Hz, H), 7.40 (d, J = 1.5 Hz, 1H), 6.97 (d, J =
8.5 Hz, 1H). 13C NMR (CDCl3, 125 MHz): δ 190.9, 154.5, 149.6,
130.1, 126.9, 110.4, 108.9, 55.4 (m, J = 21.9 Hz).
(1E,4E,6E)-5-Hydroxy-1,7-bis(3-fluoro-2-
methoxyphenyl)hepta-1,4,6-trien-3-one 14a: Yield 36%, yellow
solid, mp 85-89°C, Rf 0.84 (40% EtOAc in hexane). 1H NMR
(CDCl3, 500 MHz): δ 7.93 (d, J = 16.5 Hz, 2H), 7.36 (d, J = 7.5
Hz, 2H), 7.13 (m, 2H), 7.04 (m, 2H), 6.73 (d, J = 16.0 Hz, 2H),
4.01 (s, 1H). 13C NMR (CDCl3, 125 MHz): δ 183.4, 155.8 (d, 1JCF
= 247.0 Hz), 146.8 (d, J = 11.4 Hz), 134.5 (d, J = 3.8 Hz), 129.9
(d, J = 2.9 Hz), 126.1, 123.6 (d, J = 8.5 Hz), 123.0 (d, J = 2.9 Hz),
2,3-Dimethoxy-d6-benzaldehyde: Yield 58%, Rf 0.53 (20%
1
EtOAc in hexane). H NMR (CDCl3, 500 MHz): δ 10.43 (s, 1H),
7.41 (dd, J = 2.5 and 6.5 Hz, 1H), 7.11-7.15 (m, 2H) . 13C NMR
(CDCl3, 125 MHz): 13C NMR (CDCl3, 125 MHz): δ 190.1, 153.0,
152.7, 129.8, 124.1, 119.2, 118.1, 62.3, 56.0.
5
118.2 (d, J = 20.0 Hz), 102.0, 61.8 (d, JCF = 6.7 Hz. OMe). 19F
NMR (CDCl3, 470 MHz): δ -130.0 (m). HRMS (ESI): m/z [M+H]+
calcd for C21H19F2O4: 373.12514; found: 373.12738. IR (cm-1):
2953-2839, 1626, 1574, 1472, 1275, 1213, 1136, 1070, 1001.
3-Fluoro-2-methoxy-d3-benzaldehyde: Yield 39%, oil, Rf 0.82
1
(40% EtOAc in hexane). H NMR (CDCl3, 500 MHz): δ 10.42 (d,
1.0 Hz, 1H), 7.61 (dt, J = 8.0 and 1.0 Hz, 1H), 7.34 (m, 1H), 7.10
(m, 1H). 13C NMR (CDCl3, 125 MHz): δ 188.9 (d, J = 2.9 Hz),
1
155.0 (d, JCF = 249.0 Hz), 150.3 (d, J = 11.4 Hz), 129.9 (d, J =
8
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
2.8 Hz), 123.4 (d, J = 3.8 Hz), 123.3 (d, J = 7.7 Hz), 122.9 (d, J =
20.1 Hz), 61.0 (m, CD3). 19F NMR (CDCl3, 470 MHz): δ -123.0 (dd,
J = 11.8 and 5.2 Hz).
hydrogens, merger of nonpolar hydrogens to the atom to which
they were linked, and assignment of partial charges were
computed with AutoDockTools. Docking areas were constrained
to a 30x30x30 Å box centered at the active site of the proteins,
providing proper space for rotational and translational movement
of the ligands.
3-Fluoro-2-methoxybenzaldehyde: Yield 57%, yellow oil, Rf
0.88 (40% EtOAc in hexane). 1H NMR (CDCl3, 500 MHz): δ 10.42
(s, 1H), 7.62 (d, J = 8.0 Hz, 1H), 7.34 (m, 1H), 7.10 (m, 1H) 4.11
(d, 5JCF = 3.0 Hz, 3H, OMe). 13C NMR (CDCl3, 125 MHz): δ 188.9
(d, 4JCF = 3.9 Hz), 155.0 (1JCF = 250 Hz), 150.4 (d, J = 10.4 Hz),
130.0 (d, J = 1.9 Hz), 123.4 (d, J = 1.9 Hz), 123.3, 122.9 (d, J =
X-ray Crystallography
Single crystals for X-ray diffraction studies were obtained for 1
and 3 from dichloromethane. Crystal data of compounds 1 and 3
were collected by exactly the same method by mounting a crystal
onto a thin glass fiber from a pool of FluorolubeTM and immediately
placing it under a liquid N2 cooled stream, on a Bruker AXS
diffractometer upgraded with an APEX II CCD detector. The
radiation used is graphite monochromatized Mo K radiation ( =
0.7107 Å). The lattice parameters are optimized from a least-
squares calculation on carefully centered reflections. Lattice
determination, data collection, structure refinement, scaling, and
data reduction were carried out using APEX2 Version 2014.11
software package.[40,41] The data were corrected for absorption
using the SCALE program within the APEX2 software
package.[40,41] The structure were solved using SHELXT.[42] This
procedure yielded a number of the C, B, F, and O atoms.
Subsequent Fourier synthesis yielded the remaining atom
positions. The hydrogen atoms are fixed in positions of ideal
geometry (riding model) and refined within the XSHELL software
package.[43] These idealized hydrogen atoms had their isotropic
temperature factors fixed at 1.2 or 1.5 times the equivalent
isotropic U of the C atoms to which they were bonded. A few
hydrogen atoms could not be adequately predicted via the riding
model within the XSHELL software.[43] These hydrogen atoms
were located via difference-Fourier mapping and subsequently
refined. The final refinement of each compound included
anisotropic thermal parameters on all non-hydrogen atoms. The
crystal data for compounds 1 and 3 are given in Table S1. The
crystal for 3 diffracted weakly and only the unit cell and atom
connectivity could be obtained (Figure S2). For 1, the thermal
ellipsoid plot is shown in Figure 4. A packing diagram for 1 is
shown in Figure S1.[44] Crystallographic data for the structures
have been deposited with the Cambridge Crystallographic Data
Centre as supplementary publication no: CCDC 1889579 for 1.
Copies of the data can be obtained, free of charge via application
to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax, +44-
(0)1223-336033; or e-mail, deposit@ccdc.cam.ac.uk).
4
20.1 Hz), 62.3 (d, JCF = 7.5 Hz, OMe). 19F NMR (CDCl3, 470
MHz): δ -129.9 (dd, J = 11.8 and 3.3 Hz).
4-Fluoro-2-methoxy-d3-benzaldehyde: Yield 79%, off-white
solid, Rf 0.84 (40% EtOAc in hexane). 1H NMR (CDCl3, 500 MHz):
δ 10.36 (d, 1.5 Hz, 1H), 7.85 (dd, J = 8.7 and 6.5 Hz, 1H), 6.72
1
(m, 2H). 13C NMR (CDCl3, 125 MHz): δ 188.2, 167.8 (d, JCF
=
256.6 Hz), 163.6 (d, J = 11.4 Hz), 130.9 (d, J = 11.4), 121.6 (d, J
= 2.8 Hz), 108.1 (d, J = 22.9), 99.7 (d, J = 25.8 Hz), 55.2 (m,
OCD3). 19F NMR (CDCl3, 470 MHz): δ -99.6 (m).
4-Fluoro-2-methoxybenzaldehyde: Yield 74%, off-white solid,
1
Rf 0.84 (40% EtOAc in hexane). H NMR (CDCl3, 500 MHz): δ
10.37 (s, 1H), 7.87 (dd, J = 8.5 and 7.5 Hz, 1H), 6.72 (m, 2H),
3.94 (s, 3H, OMe). 13C NMR (CDCl3, 125 MHz): δ 183.5, 163.0
(1JCF = 255.6 Hz), 158.9 (d, J = 10.6 Hz), 126.2 (d, J = 11.4 Hz),
116.9 (d, J = 2.9 Hz), 103.4 (d, J = 21.9 Hz), 94.9 (d, J = 25.8 Hz),
51.2 (OMe). 19F NMR (CDCl3, 470 MHz): δ -99.5 (m).
5-Fluoro-2-methoxy-d3-benzaldehyde: Yield 77%, light-yellow
solid, Rf 0.77 (40% EtOAc in hexane). 1H NMR (CDCl3, 500 MHz):
δ 10.44 (d, J = 3.0 Hz, 1H), 7.52 (dd, J = 8.5 and 3.0 Hz, 1H), 7.27
(m, 1H), 6.96 (dd, J = 9.5 and 4.0 Hz, 1H). 13C NMR (CDCl3, 125
1
MHz): δ 188.7 (d, J = 1.9 Hz), 158.2, 156.9 (d, JCF = 241.3 Hz),
125.5 (d, J = 5.7 Hz), 122.5 (d, J = 24.8 Hz), 114.1 (d, J = 22.9
Hz), 113.1 (d, J = 7.5 Hz), 55.4 (m, OCD3). 19F NMR (CDCl3, 470
MHz): δ -122.8 (m).
5-Fluoro-2-methoxybenzaldehyde: Yield 74%, white solid, Rf
0.75 (40% EtOAc in hexane). 1H NMR (CDCl3, 500 MHz): δ 10.42
(d, J = 3.0 Hz, 1H), 7.51 (dd, J = 8.2 and 3.5 Hz, 1H), 7.26 (m),
6.96 (dd, J = 4.5 and 4.0 Hz, 1H), 3.93 (s, 3H, OMe). 13C NMR
(CDCl3, 125 MHz): δ 188.7 (d, J = 1.9 Hz), 158.2 (d, J = 1.9 Hz),
156.9 (d, 1JCF = 241.3 Hz), 125.5 (d, J = 5.7 Hz), 122.5 (d, J = 23.7
Bioassay Methods
Hz), 114.1 (d, J = 23.9 Hz), 113.2 (d, J = 7.7 Hz), 56.2 (OMe). 19
F
NCI-60 assay: Samples were submitted to the National Cancer
Institute (NCI of NIH) Developmental Therapeutics anticancer
screening program (DTP) for human tumor cell line assay by NCI-
60 screening against leukemia, lung, colon, and CNS cancers, as
well as melanoma, ovarian, renal, prostate, and breast cancers.
Compounds are initially tested at a single dose of 10-5 molar. Data
are reported as mean graph of percent growth (GP). Selected
data output are shown in SI file. Growth inhibition is represented
by values between 0 and 100 and lethality by values less than
zero. Compounds that meet selection criteria based on one-dose
assay are then tested against 60-cell panel at five concentrations.
More details on operating procedures and sample preparation are
reported here: https://dtp.cancer.gov/discovery_development/nci-
60/methodology.htm
NMR (CDCl3, 470 MHz): δ -122.79 (m).
5-Chloro-2-methoxy-d3-benzaldehyde: Yield 79%, white solid,
1
Rf 0.88 (40% EtOAc in hexane). H NMR (CDCl3, 500 MHz): δ
10.42 (s, 1H), 7.80 (d, J = 3.0 Hz, 1H), 7.51 (dd, J = 9.0 and 2.5
Hz, 1H), 6.95 (d, J = 9.5 Hz, 1H). 13C NMR (CDCl3, 125 MHz): δ
188.5, 160.3, 135.4, 128.0, 126.4, 125.6, 113.3, 55.3 (m, OCD3).
Computational Methods
B3LYP/6-31G*[33] geometry optimizations were carried out with
the Gaussian 09 package of programs.[34] Molecular docking
calculations were performed with the software AutoDock Vina
(version 1.1.2)[35] for modeling the binding modes and assessing
the interaction energies of the studied compounds as ligands for
several enzymes. The three-dimensional coordinates of the
proteins were obtained from the RCSB Protein Data Bank (PDB
IDs: 3PP0[36] (HER2), 5XDL[37] (HER1), 3SDK[38] (20S
proteasome), 4AG8[15] (VEGFR2), 4XV2[19] (BRAF), 4LVT[20] (Bcl-
2), and 5X5D[39] (hTS)). Chain A of HER2, HER1, VEGFR2, BRAF,
Bcl-2 and hTS, and chains K (5 subunit) and L (6 subunit) of
20S proteasome were selected as target templates for the
Cell viability, cytotoxicity and apoptosis assay for
colorectal cells: Colorectal cancer (HCT116, HT29, DLD-1,
RKO, SW837 and Caco2) and normal colon cell lines
(CCD841CoN) were obtained from the American Type Culture
Collection (ATCC, Manassas, VA). Cells were maintained in
DMEM medium (Life Technologies, Carlsbad, CA)
supplemented with 10% fetal bovine serum (Life Technologies),
1% non-essential amino acids (Life Technologies), 1%
penicillin-streptomycin (Life Technologies), and 1% glutamine
(Life Technologies) at 37°C and 5% CO2.
docking
computations.
Co-crystallized
ligands
and
crystallographic water molecules were removed. Addition of
9
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
[10]
[11]
K. K. Laali, W. J. Greves, A. T. Zwarycz, S. J. Correa Smits, F. J.
Troendle, G. L. Borosky, S. Akhtar, A. Manna, A. Paulus, A.
Chanan-Khan, M. Nukaya, and G. D. Kennedy. ChemMedChem,
2018, 13, 1895-1908
W. Li, M.-M. Wang, Y. Hu, T. Werner Org. Lett. 2017, 19, 5768-
5771
For the assessment of cell viability, cells were seeded in 96-well
plates with approximately 5.0 x 103 cells / well and incubated in
RPMI1640 medium (supplemented with 10% fetal bovine serum
and 1% glutamine) for 24 hours. Cells were then treated with
RPMI1640 medium containing CUR compounds (10 M, or 1
nM-200 M) or vehicle (DMSO) for 72 hours and the number of
viable cells was determined using CellTiter-Glo cell viability
assay system (Promega, Madison WI). The 50% inhibitory
concentration (IC50) was calculated using GraphPad Prism 7
software (GraphPad Software, San Diego CA).
To investigate cytotoxicity and cell apoptosis induced by CUR
compounds, we used CytoToxTM-Glo assay and Caspase-Glo
3/7 assay systems (Promega). Approximately 1.0×104 cells of
CRC cells (per well) were seeded in a 96-well plate and treated
with RPMI1640 medium containing CUR compounds (10 M or
20 M) or vehicle (DMSO) for 24 hours. After addition of the
reagent (CytoTox-GloTM or Caspase-Glo 3 / 7 Assay System) to
the cell culture medium, luminescence was measured by infinite
M200 Pro microplate reader (TECAN).
[12]
[13]
[14]
[15]
N. Iqbal, N. Iqbal, Mol. Biol. Intell. 2014, 2014, 852748.
I. Alroy, Y. Yarden, FEBS Lett. 1997, 410, 83–86.
N. E. Hynes, H. A. Lane, Nat. Rev. Cancer 2005, 5, 341–354.
M. McTigue, B. W. Murray, J. H. Chen, Y.-L. Deng, J. Solowiej, R.
S. Kania, Proc. Natl. Acad. Sci. USA 2012, 109, 18281–18289.
K. -L. Tan, S. -B. Koh, R. P. -L. Ee, M. Khan, M. -L. Go,
ChemMedChem 2012, 7, 1567–1579.
S. B. Wan, H. Yang, Z. Zhou, Q. -C. Cui, D. Chen, J. Kanwar, I.
Mohammad, Q. P. Dou, T. H. Chan, Int. J. Mol. Med. 2010, 26,
447–455.
V. Milacic, S. Banerjee, K. R. Landis-Piwowar, F. H. Sarkar, A. P.
N. Majumdar, Q. P. Dou, Cancer Res. 2008, 68, 7283-7292.
C. Zhang, W. Spevak, Y. Zhang, E. A. Burton, Y. Ma, G. Habets, J.
Zhang, J. Lin, T. Ewing, B. Matusow, G. Tsang, A. Marimuthu, H.
Cho, G. Wu, W. Wang, D. Fong, H. Nguyen, S. Shi, P. Womack,
M. Nespi, R. Shellooe, H. Carias, B. Powell, E. Light, L. Sanftner,
J. Walters, J. Tsai, B. L. West, G. Visor, H. Rezaei, P. S. Lin, K.
Nolop, P. N. Ibrahim, P. Hirth, G. Bollag, Nature 2015, 526, 583–
586.
[16]
[17]
[18]
[19]
Statistical analysis: All statistical analyses were performed
using GraphPad Prism 7 software. A statistically significant
difference between CUR compound 11 and 11a was determined
using unpaired t-test with Welch’s correction or two-way ANOVA
(Tukey's comparison test). Data were presented as mean ±
standard error of mean and was considered statistically significant
when p-value was < 0.05.
[20]
A. J. Souers, J. D. Leverson, E. R. Boghaert, S. L. Ackler, N. D.
Catron, J. Chen, B. D. Dayton, H. Ding, S. H. Enschede, W. J.
Fairbrother, D. C. S. Huang, S. G. Hymowitz, S. Jin, S. L. Khaw,
P. J. Kovar, L. T. Lam, J. Lee, H. L. Maecker, K. C. Marsh, K. D.
Mason, M. J. Mitten, P. M. Nimmer, A. Oleksijew, C. H. Park, C.-M.
Park, D. C. Phillips, A. W. Roberts, D. Sampath, J. F. Seymour,
M. L. Smith, G. M. Sullivan, S. K. Tahir, C. Tse, M. D. Wendt, Y.
Xiao, J. C. Xue, H. Zhang, R. A.
Humerickhouse, S. H.
Rosenberg, S. W. Elmore, Nat. Med. 2013, 19, 202–208.
[21]
[22]
[23]
P. M. Wilson, P. V. Danenberg, P. G. Johnston, H. J. Lenz, R. D.
Acknowledgements
Ladner, Nat. Rev.
S. P. Ackland, S. J. Clarke, P. Beale, G. J. Peters, Update Cancer
Therap. 2006, 1, 403–427.
T. J. Ettrich, T. Seufferlein in Small Molecules in Oncology, Third
Edition (Ed.: U. M. Martens), Recent Results in Cancer
Clin. Oncol. 2014, 11, 282–298.
KKL thanks University of North Florida for the outstanding faculty
scholarship and presidential professorship awards, faculty
scholarship and UNF Foundation Board grants.
acknowledges funding from CONICET and Secyt-UNC. We also
acknowledge the Developmental Therapeutics Program (DTP) of
the National Cancer Institute for in vitro anticancer screening.
GLB
Research 212. Springer International Publishing AG, Cham,
2018, pp. 45-56.
X. Zhang, Y. Tian, P. Yuan, Y. Li , M.-A. Yaseen, J. Grutzendler J,
A. Moore, C. Ran, Chem. Commun. 2014, 50,1550-1553, b) X.
Zhang, Y. Tian, Z. Li, X. Tian, H. Sun, H. Liu, A. Moore, C. Ran J.
Am. Chem. Soc. 2013, 135, 16397-16409
P. Maiti, G. L. Dunbar Int. J. Mol. Sci. 2018, 19. 1637.
D. Ahmed, P. W. Eide, I. A. Eilertsen, S. A. Danielsen, M. Eknæs,
M. Hektoen, G. E. Lind, R. A. Lothe BMC Cancer. 2018, 18. 1068.
G. Sa, T. Das T. Cell Div. 2008, 3. 14.
A. Link, F. Balaguer, Y. Shen, J. J. Lozano, H. C. Leung, C. R.
Boland, A. Goel PLoS One 2013, 8. e57709.
T. G. Lim, S. Y. Lee, Z. Huang, D. Y. Lim, H. Chen, S. K. Jung, A.
M. Bode, K. W. Lee KW, Dong Z. Cancer Prev. Res. (Phila). 2014,
7. 466-74.
A. Agarwal, A. Kasinathan, R. Ganesan, A. Balasubramanian, J.
Bhaskaran, S. Suresh, R. Srinivasan, K. B. Aravind, N. Sivalingam
Nutr. Res. 2018, 51. 67-81.
S. Sreevalsan, S. Safe S. Curr. Colorectal Cancer Rep. 2013, 9.
350-357.
D. Obermayer, D. Znidar, G. Glotz, A. Stadler, D. Dallinger, C. O.
Kappe J. Org. Chem. 2016, 81, 11788−11801.
[24]
Keywords: CUR-BF2 and CURs; deuterated analogs; X-ray
structures and computational/docking; comparative cytotoxicity;
colorectal cancer
[25]
[26]
[27]
[28]
References
[29]
[30]
[1]
a) G. R. Pillai1, A. S. Srivastava1, T. I. Hassanein, D. P. Chauhan,
E. Carrier, Cancer Letters 2004, 208,163–170; b) A. L. Lopresti1,
S. D. Hood, P. D. Drummond, J. Psychopharmacology 2012, 26,
1512 –1524; c) D. Perrone, F. Ardito, G. Giannatempo, M.
Dioguardi, G. Troiano, L. Lo Russo, A. De Lillo, L. Laino, L. Lo
Muzio, Experimental and Therapeutic Medicine 2015, 10, 1615-
1623
[31]
[32]
[33]
[2]
[3]
[4]
[5]
[6]
[7]
S. C. Gupta, S. Prasad, J. H. Kim, S. Patchva, L. J. Webb, I. K.
Priyadarsini, B. B. Aggarwal, Nat. Prod. Rep. 2011, 28, 1937-1955.
A. Minassi, G. Sánchez-Duffhues, J.A. Collado, E. Muñoz, G.
Appendino, J. Nat. Prod. 2013, 76, 1105-1112.
K. Bairwa, J. Grover, M. Kania, S. M. Jachak, RSC.
Adv. 2014, 4, 13946-13978.
Vyas, P. Dandawate, P. S. Padhye, A. Ahmad, A. F. Sarkar, Curr.
Pharm. Des. 2013, 19, 2047-2069.
S. Burapan, M. Kim, J. Han, J. Agric. Food. Chem. 2017, 65, 3305-
a) A. D. Becke, J. Chem. Phys. 1993, 98, 5648–5652; b) C. Lee,
W. Yang, R. G. Parr, Phys. Rev. B 1988, 37, 785–789; c) B.
Miehlich, A. Savin, H. Stoll, H. Preuss, Chem.
1989, 157, 200–206.
Phys. Lett.
[34]
Gaussian 09, Revision E.01, M. J. Frisch, G. W. Trucks, H. B.
Schlegel, G. E. Scuseria, M. A. Robb, J. R. Cheeseman, G.
Scalmani, V. Barone, B. Mennucci, G. A. Petersson, H.
Nakatsuji, M. Caricato, X. Li, H. P. Hratchian, A. F. Izmaylov, J.
Bloino, G. Zheng, J. L. Sonnenberg, M. Hada, M. Ehara, K.
Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y.
3310
a) S. H. DeWitt, B. E. Maryanoff, Biochemistry, 2018, 57, 472-473;
b) G. S. Timmins Expert Opin Ther Pat. 2014, 24, 1067-1075; Z.
Ding, H. Cheng, S. Wang, Y. Hou; J. Zhao, H. Guan, W. Li, Bioorg
& Med. Chem. Lett. 2017, 27, 1416-1419; Z. Ding, Y. Hou, S.
Wang, T. Sun, M. Ma, H. Guan, W. Li, Mol.Divers 2017, 21, 577-
583; A. Katsnelson, Nature Medicine 2013, 19, 656; A. Mullard,
Nature Rev. Drug. Discovery 2016, 15, 219-221; L. Shao, C.
Abolin, M. C. Hewitt, P. Koch, M. Varney Biochem & Med. Chem.
Lett. 2006, 16, 691-694; R. H. Howland, J. Psychosocial.Nursing
2015, 53, 13-16.
Honda, O. Kitao, H. Nakai, T. Vreven, J. A.
Jr. , J. E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers,
K. N. Kudin, V. N. Staroverov, R. Kobayashi, J. Normand, K.
Montgomery,
Raghavachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi,
M. Cossi, N. Rega, J. M. Millam, M. Klene, J. E. Knox, J. B.
Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E.
Stratmann,
W. Ochterski, R. L. Martin, K.
G. A. Voth, P. Salvador, J. J. Dannenberg, S.
O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J.
Morokuma, V. G. Zakrzewski,
Dapprich, A. D.
[8]
[9]
K.K. Laali, B.M. Rathman, S.D. Bunge, X. Qi, G.L. Borosky, J.
Fluorine.Chem. 2016, 191, 29-41
K. K. Laali, W. J. Greve, S. J. Correa-Smits, A. T. Zwarycz, S. D.
Bunge, G. L. Borosky, A. Manna, A. Paulus, A. Chanan-Khand, J.
Fluorine. Chem. 2018, 206, 82-98
Daniels, Ö. Farkas, J. B. Foresman, J. V. Ortiz, J. Cioslowski, D. J.
Fox, Gaussian, Inc., Wallingford, CT, 2009.
O. Trott, A. J. Olson, J. Comput. Chem. 2010, 31, 455–461.
K. Aertgeerts, R. Skene, J. Yano, B.-C. Sang, H. Zou, G. Snell, A.
[35]
[36]
Jennings, K.
Iwamoto, N. Habuka, A. Hirokawa, T. Ishikawa, T.
10
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
Tanaka, H. Miki, Y. Ohta, S. J.
286, 18756–18765.
X. E. Yan, S. J. Zhu, L. Liang, P. Zhao, H. G. Choi, C. H. Yun,
Oncotarget 2017, 8, 53508-53517.
C. Blackburn, C. Barrett, J. L. Blank, F. J. Bruzzese, N. Bump, L.
R. Dick, P. Fleming, K. Garcia, P. Hales, Z. Hu, M. Jones, J.
Sogabe, J. Biol. Chem. 2011,
[37]
[38]
X. Liu, D. S. Sappal, M. D. Sintchak, C. Tsu, K. M. Gigstad,
Bioorg. Med. Chem. Lett. 2010, 20, 6581–6586.
[39]
[40]
[41]
D. Chen, A. Jansson, D. Sim, A. Larsson, P. Nordlund, J. Biol.
Chem. 2017, 292, 13449-13458.
APEX II, 2005, Bruker AXS, Inc., Analytical X-ray Systems, 5465
East Cheryl Parkway, Madison WI 53711-5373.
SAINT Version 6.45A, 2003, Bruker AXS, Inc., Analytical X-ray
Systems, 5465 East Cheryl Parkway, Madison WI 53711-5373.
G. M. Sheldrick, SHELXT Acta Cryst., 2015, A71 3-8.
SHELXTL V6.12, 2002, Bruker AXS, Inc., Analytical X-ray
Systems, 5465 East, Cheryl Parkway, Madison WI 53711-5373.
K. Brandenburg, 1999. DIAMOND. Crystal Impact GbR, Bonn,
Germany.
[42]
[43]
[44]
11
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201900179
ChemMedChem
FULL PAPER
Entry for the Table of Contents
Text for TOC: Libraries of deuterated CUR-BF2 adducts and CURs bearing two to six OCD3 groups in the aryl rings were synthesized,
in some compounds in combination with OMe and in others in combination with fluorine substituents, for comparison with their
corresponding non-deuterated analogs. The anti-proliferative activity of these compounds were studied by in-vitro bioassay against a
panel of 60 cancer cell lines, and more specifically in human colorectal cancer cells (HCT116, HT29, DLD-1, RKO, SW837, and Caco2)
and in normal colon cells (CCD841CoN).
12
This article is protected by copyright. All rights reserved.