Synthesis of PSMA-targeted 131- and 152-substituted chlorin e6 derivatives and their biological properties

Article abstract of DOI:10.1142/S1088424618501006

Prostate cancer is an extremely common cancer among older men. Conventional chemotherapy has proven to be not effective enough in battling it due to its high systemic toxicity and low selectivity. An alternative method of cancer treatment known as photodynamic therapy (PDT) has been shown to be effective. It is not without its faults either: one of the issues it's been known to have is the insufficient selectivity of photosensitizer accumulation in tumor tissues. Recent studies, however, seem to indicate that introducing a PSMA-targeted moiety into photosensitizer might prove to be a solution to this problem. The present paper is concerned with synthesis of PSMA-targeted 13¹- and 15²-substituted chlorin e₆ conjugates and their biological characteristics. Our data suggests that the developed conjugates show potential as targeted agents for photodynamic therapy.

Full text of DOI:10.1142/S1088424618501006

Journal of Porphyrins and Phthalocyanines
J. Porphyrins Phthalocyanines 2018; 22: 1–9
DOI: 10.1142/S1088424618501006
Published at http://www.worldscinet.com/jpp/
1
2
Synthesis of PSMA-targeted 13 - and 15 -substituted
chlorin e derivatives and their biological properties
6
a
c
a
a
Nikita V. Suvorov* , Alexey E. Machulkin , Anna V. Ivanova , Alexander M. Popkov ,
a
d
d
Elizaveta A. Bondareva , Ekaterina A. Plotnikova , Raisa I.Yakubovskaya ,
Alexander G. Majouga , Andrey F. Mironov and Mikhail A. Grin
b,c
a
a
a
MIREA — Russian Technological University, Institute of Fine Chemical Technology, 86, Vernadskogo Avenue,
Moscow, 119571, Russian Federation
Dmitry Mendeleev University of Chemical Technology of Russia, 9, Miusskaya Square, Moscow, 125047,
b
Russian Federation
c
Lomonosov Moscow State University, 1, Leninskie Gori, Building 3, Moscow, 119991, Russian Federation
P. A. Herzen Moscow Oncology Research Institute, 3, 2th Botkinsky Driveway, Moscow, 125284, Russian Federation
d
Received 16 July 2018
Accepted 29 August 2018
ABSTRACT: Prostate cancer is an extremely common cancer among older men. Conventional
chemotherapy has proven to be not effective enough in battling it due to its high systemic toxicity and low
selectivity. An alternative method of cancer treatment known as photodynamic therapy (PDT) has been
shown to be effective. It is not without its faults either: one of the issues it’s been known to have is the
insufficient selectivity of photosensitizer accumulation in tumor tissues. Recent studies, however, seem
to indicate that introducing a PSMA-targeted moiety into photosensitizer might prove to be a solution to
1
2
this problem. The present paper is concerned with synthesis of PSMA-targeted 13 - and 15 -substituted
chlorin e conjugates and their biological characteristics. Our data suggests that the developed conjugates
6
show potential as targeted agents for photodynamic therapy.
KEYWORDS: PDT, PSMA, chlorin e , prostate cancer.
6
multitude of oxygen molecules from the triplet state to a
INTRODUCTION
singlet [3]. The reactive forms of oxygen (ROS) obtained
during this process trigger a cascade of biochemical
reactions leading to cell death caused by apoptosis or
necrosis. Most PSs utilized in clinical practice are based
on macroheterocycles of a porphyrin nature, including
porphyrins and their hydrogenated analogs (chlorins
and bacteriochlorins) [4]. To date, a number of PS are
used in urology: Photofrin II, Temoporfin, Motexafin
lutetium, Tookad soluble (WST11) and Radachlorin.
Presently, the PS that show the most promise are those
based on chlorophyll a, which not only have attractive
spectral characteristics (the absorption spectrum enters
the tissue transparency window) but also minimal dark
and skin toxicity [5]. In addition, the raw materials for
their production are readily available and not expensive.
At the same time, one of the disadvantages of cancer
PDT is the insufficient selectivity of photosensitizer
Prostate cancer is an extremely common cancer
among older men and one of the most dangerous, its
lethality being second only to lung cancer and colon
cancer in the United States [1]. While conventional
chemotherapy has proven to be not effective enough
against it due to the therapy’s high systemic toxicity
and low selectivity, several promising alternatives
have been developed in recent years. One of the
promising methods of treating oncological diseases
in urology is photodynamic therapy (PDT), which
requires a photosensitizer, light and oxygen [2]. The
photosensitizer (PS) acts as a photocatalyst, enabling
one molecule of PS under light irradiation to transfer a
*
3
Correspondence to: Nikita V. Suvorov, tel.: +7-915-756-37-
1; email: suvorov.nv@gmail.com.
Copyright © 2018 World Scientific Publishing Company

2
N. V. SUVOROV ET AL.
accumulation in tumor tissues, leading to diminished
effectiveness of the method [6].
approach allowed us to introduce a spacer group into
the molecules and achieve high yields of the desired
The introduction of small, targeted molecules into the
PS appears to be a promising solution for this problem.
Various conjugates of derivatives of natural chlorins
with certain vectors on various types of tumors have
been developed and studied, particularly, conjugates of
photosensitizers with folic acid and targeted peptides
products. As an alkyne component, zinc complexes of
1
dimethyl ester of 13 -(propargylcarbamoyl)chlorin e (8)
6
2
and dimethyl ester of 15 -(propargylcarbamoyl)chlorin e
6
(11) were obtained.
The synthesis of 8 was carried out by opening the
exocycle E in pheophorbide a methyl ester (6) with
propargylamine. A recent study has described a method
[
7–10]. One of these is the ligand for the prostate-specific
2
membrane antigen (PSMA). PSMA is a transmembrane
glycoprotein, also known as glutamate carboxypeptidase
II (GCPII), which is a promising receptor for a targeted
delivery of drugs and diagnostic agents. It is highly
homologous to N-acetylated a-linked acidic dipeptidase
for the selective preparation of amides at the 15 -position
of the chlorin e through the formation of anhydride under
6
the action of carbodiimides [22]. Utilizing this method,
2
we obtained dimethyl ester of 15 -(propargylcarbamoyl)
chlorin e (10) starting from chlorin e (9) and pro-
6
6
(
NAALADase), which natively catalyzes the hydrolysis
pargylamine under the action of EDC, followed by
3
1
of N-acetyl-aspartyl-glutamate (NAAG) to glutamate
and N-acetyl-aspartate (NAA) [11]. Overexpression of
these receptors is observed in prostate cancer cells and
is strongly correlated with the tumor histological grade,
especially in cases with metastases. PSMA ligands can
be divided into two groups: transition state and substrates
analogues of NAAG [12]. Substrate analogues usually
include amide and urea derivatives while transition state
analogues are represented by phosphinate, phosphonate
and thiol-containing ligands. These ligands have plenty
of disadvantages due to poor pharmacokinetic profiles
and low metabolic stability [13]. At the same time, urea-
based ligands have been shown to be a potent tool for
targeted delivery of therapeutic and diagnostic agents
methylation of the 17 - and 13 -carboxyl groups with
diazomethane. Using NMR spectroscopy, we managed
to confirm the success of the selective introduction of the
1
2
propargyl group at the 13 - and 15 -positions. Signals of
3
2
1
17 -Me, 15 -Me and 13 -propargyl groups were found
1
on the H NMR spectrum for compound 7, in line with
the results of the aforementioned research [23]. The
regioselective introduction of a propargyl group at the
2
15 -position of compound 10 was confirmed by NMR
spectroscopy, which showed no signal of the methyl group
2
1
at the 15 -position, but did reveal signals of the 13 - and
3
17 -methyl groups. The assignment of signals of methyl
groups was carried out on the basis of the described
spectrum of chlorin e trimethyl ester [24]. At the same
6
[
14, 15]. We chose the Glu-urea-Lys PSMA ligand due to
time, the chemical shifts of the signals of the propargyl
groupof10differedfromthosein7.Thepresenceofcopper
in a click-reaction process makes it possible to metallize a
chlorin macrocycle. It is known that the removal of copper
from the chlorin cycle occurs under harsh conditions [23].
In light of that, we introduced a zinc atom into chlorins 7
and 10 in order to “protect” the macrocycle, which resulted
in demetallization after a click-reaction.
its good binding ability (K = 44 nM) and its opportunity
for modification due to the presence of amino groups
[
i
16].
One of targeted drugs for the diagnosis of prostate
cancer, approved by the FDA, is Prostascint, a monoclonal
antibody to PSMA with a radiolabel [17]. Recently, a
conjugate of PS with a PSMA ligand has been obtained
for targeted PDT in oncology [18]. There have also been
The azide component 5 was prepared by acylation
of the terminal amino group of the aforementioned
PSMA ligand in accordance with a previously described
procedure [25], starting from commercially available
di-tert-butyl glutamic acid ester 1 via the formation
of intermediate isocyanate in situ in the presence of
triphosgene and DIPEA, followed by the reaction with
benzyl carbamate-protected tert-butyl substituted lysine.
After removal of the tert-butyl groups, click-reactions
were performed to produce compounds 12 and 14. The
main difficulty in performing the click-reaction was
selecting a solvent, since the PSMA ligand dissolves
poorly in both non-polar solvents and in polar solvents,
and readily esterifies in the presence of alcohols. The
reaction was carried out in DMF, which had been
thoroughly degassed. After carrying out the reaction,
the desired products 12 and 14 were crystallized using
acetonitrile, followed by subsequent washing of the
crystals by a mixture of acetonitrile/water (1/1, v/v),
acetonitrile and hexane. Corresponding molecular
reports of successful preparation of chlorin e constructs
6
with a PSMA ligand in which the target moiety was
3
attached at the 17 -position [19]. It was shown that such
a modification promotes an increase in the phototoxicity
of the conjugates. In turn, K. Smith and co-workers
describe the synthesis of chlorin e conjugates with
6
2
1
amino acids and amines at positions 15 - and 13 -, and
also study their biological properties [20, 21]. It has been
found that the method of attachment significantly affects
the phototoxicity, as well as the dark/photo cytotoxicity
ratios. Thus, our work was concerned with synthesis of
targeted photosensitizers based on chlorin e containing
6
1
2
a PSMA ligand in 13 - and 15 -positions and their study
via various biological tests.
RESULTS AND DISCUSSION
The synthesis strategy involved the reaction of copper-
catalyzed azide-alkyne cycloaddition (Scheme 1). This
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 2–9

1
2
SYNTHESIS OF PSMA-TARGETED 13 - AND 15 -SUBSTITUTED CHLORIN e DERIVATIVES
3
6
O
CO2t-Bu
CO t-Bu
2
NHCbz
2
CO H
N
H
(CH2)10
(ii, iii, iv)
(
i)
O
N3
O
t-BuO2C
NH2
t-BuO C
N
H
2
N
H
CO2t-Bu
HO C
N
H
2
N
H
CO2H
1
2
5
N
N
N
NH
N
N
N
M
N
N
(
v)
M
H
N
H
HN
H
N
H3C
H
H3C
3
H C
MeOOC
O
H
H
HN
O
MeOOC
MeOOC
O
MeOOC
MeOOC
O
MeOOC
HN
N
6
(CH2)10
N
N
CO2R
N
H
1
1
2: M = Zn, R = H
3: M = 2H, R = H
(
vi)
(xi)
O
7
: M=2H
8: M=Zn
(
xii)
RO2C
N
N
CO R
2
H
H
(
vii, viii)
(xiii)
e
1
6: M = 2H, R = M
N
N
N
N
N
N
NH
N
N
(
ix, x)
N
M
M
H
H
HN
H
N
H3C
H
COOMe
H3C
MeOOC
H
COOH
H
COOMe
MeOOC
O
HOOC
O
HOOC
NH
NH
O
9
N
1
4: M = Zn, R = H
5: M = 2H, R = H
CO2R
N
H
(CH2)10
N
N
(xii)
(
vi)
(xi)
O
1
0: M=2H
11: M=Zn
1
RO2C
N
H
N
H
2
CO R
(
xiii)
e
1
7: M = 2H, R = M
Scheme 1. Synthesis of PSMA-targeted chlorin conjugates. Reactants and conditions: (i) L-tBu-Z-Lys, triphosgene, -83°C; (ii) H2,
Pd/C, CH OH; (iii) 11-azidoundecanoic acid, EDC, NHS, DMF; (iv) 11% TFA/DCM; (v) propargylamine, DCM; (vi) Zn(OAc) ;
3
2
(
(
vii) NaOH, acetone, 50°C; (viii) HCl; (ix) EDC, DMAP, propargylamine, DCM; (x) CH N , DCM; (xi) 5, CuI, DIPEA, DMF;
2
2
xii) 10% TFA/DMSO; (xiii) SOCl , MeOH/DCM
2
ions were found on high-resolution mass spectra. Zinc
removal was carried out in a 10%vol solution of TFA in
DMSO, followed by precipitation of the final products
and water, it was not possible to confirm the structure
of the compounds obtained by the NMR spectroscopy.
Therefore, we decided to methylate the carboxyl groups
of the PSMA moiety using thionyl chloride in a mixture of
methanol/DCM. As a result, compounds 16 and 17 were
1
3 and 15 with deoxygenated distilled water. In this
case, a characteristic change in the absorption spectrum
corresponding to the formation of the free base was
observed, which was confirmed by mass spectroscopy.
Due to the low solubility of the resulting conjugates 13
and 15 in DMSO as well as in other polar organic solvents
readily dissolved in CDCl . NMR spectra of the resulting
3
compounds corresponded to the proposed structures 16
and 17 as well as confirming methylation of all carboxyl
groups of 13 and 15. Corresponding signals of the chlorin
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 3–9

4
N. V. SUVOROV ET AL.
macrocycle, triazole, undecane spacer and PSMA ligand
were found for compounds 16 and 17 (Table S2).
against prostate tumor cells (Table 1). The maximum
photoactivity of conjugate 13 was determined after a
6 h incubation of PS with the cells. The IC50 of chlorin
e6 with the PSMA ligand for 22Rv1 cells was 1.2 ± 0.1
mM and exceeds the photoactivity obtained on PC-3 cells
7-fold, probably due to the high expression of PSMA
receptors in this cell culture [26]. In contrast, PC-3 cells
have no such receptors on their surface. It should be
noted that Radachlorin was less effective when it came to
The absorption and fluorescence spectra of 13 and 15
in buffer solution (pH = 7.2) are presented in Figs S32–
S34. It should be noted that the introduction of the
PSMA moiety into different positions of the macrocycle
significantly affects absorption and the fluorescence
quantum yield of compounds 13 and 15 (Table S1). The
extinction coefficient of the long-wavelength absorption
-
1
-1
.
band of compound 13 was e6 = 44100 M sm , as
22Rv1 cells (IC = 3.0 ± 0.2 mM) compared to conjugate
65
50
-
1
-1
.
compared with e660 = 32200 M sm in compound 15.
Quantum yields of fluorescence were f = 0.11 and 0.15
respectively.
13. However, during a phototoxicity study, conjugate 15
did not show significant improvement in effectiveness
compared to Radachlorin. The IC values of 15 were
5
0
Partion coefficients were measured in a 1-octanol/
water system. The logP values for compounds 13 and 15
were -0.88 and -0.79, respectively. These measurements
indicate a low lipophilicity of the resulting conjugates,
despite the large hydrophobic parts in their molecules.
This allows us to conclude that the ability of these
substances to passive transmembrane transfer will
be reduced, and the pathway of receptor-mediated
endocytosis will be preferable.
Thus we obtained conjugates 13 and 15 which
include a photodynamic moiety represented by a chlorin
macrocycle, a PSMA-vector and a spacer that distances
the photoactive and targeting components in space.
Phototoxicity of conjugates 13 and 15 was evaluated
on 22Rv1 and PC-3 prostate cancer cell lines at 0.5, 1, 2,
approximately the same for both cell lines. Thus, we have
demonstrated that the introduction of PSMA-ligand into
various positions of the macrocycle significantly affects
the effectiveness of the photosensitizer. All the following
experiments were performed using conjugate 13.
Fluorescence measurements during biological tests
were performed using a local fluorescence spectroscopy
technique with a LESA-06 (Biospec, Russia) laser
spectrum analyzer. The fluorescence maximum of chlorin
conjugate 13 was detected at 667 ± 2 nm. The ability
of 13 to fluorescence allows the use of fluorescence
microscopy to study the interaction of PS with tumor
cells. It was found that conjugate 13 penetrates and
accumulates in 22Rv1 prostate cancer cells 15 min after
incubation, and 4 h after incubation in PC-3 cells. With
PS diffusely distributed in the cytoplasm region, the
staining increases in the near-nuclear region, but does not
penetrate into the nuclei of the cells (Fig. 1). The intensity
of the fluorescence of the PS localized in the 22Rv1 cells
after 4 h of incubation (50.5 ± 4.9) is five-fold higher than
in the PC-3 cells (10.1 ± 1.8). Thus, conjugate 13 is well
accumulated in 22Rv1 human prostate cells, which are
characterized by high expression of PSMA.
4
, and 6 h of incubation after irradiation with a halogen
lamp with a wideband filter (l = 620 nm, power density
2
2
1
8.2 ± 0.7 mW/cm , light dose 10 J/cm ). As a reference
PS, we used Radachlorin (RadaPharma, Russia) which is
accepted for clinical PDT in Russia . This photosensitizer
4
is a derivative of chlorin e and has similar photophysical
6
properties to conjugates 13 and 15. When studying
the phototoxicity of chlorin e with a PSMA-targeted
6
moiety in comparison with the officinal preparation of
Radachlorin, we found that all three PSs were effective
Dark toxicity was assessed after 24 h dark incubation
of the cells with the PS. We found that without light
Table 1. Phototoxicity of chlorin e with PSMA-moiety and Radachlorin in dependence
6
on the incubation time before exposure
IC , μM
5
0
PS/Incubation time
0.5 h
1 h
2 h
4 h
6 h
2
2Rv1
Conjugate 13
Conjugate 15
Radachlorin
5.8 ± 0.2
6.4 ± 0.3
8.5 ± 0.3
4.0 ± 0.3
5.7 ± 0.2
5.1 ± 0.3
2.7 ± 0.2
5.5 ± 0.2
4.4 ± 0.2
2.7 ± 0.1
5.4 ± 0.2
2.9 ± 0.1
1.2 ± 0.1
5.2 ± 0.2
3.0 ± 0.2
PC-3
Conjugate 13
Conjugate 15
Radachlorin
12.0 ± 0.4 11.4 ± 0.2 10.9 ± 0.4
10.2 ± 0.5
5.5 ± 0.2
5.1 ± 0.4
8.5 ± 0.3
5.4 ± 0.2
4.3 ± 0.2
13.6 ± 0.5
8.3 ± 0.3
6.2 ± 0.3
6.9 ± 0.3
17.2 ± 0.4 13.3 ± 0.3
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 4–9

1
2
SYNTHESIS OF PSMA-TARGETED 13 - AND 15 -SUBSTITUTED CHLORIN e DERIVATIVES
5
6
Fig. 1. Normal and fluorescent images of intracellular biodistribution of conjugate 13 in 22Rv1 and PC-3 cancer cell lines after
0
.25 and 4 h
exposure, inhibition of cell proliferation (with the use
22Rv1 human prostate carcinoma cells and PC-3 human
prostate adenocarcinoma cells were purchased from the
American Type Culture Collection (ATCC, Manassas,
VA, USA) and cultured in RPMI-1640 media (PanEco,
Russia) supplemented with L-glutamine (PanEco,
Russia) and 10% fetal calf serum (FCS, PanEco, Russia)
of chlorin e with a PSMA-targeted moiety) was 16 and
6
1
2
8%, and with a Radachlorin application, 27 and 30% for
2Rv1 and PC-3, respectively (Fig. S37).
EXPERIMENTAL
in a 37°C, 5% CO atmosphere. All cell lines routinely
2
tested negative for mycoplasma. The cell line 22Rv1
expresses prostate specific antigens (PSA). In biological
research, the preparations were analyzed by fluorescence
microscopy using an EVOS (life technologies) Lens
PlanFluor 60 × /0.75 fluoresence microscope.
General
1
13
H and C NMR spectra were registered on Bruker
DPX 300 and Avance 400 spectrometers in CDCl or
DMSO-d . Signals of residual H nuclei were used for
3
1
6
scale calibration. Preparative column chromatography
was performed on Merck 40/60 430 silica gel sorbent.
High resolution mass spectra were registered on an
Orbitrap Elite mass spectrometer (Thermo Scientific)
and on a Bruker micrOTOF II instrument using ESI
ionization [27]. We used DMSO and di-isooctylphthalate
as internal calibration signals (m/z 157.03515 and
Synthesis
Preparation of (9S,13S)-tri-tert-butyl 3,11-dioxo-1-
phenyl-2-oxa-4,9,12-triazapentadecane-9,13,15-
tricarboxylate (2). L-glutamic acid di-tert butyl ester
hydrochloride 1 (500 mg, 1.69 mmol) and triethylamine
(800 μl, 5.7 mmol) were dissolved in CH Cl (15 ml) and
2 2
4
2
13.26623) in positive mode and dodecylsulfate (m/z
65.14790) in negative mode. Absorbance spectra were
the resulting solution was cooled to -78°C. Solution of
triphosgene (163 mg, 0.57 mmol, 0.34 equiv.) in DCM
(5 ml) was added dropwise to the reaction mixture. Upon
complete addition, the reaction was allowed to warm to
room temperature and then stirred for additional 30 min.
H-Lys(Z)-O(t-Bu) hydrochloride (630 mg, 1.69 mmol)
was added, followed by triethylamine (1 ml, 7.2 mmol)
and DCM (3 ml). The reaction was stirred at room
temperature overnight for at least 16 h. Then the reaction
registered on a Shimadzu UV1800 UV/vis spectrometer
in water and CH Cl2 (DCM). Fluorescence spectra
2
were recorded on a CARY Eclipse spectrofluorimeter
(
Varian, USA). The fluorescence quantum yield was
determined by the relative method. A solution of chlorin
e6 in water was used as a standard [28]. Fluorescence
measurements were also performed using a local
fluorescence spectroscopy technique with a LESA-06
mixture was diluted with CH
with H O (2 × 100 ml). The crude mixture was dried
over Na SO and concentrated under reduced pressure.
Cl (50 ml) and washed
2
2
(
Biospec, Russia) laser spectrum analyzer. Fluorescence
2
spectra were measured ex tempore. Partion coefficients
were measured in 1-octanol/water system using the
shake-flask method. Chlorin e6 (9) was obtained
according to a previously described procedure [29].
2
4
The product was purified by column chromatography on
silica gel (hexane/EtOAc, 3/2, v/v). 2 was obtained as a
colorless oil (420 mg, yield 78%). H NMR (400 MHz,
1
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 5–9

6
N. V. SUVOROV ET AL.
CDCl , d, ppm): 7.40–7.25 (m, 5H), 5.60–5.30 (m, 3H),
Preparation of (S)-2-(3-((S)-5-(11-azidoundecan-
amido)-1-carboxypentyl)ureido)pentanedioic acid (5).
Compound 4 (73 mg, 0.037 mmol) was dissolved in an
11% solution ofTFA in DCM (5 ml) and stirred overnight.
The solution was dried in vacuo, the crude product was
washed with dry diethyl ether (15 ml). Compound 5 was
purified by reversed-phase chromatography using a C18
PuriFlash column (15μ, HP) employing a gradient of
acetonitrile in water (5–80%, 25 min, 20 ml/min) that
3
5
2
.20–5.03 (m, 2H), 4.45–4.27 (m, 2H), 3.25–3.07 (m,
H), 2.40–2.20 (m, 2H), 2.12–1.99 (m, 1H), 1.90–1.67
(
1
m, 2H), 1.67–1.56 (m, 1H), 1.56–1.47 (m, 2H), 1.40–
.47–1.40 (m, 27H), 1.40–1.20 (m, 2H). C NMR (100
1
3
MHz, CDCl , d, ppm): 172.5, 172.4, 157.0, 156.6, 136.7,
3
1
4
28.5, 128.1, 128.0, 82.2, 81.7, 80.5, 66.5, 52.3, 53.0,
0.6, 32.6, 31.6, 29.3, 28.3, 28.1, 28.0, 22.3. ESI-HRMS:
+
m/z calc. for C H N O [M + H ]: 622.3698, found:
3
2
51
3
9
+
1
6
6
6
22.3702; m/z calc. for [M + Na ]: 644.3518, found:
gave the title compound (48 mg, yield 91%). H NMR
+
44.3521; m/z calc. for [M + K ]: 660.3257, found:
(400 MHz, DMSO-d , d, ppm): 7.75 (br s, 1H), 6.33 (br
6
60.3259.
s, 2H), 4.07 (s, 1H), 4.02 (s, 1H), 3.27 (t, 1H), 3.04–2.92
(m, 2H), 2.90–2.75 (m, 1H), 2.55–2.45 (m, 2H), 2.30
–2.15 (m, 2H), 2.04 –1.95 (m, 2H), 1.94–1.85 (m, 1H),
1.75–1.55 (m, 2H), 1.55 –1.39 (m, 5H), 1.39–1,30 (m,
Preparation of (S)-di-tert-butyl 2-(3-((S)-6-amino-
-(tert-butoxy)-1-oxohexan-2-yl)ureido)pentanedioate
1
(
3). Compound 2 (373 mg, 0.6 mmol) was dissolved
1
3
in methanol (30 ml) under vigorous stirring which was
followed by adding a volume of 10% Pd/C (98 mg). The
reaction mixture was magnetically stirred overnight under
2H), 1.30–1.9 (m, 16H). C NMR (100 MHz, DMSO-d ,
6
d, ppm): 175.0, 174.6, 174.1, 172.6, 157.8, 52.7, 52.1,
51.1, 48.7, 38.7, 35.9, 32.9, 32.2, 31.05, 30.32, 29.0,
28.7, 27.9, 26.6, 26.2, 25.8, 23.1; ESI-HRMS: m/z calc.
H atmosphere (p = 1 bar). The reaction was controlled by
2
+
TLC (DCM/MeOH, 30/1, v/v). The reaction mixture was
filtered through Celite and then concentrated in vacuo to
produce a viscous oil of 3 (287 mg, 0.59 mmol, 98%)
for C H N O [M + H ]: 529.2980, found: 529.2979;
2
3
40
6
8
+
m/z calc. [M + Na ]: 551.2800, found: 551.2800.
1
Preparation of dimethyl ester 13 -(propargylcar-
1
which was used without further purification. H NMR
bamoyl)chlorin e (7). Methyl ester of pheophorbide
6
(
2
1
(
1
3
400 MHz, CDCl , d, ppm): 5.50–5.30 (m, 2H), 4.33 (m,
a 6 (40 mg; 0.063 mmol) and propargylamine (200 ml;
3.1 mmol) were dissolved in DCM (2 ml) with addition
of DIPEA (100 ml). The reaction was controlled by
TLC. Then the reaction mixture was diluted with DCM
(100 ml) and washed with acidic water pH = 4 (3 ×
50 ml). The organic fraction was dried over Na SO and
filtered, and the solvent was then evaporated in vacuo.
Purification of the substance was performed using
preparative TLC chromatography on silica gel (DCM/
3
H), 2.66 (m, 2H), 2.50–2.20 (m, 5H), 2.15–2.00 (m,
H), 1.90–2.70 (m, 2H), 1.69–1.53 (m, 2H), 1.53–1.31
1
3
m, 30H). C NMR (100 MHz, CDCl , d, ppm): 172.6,
3
72.5, 172.4, 157.0, 82.0, 81.6, 80.5, 53.4, 53.0, 41.5,
2.8, 32.5, 31.6, 28.4, 28.07, 28.02, 28.00, 22.3. ESI-
2
4
+
HRMS: m/z calc. for C H N O [M + H ]: 488.3330,
found: 488.3340; m/z calc. for [M + Na ]: 510.3150,
found: 510.3150.
2
4
45
3
7
+
Preparation of (S)-di-tert-butyl 2-(3-((S)-6-(11-azido-
undecanamido)-1-(tert-butoxy)-1-oxohexan-2-yl)-ureido)
pentanedioate (4). To a solution of 11-azidoundecanoic
acid (173 mg, 0.76 mmol) in DMF (4 ml) we added EDC
MeOH, 50/1, v/v) and gave compound 7 (43 mg, yield
1
98%). H NMR (300 MHz, CDCl , d, ppm): 9.71 (s, 1H),
3
9.64 (s, 1H), 8.82 (s, 1H), 8.16–8.04 (dd, 1H), 6.68–6.61
(t, 1H), 6.42–6.32 (dd, 1H), 6.19–6.13 (dd, 1H), 5.55–
5.45 (d, 1H), 5.33–5.23 (d, 1H), 4.61–4.51 (m, 2H), 4.50–
4.46 (d, 1H), 4.46 (m, 1H), 4.45–4.35 (m, 1H), 3.87–3.76
(s, 4H), 3.63 (s, 3H), 3.59 (s, 3H), 3.51 (s, 3H), 3.30 (s,
3H), 2.61–2.56 (m, 1H), 2.43–2.39 (t, 1H), 2.25 (m, 1H),
2.29–2.11 (m, 1H), 1.91–1.67 (m, 9H), -1.60 (s, 1H),
(
78.5 mg, 0.5 mmol) and NHS (58.3 mg, 0.51 mmol) under
the stirring. After 1 h solution of compound 3 (70 mg,
.1 mmol) in DMF (1 ml) was added and reaction mixture
0
was stirred for 48 h. Then reaction mixture was diluted with
DCM (50 ml) and washed with brine (3 × 50 ml). Organic
fraction was dried over Na SO and filtered, the solvent
1
3
-1.83 (s, 1H). C NMR (75 MHz, DMSO-d , d, ppm):
2
4
6
was then evaporated in vacuo. Purification of crude oil by
174.13, 173.57, 169.26, 169.03, 166.66, 154.40, 149.06,
144.86, 139.05, 136.12, 135.18, 134.99, 134.82, 134.62,
130.32, 129.75, 129.42, 127.01, 121.72, 102.08, 101.54,
98.82, 93.71, 78.93, 72.41, 53.04, 52.38, 51.66, 49.27,
37.95, 31.14, 0 30.43, 29.74, 23.05, 19.68, 17.75, 12.19,
column chromatography on silica gel (hexane/EtOAc, 3/2,
1
v/v) gave the compound 4 (73 mg, yield 30%). H NMR
(
400 MHz, CDCl , d, ppm): 6.76 (br s, 1H), 5.86 (br s, 1H),
3
5
3
2
1
.62 (br s, 1H), 4.27 (m, 1H), 4.15 (m, 1H), 3.22–3.15 (m,
-1
-1
.
H), 3.15–3.07 (m, 1H), 2.32–2.20 (m, 2H), 2.14 (t, 2H),
11.93, 11.35. UV/vis (CHCl ), lmax, nm (e, M sm ):
3
.05–1.95 (m, 1H), 1.83–1.72 (m, 1H ), 1.70–1.65 (m,
391 (116500), 500 (11550), 528 (4300), 557 (2100), 608
(4200), 663 (33500).
2
H), 1.60–1.40 (m, 7H) 1.40–1.32 (m, 28H), 1.30–1.15
13
1
(m, 15H); C NMR (100 MHz, CDCl , d, ppm): 173.8,
Preparation of Zn-complex of dimethyl ester 13 -
3
1
5
2
73.3, 172.4, 172.1, 157.4, 82.2, 81.3, 80.4, 53.5, 52.9,
1.4, 39.0, 36.5, 32.4, 31.6, 29.36, 29.33, 29.1, 28.9, 28.8,
(propargylcarbamoyl)chlorin e (8). To a solution of 7
6
(42.9 mg; 0.06 mmol) in DCM (1 ml) saturated solution
8.1, 27.99, 27.93, 26.6, 25.9, 22.9. ESI-HRMS: m/z calc.
of Zn(OAc) ·2H O in MeOH (100 ml) was added under
2
2
+
for C H N O [M + H ]: 697.4858, found: 697.4862; m/z
stirring (30 min). Then, a saturated aqueous solution of
35
64
6
8
+
calc. for [M + Na ]: 719.4678, found: 719.4681; m/z calc.
NaHCO (2 ml) was added to the reaction mixture and
3
+
for [M + K ]: 735.4417, found: 735.4424.
stirred for 10 min. The resulting white precipitate was
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 6–9

1
2
SYNTHESIS OF PSMA-TARGETED 13 - AND 15 -SUBSTITUTED CHLORIN e DERIVATIVES
7
6
filtered through filter paper. The solution was extracted
Preparation of conjugate of Zn-complex of dimethyl
1
with DCM (4 × 25 ml) and deoxygenated (4 × 100 ml)
and acidic (4 × 10 ml) water. The extract was dried
over Na SO and evaporated in vacuo. The dry residue
ester 13 -(propargylcarbamoyl)chlorin e with PSMA-
6
moiety (12). The reaction of cycloaddition compounds
8 (33.7 mg; 0.048 mmol) and 5 (26 mg; 0.053 mmol)
was carried out in DMF (5 ml) with the addition DIPEA
(1 eq., 0.05 mmol). The reaction was catalyzed by CuI
(0.4 mg, 0.002 mmol) and stirred for 16 h. The end-
point of the reaction was monitored by analytical TLC.
The reaction mixture was then evaporated and the dry
residue was washed with acetonitrile, acetonitrile/water
and then with hexane. The yield of compound 12 was
59 mg (98%). ESI-HRMS: m/z calc. for C H N O Zn
2
4
was redissolved and crystallized in hexane. The yield of
1
compound 8 was 33.7 mg (77%). H NMR (300 MHz,
CDCl , d, ppm): 9.36 (s, 1H), 9.31 (s, 1H), 8.59 (s, 1H),
3
7.95 (dd, 1H), 6.43 (t, 1H), 6.13–6.07 (dd, 1H), 5.96–5.93
(dd, 1H), 5.08 (d, 1H), 4.90 (d, 1H), 4.36–4.25 (m, 2H),
4.21 (d, 1H), 4.18 (m, 1H), 3.76 (s, 4H), 3.50 (s, 3H), 3.38
(
(
s, 3H), 3.36 (s, 3H), 3.13 (s, 3H), 2.48–2.35 (m, 1H), 2.32
t, 1H), 2.14 (m, 1H), 1.81 (m, 1H), 1.71–1.61 (m, 9H).
6
2
81 11 13
-1
-1
+
.
UV/vis (CHCl ), lmax, nm (e, M sm ): 413 (141000),
5
[M + H ]: 1252.5380, found 1252.5350. UV/vis (H O),
-1 -1
3
2
.
07 (11550), 530 (4300), 566 (3050), and 635 (73100).
lmax, nm (e, M sm ): 432 (177000), 521 (6050), 598
2
Preparation of 15 -(propargylcarbamoyl)chlorin e
(12100), 641 (85000).
6
1
(
10). To a solution of chlorin e (77 mg; 0.118 mmol)
Preparation of conjugate of dimethyl ester 13 -
6
in DCM (5 ml) we added a solution of EDC (20 mg;
.129 mmol) and DMAP (7 mg; 0.057 mmol) in DCM
2 ml). The mixture was then stirred for 2 h and then
(propargylcarbamoyl)chlorin e6 with PSMA-moiety
(13). Compound 9 (10 mg; 0.008 mmol) was dissolved
in a deoxygenized mixture of DMSO and TFA (10:1)
followed by stirring for 30 min with protection
from sunlight. Then the mixture was diluted with 2
volumes of water and a precipitate was extracted using
centrifugation. The obtained precipitate was then washed
with deoxygenized distilled water three times. The
0
(
propargylamine (14.5 ml, 0.234 mmol) was added and the
mixture was stirred for 17 h. Then a saturated solution
of diazomethane in diethyl ether (2 ml) was added to the
reaction mixture and stirred for 30 min. Then the mixture
was evaporated under reduced pressure, redissolved in
DCM and washed with water. The organic layer was
dried over Na SO and evaporated in vacuo. Purification
yield of compound 13 was 8.5 mg (85%). ESI-HRMS:
+
m/z calc. For C H N O [M + H ] 1190.6245; found
2
4
62 83 11 13
of substance was performed with preparative TLC
1190.6206. UV/vis data is given in Table S1.
chromatography on silica gel (DCM/MeOH, 50/1, v/v)
Preparation of conjugate of Zn-complex of dimethyl
1
2
and gave 34 mg of 10 (44%). H NMR (300 MHz, CDCl ,
ester 15 -(propargylcarbamoyl)chlorin e with PSMA-
3
6
d, ppm): 9.75 (s, 1H), 9.61 (s, 1H), 8.81 (s, 1H), 8.05 (dd,
moiety (14). The procedure is similar to the method
described for compound 12. Starting from compound 11
(34 mg; 0.051 mmol) we obtained 30.3 mg of 14 (89%).
1
1
1
3
H), 6.35 (dd, 1H), 6.15 (dd, 1H), 5.85 (t, 1H), 5.21 (d,
H), 5.05 (d, 1H), 4.42 (m, 2H), 4.27 (s, 3H), 4.12 (m,
H), 3.91 (m, 1H), 3.78 (q, 2H), 3.59 (s, 3H), 3.51 (s,
H), 3.32 (s, 3H), 2.56 (m, 1H), 2.40–2.14 (m, 3H), 1.90
+
ESI-HRMS: m/z calc. for C H N O Zn [M + H ]:
6
2
81 11 13
1252.5380, found 1252.5362. UV/vis (H O), lmax, nm (e,
2
-1
-1
.
(
(
t, 1H), 1.78 (d, 3H), 1.73 (t, 3H), -1.39 (br s, 1H), -1.53
M
sm ): 414 (171000), 519 (4200), 597 (11500), 632
1
3
br s, 1H). C NMR (75 MHz, CDCl , d, ppm): 173.31,
(62000).
3
2
1
1
1
9
4
1
71.99, 169.85, 169.36, 167.14, 155.15, 149.22, 145.29,
39.75, 136.50, 136.29, 135.54, 135.10, 134.80, 130.82,
29.55, 129.24, 123.73, 122.11, 102.38, 101.15, 99.13,
3.85, 79.21, 71.37, 53.47, 52.86, 51.73, 50.88, 49.22,
1.06, 31.31, 29.72, 29.62, 29.37, 23.25, 19.67, 17.72,
Preparation of conjugate of dimethyl ester 15 -
(propargylcarbamoyl)chlorin e6 with PSMA-moiety
(15). The procedure is similar to the method described
for compound 13. Starting from compound 14 (34 mg;
0.051 mmol) we obtained 30.3 mg of 15 (89%). ESI-
+
4.16, 12.31, 12.18, 11.35. UV/vis (CHCl ), lmax, nm
HRMS: m/z calc. for C H N O [M + H ]: 1190.6245,
3
62 83 11 13
-
1
-1
.
(e, M sm ): 399 (116500), 500 (15500), 528 (4300),
found 1190.6214. UV/vis data is given in Table S1.
1
5
57 (2100), 608 (4200), 665 (31500).
Preparation of Zn-complex of 15 -(propargyl-
Preparation of methylated derivative of PSMA-13 -
2
chlorin conjugate (16). Compound 13 (7 mg; 0.0063
carbamoyl)chlorin e (11). The procedure is similar to
mmol) was dissolved in a mixture of CH OH/DCM
6
3
the method described for compound 7. Starting from
(1ml; 1/1, v/v) to which thionyl chloride (20 ml, 0.103
mmol) was then added. The reaction was then stirred for
30 min and subsequently diluted with DCM (10 ml). The
compound 10 (34 mg; 0.051mmol), 30.3 mg of 11 (89%)
1
was obtained. H NMR (300 MHz, CDCl , d, ppm): 9.51
3
3
(
(
(
(
(
s, 1H), 9.45 (s, 1H), 8.61 (s, 1H), 8.01 (dd, 1H), 6.19
dd, 1H), 6.03 (dd, 1H), 5.83 (t, 1H), 4.81 (d, 1H), 4.63
d, 1H), 4.32 (dd, 1H), 4.19 (dd, 1H), 4.02 (s, 3H), 3.97
m, 2H), 3.70 (q, 2H), 3.39 (s, 6H), 3.35 (s, 3H), 3.24
s, 3H), 2.31 (m, 1H), 2.10–1.90 (m, 3H), 1.87 (t, 1H),
resulting mixture was washed with 5% NaHCO solution
(2 × 20 ml). Purification with preparative TLC gave
1
6 mg of compound 16 (83%). H NMR data is given in
1
3
Table S2. C NMR (75 MHz, CDCl , d, ppm): 173.78,
3
173.61, 173.52, 173.45, 173.38, 173.33, 169.31, 157.22,
144.45, 139.34, 135.94, 134.91, 130.54, 129.96, 129.30,
127.91, 122.07, 101.23, 98.77, 94.09, 70.57, 53.13,
52.61, 52.32, 52.30, 52.17, 52.02, 51.65, 51.63, 50.48,
1
.73 (d, 3H), 1.66 (t, 3H). UV/vis (CHCl ), lmax, nm
3
-1 -1
.
(e, M sm ): 414 (145000), 521 (6200), 562 (6000), 595
(
12000), 641 (47000).
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 7–9

8
N. V. SUVOROV ET AL.
4
3
2
9.28, 38.10, 36.28, 36.08, 31.55, 31.02, 30.94, 30.16,
0.06, 29.71, 29.63, 29.00, 28.87, 28.71, 28.46, 27.75,
6.26, 25.50, 23.06, 22.01, 19.68, 17.61, 14.13, 12.17.
Preparation of methylated derivative of PSMA-
detailed in vitro studies, as well as in vivo experiments on
appropriate tumor models are required. Nevertheless, our
study proves that regioselective introduction of a targeted
moiety into a chlorin macrocycle significantly affects its
biological properties. It should be noted that our study is
in agreement with the data published earlier [21]. Thus,
our future studies should address the structure-property
relationship for chlorin photosensitizers.
2
1
5 -chlorin conjugate (17). The procedure is similar to
the method described for compound 16. Starting from
compound 15 (14 mg; 0.013 mmol) we obtained 11.9 mg
1
13
of 17 (85%). H NMR data is given in Table S2. C NMR
75 MHz, CDCl , d, ppm): 173.76, 173.61, 173.46,
(
3
1
1
1
1
5
4
2
2
1
73.39, 173.33, 172.55, 169.77, 169.42, 166.94, 157.21,
55.16, 149.11, 145.27, 144.81, 139.69, 136.27, 136.23,
35.57, 135.06, 134.82, 130.87, 129.35, 129.20, 123.63,
22.42, 122.15, 102.29, 101.53, 99.00, 93.79, 53.32,
2.81, 52.61, 52.34, 52.21, 52.06, 51.72, 51.69, 50.11,
9.12, 40.96, 38.39, 36.53, 35.39, 31.67, 31.19, 30.08,
9.98, 29.73, 29.62, 28.97, 28.94, 28.90, 28.66, 28.62,
7.78, 26.14, 25.58, 22.96, 22.11, 19.67, 17.75, 12.36,
2.18, 11.36.
Acknowledgments
This work was carried out with support of the Russian
Science Foundation (grant No. 16-13-10092, chemical
1
2
synthesis of PSMA-targeted 13 - and 15 -substituted
chlorin e derivatives) and the Ministry of Education and
6
Science of the Russian Federation (No. 02.G25.31.0219,
synthesis of PSMA-moiety). High resolution mass spectra
were recorded in the Department of Structural Studies of
the Zelinsky Institute of Organic Chemistry (Moscow)
and in the Lomonosov Moscow State University. The
authors are thankful to Thermo Fisher Scientific Inc.,
Textronica AG group (Moscow, Russia), and personally
to Prof. Alexander Makarov for providing Orbitrap Elite
mass spectrometer for this work.
In vitro photo- and cytotoxicity study. For these
experiments, cells were seeded in 96-well plates (Costar,
USA) in the amount of 15 × 10 (22Rv1) and 10 ×
1
dissolved in deoxygenated PBS and filtered through
a syringe filter (size of pore — 0.2 mm). The tested PS
were added after 24 h in concentrations from 0.07 to
3
3
0 (PC-3) cells per well. Compounds 13 and 15 were
Supporting information
2
0 mM for conjugates 13 and 15, and from 1.9 to 30 mM
for Radachlorin. Phototoxicity of PSs was evaluated
at 0.5, 1, 2, 4, and 6 h of incubation (irradiation with
halogen lamp, (l ≥ 620 nm), a wideband filter, and a 5 cm
thick water filter with circulating power density of 18.2 ±
1
H NMR spectra for compounds 2–5, 7, 8, 10, 11, 16,
13
1
1
1
1
7, C NMR 2–5, 7, 10, 16, 17, H– H COSY for 16 and
7, HRMS for 2–5, 7, 8, 10, 11, 12, 13, 14, 15, UV/vis
spectra for 8, 11, 13, 15, fluorescence spectra for 13 and
5, dark cytotoxicity for compound 13 and Radachlorin,
2
2
0
.7 mW/cm and light dose of 10 J/cm ).After irradiation,
1
the cells were incubated under standard conditions for
one day. Dark toxicity was assessed after 24 h dark
incubation of the cells with PS. The assessment of cell
viability was done using light microscopy to visualize
changes in cellular morphology and by using the MTT
ex tempore fluorescence spectrum for 13, structures of 16
1
and 17, UV/vis data for 13 and 15, H NMR data for 16
and 17 are given in supporting information (Figs. S1-S37
and Tables S1–S2). This material is available free of
charge via the Internet at http://www.worldscinet.
com/jpp/jpp.shtml
[
3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium
bromide] assay. The mean inhibitory rate > 50% (IC )
5
0
was found to be as biologically significant. Three
independent tests were used for calculation of the
quantitative parameters.
REFERENCES
1
. Siegel R, Naishadham D and Jemal A. Ca Cancer J.
Clin. 2012; 62: 10–29.
2
. Bozzini G, Colin P, Betrouni N, Nevoux P, Ouzzane
A, Puech P, Villers A and Mordon S. Photodiagn.
Photodyn. Ther. 2012; 9: 261–273.
CONCLUSION
In the course of our work we synthesized novel
1
2
water-soluble 13 - and 15 -substituted PSMA-targeted
conjugates of natural chlorin. The compounds obtained
were characterized by NMR spectroscopy and high
resolution mass spectrometry. The promising outlook of
using the above conjugates is due to the high solubility
of sodium and potassium salts in aqueous solutions. In
the course of in vitro tests, we found that compound 13
had higher phototoxicity on 22Rv1 cells compared to
similar clinically accepted PS. However, for a detailed
understanding of this process and confirmation of the
targeted properties of the resulting photosensitizer, more
3. Roeder B. Lasers Med. Sci. 1990; 5: 99–106.
4. Stranadko EF. Photodyn. Ther. Photodiagn. 2015;
4: 3–10. (In Russ.)
5. Mironov AF. Russ. Chem. J. 2017; 61: 42–68. (In
Russ.)
6. Yuzhakov VV, Burmistrova NV, Fomina NK,
Bandurko LN, Sevanjkaeva LE, Starovoytova AV,
Yakovleva ND, Tsyganova MG, Ingelj IE, Ostro-
verkhov PV, Kaplan MA, Grin MA, Mazhuga AG,
Mironov AF, Galkin VN and RomankoYS. Biomed.
Photonics 2015; 5: 4–14.
Copyright © 2018 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2018; 22: 8–9

1
2
SYNTHESIS OF PSMA-TARGETED 13 - AND 15 -SUBSTITUTED CHLORIN e DERIVATIVES
9
6
7
8
. Moret F and Reddi E. J. Porphyrins Phthalocya-
nines. 2017; 21: 239–256.
. Stallivieri A, Colombeau L, Jetpisbayeva G, Mouss-
aron A, Myrzakhmetov B, Arnoux P, Acherar S,
Vanderesse R and Frochot C. Bioorg. Med. Chem.
18. Chen Y, Chatterjee S, Lisok A, Minn I, Pullamb-
hatla M, Wharram B, Wang Y, Jin J, Bhuwalla
ZM, Nimmagadda S, Mease RC and Pomper MG.
J. Photochem. Photobiol. B 2017; 167: 111–116.
19. Banevicius L, Genady A and Valliant J. J. Nucl.
Med. 2013; 54: 1179.
2
017; 25: 1–10.
9
. You H, Yoon H-E, Jeong P-H, Ko H, Yoon J-H
and Kim Y-C. Bioorg. Med. Chem. 2015; 23:
20. Chen H, Humble SW, Jinadasa RGW, Zhou Z,
Nguyen AL, Vicente MGH and Smith KM. J. Por-
phyrins Phthalocyanines. 2017; 21: 354–363.
21. Jinadasa RGW, Hu X, Vicente MGH and Smith
KM. J. Med. Chem. 2011; 54: 7464–7476.
1
453–1462.
1
1
0. Suvorov NV, Mironov AF and Grin MA. Russ.
Chem. Bull. 2017; 66: 1982–2008.
1. Stoermer D, Liu Q, Hall MR, Flanary JM, Thomas
AG, Rojas CR, Slusher BS and Tsukamoto T.
Bioorg. Med. Chem. Lett. 2003; 13: 2097–2100.
2. Maresca KP, Hillier SM, Femia FJ, Keith D, Bar-
one C, Joyal JL, Zimmerman CN, Kozikowski AP,
Barrett JA, Eckelman WC and Babich JW. J. Med.
Chem. 2009; 52: 347–357.
3. Machulkin AE, Ivanenkov YA, Aladinskaya AV,
Veselov MS, Aladinskiy VA, Beloglazkina EK,
Koteliansky VE, Shakhbazyan AG, Sandulenko
YB and Majouga AG. J. Drug Targeting 2016; 24:
22. Chen H, Jinadasa RGW, Jiao L, Fronczek FR,
Nguyen AL and Smith KM. Eur. J. Org. Chem.
2015; 17: 3661–3665.
1
1
23. Grin MA, Lonin IS, Lakhina AA, Ol’shanskaya ES,
Makarov AI, Sebyakin YL, Guryeva LY, Toukach
PV, Kononikhin AS, Kuzmin VA and Mironov AF.
J. Porphyrins Phthalocyanines. 2009; 13: 336–345.
24. Hargus JA, Fronczek FR, Vicente MGH and Smith
KM. Photochem. Photobiol. 2007; 83: 1006–1015.
25. Murelli RP, Zhang AX, Michel J, Jorgensen WL
and Spiegel DA. J. Am. Chem. Soc. 2009; 131:
17090–17092.
6
79–693.
1
1
1
1
4. Kularatne SA, Venkatesh C, Santhapuram HR,
Wang K, Vaitilingam B, Henne WA and Low PS.
J. Med. Chem. 2010; 53: 7767–7777.
5. Hillier SM, Maresca KP, Lu G, Merkin RD, Mar-
quis JC, Zimmerman CN, Eckelman WC, Joyal JL
and Babich JW. J. Nucl. Med. 2013; 54: 1369–1376.
6. Tykvart J, Schimer J, Barinkova J, Pachl P, Postova-
Slavetinska L, Majer P, Konvalinka J and Sacha P.
Bioorg Med Chem. 2014; 22: 4099–4108.
26. Gorges TM, Riethdorf S, Ahsen O, Nastały P, Röck
K, Boede M, Peine S, Kuske A, Schmid E, Kneip
C, König F, Rudolph M and Pantel K. Oncotarget.
2016; 7: 34930–34941.
27. Tsedin AM, Fakhrutdinov AN, Eremin DB,
Zalesskiy SS, Chizhov AO, Kolotyrkina NG and
Ananikov VP. Mend. Comm. 2015; 25: 454–456.
28. Parkhots MV, KnyukshtoVN, Isakov GA, Petrov PT,
Lepeshkevich SV, Khairullina AY and Dzhagarov
BA, J. Appl. Spectrosc. 2003; 70: 921–926.
7. Manyak MJ. Expert Rev. Anticancer Ther. 2008; 8:
1
75–181.
29. Patent RU 2276976, 2006; 15: 1–15.
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J. Porphyrins Phthalocyanines 2018; 22: 9–9