Antiproliferative activity of Pt(IV) complexes with lonidamine and bexarotene ligands attached via succinate-ethylenediamine linker

Article abstract of DOI:10.1016/j.ica.2019.119010

We present the synthesis and cytotoxic potencies of new Pt(IV) complexes with lonidamine and bexarotene ligand tethered to Pt-center via a succinate-ethylenediamine linker. The in vitro results for a series of complexes with cisplatin, dichloride(ethane-1,2-diamine)platinum(II), or oxaliplatin core indicate that the addition to the structure lonidamine or bexarotene moiety can confer activity or selectivity of Pt(IV) complexes.

Full text of DOI:10.1016/j.ica.2019.119010

Accepted Manuscript
Antiproliferative activity of Pt(IV) complexes with Lonidamine and Bexarotene
ligands attached via succinate-ethylenediamine linker
Y.N. Okulova, I.V. Zenin, I.A. Shutkov, K.I. Kirsanov, O.N. Kovaleva, E.A.
Lesovaya, T.I. Fetisov, E.R. Milaeva, A.A Nazarov
PII:
S0020-1693(19)30579-1
https://doi.org/10.1016/j.ica.2019.119010
119010
DOI:
Article Number:
Reference:
ICA 119010
Inorganica Chimica Acta
To appear in:
Received Date:
Revised Date:
Accepted Date:
25 April 2019
5 July 2019
10 July 2019
Please cite this article as: Y.N. Okulova, I.V. Zenin, I.A. Shutkov, K.I. Kirsanov, O.N. Kovaleva, E.A. Lesovaya,
T.I. Fetisov, E.R. Milaeva, A.A Nazarov, Antiproliferative activity of Pt(IV) complexes with Lonidamine and
Bexarotene ligands attached via succinate-ethylenediamine linker, Inorganica Chimica Acta (2019), doi: https://
doi.org/10.1016/j.ica.2019.119010
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Antiproliferative activity of Pt(IV) complexes with Lonidamine and Bexarotene ligands
attached via succinate-ethylenediamine linker.
Y.N. Okulova*a, I.V. Zenina, I.A. Shutkova, K.I. Kirsanovb,c, О.N. Kovalevad, E.A.Lesovayab,e,
Fetisov T.I.b, E.R. Milaevaa and A.A Nazarov*a
[a] Lomonosov Moscow State University, Department of Medicinal Chemistry and Fine Organic
Synthesis, Leninskie Gory 1/3, 119991 Moscow, Russian Federation E-mail:
alexey.nazarov@me.com, nosovayulia@yahoo.com
[b] N. N. Blokhin National Medical Research Centre of Oncology, 24 Kashirskoye shosse,
115478 Moscow, Russian Federation
[c] RUDN University, 6 Miklukho-Maklaya, 117198 Moscow, Russian Federation
[d] I.M.Sechenov First Moscow State Medical University, Moscow, Russia
[e] Ryazan State Medical University, 9 Visokovoltnaya, 390026 Ryazan, Russian
FederationAbstract
We present the synthesis and cytotoxic potencies of new Pt(IV) complexes with lonidamine and
bexarotene ligand tethered to Pt-center via a succinate-ethylenediamine linker. The in vitro
results for a series of complexes with cisplatin, dichloride(ethane-1,2-diamine)platinum(II), or
oxaliplatin core indicate that the addition to the structure lonidamine or bexarotene moiety can
confer activity or selectivity of Pt(IV) complexes.
1

Introduction
Cisplatin, oxaliplatin and carboplatin are currently applied in > 50% of chemotherapeutic
regimens. However, side effects such as general toxicity, low specificity, and the emergence of
resistance often limit their application [1-4]. Utilizing Pt(IV) moiety became a successful
synthetic strategy for the design of new Pt containing compounds capable of overcoming
problems associated with classical Pt drugs, largely due to low general toxicity and higher
stability [5, 6]. Several Pt(IV) compounds, namely tetraplatin, iproplatin, and satraplatin, have
entered clinical trials but none has been approved as a drug. In Phase I tetraplatin evoked high
nephrotoxicity due to a rapid reduction in the blood [4]. Iproplatin did not reach Phase III as it
was insufficiently active due to a slow reduction [7]. Satraplatin was evaluated for the treatment
of hormone-refractory prostate cancer but lack of convincing benefit for overall survival did not
promote the drug to the clinic although clinical trials in combination with various organic drugs
are currently in the active phase [8].
One of the strategies in the modern medicinal chemistry of anticancer drugs the preparation of
dual-action drugs capable to bind to more than one molecular target [6, 9]. Combination of the
platinum group and an organic moiety can generate dual activity compounds that, upon
reduction in the cell environment, produce two or more active components with definitive
molecular targets [10].
A variety of promising Pt(IV) complexes containing targeting axial ligands such as
dichloroacetate [11], short peptides [12], inhibitors of glutathione-S-transferase [13-15],
cyclooxygenase[16-18], p53 activators [19] or albumin-binding part [20] have been recently
prepared. The approach of coupling the pharmacophore to a metal center through the linker is
widely used. Several studies have shown advantages of different linkers in Pt(IV) carboxylate
complexes: formylbenzoate platinum derivatives ligated with amines [21], PEG-containing linker
for folic acid [11], amide linker for estradiol [22].
Recently we have shown that the introduction of Lonidamine, a selective inhibitor of aerobic
glycolysis by targeting the mitochondria-bound hexokinase; active against lung, prostate, breast,
and non-small cell lung cancer [23-25]), as well as Bexarotene, a selective agonist of retinoid X
receptors used in cutaneous T-cell lymphoma to induce differentiation and apoptosis [26, 27])
significantly increased the cytotoxicity of Pt (IV) complexes [28, 29]. Lonidamine and
Bexarotene served as axial ligands.
2

Cl
N
OH
N
Cl
OH
O
O
Figure 1. Lonidamine (left) and bexarotene (right).
In this study, we report the synthesis and characterization, including antiproliferative activity, of
new Pt(IV) complexes in which lonidamine and bexarotene were tethered to Pt via a succinate-
ethylenediamine linker.
Results and Discussion
Synthesis and characterization
Reactions were carried out in argon atmosphere and DMF as a solvent due to the low solubility
of all reagents. Complexes 8-13 (Scheme 1) were synthesized starting from succinate
platinum(IV) analogues of cisplatin 5, oxaliplatin 7 and the ethylenediamine analogue. The
ethylenediamine moiety was prepared in the reaction of acid chlorides obtained in situ from
lonidamine or bexarotene and an excess of oxalyl chloride with Boc-protected ethylenediamine
and subsequent removal of the Boc-group. The resulting amines were introduced into the
peptide synthesis reaction with the carboxyl group of the platinum part using carbonyl
diimidazole (CDI) as a coupling reagent. Pure complexes were isolated using column
chromatography on Silica Gel.
1
Complexes 8–13 were characterized by H, 13C{1H}, 15N, 195Pt 1D and 2D NMR spectroscopy,
ESI mass spectrometry and elemental analysis. The coordination sphere of the Pt(IV) centre
was confirmed by 195Pt NMR spectroscopy: for 10-13 the resonance at 3231 ppm and 3232
ppm, respectively, indicate a Pt(IV)N2O4 coordination sphere while resonance at 2843, 2654,
2843 and 2655 indicates the formation of Pt(IV)Cl2N2O2 configured complexes.
3

O
O
R-Cl
TFA
H
N
H
N
H2N
O-Bu-t
O-Bu-t
N
N
NH2
R
R
H
H
O
O
Cl
Cl
1
R =
R =
3
R =
R =
N
N
N
N
Cl
Cl
O
O
2
4
O
O
H
N
Cl
N
O
N
H
N
O
R4
R3
R1
R2
Cl
Pt
O
Cl
O
N
N
H
8
9
10
R1=R2=NH3, R3=R4=Cl
R1,R2=ethane-1,2-diamine, R3=R4=Cl
R1,R2= 1R,2R-DACH, R3,R4=oxalate
N
Cl
N
H
O
O
Cl
N
N
H
CDI
O
N
Cl
NH2
O
3
OH
O
Pt
O
O
R3
R4
R1
R2
5
6
7
R1=R2=NH3, R3=R4=Cl
R1,R2=ethane-1,2-diamine, R3=R4=Cl
R1,R2= 1R,2R-DACH, R3,R4=oxalate
O
HO
O
H
N
CDI
O
NH2
O
4
O
H
N
N
H
O
Pt
O
O
R3
R4
R1
R2
O
11
12
13
R1=R2=NH3, R3=R4=Cl
R1,R2=ethane-1,2-diamine, R3=R4=Cl
R1,R2= 1R,2R-DACH, R3,R4=oxalate
H
N
N
H
O
Scheme 1. Synthesis of amines and Pt(IV) complexes 8-13
Cytotoxicity
Cytotoxicity of complexes 8–13, as well as of lonidamine, bexarotene and cisplatin was
determined against human cancer cell lines (colon carcinoma SW480, non-small cell lung
4

carcinoma A549, MCF7 breast and its doxorubicin/cisplatin resistant analogue variant MCF7D,
and on immortalized human keratinocytes HaCat) by an MTT colourimetric assay.
Table 1. Cytotoxicity of complexes 8–13, lonidamine, bexarotene and cisplatin (IC50 value after
72 h of incubation, µM.)
SW480
>90
A549
>90
MCF7
30±10
27±4
MCF7D
60±5
HaCat
25±10
>100
Lonidamine
8
48±6
>100
53±7
9
43±1
>100
3.4±0.5
56±12
67±13
50±6
5.9±0.1
>100
42±8
10
Bexarotene
11
>100
>100
>100
80±10
24±0,8
0.8±0.1
35±0,6
17.6±5
85±9
71±21
>100
>90
>100
48±10
0.7±0.01
23±2.5
4.8±1.2
12
1±0.01
52±5
0.75±0.1
23±5
0.85±01
24±3,2
70±12
13
Cisplatin
20.1±1.9
15.2±5
Complexes showed a marginal activity in the micromolar range of concentrations. The most
cytotoxic was 12 with the bexarotene ligand active against a number of cancer cell lines/
However, no preferential potency for malignant vs non-malignant cells was found. Interestingly,
complex 9 with lonidamine showed some activity against breast cancer cells and almost no
activity against HaCat cells. It is worth to mention that in the experiment with mechanical
mixture of ligand 3 and cis-dichlorideethylenediamineplatinum(II) in the ratio 2:1 the IC50 value
on the MC7 cell line was found close to the value of cis-dichlorideethylenediamineplatinum(II)
(18.3 and 16.5 µM correspondingly) confirming the synergistic effect of two active part in the
complex 9.
Conclusions
5

In this study, several Pt(IV) complexes with bexarotene and lonidamine moiety linked to the
platinum centre were synthesized and characterized. The in vitro results for a series of
complexes with cisplatin, dichloride(ethane-1,2-diamine)platinum(II), or oxaliplatin core indicate
that the biologically active moiety can confer activity or selectivity of Pt(IV) complexes. The
complex 12 displays the most promising cytotoxic profile, while 9 showed higher activity against
breast cancer cell lines with some preference towards cancer cells.
Experimental
Materials
(OC-6-33)-(diamine)bis(3-carboxypropanoato)(dichlorido)platinum(IV) [30], (OC-6-33)- bis(3-
carboxypropanoato)dichlorido(ethane-1,2-diаmine)platinum(IV) [31] and (OC-6-33)-bis(3-
carboxypropanoato)(trans-1R,2R-diaminocyclohexane)oxalatoplatinum(IV) [30] prepared using
published procedure. The purity of all starting compounds was 95% or higher.
Physical measurements
NMR spectra were recorded on a Bruker FT-NMR Avance III 500 MHz instrument at 500.32
(1H), 125.81 (13C), 50.70 (15N) and 107.57 (195Pt) MHz. 2D NMR measurements were carried out
using standard pulse programs. Chemical shifts were referenced relative to the solvent signal
1
for H and 13C spectra. For 15N and 195Pt spectra, the external standards NH4Cl and K2[PtCl4]
were used. ESI mass spectra were recorded on LC/MSn ion trap mass spectrometer amaZon
SL (Bruker, Bremen, Germany) with MeOH as a solvent. Elemental analysis was performed at
Moscow State University with MicroCube Elementar analyzer.
Cell lines and culture conditions
The MCF7, MCF7D (gift of N.I.Moiseeva), HaCat, A549, and SW480 cell lines were cultured in
Dulbecco modified Eagle’s medium (DMEM; PanEco, Russia) with 10% fetal bovine serum
(HyClone, USA) and antibiotics (PanEco, Russia) in 5% CO2, 37ºC. The compounds were pre-
dissolved at 20 mM in dimethyl sulfoxide (DMSO) and added to the cell culture at the required
concentration with maximum DMSO content of 0.5 v/v%. Cells in 96-well plates (7×103
cells/well) were treated with various concentrations of 3, 4, cisplatin or bexarotene at 37ºC for
72 h. Cell viability was determined using the MTT assay as follows: cells were incubated at
37ºC for 4 h with 20 µl of 5 mg/ml solution of 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium
bromide (Sigma-Aldrich, St. Louis, USA). The supernatant was discarded and formazan was
6

dissolved in 150 µl of DMSO. The optical density of the solution was measured at 550 nm on a
multiwell plate reader (Multiskan FC, Thermo Fisher Scientifics, USA). The percentage of viable
(i.e., MTT converting) cells was calculated from the absorbance of untreated cells (100%). Each
experiment was repeated three times, each concentration was tested in three replicates.
Tert-butyl-2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamido)ethylcarbamate 1
6
7
Cl
11
5
9
8
10
15
O
12
Cl
4
N
3
2
H a
22
21
20
17
N
N
1
13
18
O
N
14
19
H b
16
O
Oxalyl chloride (2.0 mL, 23.3 mmol) and one-two drops of DMF was added to a stirred
suspension of 1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid (500 mg, 1.55 mmol) in
CH2Cl2 (25 mL). The reaction mixture was refluxed for 1 h until a clear solution was formed.
Solvent and unreacted oxalyl chloride were removed under reduced pressure to yield the acid
chloride as a pale yellow solid that was used without purification. A solution of tert-butyl N-(2-
aminoethyl)carbamate (248 mg, 1.54 mmol) in CH2Cl2 (5 mL) was added to a mixture of 1-(2,4-
dichlorobenzyl)-1H-indazole-3-carbonyl chloride and triethylamine (433 μL, 3.12 mmol) in
CH2Cl2 (40 mL). The reaction mixture was stirred 12 h at room temperature and washed with a
saturated solution of NaHCO3 (2х20 mL). The organic phase was dried with Na2SO4 and the
solvent was removed under reduced pressure. Hexane (20 mL) and diethyl ether (5 mL) were
added to a yellow oil and precipitated white product was filtered off and dried under reduced
pressure. Yield: 415 mg (57%), elem. anal. calc (%) for (C22H24Cl2N4O3): C 57.13, H 5.23, N
1
12.12, found: C 56.68, H 4.92, N 11.79. H NMR (CDCl3) δ: 8.42 (dt, 1Н, J=8.1, 1.0 Hz, H4),
7.49-7.29 (m, 5Н, Н5, H6, H7, H12, NHa), 7.13 (dd, 1H, J=8.4, 2.1 Hz, Н14), 6.70 (d, 1Н, J=8.1
Hz, Н15), 5.68 (s, 2Н, H9), 5.02 (brs, 1H, NHb), 3.66-3.58 (m, 2Н, H16), 3.48-3.38 (m, 2Н,
H17), 1.42 (s, 9Н, H20, H21, H22) ppm. 13C{1H} NMR (CDCl3) δ: 163.1 (C1), 156.4 (C18), 141.1
(C8), 138.2 (C2), 134.5 (C10), 133.2 (C11, C13), 132.3 (C3), 129.5 (C12, C15), 127.6 (C14),
127.4 (C6),123.0 (C4, S5), 109.3 (C7), 79.9 (C19), 50.0 (C9), 40.7 (C17), 39.7 (C16), 28.3
(C20, C21, C22) ppm. 15N NMR (CDCl3) δ: 81.7 (NHa), 57.4 (NHb) ppm.
N-(2-aminoethyl)-1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamide 3
7

6
7
Cl
11
5
9
8
10
15
12
Cl
4
N
3
2
H
17
N
N
1
13
NH2
14
16
O
Trifluoroacetic acid (7 mL) was added to tert-butyl 2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-
carboxamido)ethylcarbamate 1 (380 mg, 0.82 mmol) and stirred for 20 min. Trifluoroacetic acid
was removed under reduced pressure, oil residue was dissolved in CH2Cl2 (30 mL) and washed
with a saturated solution of NaHCO3 (25 mL). The organic phase was dried over Na2SO4, the
solvent was removed under reduced pressure and dried under reduced pressure. Amine was
used without further purification.
Tert-butyl-2-(4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphtyl)vinyl)
benzamide)ethylcarbamate 2
12
10
13
7
9
4
5
8
14
15
O
3
2
11
16
6
H a
29
30
31
26
23
22
1
N
O
19
21
27
N
20
28
25
24
H b
O
17
18
Oxalyl chloride (4.0 mL, 45.6 mmol) and one-two drops of DMF was added to a stirred
suspension of 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphtyl)-vinyl]benzoic acid (1.0
g, 2.87 mmol) in CH2Cl2 (40 mL). The reaction mixture was refluxed for 1 h until a clear solution
was formed. Solvent and unreacted oxalyl chloride were removed under reduced pressure to
yield the acid chloride as a pale-yellow solid that was used without purification. A solution of tert-
butyl N-(2-aminoethyl)carbamate (448 mg, 2.8 mmol) in CH2Cl2 (5 mL) was added to a mixture
of 1-(2,4-dichlorobenzyl)-1H-indazole-3-carbonyl chloride and triethylamine (776 μL, 5.6 mmol)
in CH2Cl2 (40 mL). The reaction mixture was stirred 12 h at room temperature and washed with
saturated solution of NaHCO3 (2х20 mL). The organic phase was dried with Na2SO4 and the
solvent was removed under reduced pressure, hexane (20 mL) and diethyl ether (5 mL) were
added to yellow oil and precipitated white product was filtered off and dried under reduced
pressure. Yield: 890 mg (63%), elem. anal. calc (%) for (C31H42N2O3): C 75.88, H 8.63, N 5.71,
1
found: C 75.58, H 9.03, N 5.27. H NMR (CDCl3) δ: 7.75 (d, 2H, J=8.1 Hz, H3, H24), 7.34 (d,
2H, J=8.1 Hz, H4, H23), 7.14 (s, 2H, H20, NHa), 7,09 (s, 1H, H9), 5.80 (s,1H, H7), 5.31 (s,1H,
H7), 5.02 (t, 1H, J=5.0 Hz, NHb), 3.59 (m, 2H, H25), 3.41 (m, 2Н, H26), 1.95 (s, 3H, C22), 1.72
8

(s, 4H, H14, H15), 1.43 (s, 9Н, H29, H30, H31), 1.32 (s, 6H, H12, H13, H17, H18), 1.29 (s, 6H,
H12, H13, H17, H18) ppm. 13C{1H} NMR (CDCl3) δ: 167.6 (C1), 157.5 (C27), 149.1 (C6), 144.3
(C19), 144.2 (C5), 142.3 (C10), 138.1 (C8), 132.9 (C2), 132.8 (C21), 128.0 (C9, S20), 127.0
(C3, C24), 126.7 (C4, C23), 116.3 (C7), 79.9 (C28), 42.0 (C25), 40.1 (C26), 35.2 (C14, C15),
34.0 (C11/C16), 34.0 (C11/ C16), 31.9 (C12, C13/C17, C18), 31.8 (C12, C13, C17, C18), 28.3
(C29, C30, C31), 19.9 (C22) ppm. 15N NMR (CDCl3) δ: 85.6 (NHa), 59.6 (NHb) ppm.
N-(2-aminoethyl)-4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphtalene-2-
yl)vinyl)benzamide 4
12
10
13
7
9
4
5
8
14
15
3
2
11
16
6
H
26
23
22
1
N
19
21
NH2
20
25
24
O
17
18
Trifluoroacetic acid (7 mL) was added to tert-butyl-2-(4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-
tetrahydro-2-naphtyl)vinyl)benz-amide)ethylcarbamate 2 (370 mg, 0.755 mmol) and stirred for
20 min. Trifluoroacetic acid was removed under reduced pressure, oil residue was dissolved in
CH2Cl2 (30 mL) and washed with saturated solution of NaHCO3 (25 ml). Organic phase was
dried over Na2SO4, the solvent was removed under reduced pressure and product was dried
under reduced pressure. Amine was used without further purification.
(OC-6-33)-(Diamine)dichlorido(bis(4-(2-(1-(2,4-dichlorobenzyl)-1H-indazole-3-
carboxamido)ethylamino)-4-oxobutanoate))platinum(IV) 8
O
O
H
N
Cl
N
O
Pt
O
N
N
H
O
Cl
NH3
NH3
6
Cl
7
5
Cl
9
8
11
Cl
10
O
12
4
N
3
2
H a
17
20
N
15
N
21
1
16
Cl
13
18
N
14
19
H b
O
O
Carbonyldiimidazole (CDI) (89 mg, 0.55 mmol) in dry DMF (10 mL) was added to a suspension
of (OC-6-33)-(diamine)bis(3-carboxypropanoato)(dichlorido)platinum(IV) (173 mg, 0.31 mmol) in
dry DMF (10 mL) and the mixture heated to 60°C. After 20 min of stirring the solution was
cooled down to room temperature and CO2 was removed by flushing with argon for 5 min. N-(2-
9

aminoethyl)-1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamide 3 (218 mg, 0.60 mmol) in dry
DMF (10 mL) was added to the solution and the reaction mixture was stirred for 12 h at room
temperature. The solvent was removed under reduced pressure and the product was purified by
column chromatography on SilicaGel (CH2Cl2/EtOH, 6:1). Yield: 74 mg (22%), m.p. 92–94 °C
(decomp), elem. anal. calc (%) for (C42H44Cl6N10O8Pt·2H2O): C 40.01, H 3.84, N 11.11, found: C
39.90, H 3.78, N 11.17. 1Н NMR ([d6]-DMSO) δ: 8.38 (t, 2H, J=5.4 Hz, NHa), 8.23 (d, 2H, J=7.9
Hz, H4),7.98 (t, 2H, J=5.6 Hz, NHb), 7.74 (d, 2H, J=8.4 Hz, H7), 7.71 (s, 2H, H12), 7.48 (t, 2H,
J=7.3 Hz, H6), 7.37 (d, 2H, J=7.8 Hz, H14), 7.31 (t, 2H, J=7.2 Hz, H5), 6.82 (d, 2H, J=8.2 Hz,
H15), 6.51 (brs, 6H, NH3), 5.83 (s, 4H, H9), 3.40 (m, 4Н, H16), 3.29 (m, 4Н, H17), 2.46 (t, 4Н,
J=6.5 Hz, H19/H20), 2.28 (t, 4Н, J=6.7 Hz, H19/H20) ppm. 13C{1H} NMR ([d6]-DMSO) δ: 180.5
(C21), 172.1 (C18), 162.3 (C1), 141.5 (C8), 138.7 (C2), 133.9 (C10), 133.7 (C11/C13), 133.4
(C11/C13), 130.8 (C15), 129.5 (C12), 128.3 (C14), 127.6 (C6), 123.1 (C5), 122.7 (C3), 122.6
(C4), 110.8 (C7), 50.0 (C9), 39.0 (C16/C17), 38.8 (C16/C17), 31.9 (C19/C20), 31.8 (C19/C20)
ppm. 15N NMR ([d6]-DMSO) δ: -40.2 (NH3). 86.0 (NHa), 92.2 (NHb) ppm. 195Pt ([d6]-DMSO) δ:
2843 ppm. ESI-MS: m/z = 1223 [M - H+]-.
(OC-6-33)-Dichlorido(bis(4-(2-(1-(2,4-dichloridobenzyl)-1H-indazole-3-
carboxamido)ethylamine)-4-oxobutanoato))(ethane-1,2-diаmine)platinum(IV) 9
O
O
H
N
Cl
N
O
Pt
O
N
N
H
H2
N
O
23
22
Cl
6
Cl
7
5
Cl
9
8
11
Cl
N
10
O
H2
12
4
N
3
2
H a
17
20
N
15
N
21
1
16
Cl
13
18
N
14
19
H b
O
O
Compound was prepared similar to complex 8 from CDI (105 mg, 0.65 mmol), (OC-6-33)- bis(3-
carboxypropanoato)dichlorido(ethane-1,2-diаmine)platinum(IV) (173 mg, 0.31 mmol) and N-(2-
aminoethyl)-1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamide 3 (260 mg, 0.72 mmol). Yield:
140 mg (36%), m.p. 175-177 °C (decomp), elem. anal. calc (%) for (C44H46Cl6N10O8Pt): C 42.25,
H 3.71, N 11.20, found C 41.86, H 3.62, N 10.96. 1Н NMR ([d6]-DMSO) δ: 8.43 (brs, 4H, NH2),
8.36 (t, 2H, J=5.90 Hz, NHa), 8.23 (d, 2H, J=8.2 Hz, H4), 7.95 (t, 2H, J=5.6 Hz, NHb), 7.74 (d,
2H, J=8.6 Hz, H7), 7.70 (d, 2H, J=2.1 Hz, H12), 7.50 (m, 2H, H6), 7.37 (dd, 2H, J=8.4, 2.2 Hz,
H14), 7.33-7.28 (m, 2H, H5), 6.82 (d, 2H, J=8.4 Hz, H15), 5.82 (s, 4H, H9), 3.38-3.32 (m, 4Н,
H16), 3.26-3.19 (m, 4Н, H17), 2.68 (brs., 4H, H22, H23), 2,47 (t, 4Н, J=7.4 Hz, H19/H20), 2.29
10

(t, 4Н, J=7.3 Hz, H19/H20) ppm. 13C{1H} NMR ([d6]-DMSO) δ: 181.7 (C21), 171.9 (C18), 162.3
(C1), 141.5 (C8), 138.7 (C2), 133.9 (C10), 133.7 (C11/C13), 133.4 (C11/C13), 130.8 (C15),
129.5 (C12), 128.3 (C14), 127.6 (C6), 123.1 (C5), 122.7 (C3), 122.6 (C5), 110.8 (C7), 50.0 (C9),
49.1 (C22/C23), 39.1 (C16/C17), 38.8 (C16/C17), 32.2 (C19/C20), 31.8 (C19/C20) ppm. 15N
NMR ([d6]-DMSO) δ: -5.1 (NH2), 85.1 NHa), 91.0 (NHb) ppm. 195Pt NMR ([d6]-DMSO) δ: 2654
ppm. ESI-MS: m/z: 1249 [M - H+]-.
(OC-6-33)-(Trans-1R,2R-diamincyclohexane)bis(4-(1-(2,4-dichloridobenzyl)-1H-indazole-
3-carboxamido)ethylаmine)-4-oxobutanoato)oxalatoplatinum(IV) 10
O
O
H
N
Cl
N
O
Pt
O
N
N
H
H2
N
25 O
O
O
23
24
29
O
O
6
26
27
Cl
7
22
5
Cl
9
8
11
N
10
28
O
12
4
H2
N
3
2
H a
17
20
N
15
N
21
1
16
Cl
13
18
N
14
19
H b
O
O
Complex was prepared similar to comlex 8 from CDI (88 mg, 0.54 mmol), (OC-6-33)-bis(3-
carboxypropanoato)(trans-1R,2R-diaminocyclohexane)oxalatoplatinum(IV) (170 mg, 0.27 mmol)
and N-(2-aminoethyl)-1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxamide 3 (210 mg, 0.58
mmol). Yield: 80 mg (22%), m.p. 109-110 °C (decomp), elem. anal. calc (%) for
(C50H52Cl4N10O12Pt.): C 45.43, H 3.96, N 10.60, found: C 44.95, H 3.99, N 10.85. 1Н NMR ([d6]-
DMSO) δ: 8.38 (t, 2H, J=5.9 Hz, NH2), 8.34 (brs, 2H, NHa), 8.24 (m, 2H, H4), 8.14 (t, 2H, J=9.0
Hz, NHb), 7.99 (t, 2H, J=5.6 Hz, NH2), 7.75 (m, 2H, H7), 7.71 (d, 2H, J=2.2 Hz, H12), 7.48 (m,
2H, H6), 7.37 (dd, 2H, J=8.4, 2.2 Hz,H14), 7.30 (m, 2H, H5), 6.81 (d, 2H, J=8.4 Hz, H15), 5.83
(s, 4H, H9), 3.35 (m, 4Н, H16), 3.25-3.18 (m, 4Н, H17), 2.68 (brs, 2Н, H24, H29), 2.51-2.47 (m,
4Н, H19/H20), 2.39-2.21 (m, 4Н, H19/H20), 2.09 (d, 2Н, J=11.9 Hz, H25, H28), 1.50-1.33 (m,
4Н, H25, H26, H27, H28), 1.16 (t, 2H, J=9.6 Hz, H26, H27) ppm. 13C{1H} NMR ([d6]-DMSO) δ:
180.7 (C21), 171.9 (C18), 163.8 (C22, C23), 162.3 (C1), 141.5 (C8), 138.7 (C2), 133.9 (C10),
133.7 (C11/C13), 133.4 (C11/C13), 130.8 (C15), 129.5 (C12), 128.3 (C14), 127.6 (C6), 123.1
(C5), 122.7 (C3), 122.5 (C4), 110.8 (C7), 61.2 (C24, C29), 50.0 (C9), 39.1 (C16/C17), 38.8
(C16/C17), 31.6 (C19/C20), 31.5 (C19/C20), 31.4 (C25, S28), 23.9 (C26, C27) ppm. 15N NMR
([d6]-DMSO) δ: -6.7 (NH2), -6.6 (NH2), 85.8 (NHa), 91.1 (NHb) ppm. 195Pt NMR([d6]-DMSO) δ:
3231 ppm. ESI-MS: m/z = 1345 [M + Na+]+.
11

(OC-6-33)-(Diamine)dichlorido(bis(4-(4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-
naphtyl)vinyl) benzamide)ethylаmine)-4-oxobutanoato))platinum(IV) 11
O
O
H
N
N
O
Pt
O
H
O
Cl
NH3
NH3
12
10
13
7
6
9
4
Cl
5
8
O
14
15
3
2
11
16
H a
26
29
23
22
N
30
1
25
27
19
21
N
28
20
24
H b
O
O
17
18
CDI (94 mg, 0.58 mmol) in dry DMF (10 mL) was added to a suspension of (OC-6-33)-
(diamine)bis(3-carboxypropanoato)(dichlorido)platinum(IV) (150 mg, 0.28 mmol) in dry DMF (10
mL) and the mixture heated to 60°C. After 20 min of stirring the solution was cooled down to
room temperature and CO2 was removed by flushing with argon for 5 min. N-(2-aminoethyl)-4-
(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphtalene-2-yl)vinyl)benzamide 4 (226 mg, 0.58
mmol) in dry DMF (10 mL) was added to the solution and the reaction mixture was stirred for 12
h at room temperature. The solvent was removed under reduced pressure and the product was
purified by column chromatography on SilicaGel (CH2Cl2/EtOH, 10:1). Yield: 91 mg (26%), m.p.
151-153 °C (decomp), elem. anal. calc (%) for (C60H80Cl2N6O8Pt·H2O):C 55.55, H 6.37, N 6.48,
1
found: C 55.52, H 6.51, N 6.84. Н NMR ([d6]-DMSO) δ: 8.47 (t, 2H, J=5.5 Hz, NHa), 7.97 (c,
2H, J=5.6 Hz, NHb), 7.79 (d, 4Н, J=8.57 Hz, H3, H24), 7.30 (d, 4Н, J=8.4 Hz, H4, H23), 7.15 (s,
2Н, H20), 7.08 (s, 2Н, H9), 6.50 (brs, 6H, NH3), 5.89 (s, 2Н, H7), 5.23 (s, 2Н, H7), 3.30 (m, 4H,
H25), 3.24-3.16 (m, 4H, H26), 2.46 (t, 4H, J=7.5 Hz, H28, H29), 2.29 (t, 4H, J=7.5 Hz, H28,
H29), 1.90 (s, 6Н, H22), 1.65 (s, 8Н, H14, H15), 1.26 (c, 12Н, H12, H13, H17, H18), 1.23 (c,
12Н, H12, H13, H17, H18) ppm. 13C{1H} NMR ([d6]-DMSO) δ: 180.4 (C30), 172.1 (C27), 166.5
(C1), 148.7 (C6), 144.2 (C19), 143.2 (C5), 142.3 (C10), 138.4 (C8), 134.0 (C2), 132.6 (C21),
128.3 (C20), 127.9 (C9), 127.7 (C3, C24), 126.4 (C4, C23), 117.0 (C7), 39.5 (C25), 38.8 (C26),
35.1 (C14, C15), 34.1 (C11/ C16), 34.0 (C11/ C16), 32.1 (C12, C13/C17, C18), 32.1 (C12,
C13/C17, C18), 32.0 (C28/C29), 31.8 (C28/C29), 20.0 (C22) ppm. 15N NMR ([d6]-DMSO) δ: -
41.4 (NH3), 87.3 (NHa), 91.6 (NHb) ppm. 195Pt ([d6]-DMSO) δ: 2843 ppm. ESI-MS: m/z = 1277
[M - H+]-.
(OC-6-33)-Dichloridobis(4-(2-(4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-
naphtyl)vinyl)benzamide)ethylamine)-4-oxobutanoato))(ethane-1,2-diаmin)-platinum(IV)
12
12

O
O
H
N
N
O
Pt
O
H
H2
N
O
31
32
Cl
12
10
13
7
6
9
4
Cl
N
5
8
O
14
15
H2
3
2
11
16
H a
26
29
23
22
N
30
1
25
19
21
N
H b27
28
20
24
O
O
17
18
Complex was prepared similar to 11 from CDI (75 mg, 0.46 mmol), (OC-6-33)- bis(3-
carboxypropanoato)dichlorido(ethane-1,2-diаmine)platinum(IV) (128 mg, 0.23 mmol) and N-(2-
aminoethyl)-4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphtalene-2-yl)vinyl)benzamide
4
(188 mg, 0.48 mmol). Yield: 130 mg (46%), m.p. 153-155 °C (decomp), elem. anal. calc (%) for
(C62H82Cl2N6O8Pt·H2O.): C 56.27, H 6.40, N 6.34, found: C 55.95, H 6.54, N 6.41. 1Н NMR [d6]-
DMSO) δ: 8.56-8.35 (m, 6H, NHa, NH2), 7.95 (t, 2H, J=5.7 Hz, NHb), 7.79 (d, 4Н, J=8.5 Hz, H3,
H24), 7.30 (d, 4Н, J=8.5 Hz, H4, H23), 7.15 (s, 2Н, H20), 7.07 (s, 2Н, H9), 5.89 (s, 2Н, H7),
5.23 (s, 2Н, H7), 3.32-3.24 (m, 4H, H25), 3.24-3.16 (m, 4H, H26), 2.67 (brs, 4H, H31, H32),
2.47 (t, 4H, J=7,4 Hz, H28, H29), 2.29 (t, 4H, J=7,3 Hz, H28, H29), 1.91 (s, 6Н, H22), 1.66 (s,
8Н, H14, H15), 1.27 (c, 12Н, H12, H13, H17, H18), 1.23 (c, 12Н, H12, H13, H17, H18) ppm.
13C{1H} NMR ([d6]-DMSO) δ: 181.7 (C30), 172.0 (C27), 166.5 (C1), 148.7 (C6), 144.2 (C19),
143.3 (C5), 142.3 (C10), 138.4 (C8), 134.0 (C2), 132.6 (C21), 128.3 (C20), 127.9 (C9), 127.7
(C3, C24), 126.4 (C4, C23), 117.0 (C7), 49.2 (C31, S32), 39.5 (C25), 38.9 (C26), 35.1 (C14,
C15), 34.1 (C11/S16), 34.0 (S11/C16), 32.2 (C28/C29), 32.1 (C12, C13/C17, C18), 32.1 (C12,
C13/C17, C18), 31.8 (C28/C29), 20.0 (C22) ppm. 15N NMR ([d6]-DMSO) δ: -6.6 (NH2), 87.9
(NHa), 92.8 (NHb) ppm. 195Pt NMR ([d6]-DMSO) δ: 2655 ppm. ESI-MS: m/z = 1303.5 [M - H+]-.
(OC-6-33)-(Trans-1R,2R-diaminecyclohexane)bis(4-(4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-
tetrahydro-2-naphtyl)vinyl) benzamide)ethylаminne)-4-oxobutanoato))oxalato-
platinum(IV) 13
O
O
H
N
N
O
Pt
O
H
H2
N
34 O
O
O
32
33
38
O
O
35
36
12
10
13
7
6
31
9
4
N
5
8
37
O
14
15
3
2
H2
11
16
H a
26
29
23
22
N
30
1
25
27
19
21
N
28
20
24
H b
O
O
17
18
13

Complex was prepared similar to 11 from CDI (67 mg, 0.41 mmol), (OC-6-33)-bis(3-
carboxypropanoato)(trans-1R,2R-diaminocyclohexane)oxalatoplatinum(IV) (130 mg, 0.21 mmol)
and
N-(2-aminoethyl)-4-(1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphtalene-2-
yl)vinyl)benzamide 4 (270 mg, 0.69 mmol). Yield: 130 mg (46%), m.p. 153-155 °C (decomp),
elem. anal. calc (%) for (C68H88N6O12Pt): C 59.33, H 6.44, N 6.11, found: C 59.08, H 6.74, N
6.39. 1Н NMR ([d6]-DMSO) δ: 8.74 (t, 2H, J=5.6 Hz, NHa), 8.35 (d, 2Н, J=6.2 Hz, NH2), 8.13 (t,
2Н, J=9.9 Hz, NH2), 7.99 (t, 2H, J=5.7 Hz, NHb), 7.79 (d, 4Н, J=8.6 Hz, H3, H24), 7.30 (d, 4Н,
J=8.5 Hz, H4, H23), 7.15 (s, 2Н, H20), 7.07 (s, 2Н, H9), 5.89 (s, 2Н, H7), 5.23 (s, 2Н, H7), 3.30
(m, 4H, H25), 3.23-3.17 (m, 4H, H26), 2.71-2.60 (m, 2Н, H33, H38), 2.54-2.46 (m, 4H, H28,
H29), 2.34-2.25 (m, 4H, H28, H29), 2.09 (d, 2Н, J=11,2 Hz, H34, H37), 1.90 (s, 6Н, H22), 1.65
(s, 8Н, H14, H15), 1.49-1.35 (m, 4H, H34, H35, H36, H37), 1.26 (c, 12Н, H12, H13, H17, H18),
1.23 (c, 12Н, H12, H13, H17, H18), 1.19-1.11 (m, 2H, H35, H36) ppm. 13C{1H} NMR ([d6]-
DMSO) δ: 180.6 (C30), 172.0 (C27), 166.5 (C1), 163.9 (C31, C32), 148.7 (C6), 144.2 (C19),
143.2 (C5), 142.3 (C10), 138.4 (C8), 134.0 (C2), 132.6 (C21), 128.3 (C20), 127.9 (C9), 127.7
(C3, C24), 126.4 (C4, C23), 117.0 (C7), 61.2 (C33, C38), 39.5 (C25), 38.8 (C26), 35.1 (C14,
C15), 34.1 (C11/ C16), 34.0 (C11/ C16), 32.1 (C12, C13/C17, C18), 32.1 (C12, C13/C17, C18),
15
31.6 (C28/C29), 31.5 (C28/C29), 31.4 (C34, C37), 23.9 (C35, C36), 20.0 (C22) ppm. N NMR
([d6]-DMSO) δ: -6.5 (NH2), -6.4 (NH2), 87.0 (NHa), 91.0 (NHb) ppm. 195Pt NMR ([d6]-DMSO) δ:
3232 ppm. ESI-MC: m/z: 1400 [M + Na+]+.
Acknowledgements
Y.N. Okulova, I.V. Zenin and I.A. Shutkov are grateful to the Russian Science Foundation (grant
№ 18-73-00073).
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16

17

Highlights:
The new Pt(IV) complexes with lonidamine and bexarotene ligand tethered
to Pt-center via a succinate-ethylenediamine linker were prepared.
The in vitro results indicate that incorporating the lonidamine or bexarotene
moiety can confer activity and selectivity of Pt(IV) complexes.
18