Synthesis and anticancer activity of 4β-alkylamidochalcone and 4β-cinnamido linked podophyllotoxins as apoptotic inducing agents

Article abstract of DOI:10.1016/j.ejmech.2011.11.024

A series of 4β-alkylamidochalcone and 4β-cinnamido linked podophyllotoxin congeners have been synthesized. All the twenty nine compounds were evaluated for anticancer activity against five human cancer cell lines (A-549, A375, MCF-7, HT-29 and ACHN). Some of the synthesized compounds showed good anticancer activity that is comparable to etoposide. The IC₅₀ of compounds 17a and 17f is 2.7 and 2.1 μM respectively against A-549 cancer cell line. Flow cytometric analysis showed that these two compounds arrested the cell cycle in the G2/M phase leading to caspase-3 dependent apoptotic cell death. Further, Hoechst 33258 staining and DNA fragmentation assay also suggested that 17a and 17f induced cell death by apoptosis.

Full text of DOI:10.1016/j.ejmech.2011.11.024

European Journal of Medicinal Chemistry 47 (2012) 530e545
Contents lists available at SciVerse ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and anticancer activity of 4b-alkylamidochalcone and 4b-cinnamido
linked podophyllotoxins as apoptotic inducing agents
,
c
,
a
a
b
a
Ahmed Kamal a , Adla Mallareddy , Paidakula Suresh , V. Lakshma Nayak , Rajesh V.C.R.N.C. Shetti ,
*
N. Sankara Rao a, Jaki R. Tamboli a, Thokhir B. Shaik a, M.V.P.S. Vishnuvardhan b, S. Ramakrishna b
a Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500 607, India
b Pharmacology Division, Indian Institute of Chemical Technology, Hyderabad 500 607, India
c Catalytic Chemistry Chair, Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of 4b-alkylamidochalcone and 4b-cinnamido linked podophyllotoxin congeners have been
Received 23 September 2011
Received in revised form
10 November 2011
Accepted 10 November 2011
Available online 20 November 2011
synthesized. All the twenty nine compounds were evaluated for anticancer activity against five human
cancer cell lines (A-549, A375, MCF-7, HT-29 and ACHN). Some of the synthesized compounds showed
good anticancer activity that is comparable to etoposide. The IC50 of compounds 17a and 17f is 2.7 and
2.1
mM respectively against A-549 cancer cell line. Flow cytometric analysis showed that these two
compounds arrested the cell cycle in the G2/M phase leading to caspase-3 dependent apoptotic cell
death. Further, Hoechst 33258 staining and DNA fragmentation assay also suggested that 17a and 17f
induced cell death by apoptosis.
Keywords:
Apoptosis
Anticancer activity
Caspase-3
Ó 2011 Elsevier Masson SAS. All rights reserved.
Cell cycle analysis
Podophyllotoxin
1. Introduction
nitroanilino moiety at the 4-position instead of a glycoside of eto-
poside, which proved to be more potent than etoposide. GL-331 is
Podophyllotoxin (1) is a well known naturally occurring anti-
tumor lignan lactone isolated from the genus Podophyllum [1].
Podophyllotoxin exhibits cytotoxicity by inhibition of tubulin poly-
merization [2]. The structural modifications of podophyllotoxin
resulted in the development of several clinically useful compounds
like etoposide (2), teniposide (3) and the water-soluble prodrug,
etopophos (4) [3e5]. These compounds have shown to inhibit DNA
topoisomerase-II (topo-II) by stabilizing the covalent topo-II DNA
complex [6] and are used against a variety of cancers [7e9].
However, their clinical use has encountered certain limitations, such
as poor water solubility, development of drug resistance, metabolic
inactivation, and certain toxic effects [10]. In order to obtain better
therapeutic agents, a great number of podophyllotoxin analogs have
been synthesized. This has led to the development of NK-611 (5) and
GL-331 (6) (Fig. 1). The biological studies on these synthesized
analogs have provided a better understanding in the knowledge
relating to the structureeactivity relationships. GL-331 contains a p-
also an inhibitor of topo-II and induces apoptotic cell death through
independent mechanism which contributes to its cytotoxicity [11].
This compound has underwent phase II clinical trials for the treat-
ment of various cancers [12].
Chalcones represent an important group of natural products
[13,14], that received significant attention for their antitumor
properties. In addition, chalcones have been reported for a wide
range of pharmacological activities including cytotoxicity [15] and
anticanceractivity [16,17]. Moreover, recent studieshaveshownthat
these chalcones induce apoptosis in a variety of cell types [18,19].
In chalcones, particularly methoxy chalcones possess potential
anticancer activity. The trimethoxy chalcones synthesized by Ducki
and co-workers [20] showed potential anticancer activity by
binding strongly to tubulin at a site shared with, or close to, the
colchicines binding site [21,22]. The anticancer activity and tubulin
binding property of these chalcones are comparable with com-
bretastatin A-4 (CA-4) and prodrugs of these potential chalcones
are under pre-clinical evaluation. Further, in this trimethoxy chal-
cone series different analogues have been synthesized by different
groups and evaluated for their cytotoxicity. These compounds have
shown promising activity against different cancer cell lines [23].
Substituted cinnamic acids and its derivatives [24] are widely
* Corresponding author. Division of Organic Chemistry, Indian Institute of
Chemical Technology, Hyderabad 500 607, India. Tel.: þ91 40 27193157; fax: þ91 40
27193189.
E-mail address: ahmedkamal@iict.res.in (A. Kamal).
0223-5234/$ e see front matter Ó 2011 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2011.11.024

A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
531
H
In an ongoing effort we have been involved in the development
of new synthetic procedures [32] for the podophyllotoxin-based
compounds and also in the design and synthesis of new analogs
of podophyllotoxin as potential anticancer agents [33,34]. In
continuation of these efforts in search for novel and selective
anticancer agents, we synthesized some new conjugates of podo-
phyllotoxin by linking the chalcone and cinnamic acid moieties to
OH
4
R1
O
5
8
11
10
9
3
2
6
7
O
HO
O
O
R2
O
O
O
1
O
O
O
O
H3CO
OCH3
the
4b-aminopodophyllotoxin scaffold through stable alkane
OCH3
spacers and amide bond formation. These compounds were eval-
uated for their anticancer activity and based on the promising
activity obtained it was considered of interest to investigate their
role in the cell proliferation and apoptosis by using human lung
cancer cell line A-549.
H3CO
OCH3
R3
OR3
(1)
Podophyllotoxin
NO2
R1
R2
HN
O
O
CH3
OH
OH
Etoposide (2)
Teniposide (3)
H
O
O
2. Results and discussion
H
S
2.1. Chemistry
OH
P
HO
Etopophos (4)
NK-611 (5)
OH
CH3
O
H3CO
OCH3
The synthesis of chalcone intermediates 9aeh and 11aeh has
been carried out by synthetic sequence illustrated in Scheme 1.
ClaiseneSchmidt condensation of different acetophenones with
benzaldehydes using ethanol in the presence of aqueous KOH
provide chalcones 9aeh predominantly with E-configuration.
OH
NMe2 NMe2
H
GL 331 (6)
Fig. 1. Structures of podophyllotoxin derivatives.
These chalcones undergo etherification of hydroxyl group with a-
bromoethyl acetate by using K2CO3 as a base in dry DMF to afford
the intermediates 10aeh, which upon hydrolysis with LiOH$H2O
provide the chalcone acids 11aeh. The synthesis of podophyllo-
toxin analogues 14aeh and 15aeh is described in Schemes 2 and 3.
distributed in the plant kingdom and are reported as cellular
antioxidants, anti-inflammatory agents, or inhibitors of enzymes
involved in cell proliferation, and some biological activities
[25e27]. Antitumor activities of various cinnamic acid derivatives
were also explored by many research groups. Particularly, cinnamic
acid ester derivatives showed the potential antitumor activity
[28e30]. Some of methoxy and halo substituted cinnamic acid
derivatives showed good anticancer activity [31].
4b-Aminopodophyllotoxin (12) has been synthesized as described
in our previously reported procedure [32a,33a]. This upon treat-
ment with 6-bromohexanoylchloride gives 13, then followed by
ether bond formation with 9aeh provide the desired conjugates
14aeh as depicted in Scheme 2. Chalcone acids 11aeh on amide
O
O
CHO
R
O
(i)
OH
R1
R1
or
+
OH
9g,h
R1
9a-f
R
R
8
7
(ii)
(ii)
O
O
O
O
R
O
R1
OEt
R1
OEt
OH
O
10g,h
O
O
R
10a-f
(iii)
(iii)
O
O
R
O
R1
OH
R1
O
11a-f
R
11g,h
11a : R = H, R1 = 3,4,5-trimethoxy
11b : R = 3-methoxy, R1 = 3-methoxy
11c : R = 3-methoxy, R1 = 4-methoxy
11d : R = 3-methoxy, R1 = 3-nitro
11e : R = 3-methoxy, R1 = 3,4,5-trimethoxy
11f : R = 3-methoxy, R1 = 4-fluoro
11g : R = H, R1 = 3,4,5-trimethoxy
11h : R = 4-methoxy, R1 = 3,4,5-trimethoxy
Scheme 1. Synthesis of 11aeh. Reagents and conditions: (i) KOH, Ethanol, rt, 12 h; (ii) a-Bromoethyl acetate, K2CO3, DMF, rt, 12 h; (iii) LiOH.H2O, THF, Water, rt, 12 h.

532
A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
O
Br
HN
NH2
O
O
(i)
O
O
O
O
O
O
13
H3CO
OCH3
OCH3
H3CO
OCH3
OCH3
12
(ii)
(ii)
O
O
O
O
O
HN
HN
R3
R3
5
8
4
11
10
3
2
6
7
O
O
O
O
R2
14g,h
R2
O
O
O
9
1
O
O
H3CO
OCH3
OCH3
H3CO
OCH3
OCH3
14a : R2 = H, R3 = 3,4,5-trimethoxy
14a-f
14b : R2 = 3-methoxy, R3 = 3-methoxy
14c : R2 = 3-methoxy, R3 = 4-methoxy
14d : R2 = 3-methoxy, R3 = 3-nitro
14e : R2 = 3-methoxy, R3 = 3,4,5-trimethoxy
14f : R2 = 3-methoxy, R3 = 4-fluoro
14g : R2 = H, R3 = 3,4,5-trimethoxy
14h : R2 = 4-methoxy, R3 = 3,4,5-trimethoxy
Scheme 2. Synthesis of 14aeh. Reagents and conditions: (i) 6-Bromohexanoylchloride, TEA, DCM, rt, 8 h; (ii) 9aeh, K2CO3, Acetone, Reflux, 12 h.
R4
O
R5
O
NH2
HN
O
O
(i)
O
O
O
O
O
O
O
O
H3CO
12
OCH3
15a-f
H3CO
OCH3
OCH3
(ii)
OCH3
O
R5
(iii)
O
HN
O
O
R4
O
O
O
HN
R6
15g,h
O
O
O
H3CO
OCH3
OCH3
O
17a-i
15a : R4 = H, R5 = 3,4,5-trimethoxy
H3CO
OCH3
OCH3
15b : R4 = 3-methoxy, R5 = 3-methoxy
15c : R4 = 3-methoxy, R5 = 4-methoxy
15d : R4 = 3-methoxy, R5 = 3-nitro
17a : R6 = H
17b : R6 = 4-fluoro
15e : R4 = 3-methoxy, R5 = 3,4,5-trimethoxy
15f : R4 = 3-methoxy, R5 = 4-fluoro
15g : R4 = H, R5 = 3,4,5-trimethoxy
15h : R4 = 4-methoxy, R5 = 3,4,5-trimethoxy
17c : R6 = 4- chloro
17d : R6 = 4-bromo
17e : R6 = 4-methoxy
17f : R6 = 4-trifluromethyl
17g : R6 = 4-nitro
17h : R6 = 3,4-dichloro
17i : R6 = 3,4,5-trimethoxy
Scheme 3. Synthesis of 15aeh and 17aei. Reagents and conditions: (i) 11aef, EDCI, HOBT, Dry DCM, rt, 12 h; (ii) 11g,h, EDCI, HOBT, Dry DCM, rt, 12 h; (iii) trans Cinnamic acids
16aei, EDCI, HOBT, Dry DCM, rt, 12 h.

CHO
R7
N
O
O
O
R7
N
O
O
OMe
OH
(ii)
R7
(i)
+
OMe
NH2
20a,b
(iii)
OH
18a : R7 = Me
8b
19a,b
18b : R7 = Ph
R7
N
(vi)
OMe
O
OEt
OH
O
21a,b
O
O
N
(iv)
HN
O
R7
N
H3CO
O
O
R7
OMe
O
O
O
22a,b
24a : R7 = Me
24b : R7 = Ph
O
H3CO
OCH3
OCH3
(v)
O
OCH3
O
N
HN
O
O
O
O
R7
O
23a : R7 = Me
23b : R7 = Ph
H3CO
OCH3
OCH3
Scheme 4. Synthesis of 23a,b and 24a,b. Reagents and conditions: (i) 2,4-Pentanedione, Acetonitrile, HCl, rt, 12 h; (ii) KOH, Ethanol, rt, 12 h; (iii) a-Bromoethyl acetate, K2CO3, DMF,
rt, 12 h; (iv) LiOH.H2O, THF, Water, rt, 12 h; (v) Compound 12, EDCI, HOBT, Dry DCM, rt, 12 h; (vi) Compound 13, K2CO3, Acetone, Reflux, 12 h.
Table 1
Anticancer activity data of compounds 14aeh, 15aeh, 23a,b, 24a,b and 17aeh.
bond formation with 12 using EDCI/HOBt afford the required
analogues 15aeh in good yields as shown in Scheme 3. Precursor 12
on amide bond formation with different trans cinnamic acids
Compound
IC50 values (mM)
Ae549a
A375b
MCF-7c
HT-29d
ACHNe
(16aei) using EDCI/HOBt afford 4b-cinnamido podophyllotoxin
derivatives (17aei) in good yields as shown in Scheme 3.
14a
14b
14c
14d
14e
14f
14g
14h
15a
15b
15c
15d
15e
15f
15g
15h
23a
23b
24a
24b
17a
17b
17c
17d
17e
17f
17g
17h
21.5
14.4
19
10.7
13.6
5.9
14.7
16.7
19.1
9.1
18.4
20.1
13
10.8
9.8
11.4
11.5
10.3
25.8
13.8
9.3
24.8
17.5
12
18.1
10.2
15.8
8.3
12.6
24.2
21.8
16.2
6.7
14.9
19.1
24.4
15.4
13.8
11.2
8.6
15.3
11.9
16
8.75
12.1
11.7
21.1
6.47
12.4
8.1
16.9
8.41
9.54
21.6
15.6
5.98
12.3
7.75
11.8
8.9
16.5
13.7
10
11.9
19.5
9.3
The synthesis of conjugates 23 and 24 is described in Scheme 4.
2-Aminoacetophenone or 2-aminobenzophenone is reacted with
2,4-pentanedione in the presence of acidic medium to give 3-
acetylquinolines (19) which upon ClaiseneSchmidt condensation
with vanillin provide the quinolinochalcones (20). These chalcones
20.8
13.4
10.18
13.8
16.1
13.2
8.51
26.7
9.1
11.1
10.8
15.7
10.7
9.46
3.91
18.6
7.54
14.3
17.8
2.18
12.8
17.7
13.1
0.79
7.61
2.12
91
upon etherification with
a-bromoethyl acetate followed by
hydrolysis provide the intermediates (22) which upon amide bond
formation with precursor 12 using EDCI/HOBt afford the desired
conjugates (23), whereas the conjugates 24 are prepared by
etherification of chalcone intermediates 20 with podophyllotoxin
intermediate (13) as shown in Scheme 4.
8.3
9
5.3
7.8
10.7
26.4
16.8
11.7
15.4
13.4
10.6
7.7
2.7
6.8
8.8
9.5
12.2
18.2
11.5
14.5
7.7
10.3
6.8
13.4
9.5
2.2. Evaluation of biological activity
2.2
19.7
14.6
13.7
11.2
15.7
19.2
10.1
20.1
17.7
2.02
0.68
1.18
108
142
2.36
7.1
2.2.1. Anticancer activity
The newly synthesized compounds (14aeh, 15aeh, 17aei, 23a,b
and 24a,b) were evaluated for their in vitro anticancer activity
against a panel of five human cancer cell lines, A-549 (lung), A375
(melanoma), MCF-7 (breast), HT-29 (colon) and ACHN (renal) by
employing MTT assay. Etoposide, podophyllotoxin and doxorubicin
were used as reference drugs. The results are summarized in Table 1
and expressed as IC50 values. The in vitro screening results revealed
that some of the compounds possess considerable anticancer
activity. Chalcone-podophyllotoxin conjugates (14 and 15) showed
5.7
11.4
19.2
17.6
0.37
18.1
21
8.34
1.06
1.81
0.78
114
75
17.8
19.1
18
14.5
13.2
14
5.51
1.39
2.62
64
7.7
2.1
8.2
8.4
17i
7.9
Doxorubicin
Etoposide
Podophyllotoxin
16a
2.18
2.34
3.75
87
moderate activity against different cancer cell lines (IC50
,
16f
56
91
128
5.3e26.7 M). There is no change in activity with the difference in
m
a
Lung cancer.
Melanoma cancer.
Breast cancer.
Colon cancer.
the length of alkane chain spacer between chalcone and podo-
phyllotoxin moieties. The quinolino-chalcone linked podophyllo-
toxins (23 and 24) showed promising activity with IC50 values
b
c
d
e
ranging from 2.2 to 15.4
mM compared to compounds 14 and 15.
Renal cancer

534
A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
The cinnamido-podophyllotoxinconjugates(17aei)showedgood
activity against A-549 cancer cell line with IC50 values ranging from
2.1 to 9.5 M (Table 1), however showed good to moderate activity
against other cell lines. Moreover 17a and 17f showed significant
activity against A-549 (IC50 of 17a is 2.7 M and 17f is 2.1 M), HT-29
(IC50 of 17a is 2.36 M and 17f is 0.37 M) and ACHN (IC50 of 17a is
3.91 M and 17f is 2.18 M) cancer cell lines whereas etoposide
showed IC50 values 2.34 M, 1.81 M and 7.61 M in respective cell
known as the classic characteristics of apoptosis. It was considered
of interest to investigate the apoptotic inducing effect of the two
potent compounds (17a and 17f) by Hoechst staining (H 33258)
method in A-549 cancer cell line. Therefore cells were treated with
m
m
m
m
17a and 17f at 2 mM and 5 mM concentrations for 24 h wherein
m
etoposide was used as the standard. Manual field quantification of
apoptotic cells based on cytoplasmic condensation, presence of
apoptotic bodies, nuclear fragmentation and relative fluorescence
of the test compounds (17a, 17f and etoposide) revealed that there
was significant increase in the percentage of apoptotic cells
(Fig. 2).
m
m
m
m
m
lines. The IC50 values of these compounds revealed that the cinnamic
acid moiety enhances the anticancer activity compared to the chal-
cone moiety upon linking through alkane spacer.
2.2.2. Hoechst staining
2.2.3. DNA fragmentation assay
Apoptosis is one of the major pathways that lead to the process
of cell death. Chromatin condensation and fragmented nuclei are
DNA fragmentation is well known and a typical biochemical
hallmark of apoptotic cell death. From the in vitro anticancer
Fig. 2. Hoechst staining in A-549 lung cancer cell line, A: A-549 control cells, B: 17a at 2 mM, C: 17a at 5 mM, D: 17f at 2 mM, E: 17f at 5 mM and F: Etop (etoposide) at 2 mM, G: Etop
(etoposide) at 5 mM. The scale bar is 20 mm.

studies it was observed that compounds 17a and 17f significantly
inhibits the growth of human lung cancer cell line A-549. There-
fore it was of interest to determine the mechanism of cell death in
the same cell line. The DNA fragmentation analysis revealed that
compounds 17a and 17f induced a discrete ladder pattern in A-549
cell line at 5
mM after 48 h of incubation thereby showing
significant fragmentation. Etoposide also exhibits DNA fragmen-
tation, however, no fragmentation was observed in untreated cells
(Fig. 3).
2.2.4. Cell cycle analysis
On the basis of the results of anticancer data, detailed biological
studies were focused on compounds 17a and 17f. With a view to
further understand the mode of action of these compounds (17a
and 17f), we examined the effects on cell cycle by flow cytometry in
A-549 cancer cells. In this study A-549 cells were treated with
compounds 17a and 17f for 48 h at concentrations 1 mM and 5 mM.
The data obtained clearly indicated that these compounds show
G2/M cell cycle arrest as compared to the untreated control. These
compounds (17a and 17f) show 61% and 38% of cell accumulation in
G2/M phase respectively at 1
exhibited 67%, 43% of cell accumulation in G2/M phase at 5
concentration (Fig. 4). However, etoposide showed 19% of cell
accumulation in G2/M phase at 1 M concentration and in control
(untreated cells) 9% of G2/M phase was observed. Increase in cell
cycle arrest at G2/M phase was observed upon treatment of A-549
mM concentration, whereas it
mM
m
Fig. 3. DNA fragmentation of compounds 17a and 17f in A-549 lung cancer cells. Lane-
1: Marker (50bp), Lane-2: C-1, untreated control DNA (1 l), Lane-3: C-2, untreated
control DNA (5 l), Lane-4: 17a at 5 M, Lane-5: 17f at 5 M and Lane-6: Etop (eto-
poside) at 5 M. Loaded DNA for 17a, 17f and etoposide is 5 l.
m
m
m
m
cells by these compounds from 1 mM to 5 mM concentration.
m
m
Fig. 4. Flow cytometric analysis of compounds 17a, 17f and etoposide in A-549 lung cancer cell line.

536
A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
180000
160000
140000
120000
100000
80000
60000
40000
20000
0
Reactions were monitored by TLC, performed on silica gel glass
plates containing 60 GF-254, and visualization on TLC was achieved
by UV light or iodine indicator. Column chromatography was per-
formed with Merck 60e120 mesh silica gel. 1H and C-13 NMR
spectra were recorded on Gemini Varian-VXR-unity (200 MHz) or
Bruker UXNMR/XWIN-NMR (300 MHz) instruments. Chemical
shifts (d) are reported in ppm downfield from internal TMS stan-
dard. ESI spectra were recorded on Micro mass, Quattro LC using
ESI þ software with capillary voltage 3.98 kV and ESI mode positive
ion trap detector. High-resolution mass spectra (HRMS) were
recorded on QSTAR XL Hybrid MS/MS mass spectrometer. Melting
points were determined with an Electro thermal melting point
apparatus, and are uncorrected.
Control
17a
17f
Etop
Fig. 5. Effect of compounds 17a and 17f on caspase-3 activity: A-549 cells were treated
for 48 h with 2 M concentration of compounds 17a and 17f. Etoposide (Etop) is used
m
4.1.1. General procedure for the synthesis of compounds 9aeh
Chalcones (9a, 9e, 9g and 9h) were synthesized by means of
a ClaiseneSchmidt condensation reaction, as previously reported
as a positive control. Values indicated are the mean ꢁ SD of two different experiments
performed in triplicates.
[20b,38]. To
a stirred mixture of substituted acetophenone
(1 mmol) and corresponding benzaldehyde (1.1 mmol) in ethanol
(10 ml) was added 50% aqueous solution of potassium hydroxide
(1 ml) and stirred for 6 h at room temperature. After completion of
the reaction checked by TLC, the solvent was evaporated, neutral-
ized with 1N HCl solution and extracted with ethyl acetate
(2 ꢀ 50 ml). The combined organic fractions were washed with
water followed by brine, dried over Na2SO4 and purified by column
chromatography on silica gel using ethyl acetate and hexane to
afford yellow solid.
2.2.5. Caspase-3 activation assay
There are some reports [35e37] that the cell cycle arrest at G2/M
phase takes place by the induction of cellular apoptosis. Hence, it
was considered of interest to understand the correlation of cyto-
toxicity with that to apoptosis by 17a and 17f. Cysteine aspartase
group, namely, caspases play a crucial role in the induction of
apoptosis and amongst them caspase-3 happens to be one of the
effecter caspase. Hence, we treated A-549 cells with 17a and 17f
along with the positive control etoposide and examined the acti-
vation of caspase-3. The results indicate that there is nearly 4e8
4.1.1.1. (E)-3-(4-Hydroxyphenyl)-1-(3,4,5-trimethoxyphenyl)prop-2-
fold induction in caspase-3 activity in cells treated with 2
concentration by these compounds. Interestingly under similar
conditions, etoposide (2 M) also induced the caspase activity by
nearly 6-fold as compared to control as shown in Fig. 5. Therefore
activation of caspase-3 by 17a and 17f indicate that they have the
capacity to induce apoptosis in A-549 cells.
mM
en-1-one (9a). Yellow solid; yield 81%; 1H NMR (300 MHz, CDCl3):
d
7.79 (d, J ¼ 15.1 Hz, 1H, dbH), 7.57 (d, J ¼ 9.0 Hz, 1H, ArH), 7.36 (d,
m
J ¼ 15.1 Hz, 1H, dbH), 7.27 (s, 2H, ArH), 6.91 (d, J ¼ 8.3 Hz, 1H, ArH),
6.05 (br s, 1H, ArOH), 3.95 (s, 6H, eOCH3), 3.93 (s, 3H, eOCH3); ESI-
MS: 315 (M þ H)þ.
4.1.1.2. (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(3-methoxyphenyl)
3. Conclusion
prop-2-en-1-one (9b). Yellow solid; yield 71%; 1H NMR (300 MHz,
CDCl3):
d
7.7 (d, J ¼ 15.67 Hz, 1H, dbH), 7.52e7.58 (dd, J ¼ 7.55,
In conclusion, twenty nine congeners of 4
b-alkylamidochalcone
1.51 Hz, 1H, ArH), 7.49 (d, J ¼ 2.64 Hz, 1H, ArH), 7.3e7.42 (m, 2H,
ArH, dbH), 7.11e7.21 (m, 2H, ArH), 7.03e7.1 (dd, J ¼ 8.1, 2 Hz, 1H,
ArH), 6.78 (d, J ¼ 7.93 Hz, 1H, ArH), 6.01 (br s, 1H, ArOH), 3.94 (s, 3H,
eOCH3), 3.87 (s, 3H, eOCH3); ESI-MS: 285 (M þ H)þ.
as well as 4 -cinnamido linked podophyllotoxins have been
b
synthesized and evaluated for their anticancer potential against
five human cancer cell lines (A-549, A375, MCF-7, HT-29 and
ACHN). Some of these compounds exhibit significant in vitro anti-
cancer activity at micro molar (
compounds (17a and 17f) exhibited promising anticancer activity
(IC50, 2.7 and 2.1 M respectively) against A-549 cancer cell line.
mM) concentration. Two most potent
4.1.1.3. (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(4-methoxyphenyl)
prop-2-en-1-one (9c). Yellow solid; yield 70%; 1H NMR (200 MHz,
m
CDCl3):
d
8.04 (d, J ¼ 8.87 Hz, 2H, ArH), 7.75 (d, J ¼ 15.48 Hz, 1H,
Flow cytometric analysis of these compounds arrested the cell cycle
in the G2/M phase. Hoechst 33258 staining and DNA fragmentation
assay revealed that these compounds induce cell death by
apoptosis. Further, activation of caspase-3 also suggested that these
compounds produce apoptotic cell death. Hence from this data it
can be concluded that linking ofchalcone and cinnamic acid
moieties with podophyllotoxin scaffold through amide bond and
with alkane spacers has not only shown significant anticancer
activity but has provided an insight for future direction in the
development of such molecules.
dbH), 7.4 (d, J ¼ 15.48 Hz, 1H, dbH), 7.19e7.25 (dd, J ¼ 8.3, 1.71 Hz,
1H, ArH), 7.13 (d, J ¼ 1.51 Hz, 1H, ArH), 6.92e7.03 (m, 3H, ArH), 5.96
(br s, 1H, ArOH), 3.96 (s, 3H, eOCH3), 3.89 (s, 3H, eOCH3); ESI-MS:
285 (M þ H)þ.
4.1.1.4. (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(3-nitrophenyl)prop-
2-en-1-one (9d). Yellow solid; yield 75%; 1H NMR (200 MHz,
CDCl3):
d
8.8 (s, 1H, ArH), 8.4e8.44 (dd, J ¼ 7.91, 2.96 Hz, 1H, ArH),
8.32 (d, J ¼ 6.92 Hz, 1H, ArH), 7.8 (d, J ¼ 15.83 Hz, 1H, dbH), 7.69 (t,
J ¼ 7.91 Hz, 1H, ArH), 7.33 (d, J ¼ 15.83 Hz, 1H, dbH), 7.23e7.27 (m,
1H, ArH), 7.12 (d, J ¼ 1.98 Hz, 1H, ArH), 6.95 (d, J ¼ 7.91 Hz, 1H, ArH),
5.83 (br s, 1H, ArOH), 4.0 (s, 3H, eOCH3); ESI-MS: 300 (M þ H)þ.
4. Experimental
4.1. General methods
4.1.1.5. (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(3,4,5-trimethoxy-
phenyl)prop-2-en-1-one (9e). Yellow solid; yield 82%; 1H NMR
All chemicals and reagents were obtained from Aldrich (Sig-
maeAldrich, St. Louis, MO, USA), Lancaster (Alfa Aesar, Johnson
Matthey Company, Ward Hill, MA, USA) or Spectrochem Pvt. Ltd
(Mumbai, India) and were used without further purification.
(200 MHz, CDCl3):
d
7.68 (d, J ¼ 15.86 Hz, 1H, dbH), 7.27 (d,
J ¼ 15.86 Hz, 1H, dbH), 7.16e7.23 (m, 3H, ArH), 7.05 (s, 1H, ArH), 6.89
(d, J ¼ 8.3 Hz, 1H, ArH), 6.16 (br s,1H, ArOH), 3.96 (s, 9H, eOCH3), 3.89
(s, 3H, eOCH3); ESI-MS: 345 (M þ H)þ.

A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
537
4.1.1.6. (E)-1-(4-Fluorophenyl)-3-(4-hydroxy-3-methoxyphenyl)prop-
1H, ArH), 6.82 (d, J ¼ 8.3 Hz, 1H, ArH), 4.7 (s, 2H, eOCH2COe),
4.21e4.31 (q, 2H, eOCH2e), 3.97 (s, 3H, eOCH3), 1.31 (t, J ¼ 7.55,
6.79 Hz, 3H, -CH3); ESI-MS: 386 (M þ H)þ.
2-en-1-one (9f). Yellow solid; yield 67%; 1H NMR (300 MHz, CDCl3):
d
7.98e8.07 (m, 2H, ArH, dbH), 7.66 (d, J ¼ 15.86 Hz,1H, ArH), 7.34 (d,
J ¼ 15.86 Hz,1H, dbH), 7.21e7.29 (m, 1H, ArH), 7.17 (d, J ¼ 8.3 Hz, 2H,
ArH), 7.06 (d, J ¼ 1.51 Hz, 1H, ArH), 6.96 (d, J ¼ 8.3 Hz, 1H, ArH), 3.96
(s, 3H, eOCH3); ESI-MS: 273 (M þ H)þ.
4.1.2.5. (E)-ethyl-2-(2-methoxy-4-(3-oxo-3-(3,4,5-trimethoxyphenyl)
prop-1-en-1-yl)phenoxy)acetate (10e). Yellow solid; yield 76%; 1H
NMR (300 MHz, CDCl3):
d
7.69 (d, J ¼ 15.83 Hz, 1H, dbH), 7.28 (d,
4.1.1.7. (E)-3-(3-Hydroxyphenyl)-1-(3,4,5-trimethoxyphenyl)prop-2-
J ¼ 15.83 Hz,1H, dbH), 7.21 (s, 2H, ArH), 7.17e7.2 (dd, J ¼ 7.9, 1.91 Hz,
1H, ArH), 7.14 (d, J ¼ 1.91 Hz, 1H, ArH), 6.82 (d, J ¼ 8.9 Hz, 1H, ArH),
4.68 (s, 2H, -OCH2CO-), 4.22e4.29 (q, 2H, -OCH2-), 3.94 (s, 6H,
eOCH3), 3.9 (s, 3H, eOCH3), 1.3 (t, J ¼ 6.92 Hz, 3H, eCH3); ESI-MS:
431 (M þ H)þ.
en-1-one (9g). Yellow solid; yield 79%; 1H NMR (200 MHz, CDCl3):
d
7.78 (d, J ¼ 15.79 Hz, 1H, dbH), 7.45 (d, J ¼ 15.79 Hz, 1H, dbH),
7.25e7.34 (m, 3H, ArH), 7.21 (m, 2H, ArH), 6.9e6.98 (m, 1H, ArH),
6.56 (br s, 1H, ArOH), 3.95 (s, 3H, eOCH3), 3.93 (s, 6H, eOCH3); ESI-
MS: 315 (M þ H)þ.
4.1.2.6. (E)-ethyl-2-(4-(3-(4-fluorophenyl)-3-oxoprop-1-en-1-yl)-2-
methoxyphenoxy)acetate (10f). Yellow solid; yield 78%; 1H NMR
4.1.1.8. (E)-3-(3-hydroxy-4-methoxyphenyl)-1-(3,4,5-trimethoxyph-
enyl)prop-2-en-1-one (9h). Yellow solid; yield 85%; 1H NMR
(300 MHz, CDCl3):
d
7.98e8.07 (m, 2H, ArH), 7.66 (d, J ¼ 15.86 Hz,1H,
(300 MHz, CDCl3):
d
7.76 (d, J ¼ 16.02 Hz, 1H, dbH), 7.36 (d,
dbH), 7.34 (d, J ¼ 15.86 Hz, 1H, dbH), 7.21e7.29 (m, 1H, ArH), 7.17 (d,
J ¼ 8.3 Hz, 2H, ArH), 7.06 (d, J ¼ 1.51 Hz, 1H, ArH), 6.96 (d, J ¼ 8.3 Hz,
1H, ArH), 4.64 (s, 2H, -OCH2CO-), 4.22e4.32 (q, 2H, -OCH2-), 3.96 (s,
3H, eOCH3), 1.31 (t, J ¼ 7.06 Hz, 3H, eCH3); ESI-MS: 359 (M þ H)þ.
J ¼ 16.02 Hz, 1H, dbH), 7.25e7.32 (m, 3H, ArH), 7.14 (dd, J ¼ 8.73,
2.18 Hz, 1H, ArH), 6.89 (d, J ¼ 8.7 Hz, 1H, ArH), 5.74 (br s, 1H, ArOH),
3.96 (s, 9H, eOCH3), 3.94 (s, 3H, eOCH3); ESI-MS: 345 (M þ H)þ.
4.1.2. General procedure for the synthesis of compounds 10aeh
To a solution of chalcone (9aeh) (1 mmol) in dry DMF (10 ml)
4.1.2.7. (E)-ethyl-2-(3-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-
1-yl)phenoxy)acetate (10g). Yellow solid; yield 82%; 1H NMR
was added, anhydrous K2CO3 (1 mmol),
a
-bromoethyl acetate
(200 MHz, CDCl3):
d
7.71 (d, J ¼ 15.83 Hz, 1H, dbH), 7.41 (d,
(1.1 mmol) and the mixture was stirred at room temperature for
14 h. The reaction was monitored by TLC. After completion of the
reaction K2CO3 was removed by filtration and diluted the filtrate
with water and extracted with dichloromethane (2 ꢀ 20 ml). The
organic phases were washed with water followed by brine solution,
dried over Na2SO4 and evaporated under vacuum. The residue, thus
obtained was purified by column chromatography using ethyl
acetate and hexane to afford yellow solid.
J ¼ 15.83 Hz, 1H, dbH), 7.28e7.34 (m, 1H, ArH), 7.23 (s, 2H, ArH),
7.21e7.26 (m, 2H, ArH), 7.16 (d, J ¼ 2.26 Hz, 1H, ArH), 6.88e6.93 (dd,
J ¼ 8.3, 2.26 Hz, 1H, ArH), 4.63 (s, 2H, eOCH2COe), 4.23e4.3 (q, 2H,
eOCH2e), 3.94 (s, 6H, eOCH3), 3.9 (s, 3H, eOCH3), 1.31 (t,
J ¼ 6.92 Hz, 3H, eCH3); ESI-MS: 401 (M þ H)þ.
4.1.2.8. (E)-ethyl-2-(2-methoxy-5-(3-oxo-3-(3,4,5-trimethoxyphenyl)
prop-1-en-1-yl)phenoxy)acetate (10h). Yellow solid; yield 79%; 1H
NMR (300 MHz, CDCl3):
d
7.73 (d, J ¼ 15.67 Hz, 1H, dbH), 7.36 (d,
4.1.2.1. (E)-ethyl-2-(4-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-
J ¼ 15.67 Hz, 1H, dbH), 7.27e7.33 (m, 3H, ArH), 7.14e7.18 (dd,
J ¼ 7.83, 1.56 Hz, 1H, ArH), 6.94 (d, J ¼ 7.83 Hz, 1H, ArH), 4.74 (s, 2H,
eOCH2COe), 4.24e4.32 (q, 2H, eOCH2e), 3.96 (s, 9H, eOCH3), 3.94
(s, 3H, eOCH3), 1.31 (t, J ¼ 7.05 Hz, 3H, -CH3); ESI-MS: 431 (M þ H)þ.
1-yl)phenoxy)acetate (10a). Yellow solid; yield 81%; 1H NMR
(300 MHz, CDCl3):
d
7.73 (d, J ¼ 15.86 Hz, 1H, dbH), 7.59 (d,
J ¼ 9.06 Hz, 2H, ArH), 7.32 (d, J ¼ 15.86 Hz, 1H, dbH), 7.22 (s, 2H,
ArH), 6.91 (d, J ¼ 8.3 Hz, 2H, ArH), 4.63 (s, 2H, -OCH2CO-), 4.22e4.32
(q, 2H, eOCH2e), 3.95 (s, 6H, eOCH3), 3.9 (s, 3H, eOCH3), 1.32 (t,
J ¼ 7.06 Hz, 3H, eCH3); ESI-MS: 401 (M þ H)þ.
4.1.3. General procedure for the synthesis of compounds 11aeh
To a solution of compound (10aeh) (1 mmol) in THF (15 ml) and
water (2 ml), LiOH.H2O (3 mmol) was added, and the mixture was
stirred at room temperature for 12 h. The reaction was monitored
by TLC using ethyl acetate. After completion of the reaction the
solvent was removed under vacuum, neutralized with 1N HCl
solution and extracted with dichloromethane (2 ꢀ 20 ml). The
organic phases were washed with water followed by brine solution,
dried over Na2SO4 and evaporated under vacuum to obtain crude
compound which was purified by recrystalization by using ethyl
acetate as solvent to obtain the pure product 11aeh as yellow solid.
4.1.2.2. (E)-ethyl-2-(2-methoxy-4-(3-(3-methoxyphenyl)-3-oxoprop-
1-en-1-yl)phenoxy)acetate (10b). Yellow solid; yield 82%; 1H NMR
(300 MHz, CDCl3):
d
7.7 (d, J ¼ 15.67 Hz, 1H, dbH), 7.52e7.58 (dd,
J ¼ 7.55,1.51 Hz,1H, ArH), 7.49 (d, J ¼ 2.64 Hz,1H, ArH), 7.3e7.42 (m,
2H, ArH, dbH), 7.11e7.21 (m, 2H, ArH), 7.03e7.1 (dd, J ¼ 8.1, 2 Hz,1H,
ArH), 6.78 (d, J ¼ 7.93 Hz, 1H, ArH), 4.68 (s, 2H, eOCH2COe),
4.22e4.31 (q, 2H, -OCH2-), 3.94 (s, 3H, eOCH3), 3.87 (s, 3H, eOCH3),
1.3 (t, J ¼ 7.17 Hz, 3H, -CH3); ESI-MS: 371 (M þ H)þ.
4.1.2.3. (E)-ethyl-2-(2-methoxy-4-(3-(4-methoxyphenyl)-3-oxoprop-
4.1.3.1. (E)-2-(4-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-1-yl)
1-en-1-yl)phenoxy)acetate (10c). Yellow solid; yield 80%; 1H NMR
phenoxy)acetic acid (11a). Yellow solid; yield 72%; 1H NMR
(200 MHz, CDCl3):
d
7.98 (d, J ¼ 9.08 Hz, 2H, ArH), 7.68 (d,
(200 MHz, CDCl3):
d
7.97 (br s, 1H, -COOH), 7.74 (d, J ¼ 15.86 Hz, 1H,
J ¼ 16.15 Hz, 1H, dbH), 7.35 (d, J ¼ 16.15 Hz, 1H, dbH), 7.12e7.18 (m,
2H, ArH), 6.93 (d, J ¼ 9.08 Hz, 2H, ArH), 6.8 (d, J ¼ 8.07 Hz, 1H, ArH),
4.67 (s, 2H, -OCH2CO-), 4.21e4.29 (q, 2H, -OCH2-), 3.94 (s, 3H,
eOCH3), 3.88 (s, 3H, eOCH3), 1.3 (t, J ¼ 7.06 Hz, 3H, -CH3); ESI-MS:
371 (M þ H)þ.
dbH), 7.61 (d, J ¼ 9.06 Hz, 2H, ArH), 7.33 (d, J ¼ 15.86 Hz, 1H, dbH),
7.22 (s, 2H, ArH), 6.92 (d, J ¼ 8.3 Hz, 2H, ArH), 4.65 (s, 2H, eOCH2CO-),
3.95 (s, 6H, eOCH3), 3.9 (s, 3H, eOCH3); ESI-MS: 373 (M þ H)þ.
4.1.3.2. (E)-2-(2-methoxy-4-(3-(3-methoxyphenyl)-3-oxoprop-1-en-
1-yl)phenoxy)acetic acid (11b). Yellow solid; yield 70%; 1H NMR
4.1.2.4. (E)-ethyl-2-(2-methoxy-4-(3-(3-nitrophenyl)-3-oxoprop-1-
(200 MHz, CDCl3):
d
7.94 (br s, 1H, -COOH), 7.7 (d, J ¼ 15.67 Hz, 1H,
en-1-yl)phenoxy)acetate (10d). Yellow solid; yield 75%; 1H NMR
dbH), 7.51e7.58 (dd, J ¼ 7.55, 1.51 Hz, 1H, ArH), 7.5 (d, J ¼ 2.64 Hz,
1H, ArH), 7.31e7.42 (m, 2H, dbH, ArH), 7.13e7.22 (m, 2H, ArH),
7.05e7.11 (dd, J ¼ 8.1, 2 Hz, 1H, ArH), 6.79 (d, J ¼ 7.93 Hz, 1H, ArH),
4.7 (s, 2H, -OCH2CO-), 3.95 (s, 3H, eOCH3), 3.87 (s, 3H, eOCH3); ESI-
MS: 343 (M þ H)þ.
(200 MHz, CDCl3):
d
8.8 (s, 1H, ArH), 8.4e8.46 (dd, J ¼ 8.3, 2.26 Hz,
1H, ArH), 8.3e8.35 (dd, J ¼ 8.3,1.51 Hz,1H, ArH), 7.8 (d, J ¼ 15.86 Hz,
1H, dbH), 7.7 (t, J ¼ 8.3, 7.75 Hz, 1H, ArH), 7.36 (d, J ¼ 15.86 Hz, 1H,
dbH), 7.19e7.24 (dd, J ¼ 8.3, 2.26 Hz, 1H, ArH), 7.17 (d, J ¼ 1.51 Hz,

538
A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
4.1.3.3. (E)-2-(2-methoxy-4-(3-(4-methoxyphenyl)-3-oxoprop-1-en-
White solid; yield 71%; 1H NMR (200 MHz, CDCl3):
d 6.74 (s, 1H,
1-yl)phenoxy)acetic acid (11c). Yellow solid; yield 69%; 1H NMR
ArH), 6.47 (s, 1H, ArH), 6.2 (s, 2H, ArH), 5.96e6.01 (m, 3H,
eOCH2Oe, eNH), 4.53 (d, J ¼ 4.7 Hz, 1H, 1-H), 4.31e4.48 (m, 2H, 11-
H), 3.94 (d, J ¼ 6.04 Hz, 1H, 4-H), 3.74 (s, 3H, eOCH3), 3.71 (s, 6H,
eOCH3), 3.51 (t, J ¼ 6.6 Hz, 1H, eCH2Br), 2.82e2.94 (m, 1H, 3-H),
2.72e2.83 (dd, J ¼ 14.3, 4.7 Hz, 1H, 2-H), 2.2 (t, J ¼ 7.3, 7.1 Hz, 1H,
eCH2COe), 1.79e1.93 (m, 2H, eCH2e), 1.59e1.74 (m, 2H, eCH2e),
1.4e1.54 (m, 2H, eCH2e); ESI-MS: 591 (M þ H)þ.
(200 MHz, CDCl3):
d
7.99 (d, J ¼ 9.08 Hz, 2H, ArH), 7.95 (br s, 1H,
-COOH), 7.68 (d, J ¼ 16.15 Hz, 1H, dbH), 7.36 (d, J ¼ 16.15 Hz, 1H,
dbH), 7.12e7.2 (m, 2H, ArH), 6.95 (d, J ¼ 9.08 Hz, 2H, ArH), 6.81 (d,
J ¼ 8.07 Hz, 1H, ArH), 4.68 (s, 2H, eOCH2COe), 3.95 (s, 3H, eOCH3),
3.88 (s, 3H, eOCH3); ESI-MS: 343 (M þ H)þ.
4.1.3.4. (E)-2-(2-methoxy-4-(3-(3-nitrophenyl)-3-oxoprop-1-en-1-
yl)phenoxy)acetic acid (11d). Yellow solid; yield 61%; 1H NMR
4.1.5. General procedure for the synthesis of compounds 14aeh
To a solution of the compound 13 (1 mmol) and corresponding
chalcone 9aeh (1 mmol) in acetone (15 ml), K2CO3 (1 mmol) was
added and the mixture stirred at reflux for 18 h. The reaction was
monitored by TLC. After completion of the reaction K2CO3 was
removed by filtration and the filtrate was evaporated under
reduced pressure. The residue was purified by column chroma-
tography on silica gel using ethyl acetate and hexane to afford solid.
(300 MHz, CDCl3):
d
8.83 (s,1H, ArH), 8.42e8.47 (dd, J ¼ 8.3, 2.26 Hz,
1H, ArH), 8.31e8.35 (dd, J ¼ 8.3, 1.51 Hz, 1H, ArH), 8.12 (br s, 1H,
eCOOH), 7.82 (d, J ¼ 15.86 Hz, 1H, dbH), 7.7 (t, J ¼ 8.3, 7.75 Hz, 1H,
ArH), 7.37 (d, J ¼ 15.86 Hz,1H, dbH), 7.2e7.25 (dd, J ¼ 8.3, 2.26 Hz,1H,
ArH), 7.17 (d, J ¼ 1.51 Hz,1H, ArH), 6.83 (d, J ¼ 8.3 Hz,1H, ArH), 4.71 (s,
2H, eOCH2COe), 3.95 (s, 3H, eOCH3); ESI-MS: 358 (M þ H)þ.
4.1.3.5. (E)-2-(2-methoxy-4-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-
1-en-1-yl)phenoxy)acetic acid (11e). Yellow solid; yield 76%; 1H
4.1.5.1. 4b-[6-{4-[(E)-3-Oxo-3-(3,4,5-trimethoxyphenyl)-1-propenyl]
NMR (200 MHz, CDCl3):
d
7.97 (br s, 1H, -COOH), 7.68 (d,
phenoxy}hexanamide]-4-desoxy-podophyllotoxin (14a). Yellow solid,
¼ ꢃ128.1 (c ¼ 0.5 in CHCl3); 1H
25
J ¼ 15.83 Hz, 1H, dbH), 7.3 (d, J ¼ 15.83 Hz, 1H, dbH), 7.22 (s, 2H,
ArH), 7.19e7.21 (dd, J ¼ 7.9, 1.91 Hz,1H, ArH), 7.14 (d, J ¼ 1.91 Hz, 1H,
ArH), 6.84 (d, J ¼ 8.9 Hz, 1H, ArH), 4.7 (s, 2H, -OCH2CO-), 3.94 (s, 6H,
eOCH3), 3.9 (s, 3H, eOCH3); ESI-MS: 403 (M þ H)þ.
yield 75%; mp: 242e245 ꢂC; [
NMR (200 MHz, CDCl3):
a]
D
d
7.78 (d, J ¼ 15.1 Hz, 1H, dbH), 7.59 (d,
J ¼ 9.06 Hz, 2H, ArH), 7.35 (d, J ¼ 15.1 Hz, 1H, dbH), 7.27 (s, 2H, ArH),
6.92 (d, J ¼ 9.06 Hz, 2H, ArH), 6.74 (s, 1H, ArH), 6.54 (s,1H, ArH), 6.37
(s, 2H, ArH), 5.91e5.97 (m, 3H, -OCH2O-, -NH), 4.59 (d, J ¼ 3.02 Hz,
1H, 1-H), 4.29e4.42 (m, 2H, 11-H), 4.02 (t, J ¼ 6.04 Hz, 2H, -CH2O-),
3.95 (s, 6H, eOCH3), 3.94 (s, 3H, eOCH3), 3.9 (d, J ¼ 6.04 Hz,1H, 4-H),
3.84 (s, 3H, eOCH3), 3.81 (s, 6H, eOCH3), 3.27e3.33 (dd, J ¼ 9.82,
3.02 Hz, 1H, 2-H), 3.15e3.25 (m, 1H, 3-H), 2.28 (t, J ¼ 7.55, 6.79 Hz,
2H, eCH2COe), 1.66e1.91 (m, 4H, eCH2e), 1.46e1.51 (m, 2H,
4.1.3.6. (E)-2-(4-(3-(4-Fluorophenyl)-3-oxoprop-1-en-1-yl)-2-metho-
xyphenoxy)acetic acid (11f). Yellow solid; yield 66%; 1H NMR
(300 MHz, CDCl3):
d 8e8.07 (m, 2H, ArH), 7.99 (br s, 1H, eCOOH),
7.67 (d, J ¼ 15.86 Hz, 1H, dbH), 7.36 (d, J ¼ 15.86 Hz, 1H, dbH),
7.22e7.29 (m, 1H, ArH), 7.17 (d, J ¼ 8.3 Hz, 2H, ArH), 7.08 (d,
J ¼ 1.51 Hz, 1H, ArH), 6.98 (d, J ¼ 8.3 Hz, 1H, ArH), 4.67 (s, 2H,
eOCH2COe), 3.95 (s, 3H, eOCH3); ESI-MS: 331 (M þ H)þ.
eCH2e); 13C NMR (75 MHz, CDCl3):
d 189.41, 174.34, 167.95, 158.86,
153.25, 152.32, 148.63, 147.45, 143.15, 142.84, 137.64, 134.56, 133.78,
132.45, 130.43, 129.73, 128.24, 120.71, 115.32, 110.24, 108.97, 108.17,
106.42, 101.47, 68.86, 66.28, 60.94, 60.23, 56.37, 56.02, 47.58, 43.37,
41.13, 37.87, 28.04, 26.74, 25.19, 25.48; ESI-MS: 824 (M þ H)þ; HRMS
calcd for C46H50NO13, 824.2642, found 824.2645.
4.1.3.7. (E)-2-(3-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-1-yl)
phenoxy)acetic acid (11g). Yellow solid; yield 72%; 1H NMR
(200 MHz, CDCl3):
d
7.96 (br s, 1H, -COOH), 7.72 (d, J ¼ 15.83 Hz, 1H,
dbH), 7.41 (d, J ¼ 15.83 Hz, 1H, dbH), 7.29e7.36 (m, 1H, ArH), 7.24 (s,
2H, ArH), 7.22e7.28 (m, 2H, ArH), 7.17 (d, J ¼ 2.26 Hz, 1H, ArH),
6.9e6.95 (dd, J ¼ 8.3, 2.26 Hz, 1H, ArH), 4.65 (s, 2H, eOCH2COe),
3.95 (s, 6H, eOCH3), 3.91 (s, 3H, eOCH3); ESI-MS: 373 (M þ H)þ.
4.1.5.2. 4b-[6-{2-Methoxy-4-[(E)-3-(3-methoxyphenyl)-3-oxo-1-
propenyl]phenoxy} hexanamide]-4-desoxy-podophyllotoxin (14b).
25
Yellow solid, yield 78%; mp: 220e223 ꢂC; [
a]
¼ ꢃ124.5 (c ¼ 0.5 in
D
CHCl3); 1H NMR (200 MHz, CDCl3):
d
7.75 (d, J ¼ 16.11 Hz, 1H, dbH),
4.1.3.8. (E)-2-(2-methoxy-5-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-
7.6 (d, J ¼ 8.05 Hz, 1H, ArH), 7.54 (d, J ¼ 2.19 Hz, 1H, ArH), 7.31e7.46
(m, 2H, ArH, dbH), 7.1e7.24 (m, 2H, ArH), 6.89 (d, J ¼ 8.05 Hz, 1H,
ArH), 6.7e6.81 (m, 2H, ArH), 6.54 (s, 1H, ArH), 6.36 (s, 2H, ArH),
5.88e6.03 (m, 3H, eOCH2Oe, eNH), 4.57 (d, J ¼ 4.39 Hz, 1H, 1-H),
4.25e4.45 (m, 2H, 11-H), 4.08 (t, J ¼ 7.32, 6.59 Hz, 2H, eCH2Oe),
3.91 (s, 6H, eOCH3), 3.89 (d, J ¼ 5.23 Hz, 1H, 4-H), 3.83 (s, 3H,
eOCH3), 3.81 (s, 6H, eOCH3), 3.28e3.36 (dd, J ¼ 9.52, 4.39 Hz,1H, 2-
H), 3.16e3.27 (m, 1H, 3-H), 2.27 (t, J ¼ 6.59, 5.86 Hz, 2H, eCH2COe),
1.81e1.9 (m, 2H, eCH2e), 1.66e1.77 (m, 2H, -CH2-), 1.41e1.52 (m,
1-en-1-yl)phenoxy)acetic acid (11h). Yellow solid; yield 69%; 1H
NMR (300 MHz, CDCl3):
d 7.96 (br s, 1H, -COOH), 7.75 (d,
J ¼ 15.67 Hz, 1H, dbH), 7.37 (d, J ¼ 15.67 Hz, 1H, dbH), 7.28e7.33 (m,
3H, ArH), 7.14e7.19 (dd, J ¼ 7.83, 1.56 Hz, 1H, ArH), 6.96 (d,
J ¼ 7.83 Hz, 1H, ArH), 4.75 (s, 2H, eOCH2COe), 3.97 (s, 9H, eOCH3),
3.95 (s, 3H, eOCH3); ESI-MS: 403 (M þ H)þ.
4.1.4. 4b-[6-Bromohexamido]-4-desoxy-podophyllotoxin (13)
To a solution of 6-bromohaxanoic acid (1 mmol) in dry
dichloromethane (20 ml) was added oxalyl chloride (1.5 mmol),
and 2-3 drops of DMF at 0 ꢂC. Reaction mixture was stirred for
6e8 h at room temperature. After completion of the reaction
checked by TLC, the solvent was evaporated under vacuum to get 6-
bromohexanoyl chloride as yellow solid. Dissolved the acid chlo-
ride in dry dichloromethane (20 ml) and was added compound 12
(1 mmol) and triethylamine (2 mmol) at 0 ꢂC. Reaction mixture was
stirred for 8e9 h at room temperature. After completion of reaction,
water (20 ml) was added and compound was extracted with
dichloromethane (2 ꢀ 20 ml). The organic phases were washed
with water followed by brine solution, dried over Na2SO4 and
evaporated under vacuum to obtain crude compound which was
purified by column chromatography by using ethyl acetate and
hexane as mobile phase to obtain the pure product 13 as solid.
2H, eCH2e); 13C NMR (75 MHz, CDCl3):
d 190.15, 174.18, 168.47,
159.93, 152.68, 149.85, 148.83, 148.24, 147.35, 143.69, 139.87, 137.46,
134.48, 132.2, 130.61, 129.47, 128.77, 122.38, 121.48, 120.88, 119.25,
116.8, 112.64, 111.46, 109.92, 109.05, 108.21, 101.43, 68.4, 67.79,
60.94, 56.35, 55.87, 55.25, 47.57, 43.42, 41.87, 37.28, 28.93, 26.34,
25.39, 25.62; ESI-MS: 794 (M þ H)þ; HRMS calcd for C45H48NO12
,
794.1208, found 794.1199.
4.1.5.3. 4b-[6-{2-Methoxy-4-[(E)-3-(4-methoxyphenyl)-3-oxo-1-pro-
penyl]phenoxy}hexanamide]-4-desoxy-podophyllotoxin(14c). Yellow
25
solid, yield 72%; mp: 219ꢃ222 ꢂC; [
a]
D
¼ ꢃ121.8 (c ¼ 0.5 in CHCl3);
1H NMR (200 MHz, CDCl3):
d
8.03 (d, J ¼ 8.68 Hz, 2H, ArH), 7.74 (d,
J ¼ 15.48 Hz, 1H, dbH), 7.4 (d, J ¼ 15.48 Hz, 1H, dbH), 7.17e7.24 (dd,
J ¼ 8.12, 2.2 Hz, 1H, ArH), 7.15 (d, J ¼ 2.2 Hz, 1H, ArH), 6.98 (d,
J ¼ 8.87 Hz, 2H, ArH), 6.88 (d, J ¼ 8.3 Hz, 1H, ArH), 6.74 (s, 1H, ArH),

A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
539
6.54 (s, 1H, ArH), 6.36 (s, 2H, ArH), 5.83e5.98 (m, 3H, eOCH2Oe,
eNH), 4.56 (d, J ¼ 3.8 Hz, 1H, 1-H), 4.28e4.2 (m, 2H, 11-H), 4.06 (t,
J ¼ 6.61, 6.42 Hz, 2H, eCH2Oe), 3.9 (s, 3H, eOCH3), 3.89 (s, 3H,
eOCH3), 3.87 (d, J ¼ 5.24 Hz,1H, 4-H), 3.83 (s, 3H, eOCH3), 3.8 (s, 6H,
eOCH3), 3.29e3.37 (dd, J ¼ 9.82, 3.8 Hz, 1H, 2-H), 3.14e3.28 (m, 1H,
3-H), 2.28 (t, J ¼ 7.55 Hz, 2H, eCH2COe), 1.66e1.94 (m, 4H, eCH2e),
2H, eCH2e); 13C NMR (75 MHz, CDCl3):
d
188.94, 174.11, 168.27,
152.67, 149.79, 148.87, 148.23, 147.59, 144.12, 137.21, 134.67, 132.23,
131.24, 130.89, 130.35, 128.41, 122.37, 121.27, 116.37, 116.05, 115.76,
111.85, 109.91, 109.14, 108.08, 101.44, 68.87, 67.42, 60.23, 56.97,
55.73, 47.37, 43.79, 41.46, 37.23, 28.87, 26.54, 25.61, 25.38; ESI-MS:
782 (M þ H)þ; HRMS calcd for C44H45FNO11, 782.1185, found
782.1173.
1.45e1.59 (m, 2H, eCH2e); 13C NMR (75 MHz, CDCl3):
d 188.02,
174.09, 168.43, 163.95, 152.23, 149.3, 148.65, 148.28, 147.67, 143.85,
137.54, 134.64, 132.56, 130.75, 130.36, 130.98, 128.44, 122.38, 121.3,
116.74, 113.39, 111.74, 109.94, 109.12, 108.25, 101.6, 70.64, 68.35,
60.57, 56.15, 55.67, 55.32, 47.57, 43.63, 41.08, 37.72, 28.21, 26.74, 25.6,
25.53; ESI-MS: 794 (M þ H)þ; HRMS calcd for C45H48NO12, 794.1215,
found 794.1211.
4.1.5.7. 4
b-[6-{3-[(E)-3-Oxo-3-(3,4,5-trimethoxyphenyl)-1-propenyl]
phenoxy} hexanamide]-4-desoxy-podophyllotoxin (14g). Yellow
25
solid, yield 70%; mp: 235e237 ꢂC; [
a]
¼ ꢃ127.6 (c ¼ 0.5 in CHCl3);
D
1H NMR (200 MHz, CDCl3):
d
7.76 (d, J ¼ 15.67 Hz, 1H, dbH), 7.45 (d,
J ¼ 15.67 Hz, 1H, dbH), 7.33 (t, J ¼ 7.93, 7.74 Hz, 1H, ArH), 7.27 (s, 2H,
ArH), 7.21e7.26 (m, 1H, ArH), 7.15 (d, J ¼ 2.07 Hz, 1H, ArH),
6.92e6.98 (dd, J ¼ 7.93, 2.26 Hz, 1H, ArH), 6.74 (s, 1H, ArH), 6.53 (s,
1H, ArH), 6.36 (s, 2H, ArH), 5.9e6.01 (m, 3H, eOCH2Oe, eNH), 4.59
(d, J ¼ 3.39 Hz, 1H, 1-H), 4.3e4.44 (m, 2H, 11-H), 4.02 (t, J ¼ 6.42,
6.23 Hz, 2H, eCH2Oe), 3.95 (s, 6H, eOCH3), 3.94 (s, 3H, eOCH3),
3.85 (d, J ¼ 6.04 Hz, 1H, 4-H), 3.83 (s, 3H, eOCH3), 3.81 (s, 6H,
eOCH3), 3.27e3.33 (dd, J ¼ 10.1, 3.39 Hz, 1H, 2-H), 3.15e3.25 (m,
1H, 3-H), 2.28 (t, J ¼ 7.55 Hz, 2H, eCH2COe), 1.69e1.89 (m, 4H,
eCH2e), 1.49e1.58 (m, 2H, eCH2e); 13C NMR (75 MHz, CDCl3):
4.1.5.4. 4
b-[6-{2-Methoxy-4-[(E)-3-(3-nitrophenyl)-3-oxo-1-prope-
nyl]phenoxy} hexanamide]-4-desoxy-podophyllotoxin (14d). Yellow
25
solid, yield 65%; mp: 257e260 ꢂC; [
a
]
¼ ꢃ118.6 (c ¼ 0.5 in CHCl3);
D
1H NMR (200 MHz, CDCl3):
d
8.83 (s, 1H, ArH), 8.41e8.47 (dd,
J ¼ 8.68, 2.26 Hz,1H, ArH), 8.32e8.38 (dd, J ¼ 7.55, 1.51 Hz,1H, ArH),
7.84 (d, J ¼ 15.48 Hz, 1H, dbH), 7.71 (t, J ¼ 7.93 Hz, 1H, ArH), 7.37 (d,
J ¼ 15.48 Hz, 1H, dbH), 7.23e7.26 (m, 1H, ArH), 7.17 (d, J ¼ 2.06 Hz,
1H, ArH), 6.91 (d, J ¼ 8.3 Hz, 1H, ArH), 6.74 (s, 1H, ArH), 6.54 (s, 1H,
ArH), 6.36 (s, 2H, ArH), 5.91e5.99 (m, 3H, eOCH2Oe, eNH), 4.59 (d,
J ¼ 3.8 Hz, 1H, 1-H), 4.3e4.41 (m, 2H, 11-H), 4.09 (t, J ¼ 6.61, 6.23 Hz,
2H, eCH2Oe), 3.93 (s, 3H, eOCH3),3.88 (d, J ¼ 5.54 Hz, 1H, 4-H),
3.83 (s, 3H, eOCH3), 3.81 (s, 6H, eOCH3), 3.27e3.34 (dd, J ¼ 9.81,
3.8 Hz, 1H, 2-H), 3.15e3.26 (m, 1H, 3-H), 2.29 (t, J ¼ 7.36 Hz, 2H,
eCH2COe), 1.85e1.87 (m, 2H, eCH2e), 1.69e1.82 (m, 2H, eCH2e),
1.49e1.57 (m, 2H, eCH2e); ESI-MS: 809 (M þ H)þ; HRMS calcd for
C44H45N2O13, 809.1258, found 809.1245.
d
190.14,174.13,168.23,157.28,153.45,152.55,148.64,147.42,143.18,
142.35, 137.24, 136.89, 134.57, 133.24, 132.35, 130.48, 128.69, 122.86,
122.23, 116.56, 114.82, 110.15, 108.58, 108.1, 106.08, 101.6, 68.48,
67.35, 60.85, 60.32, 56.74, 56.07, 47.21, 43.88, 41.45, 37.34, 28.64,
26.35, 25.78, 25.32; ESI-MS: 824 (M þ H)þ; HRMS calcd for
C46H50NO13, 824.1908, found 824.1925.
4.1.5.8. 4
b-[6-{2-Methoxy-5-[(E)-3-oxo-3-(3,4,5-trimethoxyphenyl)-
1-propenyl]phenoxy} hexanamide]-4-desoxy-podophyllotoxin (14h).
25
4.1.5.5. 4
b
-[6-{2-Methoxy-4-[(E)-3-(3,4,5-trimethoxyphenyl)-3-oxo-
Yellow solid, yield 71%; mp: 241e243 ꢂC; [
a]
¼ ꢃ119.5 (c ¼ 0.5 in
D
1-propenyl]phenoxy} hexanamide]-4-desoxy-podophyllotoxin (14e).
CHCl3); 1H NMR (200 MHz, CDCl3):
d
7.73 (d, J ¼ 15.61 Hz, 1H, dbH),
25
Yellow solid, yield 77%; mp: 245e248 ꢂC; [
a]
¼ ꢃ127.1 (c ¼ 0.5 in
7.32 (d, J ¼ 15.61 Hz, 1H, dbH), 7.22e7.29 (m, 3H, ArH), 7.16 (d,
J ¼ 2.08 Hz, 1H, ArH), 6.9 (d, J ¼ 8.32 Hz, 1H, ArH), 6.74 (s, 1H, ArH),
6.53 (s, 1H, ArH), 6.35 (s, 2H, ArH), 5.91e5.99 (m, 3H, eOCH2Oe,
eNH), 4.59 (d, J ¼ 3.12 Hz, 1H, 1-H), 4.29e4.41 (m, 2H, 11-H), 4.07 (t,
J ¼ 6.24 Hz, 2H, eCH2Oe), 3.94 (s, 6H, eOCH3), 3.93 (s, 3H, eOCH3),
3.91 (s, 3H, eOCH3), 3.88 (d, J ¼ 5.2 Hz, 1H, 4-H), 3.83 (s, 3H,
eOCH3), 3.8 (s, 6H, eOCH3), 3.29e3.34 (dd, J ¼ 10.41, 3.12 Hz,1H, 2-
H), 3.17e3.26 (m, 1H, 3-H), 2.29 (t, J ¼ 7.28 Hz, 2H, eCH2COe),
1.85e1.94 (m, 2H, eCH2e), 1.66e1.81 (m, 2H, eCH2e), 1.51e1.59 (m,
D
CHCl3); 1H NMR (200 MHz, CDCl3):
d
7.76 (d, J ¼ 15.48 Hz, 1H, dbH),
7.32 (d, J ¼ 15.48 Hz, 1H, dbH), 7.21e7.27 (m, 3H, ArH), 7.14 (d,
J ¼ 1.88 Hz, 1H, ArH), 6.9 (d, J ¼ 8.3 Hz, 1H, ArH), 6.74 (s, 1H, ArH),
6.54 (s, 1H, ArH), 6.36 (s, 2sH, ArH), 5.91e5.97 (m, 3H, eOCH2Oe,
eNH), 4.55 (d, J ¼ 3.39 Hz, 1H,1-H), 4.51e4.43 (m, 2H,11-H), 4.08 (t,
J ¼ 6.42 Hz, 2H, eCH2Oe), 3.95 (s, 6H, eOCH3), 3.94 (s, 3H, eOCH3),
3.88 (s, 3H, eOCH3), 3.86 (d, J ¼ 5.1 Hz, 1H, 4-H), 3.83 (s, 3H,
eOCH3), 3.81 (s, 6H, eOCH3), 3.27e3.35 (dd, J ¼ 9.82, 3.39 Hz, 1H,
2-H), 3.14e3.27 (m, 1H, 3-H), 2.28 (t, J ¼ 7.74, 7.16 Hz, 2H,
eCH2COe), 1.83e1.96 (m, 2H, eCH2e), 1.67e1.81 (m, 2H, eCH2e),
2H, eCH2e); 13C NMR (75 MHz, CDCl3):
d 188.52, 173.63, 168.57,
153.83, 152.92, 151.37, 148.4, 147.63, 147.02, 143.18, 142.49, 137.1,
135.62, 133.3, 132.58, 128.41, 124.43, 120.12, 116.23, 112.4, 109.98,
109.07, 108.86, 108.03, 106.25, 101.3, 68.97, 68.32, 60.92, 60.76,
56.42, 56.15, 47.62, 45.64, 43.25, 39.07, 37.44, 28.12, 26.81, 25.6,
1.46e1.58 (m, 2H, eCH2e); 13C NMR (75 MHz, CDCl3):
d 189.41,
178.5, 173.38, 153.5, 153.07, 149.41, 147.71, 147.26, 145, 142.31,
138.36, 133.73, 130.85, 130.47, 128.36, 127.7, 122.94, 119.68, 112.46,
111.13, 109.86, 106.54, 106.09, 104.89, 101.29, 68.76, 68.64, 60.92,
60.78, 56.4, 56.16, 47.92, 45.26, 44.59, 38.08, 36.44, 28.65, 27.61,
25.35; ESI-MS: 854 (M þ H)þ; HRMS calcd for C47H52NO14
,
854.1091, found 854.1075.
25.62, 25.29; ESI-MS: 854 (M þ H)þ; HRMS calcd for C47H52NO14
,
854.1095, found 854.1086.
4.1.6. General procedure for the synthesis of compounds 15aeh
To a solution of compound 12 (1.0 mmol) in dichloromethane
(20 ml) was added EDCI.HCl (1.1 mmol) and HOBt (0.1 mmol). Then
added corresponding chalcone acids (11aeh) (1.0 mmol) and the
reaction mixture was stirred at room temperature for 24 h. The
reaction was monitored by TLC. After completion of reaction, water
was added to reaction mixture and extracted with dichloro-
methane (2 ꢀ 30 ml). The solvent was evaporated under reduced
pressure to afford the crude product which was further purified by
column chromatography on silica gel using ethyl acetate and
hexane as solvent system to obtain the pure products as solids.
4.1.5.6. 4
b-[6-{2-Methoxy-4-[(E)-3-(4-fluorophenyl)-3-oxo-1-prope-
nyl]phenoxy} hexanamide]-4-desoxy-podophyllotoxin (14f). Yellow
25
solid, yield 73%; mp: 214e217 ꢂC; [
a]
¼ ꢃ120.4 (c ¼ 0.5 in CHCl3);
D
1H NMR (200 MHz, CDCl3):
d
7.96e8.09 (m, 2H, ArH), 7.7 (d,
J ¼ 15.86 Hz, 1H, dbH), 7.31 (d, J ¼ 15.86 Hz, 1H, dbH), 7.2e7.25 (m,
1H, ArH), 7.09 (d, J ¼ 2.26 Hz, 1H, ArH), 7.17 (d, J ¼ 9.06 Hz, 2H, ArH),
6.97 (d, J ¼ 8.3 Hz, 1H, ArH), 6.7 (s, 1H, ArH), 6.49 (s, 1H, ArH), 6.31
(s, 2H, ArH), 5.9e5.98 (m, 3H, eOCH2Oe, eNH), 4.57 (d, J ¼ 3.12 Hz,
1H,1-H), 4.22e4.42 (m, 2H,11-H), 4.04 (t, J ¼ 6.04 Hz, 2H, eCH2Oe),
3.88 (s, 3H, eOCH3), 3.85 (d, J ¼ 5.4 Hz, 1H, 4-H), 3.81 (s, 3H,
eOCH3), 3.8 (s, 6H, eOCH3), 3.16e3.23 (dd, J ¼ 9.8, 3.12 Hz, 1H, 2-
H), 3.07e3.15 (m, 1H, 3-H), 2.26 (t, J ¼ 6.79, 5.28 Hz, 2H, eCH2COe),
1.81e1.93 (m, 2H, eCH2e), 1.63e1.8 (m, 2H, eCH2e), 1.51e1.6 (m,
4.1.6.1. 4b-[2-{4-[(E)-3-Oxo-3-(3,4,5-trimethoxyphenyl)-1-propenyl]
phenoxy} acetamide]-4-desoxy-podophyllotoxin (15a). Yellow solid,
25
yield 61%; mp: 246e248 ꢂC; [
a
]
¼ ꢃ120.5 (c ¼ 0.5 in CHCl3); 1H
D

540
A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
NMR (200 MHz, CDCl3):
d
7.68 (d, J ¼ 15.86 Hz, 1H, dbH), 7.6 (d,
eOCH3), 3.88 (d, J ¼ 6.04 Hz, 1H, 4-H), 3.77 (s, 6H, eOCH3), 3.69 (s,
3H, eOCH3), 2.84e3.02 (m, 1H, 3-H), 2.65e2.76 (dd, J ¼ 14.35,
4.5 Hz, 1H, 2-H); ESI-MS: 753 (M þ H)þ; HRMS calcd for
C40H37N2O13, 753.1149, found 753.1157.
J ¼ 8.3 Hz, 2H, ArH), 7.33 (d,, J ¼ 15.86 Hz,1H, dbH), 7.23 (s, 2H, ArH),
6.93 (d, J ¼ 8.3 Hz, 2H, ArH), 6.61 (s, 1H, ArH), 6.56 (br s, 1H, eNH),
6.48 (s, 1H, ArH), 6.2 (s, 2H, ArH), 5.93 and 5.95 (AB q, J ¼ 1.51 Hz,
2H, eOCH2Oe), 4.6 (s, 2H, eCOCH2Oe), 4.51 (d, J ¼ 5.28 Hz, 1H, 1-
H), 4.36e4.44 (m, 2H, 11-H), 3.94 (s, 6H, OCH3), 3.9 (s, 3H, eOCH3),
3.87 (d, J ¼ 6.04 Hz, 1H, 4-H), 3.77 (s, 3H, eOCH3), 3.72 (s, 6H,
eOCH3), 2.85e3.03 (m, 1H, 3-H), 2.66e2.77 (dd, J ¼ 14.35, 5.28 Hz,
4.1.6.5. 4b-[2-{2-Methoxy-4-[(E)-3-(3,4,5-trimethoxyphenyl)-3-oxo-
1-propenyl]phenoxy} acetamide]-4-desoxy-podophyllotoxin (15e).
25
Yellow solid, yield 72%; mp: 248e251 ꢂC; [
a
]
D
¼ ꢃ121.8 (c ¼ 0.5 in
1H, 2-H); 13C NMR (75 MHz, CDCl3):
d
188.92,173.92, 167.89,158.43,
CHCl3); 1H NMR (200 MHz, CDCl3):
d
7.73 (d, J ¼ 15.1 Hz, 1H, dbH),
153.01, 152.51, 148.39, 147.55, 143.62, 142.42, 137.2, 134.48, 133.32,
132.35, 130.26, 129.26, 128.08, 120.39, 115.01, 110.02, 108.79, 108.08,
106.01, 101.56, 68.64, 66.98, 60.85, 60.6, 56.29, 56.09, 47.77, 43.63,
7.29 (d, J ¼ 15.48 Hz, 1H, dbH), 7.19e7.26 (m, 3H, ArH), 7.13 (d,
J ¼ 1.88 Hz, 1H, ArH), 6.8 (d, J ¼ 8.3 Hz, 1H, ArH), 6.71 (s, 1H, ArH),
6.58 (br s, 1H, eNH), 6.53 (s, 1H, ArH), 6.36 (s, 2H, ArH), 5.94 and
5.96 (AB q, J ¼ 1.4 Hz, 2H, eOCH2Oe), 4.63 (s, 2H, eCOCH2Oe), 4.45
(d, J ¼ 4.9 Hz, 1H, 1-H), 4.35e4.41 (m, 2H, 11-H), 3.94 (s, 6H,
eOCH3), 3.93 (s, 3H, eOCH3), 3.91 (s, 3H, eOCH3), 3.87 (d,
J ¼ 6.04 Hz, 1H, 4-H), 3.83 (s, 3H, eOCH3), 3.81 (s, 6H, eOCH3),
2.95e3.03 (m, 1H, 3-H), 2.85e2.55 (dd, J ¼ 14.35, 4.9 Hz, 1H, 2-H);
41.53, 37.08; ESI-MS: 768 (M þ H)þ; HRMS calcd for C42H42NO13
,
768.1764, found 768.1753.
4.1.6.2. 4b-[2-{2-Methoxy-4-[(E)-3-(3-methoxyphenyl)-3-oxo-1-pro-
penyl]phenoxy} acetamide]-4-desoxy-podophyllotoxin (15b). Yellow
25
solid, yield 67%; mp:225e228 ꢂC; [
NMR (200 MHz, CDCl3):
a]
¼ ꢃ117.1 (c ¼ 0.5 inCHCl3);1H
13C NMR (75 MHz, CDCl3):
d 189.67, 178.27, 173.5, 153.86, 153.01,
D
d
7.69 (d, J ¼ 15.86 Hz, 1H, dbH), 7.55e7.59
149.69, 147.35, 146.85, 145.21, 142.46, 138.72, 133.82, 130.8, 130.15,
128.81, 127.9, 122.91, 119.67, 112.23, 110.58, 109.36, 106.84, 106.07,
105.1, 101.2, 69.86, 68.5, 60.76, 60.05, 56.88, 56.08, 54.62, 47.26,
43.43, 41.32, 37.04; ESI-MS: 798 (M þ H)þ; HRMS calcd for
C43H44NO14, 798.2755, found 798.2761.
(dd, J ¼ 7.55, 1.51 Hz, 1H, ArH), 7.49e7.52 (dd, J ¼ 3.02, 1.51 Hz, 1H,
ArH), 7.33e7.42 (m, 2H, ArH, dbH), 7.23e7.3 (m, 1H, ArH), 7.07e7.12
(dd, J ¼ 8.3, 3.02 Hz, 1H, ArH), 7.06 (d, J ¼ 2.26 Hz, 1H, ArH), 6.98 (d,
J ¼ 8.3 Hz,1H, ArH), 6.63 (s,1H, ArH), 6.54 (s, 1H, ArH), 6.51 (br s, 1H,
eNH), 6.24 (s, 2H, ArH), 5.96 and 5.98 (AB q, J ¼ 1.51 Hz, 2H,
eOCH2Oe), 4.63 (s, 2H, eCOCH2Oe), 4.6 (d, J ¼ 4.53 Hz, 1H, 1-H),
4.34e4.42 (m, 2H,11-H), 3.89 (s, 3H, eOCH3), 3.86 (d, J ¼ 5.4 Hz, 1H,
4-H), 3.81 (s, 3H, eOCH3), 3.75 (s, 6H, eOCH3), 3.69 (s, 3H, eOCH3),
2.86e3.02 (m, 1H, 3-H), 2.75e2.83 (dd, J ¼ 14.35, 4.53 Hz, 1H, 2-H);
4.1.6.6. 4b-[2-{2-Methoxy-4-[(E)-3-(4-fluorophenyl)-3-oxo-1-prope-
nyl]phenoxy} acetamide]-4-desoxy-podophyllotoxin (15f). Yellow
25
solid, yield 67%; mp: 216e219 ꢂC; [
a]
¼ ꢃ120.8 (c ¼ 0.5 in CHCl3);
D
1H NMR (200 MHz, CDCl3):
d
7.99e8.09 (m, 2H, ArH), 7.68 (d,
13C NMR (75 MHz, CDCl3):
d
189.97, 173.99, 168.53, 159.82, 152.59,
J ¼ 15.67 Hz, 1H, dbH), 7.35 (d, J ¼ 15.67 Hz, 1H, dbH), 7.2e7.29 (m,
1H, ArH), 7.18 (d, J ¼ 8.3 Hz, 2H, ArH), 7.06 (d, J ¼ 1.51 Hz, 1H, ArH),
6.98 (d, J ¼ 8.3 Hz, 1H, ArH), 6.64 (s, 1H, ArH), 6.55 (br s, 1H, eNH),
6.53 (s, 1H, ArH), 6.24 (s, 2H, ArH), 5.96 and 5.98 (AB q, J ¼ 1.32 Hz,
2H, eOCH2Oe), 4.63 (s, 2H, eCOCH2Oe), 4.59 (d, J ¼ 4.91 Hz, 1H, 1-
H), 4.33e4.41 (m, 2H, 11-H), 3.91 (s, 3H, eOCH3), 3.88 (d, J ¼ 5.4 Hz,
1H, 4-H), 3.74 (s, 6H, eOCH3), 3.7 (s, 3H, eOCH3), 2.86e3.02 (m, 1H,
3-H), 2.74e2.83 (dd, J ¼ 13.97, 4.91 Hz, 1H, 2-H); 13C NMR (75 MHz,
149.8,148.8,148.37,147.58,143.9,139.44,137.28,134.52,132.16,130.8,
129.51, 128.58, 122.5, 121.6, 120.91, 119.06, 116.68, 112.98, 111.32,
109.96, 109.01, 108.11, 101.56, 70.11, 68.68, 60.67, 56.16, 55.64, 55.43,
47.6, 43.73, 41.69, 37.11; ESI-MS: 738 (M þ H)þ; HRMS calcd for
C41H40NO12, 738.2461, found 738.2448.
4.1.6.3. 4b-[2-{2-Methoxy-4-[(E)-3-(4-methoxyphenyl)-3-oxo-1-pro-
penyl]phenoxy} acetamide]-4-desoxy-podophyllotoxin (15c). Yellow
CDCl3):
d 188.56, 174.02, 168.48, 152.59, 149.81, 148.93, 148.37,
25
solid, yield 67%; mp: 223e226 ꢂC; [
a]
D
¼ ꢃ119.4 (c ¼ 0.5 in CHCl3);
147.58, 144.07, 137.34, 134.51, 132.16, 131.07, 130.94, 130.67, 128.59,
122.46, 121.09, 116.66, 115.82, 115.53, 111.42, 109.97, 109.01, 108.12,
101.56, 70.07, 68.68, 60.66, 56.16, 55.66, 47.59, 43.73, 41.69, 37.09;
ESI-MS: 726 (M þ H)þ; HRMS calcd for C40H37NO11, 726.2317, found
726.2301.
1H NMR (200 MHz, CDCl3):
d
8.0 (d, J ¼ 8.68 Hz, 2H, ArH), 7.66 (d,
J ¼ 15.48 Hz, 1H, dbH), 7.39 (d, J ¼ 15.48 Hz, 1H, dbH), 7.32 (d,
J ¼ 7.9 Hz, 1H, ArH), 7.21e7.27 (m, 1H, ArH), 7.05 (d, J ¼ 2.2 Hz, 1H,
ArH), 6.95 (d, J ¼ 8.63 Hz, 2H, ArH), 6.55 (br s, 1H, eNH), 6.63 (s, 1H,
ArH), 6.53 (s, 1H, ArH), 6.24 (s, 2H, ArH), 5.95 and 5.97 (AB q,
J ¼ 1.3 Hz, 2H, eOCH2Oe), 4.63 (s, 2H, eCOCH2Oe), 4.59 (d,
J ¼ 4.9 Hz, 1H, 1-H), 4.34e4.42 (m, 2H, 11-H), 3.89 (s, 3H, eOCH3),
3.87 (d, J ¼ 5.1 Hz, 1H, 4-H), 3.82 (s, 3H, eOCH3), 3.74 (s, 6H,
eOCH3), 3.69 (s, 3H, eOCH3), 2.86e3.03 (m, 1H, 3-H), 2.75e2.85
4.1.6.7. 4b-[2-{3-[(E)-3-Oxo-3-(3,4,5-trimethoxyphenyl)-1-propenyl]
phenoxy} acetamide]-4-desoxy-podophyllotoxin (15g). Yellow solid,
25
yield71%;mp:236e237ꢂC;[
(200 MHz, CDCl3):
a]
D
¼ꢃ122.7(c¼ 0.5inCHCl3);1HNMR
d
7.69 (d, J ¼ 15.1 Hz,1H, dbH), 7.41 (d, J ¼ 15.1 Hz,
(dd, J ¼ 14.35, 4.9 Hz, 1H, 2-H); 13C NMR (75 MHz, CDCl3):
d
188.44,
1H, dbH), 7.28e7.38 (m,1H, ArH), 7.22 (s, 2H, ArH), 7.13e7.21 (m, 2H,
ArH), 6.91e6.98 (dd, J ¼ 8.3, 2.26 Hz,1H, ArH), 6.61 (s,1H, ArH), 6.54
(br s,1H, eNH), 6.47 (s,1H, ArH), 6.2 (s, 2H, ArH), 5.94 and 5.96 (AB q,
J ¼ 1.51 Hz, 2H, eOCH2Oe), 4.61 (s, 2H, eCOCH2Oe), 4.5 (d, J ¼ 4.6 Hz,
1H, 1-H), 4.35e4.46 (m, 2H, 11-H), 3.94 (s, 6H, eOCH3), 3.91 (s, 3H,
eOCH3), 3.86(d, J¼6.06Hz,1H,4-H), 3.77(s, 3H,eOCH3),3.73(s,6H,
eOCH3), 2.83e3.03 (m,1H, 3-H), 2.63e2.75 (dd, J ¼ 14.35, 4.6 Hz,1H,
174.03, 168.62, 163.4, 152.56, 149.73, 148.67, 148.34, 147.55, 143.02,
137.17, 134.54, 132.12, 130.97, 130.85, 130.71, 128.56, 122.22, 121.34,
116.66, 113.77, 111.37, 109.93, 109, 108.1, 101.55, 70.09, 68.68, 60.65,
56.13, 55.6, 55.41, 47.58, 43.7, 41.66, 37.08; ESI-MS: 760 (M þ Na)þ;
HRMS calcd for C41H39NO12Na, 760.2345, found 760.2369.
4.1.6.4. 4
b-[2-{2-Methoxy-4-[(E)-3-(3-nitrophenyl)-3-oxo-1-prope-
2-H); 13C NMR (75 MHz, CDCl3):
d 188.86,173.94,168.11,157.14,153.1,
nyl]phenoxy} acetamide]-4-desoxy-podophyllotoxin (15d). Yellow
152.56, 148.45, 147.61, 143.62, 142.7, 137.26, 136.78, 134.48, 133.06,
132.42, 130.33, 128.16, 122.67, 122.43, 116.26, 114.73, 110.07, 108.78,
108.14, 106.18, 101.61, 68.69, 67.13, 60.9, 60.64, 56.37, 56.13, 47.82,
43.67, 41.58, 37.15; ESI-MS: 790 (M þ Na)þ; HRMS calcd for
C42H41NO13Na, 790.2497, found 790.2475.
25
solid, yield 62%; mp: 260e263 ꢂC; [
a
]
¼ ꢃ115.3 (c ¼ 0.5 in CHCl3);
D
1H NMR (200 MHz, CDCl3):
d
8.7 (s, 1H, ArH), 8.41e8.46 (dd, J ¼ 8.3,
2.26 Hz, 1H, ArH), 8.29e8.34 (dd, J ¼ 8.3, 1.51 Hz, 1H, ArH), 7.81 (d,
J ¼ 15.86 Hz, 1H, dbH), 7.7 (t, J ¼ 8.3, 7.75 Hz, 1H, ArH), 7.35 (d,
J ¼ 15.86 Hz, 1H, dbH), 7.2e7.24 (dd, J ¼ 8.3, 2.26 Hz, 1H, ArH), 7.15
(d, J ¼ 1.51 Hz, 1H, ArH), 6.61 (br s, 1H, eNH), 6.82 (d, J ¼ 8.3 Hz, 1H,
ArH), 6.66 (s, 1H, ArH), 6.54 (s, 1H, ArH), 6.24 (s, 2H, ArH), 5.93 and
5.95 (AB q, J ¼ 1.51 Hz, 2H, eOCH2Oe), 4.69 (s, 2H, eCOCH2Oe),
4.58 (d, J ¼ 4.5 Hz, 1H, 1-H), 4.34e4.42 (m, 2H, 11-H), 3.97 (s, 3H,
4.1.6.8. 4b-[2-{2-methoxy-5-[(E)-3-oxo-3-(3,4,5-trimethoxyphenyl)-
1-propenyl]phenoxy} acetamide]-4-desoxy-podophyllotoxin (15h).
25
Yellow solid, yield 70%; mp: 245e248 ꢂC; [
a
]
¼ ꢃ120.3 (c ¼ 0.5 in
D
CHCl3); 1H NMR (200 MHz, CDCl3):
d
7.67 (d, J ¼ 15.48 Hz, 1H, dbH),

A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
541
7.29 (d, J ¼ 15.48 Hz, 1H, dbH), 7.19e7.26 (m, 3H, ArH), 7.15 (d,
J ¼ 2.24 Hz, 1H, ArH), 6.88 (d, J ¼ 8.3 Hz, 1H, ArH), 6.69 (s, 1H, ArH),
6.54 (br s, 1H, eNH), 6.52 (s, 1H, ArH), 6.23 (s, 2H, ArH), 5.93 and
5.95 (AB q, J ¼ 1.51 Hz, 2H, eOCH2Oe), 4.63 (s, 2H, eCOCH2Oe),
4.58 (d, J ¼ 4.72 Hz, 1H, 1-H), 4.37e4.45 (m, 2H, 11-H), 3.95 (s, 6H,
eOCH3), 3.91 (s, 3H, eOCH3), 3.86 (d, J ¼ 5.21 Hz, 1H, 4-H), 3.78 (s,
3H, eOCH3), 3.74 (s, 6H, eOCH3), 3.68 (s, 3H, eOCH3), 2.86e3.02
(m, 1H, 3-H), 2.74e2.83 (dd, J ¼ 14.16, 4.72 Hz, 1H, 2-H); 13C NMR
4.1.7.4. 4b-[(E)-3-(4-Bromophenyl)-2-propenamido]-4-desoxy-podo-
phyllotoxin (17d). Yellow solid, yield 60%; mp: 184e187 ꢂC;
25
[a]
¼ ꢃ136.8 (c ¼ 0.5 in CHCl3); 1H NMR (200 MHz, CDCl3):
d 7.58
D
(d, J ¼ 15.38 Hz, 1H, dbH), 7.46 (d, J ¼ 8.79 Hz, 2H, ArH), 7.29 (d,
J ¼ 8.79 Hz, 2H, ArH), 6.79 (s, 1H, ArH), 6.51 (s, 1H, ArH), 6.41 (d,
J ¼ 15.38 Hz, 1H, dbH), 6.32 (br s, 1H, eNH), 6.26 (s, 2H, ArH), 5.93
and 5.95 (AB q, J ¼ 1.3 Hz, 2H, eOCH2Oe), 4.52 (d, J ¼ 3.66 Hz, 1H,1-
H), 4.4e4.49 (m, 2H, 11-H), 3.84 (d, J ¼ 5.54 Hz, 1H, 4-H), 3.74 (s, 3H,
eOCH3), 3.69 (s, 6H, eOCH3), 2.93e3.06 (m, 2H, 3-H), 2.81e2.89
(75 MHz, CDCl3): d 188.89, 174.03, 168.7, 153.1, 152.61, 151.73, 148.41,
147.73, 147.27, 143.52, 142.51, 137.3, 134.51, 133.43, 132.22, 128.61,
125.55, 120.56, 116.52, 112.15, 110.02, 109.06, 108.5, 108.12, 106.09,
101.59, 70.65, 68.72, 60.93, 60.69, 56.41, 56.18, 55.7, 47.6, 43.76,
(dd, J ¼ 14.1, 3.66 Hz, 1H, 2-H); 13C NMR (75 MHz, CDCl3):
d 174.46,
165.61, 152.43, 148.22, 147.51, 141, 136.85, 134.85, 133.22, 132.14,
132.01, 129.14, 128.87, 124.16, 120, 109.86, 109.12, 107.96, 101.53, 69,
60.58, 50.04, 48.06, 43.65, 41.64, 37.3; ESI-MS: 622 (M)þ; HRMS
calcd for C31H28NO8Br, 622.0891, found 622.0895.
41.73, 37.14; ESI-MS: 798 (M þ H)þ; HRMS calcd for C43H44NO14
,
798.2724, found 798.2741.
4.1.7. General procedure for the synthesis of compounds 17aeh
4.1.7.5. 4b-[(E)-3-(4-Methoxyphenyl)-2-propenamido]-4-desoxy-
These compounds were synthesized according to the general
method described for compounds 14aeh by employing compound
12 (1.0 mmol) and corresponding trans-cinnamic acids 16aej
(1 mmol).
podophyllotoxin (17e). Yellow solid, yield 63%; mp: 187e190 ꢂC;
25
[
d
a
]
¼ ꢃ138.6 (c ¼ 0.5 in CHCl3); 1H NMR (200 MHz, CDCl3):
D
7.65 (d, J ¼ 15.1 Hz, 1H, dbH), 7.44 (d, J ¼ 8.3 Hz, 2H, ArH), 6.9 (d,
J ¼ 8.3 Hz, 2H, ArH), 6.81 (s, 1H, ArH), 6.54 (s, 1H, ArH), 6.37 (br s,
1H, eNH), 6.3 (s, 2H, ArH), 6.26 (d, J ¼ 15.1 Hz, 1H, dbH), 5.94 and
5.96 (AB q, J ¼ 1.51 Hz, 2H, eOCH2Oe), 4.61 (d, J ¼ 4.53 Hz, 1H, 1-
H), 4.43e4.52 (m, 2H, 11-H), 3.89 (d, J ¼ 5.1 Hz, 1H, 4-H), 3.84 (s,
3H, eOCH3), 3.81 (s, 3H, eOCH3), 3.75 (s, 6H, eOCH3), 2.96e3.08
(m, 1H, 3-H), 2.87e2.95 (dd, J ¼ 14.35, 4.53 Hz, 1H, 2-H); 13C NMR
4.1.7.1. 4b-[(E)-3-Phenyl-2-propenamido]-4-desoxy-podophyllotoxin
25
(17a). Yellow solid, yield 62%; mp: 175e178 ꢂC; [
a]
¼ ꢃ131.2
D
(c ¼ 0.5 in CHCl3); 1H NMR (200 MHz, CDCl3):
7.62 (d, J ¼ 15.86 Hz,
d
1H, dbH), 7.38e7.47 (m, 2H, ArH), 7.29e7.36 (m, 3H, ArH), 6.81 (s,
1H, ArH), 6.46 (s, 1H, ArH), 6.41 (d, J ¼ 15.86 Hz, 1H, dbH), 6.32 (br s,
1H, eNH), 6.21 (s, 2H, ArH), 5.92 and 5.94 (AB q, J ¼ 1.3 Hz, 2H,
eOCH2Oe), 4.47 (d, J ¼ 5.28 Hz, 1H, 1-H), 4.35e4.43 (m, 2H, 11-H),
3.81 (d, J ¼ 5.21 Hz, 1H, 4-H), 3.74 (s, 3H, eOCH3), 3.68 (s, 6H,
eOCH3), 2.89e3.01 (m, 1H, 3-H), 2.8e2.88 (dd, J ¼ 14.35, 5.28 Hz,
(75 MHz, CDCl3):
d 174.47, 166.29, 161.18, 152.53, 148.27, 147.58,
142.2, 137.07, 134.81, 132.29, 129.46, 129.05, 126.98, 116.68,
114.28, 109.96, 109.97, 108.07, 101.55, 69.15, 60.66, 56.13, 55.3,
48.12, 43.73, 41.76, 37.47; ESI-MS: 596 (M þ Na)þ; HRMS calcd for
C32H31NO9Na, 596.1896, found 596.1806.
1H, 2-H); 13C NMR (75 MHz, CDCl3):
d 174.44, 165.9, 152.49, 148.24,
147.56, 142.42, 137, 134.83, 134.3, 132.24, 130.03, 129, 128.8, 127.78,
119.29, 109.93, 109.15, 108.05, 101.53, 69.07, 60.61, 56.08, 48.09,
43.7, 41.71, 37.38; ESI-MS: 544 (M þ H)þ; HRMS calcd for
C31H29NO8, 544.1396, found 544.1378.
4.1.7.6. 4b-[(E)-3-(4-Trifluoromethylphenyl)-2-propenamido]-4-de-
soxy-podophyllotoxin (17f). Yellow solid, yield 68%; mp:
25
196e199 ꢂC; [
CDCl3):
a]
¼ ꢃ138.1 (c ¼ 0.5 in CHCl3), 1H NMR (200 MHz,
D
d
7.71 (d, J ¼ 15.86 Hz, 1H, dbH), 7.65 (d, J ¼ 9.06 Hz, 2H,
ArH), 7.59 (d, J ¼ 8.3 Hz, 2H, ArH), 6.82 (s, 1H, ArH), 6.54 (s,1H, ArH),
6.48 (d, J ¼ 15.86 Hz, 1H, dbH), 6.39 (br s, 1H, eNH), 6.30 (s, 2H,
ArH), 5.96 and 5.98 (AB q, J ¼ 1.51 Hz, 2H, eOCH2Oe), 4.61 (d,
J ¼ 5.28 Hz,1H,1-H), 4.44e4.53 (m, 2H,11-H), 3.89 (d, J ¼ 5.1 Hz,1H,
4-H), 3.81 (s, 3H, eOCH3), 3.75 (s, 6H, eOCH3), 2.97e3.13 (m, 1H, 3-
H), 2.88e2.96 (dd, J ¼ 14.35, 5.28 Hz, 1H, 2-H); 13C NMR (75 MHz,
4.1.7.2. 4b-[(E)-3-(4-Fluorophenyl)-2-propenamido]-4-desoxy-podo-
phyllotoxin (17b). Yellow solid, yield 66%; mp: 179e182 ꢂC;
25
[
a]
¼ꢃ135.5 (c¼ 0.5 inCHCl3);1HNMR (200MHz, CDCl3):
d7.66 (d,
D
J ¼ 15.86 Hz, 1H, dbH), 7.48 (t, J ¼ 9.06 Hz, 2H, ArH), 7.07 (t,
J ¼ 9.06 Hz, 2H, ArH), 6.81 (s, 1H, ArH), 6.54 (s, 1H, ArH), 6.36 (d,
J ¼ 15.86 Hz,1H, dbH), 6.33 (br s,1H, eNH), 6.3 (s, 2H, ArH), 5.95 and
5.97 (AB q, J ¼ 1.22 Hz, 2H, eOCH2Oe), 4.61 (d, J ¼ 4.53 Hz, 1H, 1-H),
4.44e4.52 (m, 2H, 11-H), 3.89 (d, J ¼ 5.48 Hz, 1H, 4-H), 3.81 (s, 3H,
eOCH3), 3.75 (s, 6H, eOCH3), 2.96e3.1 (m, 1H, 3-H), 2.87e2.96 (dd,
CDCl3): d 174.42, 165.29, 152.51, 148.33, 147.6, 140.63, 137.78, 137.02,
134.8, 132.24, 131.68, 131.28, 128.81, 127.92, 125.8, 121.88, 109.93,
109.12, 108.07, 101.56, 69.01, 60.61, 56.09, 48.2, 43.7, 41.72, 37.34;
ESI-MS: 634 (M þ Na)þ; HRMS calcd for C32H28NO8F3Na, 634.1657,
found 634.1644.
J ¼ 14.35, 4.53 Hz, 1H, 2-H); 13C NMR (75 MHz, CDCl3):
d 174.42,
165.76, 152.55, 148.33, 147.62, 141.31, 137.09, 134.77, 132.31, 130.58,
129.73, 128.89, 118.94, 116.15, 115.86, 109.99, 109.14, 108.07, 101.59,
69.11, 60.67, 56.13, 48.21, 43.72, 41.77, 37.43; ESI-MS: 584 (M þ Na)þ;
HRMS calcd for C31H28NO8FNa, 584.1688, found 584.1696.
4.1.7.7. 4b-[(E)-3-(4-Nitrophenyl)-2-propenamido]-4-desoxy-podo-
phyllotoxin (17g). Yellow solid, yield 65%; mp: 197e199 ꢂC;
25
[a
]
¼ ꢃ134.7 (c ¼ 0.5 in CHCl3); 1H NMR (200 MHz, CDCl3):
d 8.25
D
(d, J ¼ 8.3 Hz, 2H, ArH), 7.74 (d, J ¼ 15.1 Hz, 1H, dbH), 7.63 (d,
J ¼ 8.3 Hz, 2H, ArH), 6.81 (s, 1H, ArH), 6.55 (s, 1H, ArH), 6.53 (d,
J ¼ 15.1 Hz, 1H, dbH), 6.4 (br s, 1H, eNH), 6.3 (s, 2H, ArH), 5.96 and
5.98 (AB q, J ¼ 1.4 Hz, 2H, eOCH2Oe), 4.62 (d, J ¼ 4.53 Hz, 1H, 1-H),
4.44e4.53 (m, 2H, 11-H), 3.88 (d, J ¼ 5.8 Hz, 1H, 4-H), 3.8 (s, 3H,
eOCH3), 3.75 (s, 6H, eOCH3), 2.97e3.12 (m, 1H, 3-H), 2.86e2.96
4.1.7.3. 4b-[(E)-3-(4-Chlorophenyl)-2-propenamido]-4-desoxy-podo-
phyllotoxin (17c). Yellow solid, yield 65%; mp: 175e178 ꢂC;
[a]
¼ ꢃ134.4 (c ¼ 0.5 in CHCl3), 1H NMR (200 MHz, CDCl3):
d 7.64
25
D
(d, J ¼ 15.38 Hz, 1H, dbH), 7.42 (d, J ¼ 8.79 Hz, 2H, ArH), 7.35 (d,
J ¼ 8.79 Hz, 2H, ArH), 6.81 (s, 1H, ArH), 6.54 (s, 1H, ArH), 6.37 (d,
J ¼ 15.38 Hz, 1H, dbH), 6.33 (br s, 1H, eNH), 6.29 (s, 2H, ArH), 5.95
and 5.97 (AB q, J ¼ 1.2 Hz, 2H, eOCH2Oe), 4.61 (d, J ¼ 4.39 Hz, 1H, 1-
H), 4.45e4.52 (m, 2H, 11-H), 3.88 (d, J ¼ 5.2 Hz, 1H, 4-H), 3.8 (s, 3H,
eOCH3), 3.75 (s, 6H,eOCH3), 2.97e3.09 (m, 1H, 3-H), 2.88e2.95 (dd,
(dd, J ¼ 14.35, 4.53 Hz,1H, 2-H); 13C NMR (75 MHz, CDCl3):
d 174.35,
164.78, 152.53, 148.4, 148.2, 147.64, 140.65, 139.64, 137.02, 134.79,
132.29, 128.64, 128.39, 124.13, 123.62, 110, 109.11, 108.08, 101.63,
69.01, 60.64, 56.14, 48.33, 43.7, 41.72, 37.35; ESI-MS: 611 (M þ Na)þ;
HRMS calcd for C31H28N2O10Na, 611.1661, found 611.1641.
J ¼ 13.91, 4.39 Hz, 1H, 2-H); 13C NMR (75 MHz, CDCl3):
d 174.46,
165.67, 152.5, 148.28, 147.58, 141.06, 136.95, 135.88, 134.81, 132.83,
132.23, 129.25, 129.09, 128.96, 119.87, 109.93, 109.13, 108.07, 101.55,
69.06, 60.62, 56.1, 48.15, 43.7, 41.72, 37.36; ESI-MS: 600 (M þ Na)þ;
HRMS calcd for C31H28NO8NaCl, 600.1401, found 600.1386.
4.1.7.8. 4b-[(E)-3-(3,4-Dichlorophenyl)-2-propenamido]-4-desoxy-
podophyllotoxin (17h). Yellow solid, yield 67%; mp: 181e183 ꢂC;
25
[a
]
¼ ꢃ131.5 (c ¼ 0.5 in CHCl3); 1H NMR (200 MHz, CDCl3):
D

542
A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
d
7.55e7.63 (m, 2H, ArH, dbH), 7.46 (d, J ¼ 8.3 Hz, 1H, ArH),
(200 MHz, CDCl3): d 7.99e8.12 (m, 2H, ArH), 7.7e7.8 (m, 1H, ArH),
7.28e7.33 (dd, J ¼ 8.3, 2.26 Hz, 1H, ArH), 6.8 (s, 1H, ArH), 6.54 (s, 1H,
ArH), 6.39 (d, J ¼ 15.86 Hz, 1H, dbH), 6.35 (br s, 1H, eNH), 6.29 (s,
2H, ArH), 5.97 and 5.99 (AB q, J ¼ 1.6 Hz, 2H, eOCH2Oe), 4.61 (d,
J ¼ 4.53 Hz, 1H, 1-H), 4.43e4.51 (m, 2H, 11-H), 3.87 (d, J ¼ 5.21 Hz,
1H, 4-H), 3.8 (s, 3H, eOCH3), 3.75 (s, 6H, eOCH3), 2.96e3.12 (m, 1H,
3-H), 2.86e2.95 (dd, J ¼ 14.35, 4.53 Hz, 1H, 2-H); 13C NMR (75 MHz,
7.53e7.64 (m, 1H, ArH), 7.08 (d, J ¼ 16.23 Hz, 1H, dbH), 6.98e7.04
(m, 2H, ArH), 6.94 (d, J ¼ 16.15 Hz, 1H, dbH), 6.9 (d, J ¼ 8.11 Hz, 1H,
ArH), 5.92 (br s, 1H, ArOH), 3.89 (s, 3H, eOCH3), 2.63 (s, 3H, eCH3),
2.59 (s, 3H, eCH3); ESI-MS: 334 (M þ H)þ.
4.1.9.2. (E)-3-(4-hydroxy-3-methoxyphenyl)-1-(2-methyl-4-phenyl-
CDCl3):
d
174.39, 165.19, 152.5, 148.33, 147.61, 139.8, 139.99, 134.8,
3-quinolyl)-2-propen-1-one (20b)
134.42, 133.89, 133.1, 132.24, 130.83, 129.11, 128.78, 126.98, 121.16,
109.95, 109.1, 108.08, 101.58, 69.01, 60.61, 56.12, 48.21, 43.69, 41.71,
37.34; ESI-MS: 613 (M þ H)þ; HRMS calcd for C31H28Cl2NO8,
613.1461, found 613.1442.
Yellow solid, yield 89%; 1H NMR (300 MHz, CDCl3):
d 8.09 (d,
J ¼ 8.3 Hz, 1H, ArH), 7.67e7.75 (m, 1H, ArH), 7.56e7.62 (dd, J ¼ 8.3,
1.51 Hz, 1H, ArH), 7.41e7.47 (m, 1H, ArH), 7.34e7.39 (m, 3H, ArH),
7.27e7.33 (m, 2H, ArH), 6.96 (d, J ¼ 15.86 Hz, 1H, dbH), 6.77e6.87
(m, 3H, ArH), 6.41 (d, J ¼ 15.86 Hz, 1H, dbH), 5.97 (br s, 1H, ArOH),
3.87 (s, 3H, eOCH3), 2.69 (s, 3H, eCH3); ESI-MS: 396 (M þ H)þ.
4.1.7.9. 4b-[(E)-3-(3,4,5-Trimethoxyphenyl)-2-propenamido]-4-des-
oxy-podophyllotoxin (17i). Yellow solid, yield 62%; mp: 199e202 ꢂC;
25
[
a
]
¼ ꢃ137.2 (c ¼ 0.5 in CHCl3); 1H NMR (200 MHz, CDCl3):
d
7.67 (d,
4.1.10. General procedure for the synthesis of compounds 21a,b
These compounds synthesized according to method described
for compounds 10aeh by employing compound 20a,b (1.0 mmol),
D
J ¼ 15.8 Hz, 1H, dbH), 7.23 (s, 2H, ArH), 6.8 (s, 1H, ArH), 6.53 (s, 1H,
ArH), 6.35 (d, J ¼ 15.18 Hz,1H, dbH), 6.33 (br s,1H, eNH), 6.31 (s, 2H,
ArH), 5.96 and 5.98 (AB q, J ¼ 1.5 Hz, 2H, eOCH2Oe), 4.61 (d,
J ¼ 4.5 Hz,1H,1-H), 4.42e4.52 (m, 2H,11-H), 3.9 (d, J ¼ 5.4 Hz,1H, 4-
H), 3.87 (s, 6H, eOCH3), 3.8 (s, 3H, eOCH3), 3.77 (s, 3H, eOCH3), 3.73
(s, 6H, eOCH3), 2.97e3.09 (m, 1H, 3-H), 2.87e2.96 (dd, J ¼ 14.3,
and
a-bromoethylacetate (1.2 mmol) to obtain the pure product as
solid.
4.1.10.1. Ethyl 2-{4-[(E)-3-(2,4-dimethyl-3-quinolyl)-3-oxo-1-prop-
4.5 Hz, 1H, 2-H); 13C NMR (75 MHz, CDCl3):
d
174.38, 165.86, 153.34,
enyl]-2-methoxyphenoxy}acetate (21a). Yellow solid, yield 80%; 1H
152.53, 148.3, 147.55, 142.46, 139.8, 137.13, 134.72, 132.32, 129.94,
128.88, 118.64, 109.96, 109.08, 108.11, 105.07, 101.53, 69.1, 60.86,
60.65, 56.14, 56.04, 48.2, 43.71, 41.75, 37.44; ESI-MS: 634 (M þ H)þ;
HRMS calcd for C34H36NO11, 634.1648.1642, found 634.1625.
NMR (200 MHz, CDCl3):
d
8.03 (d, J ¼ 8.07 Hz, 1H, ArH), 7.98 (d,
J ¼ 8.07 Hz, 1H, ArH), 7.67e7.73 (m, 1H, ArH), 7.53 (t, J ¼ 8.07,
7.06 Hz, 1H, ArH), 7.05 (d, J ¼ 16.15 Hz, 1H, dbH), 6.98e7.03 (m, 2H,
ArH), 6.88 (d, J ¼ 16.15 Hz, 1H, dbH), 6.74 (d, J ¼ 8.07 Hz, 1H, ArH),
4.65 (s, 2H, eOCH2COe), 4.19e4.26 (q, 2H, eOCH2e), 3.89 (s, 3H,
eOCH3), 2.6 (s, 3H, Ar-CH3), 2.56 (s, 3H, Ar-CH3), 1.28 (t, J ¼ 7.06 Hz,
3H, eCH3); ESI-MS: 420 (M þ H)þ.
4.1.8. General procedure for the synthesis [39] of compounds 19a,b
To a solution of compound 18 (1.0 mmol) and 2,4-pentanedione
in acetonitrile (20 ml) was added 1 ml of 1N HCl solution and the
reaction mixture was stirred at room temperature for 24 h. The
reaction was monitored by TLC. After completion of reaction
neutralize with saturated sodium bicarbonate solution and extrac-
ted with ethyl acetate (2 ꢀ 30 ml). The solvent was evaporated under
reduced pressure to afford the crude product which was purified by
column chromatography on silica gel using ethyl acetate and hexane
as solvent system to obtain the pure products as solids.
4.1.10.2. Ethyl 2-{2-methoxy-4-[(E)-3-(2-methyl-4-phenyl-3-quino-
lyl)-3-oxo-1-propenyl]phenoxy} acetate (21b). Yellow solid, yield
82%; 1H NMR (200 MHz, CDCl3):
d
8.11 (d, J ¼ 8.07 Hz, 1H, ArH), 7.71
(t, J ¼ 8.07, 7.06 Hz, 1H, ArH), 7.57e7.61 (dd, J ¼ 8.3, 1.51 Hz, 1H,
ArH), 7.4e7.45 (m, 1H, ArH), 7.34e7.39 (m, 3H, ArH), 7.27e7.31 (m,
2H, ArH), 6.98 (d, J ¼ 16.15 Hz,1H, dbH), 6.8e6.86 (m, 2H, ArH), 6.68
(d, J ¼ 8.07 Hz, 1H, ArH), 6.43 (d, J ¼ 16.15 Hz, 1H, dbH), 4.62 (s, 2H,
eOCH2COe), 4.19e4.26 (q, 2H, eOCH2e), 3.83 (s, 3H, eOCH3), 2.69
(s, 3H, Ar-CH3), 1.28 (t, J ¼ 7.06 Hz, 3H, eCH3); ESI-MS: 482
(M þ H)þ.
4.1.8.1. 3-Acetyl-2,4-dimethylquinoline (19a). Liquid, yield 81%; 1H
NMR (300 MHz, CDCl3):
d
8.01 (d, J ¼ 8.3 Hz, 1H, ArH), 7.95 (d,
J ¼ 8.3 Hz, 1H, ArH), 7.66e7.73 (m, 1H, ArH), 7.49e7.57 (m, 1H, ArH),
2.63 (s, 3H, eCOCH3), 2.58 (s, 3H, eCH3), 2.56 (s, 3H, eCH3); ESI-MS:
200 (M þ H)þ.
4.1.11. General procedure for the synthesis of compounds 22a,b
These compounds synthesized according to method described
for compounds 11aeh by employing compound 21a,b (1 mmol),
and LiOH.H2O (3 mmol) to obtain the pure product as solid.
4.1.8.2. 3-Acetyl-2-methyl-4-phenylquinoline (19b). White solid,
yield 75%; 1H NMR (200 MHz, CDCl3):
d
8.04 (d, J ¼ 8.3 Hz, 1H, ArH),
7.64e7.72 (m, 1H, ArH), 7.56e7.62 (dd, J ¼ 8.3, 1.51 Hz, 1H, ArH),
7.47e7.54 (m, 3H, ArH), 7.39e7.44 (dd, J ¼ 8.3, 1.51 Hz, 1H, ArH),
7.32e7.38 (m, 2H, ArH), 2.67 (s, 3H, eCOCH3), 1.96 (s, 3H, eCH3);
ESI-MS: 262 (M þ H)þ.
4.1.11.1. 2-{4-[(E)-3-(2,4-dimethyl-3-quinolyl)-3-oxo-1-propenyl]-2-
methoxyphenoxy}acetic acid (22a). Yellow solid, yield 71%; 1H NMR
(200 MHz, CDCl3):
d
8.05 (d, J ¼ 8.07 Hz, 1H, ArH), 7.96 (br s, 1H,
eCOOH), 7.99 (d, J ¼ 8.07 Hz, 1H, ArH), 7.66e7.72 (m, 1H, ArH), 7.53
(t, J ¼ 8.07, 7.06 Hz, 1H, ArH), 7.06 (d, J ¼ 16.15 Hz, 1H, dbH), 7e7.05
(m, 2H, ArH), 6.9 (d, J ¼ 16.15 Hz, 1H, dbH), 6.74 (d, J ¼ 8.07 Hz, 1H,
ArH), 4.67 (s, 2H, eOCH2COe), 3.9 (s, 3H, eOCH3), 2.6 (s, 3H, eCH3),
2.56 (s, 3H, eCH3); ESI-MS: 392 (M þ H)þ.
4.1.9. General procedure for the synthesis of compounds 20a,b
To a stirred mixture of acetylquinolines 19a,b (1 mmol) and
vanillin (1 mmol) in ethanol (10 ml) was added 50% aqueous
solution of potassium hydroxide (1 ml) and stirred for 12 h at reflux
temperature. After completion of the reaction checked by TLC, the
solvent was evaporated, neutralized with 1N HCl solution and
extracted with ethyl acetate (2 ꢀ 50 ml). The combined organic
fractions were washed with water followed by brine, dried over
Na2SO4 and purified by column chromatography on silica gel using
ethyl acetate and hexane to afford yellow solid.
4.1.11.2. 2-{2-methoxy-4-[(E)-3-(2-methyl-4-phenyl-3-quinolyl)-3-
oxo-1-propenyl] phenoxy}acetic acid (22b). Yellow solid, yield 65%;
1H NMR (200 MHz, CDCl3):
d
8.13 (d, J ¼ 8.07 Hz, 1H, ArH), 7.97 (bs,
1H, eCOOH), 7.71 (t, J ¼ 8.07, 7.06 Hz, 1H, ArH), 7.58e7.63 (dd,
J ¼ 8.3, 1.51 Hz, 1H, ArH), 7.42e7.45 (m, 1H, ArH), 7.35e7.4 (m, 3H,
ArH), 7.26e7.31 (m, 2H, ArH), 6.99 (d, J ¼ 16.15 Hz, 1H, dbH),
6.82e6.87 (m, 2H, ArH), 6.69 (d, J ¼ 8.07 Hz, 1H, ArH), 6.44 (d,
J ¼ 16.15 Hz,1H, dbH), 4.66 (s, 2H, eOCH2COe), 3.84 (s, 3H, eOCH3),
2.67 (s, 3H, eCH3); ESI-MS: 454 (M þ H)þ.
4.1.9.1. (E)-1-(2,4-dimethyl-3-quinolyl)-3-(4-hydroxy-3-methoxyph-
enyl)-2-propen-1-one (20a). Yellow solid, yield 85%; 1H NMR

A. Kamal et al. / European Journal of Medicinal Chemistry 47 (2012) 530e545
543
4.1.12. General procedure for the synthesis of compounds 23a,b
These compounds synthesized according to method described
for compounds 15aeh by employing compound 22a,b (1 mmol)
and compound 12(1 mmol) to obtain the pure product as solid.
eOCH3), 3.87 (d, J ¼ 5.1 Hz, 1H, 4-H), 3.83 (s, 3H, eOCH3), 3.8 (s, 6H,
eOCH3), 3.37e3.32(dd, J ¼ 9.37, 4.82 Hz, 1H, 2-H), 3.16e3.24 (m,
1H, 3-H), 2.64 (s, 3H, eCH3), 2.59 (s, 3H, eCH3), 2.26 (t, J ¼ 7.28 Hz,
2H, eCH2COe), 1.83e1.91 (m, 2H, eCH2e), 1.67e1.77 (m, 2H,
eCH2e), 1.46e1.55 (m, 2H, eCH2e); 13C NMR (75 MHz, CDCl3):
4.1.12.1. 4
b
-[2-{4-[(E)-3-(2,4-Dimethyl-3-quinolyl)-3-oxo-1-prope-
acetamide]-4-desoxy-podophyllotoxin
d 198.15, 174.06, 168.65, 154.54, 152.17, 149.94, 149.24, 148.68,
nyl]-2-methoxyphenoxy}
147.78, 147.23, 146.74, 141.12, 137.38, 134.25, 132.75, 132.14, 130.15,
129.43, 129.08, 128.4, 127.65, 126.79, 126.15, 123.64, 122.81, 116.5,
111.57, 110.24, 109.28, 108.24, 101.4, 68.87, 67.46, 60.51, 56.36, 55.78,
47.49, 43.35, 42.06, 37.51, 28.55, 29.96, 25.41, 25.2, 23.41; ESI-MS:
843 (M þ H)þ; HRMS calcd for C49H51N2O11, 843.2471, found
843.2462.
25
(23a). Yellow solid, yield 78%; mp: 267e270 ꢂC; [
a
]
¼ ꢃ154.9
D
(c ¼ 0.5 in CHCl3); 1H NMR (300 MHz, CDCl3):
8.06 (d, J ¼ 8.3 Hz,
d
1H, ArH), 8.0 (d, J ¼ 8.12 Hz, 1H, ArH), 7.69e7.77 (m, 1H, ArH), 7.55
(t, J ¼ 7.93, 7.17 Hz, 1H, ArH), 7.19 (d, J ¼ 7.36 Hz, 1H, ArH),
7.08e7.13 (dd, J ¼ 8.49, 1.52 Hz, 1H, ArH), 7.04 (d, J ¼ 16.43 Hz, 1H,
dbH), 7.87e6.97 (m, 2H, ArH, dbH), 6.6 (s, 1H, ArH), 6.52 (s, 1H,
ArH), 6.45 (br s, 1H, eNH), 6.22 (s, 2H, ArH), 5.93 and 5.95 (AB q,
J ¼ 1.51 Hz, 2H, eOCH2Oe), 4.6 (s, 2H, eOCH2COe), 4.57 (d,
J ¼ 4.72 Hz, 1H, 1-H), 4.32e4.42 (m, 2H, 11-H), 3.92 (d, J ¼ 5.6 Hz,
1H, 4-H), 3.78 (s, 3H, eOCH3), 3.74 (s, 6H, eOCH3), 3.62 (s, 3H,
eOCH3), 2.84e3.01 (m, 1H, 3-H), 2.67e2.76 (dd, J ¼ 14.16, 4.72 Hz,
1H, 2-H), 2.61 (s, 3H, eCH3), 2.58 (s, 3H, eCH3); 13C NMR (75 MHz,
4.1.13.2. 4b-[6-{2-Methoxy-4-[(E)-3-(2-methyl-4-phenyl-3-quinolyl)-
3-oxo-1-propenyl] phenoxy}hexanamido]-4-desoxy-podophyllotoxin
25
(24b). Yellow solid, yield 65%; mp: 287e290 ꢂC; [
a]
D
¼ ꢃ141.8
(c ¼ 0.5 in CHCl3); 1H NMR (300 MHz, CDCl3):
8.09 (d, J ¼ 7.89 Hz,
d
1H, ArH), 7.67e7.73 (m, 1H, ArH), 7.56e7.60 (dd, J ¼ 7.83,1.51 Hz,1H,
ArH), 7.39e7.44 (m, 1H, ArH), 7.31e7.39 (m, 3H, ArH), 7.27e7.31 (m,
2H, ArH), 7.22 (d, J ¼ 7.83 Hz, 1H, ArH), 6.96 (d, J ¼ 15.67 Hz, 1H,
dbH), 6.81e6.85 (m, 1H, ArH), 6.77 (d, J ¼ 1.51 Hz, 1H, ArH), 6.67 (s,
1H, ArH), 6.47 (s,1H, ArH), 6.41 (d, J ¼ 15.67 Hz,1H, dbH), 6.31 (s, 2H,
ArH), 6.15 (br s, 1H, eNH), 5.91 and 5.94 (AB q, J ¼ 1.51 Hz, 2H,
eOCH2Oe), 4.56 (d, J ¼ 4.21 Hz, 1H, 1-H), 4.21e4.38 (m, 2H, 11-H),
4.1 (t, J ¼ 6.85 Hz, 2H, eCH2Oe), 3.91 (s, 3H, eOCH3), 3.89 (d,
J ¼ 5.8 Hz, 1H, 4-H), 3.79 (s, 6H, eOCH3), 3.76 (s, 3H, eOCH3),
3.14e3.18(dd, J ¼ 9.79, 4.56 Hz, 1H, 2-H), 3.06e3.14 (m, 1H, 3-H),
2.68 (s, 3H, eCH3), 2.22 (t, J ¼ 7.83, 6.85 Hz, 2H, eCH2COe),
1.79e1.87 (m, 2H, eCH2e), 1.65e1.75 (m, 2H, eCH2e), 1.46e1.55 (m,
CDCl3):
d 198.82, 173.94, 168.36, 154.32, 152.59, 149.87, 149.44,
148.39, 147.57, 147.1, 146.88, 140.94, 137.31, 134.48, 132.97, 132.23,
129.98, 129.69, 129.02, 128.48, 127.62, 126.42, 126.02, 123.75,
122.89, 116.56, 111.33, 110.02, 109.01, 108.14, 101.55, 69.98, 68.68,
60.66, 56.16, 55.6, 47.65, 43.71, 41.66, 37.11, 23.55, 15.59; ESI-MS:
787 (M þ H)þ; HRMS calcd for C45H43N2O11, 787.2865, found
787.2866.
4.1.12.2. 4b-[2-{2-Methoxy-4-[(E)-3-(2-methyl-4-phenyl-3-
quinolyl)-3-oxo-1-propenyl]
phenoxy}acetamide]-4-desoxy-podo-
phyllotoxin (23b). Yellow solid, yield 71%; mp: 284e286 ꢂC;
2H, eCH2e); 13C NMR (75 MHz, CDCl3):
d 197.68, 173.48, 168.55,
25
[
a]
¼ ꢃ151.3 (c ¼ 0.5 in CHCl3); 1H NMR (300 MHz, CDCl3):
d
8.11
154.56, 152.02, 149.95, 149.21, 148.3, 147.64, 147.09, 145.97, 145.13,
137.35, 135.57, 134.79, 132.64, 132.24, 130.68, 129.61, 129.16, 128.46,
128.12, 127.89, 127.28, 126.85, 126.13, 125.68, 122.82, 116.47, 110.87,
109.84, 108.87, 108.09, 101.5, 69.94, 68.48, 60.6, 56.35, 55.48, 47.56,
43.87, 41.34, 37.25, 28.71, 26.75, 25.42, 25.35, 23.41; ESI-MS: 906
(M þ H)þ; HRMS calcd for C54H53N2O11, 906.1016, found 906.1029.
D
(d, J ¼ 8.3 Hz 1H, ArH), 7.69e7.77 (m, 1H, ArH), 7.57e7.63 (dd,
J ¼ 8.3, 1.51 Hz, 1H, ArH), 7.41e7.48 (m, 1H, ArH), 7.34e7.4 (m, 3H,
ArH), 7.27e7.33 (m, 2H, ArH), 7.23 (d, J ¼ 7.55 Hz, 1H, ArH), 6.97 (d,
J ¼ 15.86 Hz, 1H, dbH), 6.87e6.9 (m, 1H, ArH), 6.75 (d, J ¼ 1.51 Hz,
1H, ArH), 6.59 (s, 1H, ArH), 6.52 (s, 1H, ArH), 6.44 (d, J ¼ 15.86 Hz,
1H, dbH), 6.46 (br s,1H, eNH), 6.22 (s, 2H, ArH), 5.94 and 5.96 (AB q,
J ¼ 1.62 Hz, 2H, eOCH2Oe), 4.63 (s, 2H, eOCH2COe), 4.54 (d,
J ¼ 5.28 Hz,1H,1-H), 4.33e4.48 (m, 2H,11-H), 3.94 (d, J ¼ 5.1 Hz,1H,
4-H), 3.78 (s, 3H, eOCH3), 3.74 (s, 6H, eOCH3), 3.57 (s, 3H, eOCH3),
2.84e3.03 (m, 1H, 3-H), 2.7e2.78 (dd, 1H, J ¼ 14.35, 5.28 Hz, 2-H),
4.2. Evaluation of in vitro anti-cancer activity
The cytotoxic activity of the compounds was determined using
MTT assay [40]. 1 ꢀ 104 cells/well were seeded in 200
ml DMEM,
2.69 (s, 3H, -CH3); 13C NMR (75 MHz, CDCl3):
d
197.24, 173.94,
supplemented with 10% FBS in each well of 96-well microculture
plates and incubated for 24 h at 37 ꢂC in a CO2 incubator.
Compounds, diluted to the desired concentrations in culture
medium, were added to the wells with respective vehicle control.
168.24, 154.8, 152.6, 149.77, 149.17, 148.38, 147.56, 147.04, 145.79,
145.51, 137.32, 135.09, 134.48, 132.42, 132.2, 130.2, 129.95, 129.87,
128.65, 128.52, 128.29, 127.38, 126.54, 126.27, 125.25, 122.62, 116.59,
110.9, 109.91, 108.99, 108.15, 101.54, 70.04, 68.66, 60.66, 56.17, 55.51,
47.61, 43.71, 41.68, 37.09, 23.77; ESI-MS: 849 (M þ H)þ; HRMS calcd
for C50H45N2O11, 849.2986, found 849.3023.
After 48 h of incubation, 10 ml MTT (3-(4,5-dimethylthiazol-2-yl)-
2,5-diphenyl tetrazolium bromide) (5 mg/ml) was added to each
well and the plates were further incubated for 4 h. Then the
supernatant from each well was carefully removed, formazon
4.1.13. General procedure for the synthesis of compounds 24a,b
These compounds synthesized according to method described
for compounds 14aeh by employing compound 20a,b (1 mmol),
and compound 13 (1 mmol) to obtain the pure product as solid.
crystals were dissolved in 100
540 nm wavelength was recorded.
ml of DMSO and absorbance at
4.3. Hoechst staining for morphological analysis of apoptosis
4.1.13.1. 4
b
-[6-{4-[(E)-3-(2,4-Dimethyl-3-quinolyl)-3-oxo-1-
Cells were seeded at a density of 10,000 cells over 18-mm cover
slips and incubated for 24 h. Then, the medium was replaced, and
cells were treated with 17a and 17f at 2 mM and 5 mM for 24 h. Cells
propenyl]-2-methoxyphenoxy}hexanamido]-4-desoxy-podophyllo-
toxin (24a). Yellow solid, yield 69%; mp: 274e277 ꢂC;
25
[
a]
¼ ꢃ145.4 (c ¼ 0.5 in CHCl3); 1H NMR (300 MHz, CDCl3):
d
8.09
treated with vehicle (0.001% DMSO) were included as controls for
all experiments. After 24 h treatment, Hoechst 33258 (Sigma-
eAldrich) staining was added to the medium at a concentration of
0.5 mg/ml. After incubation for 30 min at 37 ꢂC, cells from each dish
were captured from randomly selected fields under fluorescent
microscope (Leica, Germany) to qualitatively determine the
proportion of viable and apoptotic cells based on their relative
fluorescence and nuclear fragmentation [41].
D
(d, J ¼ 8.32 Hz, 1H, ArH), 8.03 (d, J ¼ 8.32 Hz, 1H, ArH), 7.76 (t,
J ¼ 8.32, 7.28 Hz, 1H, ArH), 7.6 (t, J ¼ 8.32, 7.28 Hz, 1H, ArH), 7.07 (d,
J ¼ 15.61 Hz, 1H, dbH), 6.98e7.05 (m, 2H, ArH), 6.94 (d, J ¼ 15.61 Hz,
1H, dbH), 6.84 (d, J ¼ 8.32 Hz, 1H, ArH), 6.73 (s, 1H, ArH), 6.53 (s, 1H,
ArH), 6.36 (s, 2H, ArH), 6.2 (br s, 1H, eNH), 5.93 and 5.95 (AB q,
J ¼ 1.4 Hz, 2H, eOCH2Oe), 4.58 (d, J ¼ 4.82 Hz, 1H, 1-H), 4.29e4.41
(m, 2H, 11-H), 4.04 (t, J ¼ 6.24 Hz, 2H, eCH2Oe), 3.91 (s, 3H,

544
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Acknowledgments
The authors A. M. R and N. S. R are thankful to CSIR, India and P. S
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