Conjugates of natural chlorins and isobornylphenols with a different length of the spacer between the chlorin and terpenephenolic fragments: synthesis and antioxidant activity

Article abstract of DOI:10.1007/s11172-017-1997-z

Conjugates containing chlorine and isobornylphenolic fragments, which are connected by spacers of different lengths, were synthesized from methyl pheophorbide a. The toxicity and antioxidant activity of the obtained compounds were studied. Derivatives of pyropheophorbide a containing the most distant from the macrocycle terpenephenolic fragment combine a low toxicity with the high antioxidant activity, and are the most promising for further designing of new medicinal agents for the treatment of diseases associated with a disorder in oxidation-reduction processes in the body.

Full text of DOI:10.1007/s11172-017-1997-z

Russian Chemical Bulletin, International Edition, Vol. 66, No.11, pp. 2157—2164, November, 2017
2157
Conjugates of natural chlorins and isobornylphenols with
a different length of the spacer between the chlorin and terpenephenolic
fragments: synthesis and antioxidant activity
I. S. Khudyaeva,a D. V. Belykh,a O. G. Shevchenko,b M. A. Maximova,c L. F. Zainullina,c,d
Yu. V. Vakhitova,c,d O. V. Shchukina,a E. V. Buravlev,a I. Yu. Chukicheva,a and A. V. Kutchina
aInstitute of Chemistry, Komi Scientific Centre, Ural Branch of the Russian Academy of Sciences,
48 ul. Pervomayskaya, 167000 Syktyvkar, Russian Federation.
Fax: +7 (821) 221 8477. Eꢀmail: chukichevaꢀiy@chemi.komisc.ru
bInstitute of Biology, Komi Scientific Centre, Ural Branch of the Russian Academy of Sciences,
28 ul. Kommunisticheskaya, 167982 Syktyvkar, Russian Federation.
Fax: +7 (821) 224 0163
cInstitute of Biochemistry and Genetics, Ufa Scientific Centre of the Russian Academy of Sciences,
71 prosp. Oktyabrya, 450054 Ufa, Russian Federation.
Fax: +7 (347) 235 6088
dV. V. Zakusov Institute of Pharmacology,
8 ul. Baltiyskaya, 125315 Moscow, Russian Federation.
Fax: +7 (499) 151 1261
Conjugates containing chlorine and isobornylphenolic fragments, which are connected
by spacers of different lengths, were synthesized from methyl pheophorbide a. The toxicity
and antioxidant activity of the obtained compounds were studied. Derivatives of pyroꢀ
pheophorbide a containing the most distant from the macrocycle terpenephenolic fragment
combine a low toxicity with the high antioxidant activity, and are the most promising for
further designing of new medicinal agents for the treatment of diseases associated with
a disorder in oxidationꢀreduction processes in the body.
Key words: methyl pheophorbide a, pyropheophorbide a, chlorin e6, isobornylphenols,
antioxidant activity (AOA), lipid peroxidation (LPO), human embryonic kidney cells 293
(HEK 293), SHꢀSY5Y neuroblastoma cells, viability.
Synthesis and study of compounds with an antioxiꢀ
dant activity is of interest in the context of search for
new medicinal agents for the treatment of diseases assoꢀ
ciated with a disorder in oxidationꢀreduction processes in
the body (radiation sickness, neurodegenerative and onꢀ
cological diseases, etc.).1—3 Porphyrins with substituents,
which bring additional antioxidant properties, may be
promising in this aspect.4—7 One of synthetic pathways
to obtain such porphyrins is a conjugation of the porphyꢀ
rin macrocycle with molecules, which have their own
antioxidant activity. Phenols with terpene substituents
possess such properties. Synthesis of such conjugates from
chlorophyll a derivatives has a number of significant adꢀ
vantages, the most important of which are a relatively
low toxicity of these compounds8,9 and the presence of
several reaction centers that are convenient for use with
preparative purposes. The biological activity of such conꢀ
jugates may depend not only on the structure of a terpeneꢀ
phenolic fragment, but also on the manner of its conjugaꢀ
tion with the porphyrin macrocycle, in particular on the
position of the phenolic fragment in the macrocycle and
the length of a spacer connecting the porphyrin and terꢀ
penephenol fragments. Taking all these facts into account,
in the present work we report on the synthesis of some
conjugates, containing chlorine and isobornylphenol fragꢀ
ments connected by spacers of various lengths, from meꢀ
thyl pheophorbide a 1 and the evaluation of toxicity and
an antioxidant activity (AOA) of the obtained compounds.
Results and Discussion
To conjugate chlorine fragments with a terpenepheꢀ
nol, an ester bond formation was carried out by using the
Mukaiyama reagent for activation of the carboxyl groups
in chlorins 2 and 3, and also by a oneꢀpot hydrolysis of the
ester group at the exocycle of methyl pheophorbide a 1
with subsequent esterification (the carboxyl group, formed
as a result of hydrolysis, was activated by the same reꢀ
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2157—2164, November, 2017.
1066ꢀ5285/17/6611ꢀ2157 © 2017 Springer Science+Business Media, Inc.

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Khudyaeva et al.
agent) (Scheme 1). Terpenephenol derivatives 4—6, conꢀ
taining hydroxyl groups separated from the phenol fragꢀ
ment by spacers of different lengths were used as esterifyꢀ
ing alcohols. Conjugates 7 and 8 with relatively short
spacers between the terpenephenol and macrocyclic parts
were synthesized from chlorins 2 and 3 by treatment with
terpenephenol alcohol 4. The reaction of alcohol 5 with
chlorines 1—3 allowed obtaining conjugates 9—11 with
longer spacers. Using alcohol 6 for the esterification,
derivatives 12—14 were prepared, which are analogs of
conjugates 9—11, but containing only the one terpene
substituent at the terpenephenolic part of the molecule.
Therefore, the combination of terpenephenolic alcohols
with chlorins, having different positions of the esterified
groups and a structure of the peripheral substituents, alꢀ
lows one to vary the length of a spacer between the macroꢀ
cyclic and phenolic fragments.
The chemical structures of the obtained compounds
were confirmed by NMR, IR and UVꢀVis spectroscopy
methods and mass spectrometry. The peaks correspondꢀ
Scheme 1
R =
(4, 7, 8),
(5, 9—11),
(6, 12—14)
Reagents and conditions: i. collidine, reflux, 40 min; ii. 30% HCl, acetone, ~20 °C, 12 h; iii. MeNH2, H2O, THF, ~20 °C, 20 min;
iv and v. 2ꢀchloroꢀNꢀmethylpyridinium iodide, 4ꢀdimethylaminopyridine, reflux, 2 h, toluene (iv) or 0.5 h, CH2Cl2 (v).

Conjugates of natural chlorins and isobornylphenols Russ. Chem. Bull., Int. Ed., Vol. 66, No. 11, November, 2017 2159
ing to protonated molecular ions were observed
in the mass spectra (ESI) for all obtained derivatives 7—14.
UVꢀVis spectra contain absorption bands of chlorine
chromophors. 1H and 13C NMR spectra of all compounds
contain signals of the protons of the chlorine and isoꢀ
bornylphenolic fragments, while the intensity ratio of
earlier.7 The analysis of these data indicates that in some
cases the introduction of a terpenephenolic fragment into
the molecule results in a statistically significant increase
of AOA over the starting porphyrin. For example, the conꢀ
jugate 14 is more active than the nonꢀterpenic chlorine
16, while compounds 9, 7, and 12 are more active than
corresponding pyro derivative 15. The obtained data allow
one to conclude that both porphyrin and terpenephenolic
fragments contribute to AOA of the prepared conjugates, but
a contribution of the latter is much higher. The highest
AOA was observed for compounds with phenolic fragꢀ
ment most remote from the porphyrin macrocycle, which
was achieved by esterification of the carboxyl group of the
propionate substituent at position 17 with alcohols 5 and 6
with hydroxyl group separated from the terpenephenolic
moiety by a spacer containing three methylene groups.
The effect of the derivatives of chlorophyll a 15, 16
and their conjugates with terpenephenols 7—14 on the
viability of the HEK293 normal cells and the tumor
SHꢀSY5Y cells was evaluated by the ability of the cells to
absorb trypan blue (IC50 value was used as a quantitative
measure of the toxicity of the compounds; Table 2). It
was found that chlorins 15 and 16, having a similar strucꢀ
ture of the macrocycle and lacking a terpenephenolic fragꢀ
ment, show a significant ability to inhibit the survival of
HEK293 cells, while compound 16 also significantly inꢀ
hibits the survival of SHꢀSY5Y cells. The conjugation of
chlorins macrocycle with terpenephenol reduces the toxiꢀ
city in most cases (relatively high toxicity remained only
for methylamide derivatives 8 and 14).
1
those signals in H NMR spectra corresponds to conjuꢀ
gates with one terpenephenolic and one porphyrin fragꢀ
ment. Compound 6 is a mixture of enantiomers with the
1 : 1 ratio, so conjugates 12—14 prepared from 6 are also
1
mixtures of diastereomers in the same ratio. H and 13C
NMR spectra of compounds 12—14 contain a double set
of signals, coinciding in a number of peaks and, in the
case of 1H NMR spectra, multiplicity and differing from
each other by chemical shifts.
The antioxidant activity of porphyrin derivatives was
evaluated in vitro as an ability to inhibit lipid peroxidation
(LPO) in a brain of laboratory mices.10—14 In this nonꢀ
cellular model system, compounds 7—10 and 12—16
demonstrated the high antioxidant activity at concentraꢀ
tions of 500 μmol L–1, which inhibited LPO processes to
a spontaneous level and lower (Table 1). When the conꢀ
centration of compounds was decreased by an order of
magnitude (up to 50 μmol L–1), the high antioxidant
activity in this model system remained only for comꢀ
pounds 9 and 12, which are the derivatives of pyroꢀ
pheophorbide a with the most remote terpenephenolic
and macrocyclic fragments. Their antioxidant activity
was close to that of the reference drug, 2,6ꢀdiisobornylꢀ
4ꢀmethylphenol (Dibornol), whose high antioxidant
and membraneꢀprotective activities were studied by us
The analysis of results from the AOA and toxicity
studies for the obtained derivatives indicates that the
introduction of the terpenephenolic fragment on the
Table 1. Effects of compounds 7—16 in doses of 50 (I) and
500 μmol L–1 (II) on the content of secondary LPO prodꢀ
ucts (TBAꢀreactive substances, TBAꢀRS) in the brain of
laboratory mices*
Table 2. The effect of chlorophyll a derivatives and
their conjugates with terpenephenols 7—16 on the
viability of HEK293 and SHꢀSY5Y cells
Compound
TBAꢀRS/nmol L–1
I
II
Compound
IC50/μmol L–1
7
8
9
10
11
12
13
14
58.34 0.36
62.86 0.05
7.19 0.22
66.10 0.59
61.32 0.40
5.14 0.28
51.37 0.26
59.71 0.23
68.99 0.97
66.10 1.03
1.80 0.15
4.33 0.24
8.99 0.49
3.27 0.19
3.99 0.28
50.14 0.37
3.29 0.16
3.30 0.12
6.71 0.11
7.36 0.39
7.69 0.26
—0
HEK293
SHꢀSY5Y
7
8
9
10
11
12
13
14
15
16
44.0 4.8
1.9 0.7
>100
>100
>100
>100
>100
13.1 .6
4.6 1.1
0.5 0.01
38.9 2.4
4.2 0.3
>100
>100
>100
6.0
>100
7.6 1.9
16.1 6.6
3.0 0.8
15
16
Dibornol
* The content of TBAꢀreactive substances in the control
and intact samples is 63.95 0.29 and 20.22 1.19 nmol L–1
respectively. For the control sample, LPO was initiated in
the absence of the test compounds; for the intact sample,
LPO was not initiated.
,
Note. To validate the procedure, 10% DMSO (inhiꢀ
bition of the viability of HEK293 and SHꢀSY5Y cells
by 98 0.6 and 99 0.3%, respectively) was used as
a reference.

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Khudyaeva et al.
C(2´)); 48.18 (C(7), C(7´)); 49.96 (C(1), C(1´)); 62.47 (C(19));
125.38 (C(14), C(16)); 128.42, 131.72 (C(11), C(13), C(15));
152.21 (C(12)).
periphery of chlorin macrocycle not only reduces a genꢀ
eral toxicity of the compound, but also increases its AOA.
The highest AOA combined with the lowest toxicity was
demonstrated by pyropheophorbide a derivatives 9 and 12,
which contain the terpenephenolic fragment most remote
from the macrocycle.
In summary, this work reports the synthesis of a series
of based on methyl pheophorbide a 1 conjugates, that
contain the chlorins and isobornylphenolic fragments
linked by spacers of different lengths, and the evaluation
of toxicity and the AOA of the obtained compounds. Deꢀ
rivatives of pyropheophorbide a 9 and 12 with the terpeꢀ
nephenolic fragment most remote from the macrocycle
combine a low toxicity with the high AOA and are the
most promising for further search for new medicinal
agents for the treatment of diseases associated with a disꢀ
order in oxidationꢀreduction processes in the body.
Synthesis of compounds 10 and 13 (general procedure).
A solution of methyl pheophorbide a 1 (0.08—0.66 mmol),
4ꢀdimethylaminopyridine (DMAP) (the double molar excess
with respect to compound 1), 2ꢀchloroꢀNꢀmethylpyridinium
iodide (5—10% molar excess relative to compound 1), and terꢀ
penephenol 5 or 6 (50% of the number of moles of compound 1)
in toluene (25 mL) was refluxed for 2 h (control by TLC,
eluent was CCl4—acetone, 4 : 1). Then the reaction mixture
was diluted with chloroform (100 mL), transferred into a sepaꢀ
ratory funnel, and washed with 5% aqueous HCl solution and
distilled water until a neutral reaction of aqueous layer to reꢀ
move the excess of DMAP and the products of conversion of 2ꢀ
chloroꢀNꢀmethylpyridinium iodide. The organic layer was dried
over anhydrous Na2SO4 and concentrated under reduced presꢀ
sure at 40—50 °С. The residue was purified by chromatography
on silica gel (eluent was CCl4—acetone, ratio 70 : 1→1 : 1).
The eluate containing the major reaction product was concenꢀ
trated under reduced pressure and the residue was reprecipitatꢀ
ed from its solution in chloroform with hexane.
Experimental
Methyl (3S,4S)ꢀ21ꢀ{Oꢀ3ꢀ[(4ꢀhydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀ
trimethylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀ{(1R,2S,4S)ꢀ1,7,7ꢀtriꢀ
methylbicyclo[2.2.1]heptanꢀ2ꢀyl}phenyl)propyl]}carbamoylꢀ
4,8,13,18ꢀtetramethylꢀ20ꢀoxoꢀ9ꢀethenylꢀ14ꢀethylphorbinꢀ3ꢀ
propanoate (10) was prepared as a dark blue powder from meꢀ
thyl pheophorbide a 1 (47.9 mg, 0.08 mmol), DMAP (22.9 mg,
0.19 mmol), 2ꢀchloroꢀNꢀmethylpyridinium iodide (24.0 mg,
0.10 mmol), and terpenephenol 5 (19.1 mg, 0.04 mmol) in
toluene (25 mL) in the yield of 25.6 mg (64%). MS (ESI), m/z:
999.6 [MH]+. UVꢀVis, λ/nm (Irel (%)): 668.5 (41), 611.0 (8),
538.5 (10), 508.0 (11), 472.0 (6), 416.0 (100). 1H NMR, δ:
–1.65 (br.s, 1 H, N(III)H); 0.62 and 0.50 (both s, 3 H each,
С(10´)H3, С(10´´)H3); 0.69 and 0.67 (both s, 3 H each,
С(9´)H3, С(9´´)H3); 0.75 and 0.72 (both s, 3 H each, С(8´)H3,
С(8´´)H3); 1.72 (t, 3 H, С(8(2))H3, J = 8.2 Hz); 1.83 (d, 3 H,
С(18(1))H3, J = 7.3 Hz); 2.00—1.16 (m, 10 H, H(4´), H(4´´),
С(5´)H2, С(5´´)H2, С(6´)H2, С(6´´)H2); 2.35—2.15 (m, 2 H,
H(3´), H(3´´)); 2.79—2.45 (m, 4 H, С(17(1)H2, С(17(2)H2);
2.96—2.80 (m, 2 H, H(2´), H(2´´)), 3.22 (s, 3 H, С(7(1))H3);
3.43 (s, 3 H, С(2(1)H3); 3.58 (s, 3 H, С(12(1)H3); 3.73 (s, 3 H,
С(17(4)H3); 3.77—3.65 (m, 2 H, С(8(1)H2)); 4.40—4.26 (m, 3 H,
H(17), С(17´)H2)); 4.60 (s, 1 H, ArОH); 4.51 (q, 1 H, H(18),
J = 7.3 Hz); 6.20 (d, 1 H, H(3(2))trans, J = 12.0 Hz); 6.29 (d, 1 H,
H(3(2))trans, J = 18.0 Hz); 6.31 (s, 1 H, H(13(2)));
6.75 (s, 2 H, H(14´), H(16´)); 7.99 (dd, 1 H, H(3(1)), J = 18.0 Hz,
J = 12.0 Hz); 8.60 (s, 1 H, H(20)); 9.36 (s, 1 H, H(5)); 9.52
(s, 1 H, H(10)). 13С NMR, δ: 11.21 (С(7(1))), 12.09 (С(2(1))), 12.14
(С(12(1))), 12.41 and 12.46 (С(10´), С(10´´)), 17.44 (С(8(2))),
19.45 (С(8(1))), 19.75 and 19.93 (С(9´), С(9´´)), 21.19 and
21.32 (С(8´), С(8´´)), 23.20 (С(18)), 27.46 (С(5´), С(5´´)),
29.83 (С(17(1))), 30.89 (С(17(2))), 31.88 (С(17´)), 33.67 (С(5´),
С(5´´)), 33.73 (С(18´)), 39.91 and 39.96 (С(6´), С(6´´)), 45.20
and 45.27 (С(2´), С(2´´)), 45.99 and 46.17 (С(4´), С(4´´)),
47.88 and 47.98 (С(7´), С(7´´)), 49.77 (С(1´), С(1´´)), 49.81
(С(18)), 50.15 (С(17)), 51.65 (С(17(4))), 65.02 (С(18´)), 93.12
(С(20)), 97.53 (С(5)), 104.37 (С(10)), 105.45 (С(15)), 122.72
(С(3(2))), 125.27 and 125.30 (С(14´), С(16´)), 128.21 (С(13)),
128.98 (С(11´), С(13´)), 129.17 (С(3(1))), 130.94 (С(12)),
130.97 (С(2)), 131.78 (С(15´)), 136.14 (С(7)), 136.22 (С(4)),
The chemical reaction progress was monitored by TLC on
Sorbfil plates. Colorless reaction products 4—6 were detected
by treatment of TLC plates with KMnO4 solution (15 g of
KMnO4, 300 mL of H2O and 0.5 mL of conc. H2SO4). 1H and
13C NMR spectra were recorded on a Bruker Avance II 300
spectrometer (300.17 and 75.5 MHz) in CDCl3 at room temꢀ
perature. Diffuse reflectance IR spectra were recorded on
a Shimadzu IR Prestige 21 IR Fourier spectrophotometer in
the KBr pellets for solids and neat for liquids. Electrospray
ionization (ESI) mass spectra were obtained on a Thermo Finniꢀ
gan LCQ Fleet instrument using positive ions detection mode,
the sample was injected as a chloroform—methanol solution.
UVꢀVis spectra were obtained for CHCl3 solutions in quartz
cells (10 mm) on a Shimadzu UVꢀ1600 instrument. Elemental
analysis was performed using an automatic elemental EA 1110
CHNSꢀO analyzer.
Alcohols 5 and 6 were prepared according to the known
procedure.15 The spectral characteristics of 6 coincided with
previously reported data.15 Alcohol 4 was synthesized accordꢀ
ing to the published method.16 Compounds 2, 3, 15, and 16
were obtained according to the known procedure.17
4ꢀ(3ꢀHydroxypropyl)ꢀ2,6ꢀdi(1,7,7ꢀtrimethylbicyclo[2.2.1]ꢀ
heptꢀexoꢀ2ꢀyl)phenol (5). White powder, m.p. 157—159 °С.
Yield 73%. Found (%): C, 81.55; H, 10.97. C29H44O2. Calcuꢀ
lated (%): C, 82.02; H, 10.44. IR spectrum (neat), ν/cm–1
:
3604 (ArОH); 3145 (СH2ОH); 2949, 2875, 1456, 1384 (CH2,
Me); 1606 (С=С); 1182 (arom. C—O); 1049 (CH2C—O); 790
(arom. C—H). 1H NMR, δ: 0.84 (s, 6 H, C(10)H3, C(10´)H3);
0.88 (s, 6 H, C(9)H3, C(9´)H3); 0.94 (s, 6 H, C(8)H3, C(8´)H3);
1.39—1.48 (m, 5 H, H(5), H(5´), H(6), H(6´), CH2OH);
1.58—1.69 (m, 4 H, H(3), H(3´), H(6), H(6´)); 1.85—1.95 (m,
5 H, H(4), H(4´), H(5), H(5´), H(18)); 2.26—2.32 (m, 2 H,
1 H(3), 1 H(3´)); 2.67 (t, 2 H, H(17), J = 8.1 Hz); 3.03 (t, 2 H,
H(2), H(2´), J = 8.7 Hz); 3.69 (t, 2 H, H(19), J = 6.3 Hz); 4.74
(br.s, 1 H, ArОH); 7.01 (s, 2 H, H(14), H(16)). 13С NMR, δ:
12.56 (С(10), C(10´)); 20.20 (C(8), C(8´)); 21.49 (С(9), C(9´));
27.60 (C(5), C(5´)); 32.19 (C(17)); 34.03 (C(3), C(3´)); 34.76
(C(18)); 40.08 (C(6), C(6´)); 45.52 (C(4), C(4´)); 46.16 (C(2),

Conjugates of natural chlorins and isobornylphenols Russ. Chem. Bull., Int. Ed., Vol. 66, No. 11, November, 2017 2161
136.45 (С(3)), 137.96 141.97 (С(1)), 145.15 (С(8)), 149.69
(С(14)), 150.94 (С(9)), 152.14 (С(12´)), 155.55 (С(6)), 161.11
(С(16)), 169.12 (С(19)), 172.08 (С(17(3))), 173.34 (С(13(3))),
189.75 (С(13(1))).
ent was CCl4—acetone, ratio 60 : 1→1 : 1). The eluate conꢀ
taining the desired product was concentrated under reduced
pressure and the residue was reprecipitated from its solution in
chloroform with hexane.
Methyl (3S,4S)ꢀ21ꢀ{Oꢀ3ꢀ[(4ꢀhydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ
1,7,7ꢀtrimethylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀmethyl]}carbamoꢀ
ylꢀ4,8,13,18ꢀtetramethylꢀ20ꢀoxoꢀ9ꢀethenylꢀ14ꢀethylphorbinꢀ3ꢀ
propanoate (13) was prepared as a dark blue powder from meꢀ
thyl pheophorbide a 1 (398.3 mg, 0.66 mmol), DMAP (101.2 mg,
0.83 mmol), 2ꢀchloroꢀNꢀmethylpyridinium iodide (101.0 mg,
0.40 mmol), and terpenephenol 6 (102.4 mg, 0.33 mmol) in
toluene (25 mL) in the yield of 104.1 mg (36%). MS (ESI), m/z:
877.6 [MH]+. UVꢀVis, λ/nm (Irel (%)): 668.5 (50), 611.0 (9),
562.0 (3), 538.5 (10), 508.0 (10), 476.5 (2), 414.0 (100).
1H NMR, δ*: –1.63 (br.s, 1 H, N(III)H); 0.62/0.53 (s, 3 H,
C(10´)H3)); 0.65/0.63 (s, 3 H, C(9´)H3)); 0.75/0.68 (s, 3 H,
C(8´)H3)); 1.72 (t, 3 H, С(8(2))H3), J = 8.3 Hz), 1.83 (d, 3 H,
С(18(1))H3, J = 9.0 Hz); 2.06/2.05 (s, 3 H, C(13´(1))H3);
2.78—2.14 and 2.00—1.16 (both m, 6 H and 5 H, С(17(1))H2,
С(17(2))H2, C(3´)H2, H(4´), C(5´)H2, C(6´)H2); 2.92 (t, 1 H,
H(2´), J = 8.3 Hz); 3.24 (s, 3 H, C(7(1))H3); 3.43 (s, 3 H,
C(2(1))H3); 3.58 (s, 3 H, С(12(1))H3); 3.73 (s, 3 H,
C(17(4))H3); 3.77—3.65 (m, 2 H, C(8(1))H2); 4.40—4.22 (m, 3 H,
H(17), C(17´)H2); 4.46 (s, 1 H, ArОH), 4.50 (q, 1 H, H(18),
J = 8.3 Hz); 6.20 (d, 1 H, H(3(2))cis, J = 12.0 Hz); 6.30 (s, 1 H,
H(13(2))); 6.31 (d, 1 H, H(3(2))trans, J = 18.0 Hz); 6.56 (s, 1 H,
H(14´)); 6.76 (s, 1 H, H(16´)), 8.00 (dd, 1 H, H(3(1)), J = 18.0 Hz,
J = 12.0 Hz); 8.60 (s, 1 H, H(20)); 9.38 (s, 1 H, H(5)); 9.54
(s, 1 H, H(10)). 13С NMR, δ: 11.22 (С(7(1))), 12.10 (С(2(1))),
12.13 (С(12(1))), 12.29/12.32 (С(10´)), 15.99 (С(13(1´))), 17.43
(С(8(2))), 19.45 (С(8(1))), 19.86/20.01 (С(9´)), 21.17/21.30
(С(8´)), 23.16 (С(18(1))), 27.42/27.45 (С(5´)), 29.82 (С(17(2))),
31.01/30.69 (С(17(1))), 31.36/31.41 (С(18´)), 33.90/33.94
(С(3´), С(17´)), 39.98/40.02 (С(6´)), 45.28/45.35 (С(2´)), 45.59
(С(4´)), 47.80/47.90 (С(7´)), 49.51/49.53 (С(1´)), 50.13 (С(18)),
51.12 (С(17)), 51.64 (С(17(4))), 64.97/65.03 (С(19´)), 65.06
(С(13(2))), 93.11 (С(20)), 97.53 (С(5)), 104.40 (С(10)), 104.44
(С(15)), 122.36/122.76 (С(3(2))), 125.78, 215.85 and 127.89
(С(14´), С(15´), С(16´)), 128.56 (С(13)), 129.00 (С(11´)),
129.10 (С(13´)), 129.10 (С(3(1))), 129.18, 128.56 (С(12)),
131.61 (С(2)), 131.81 (С(15´)), 136.16 (С(7)), 136.27 (С(4)),
136.47 (С(3)), 137.95 (С(11)), 141.99 (С(11)), 145.20 (С(8)),
149.70 (С(14)), 151.00 (С(9)), 151.06 (С(12´)), 155.60 (С(6)),
161.10 (С(16)), 169.14 (С(13(3))), 172.10 (С(19)), 173.34
(С(17(3))), 189.78 (С(13(1))).
(3S,4S)ꢀ{Oꢀ[(4ꢀHydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀtrimethꢀ
ylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀ{(1R,2S,4S)ꢀ1,7,7ꢀtrimethylꢀ
bicyclo[2.2.1]heptanꢀ2ꢀyl}phenyl)methyl]}ꢀ4,8,13,18ꢀtetrameꢀ
thylꢀ20ꢀoxoꢀ9ꢀethenylꢀ14ꢀethylphorbinꢀ3ꢀpropanoate (7) was
obtained as a dark blue powder from compound 2 (137.4 mg,
0.26 mmol) and compound 4 (66.4 mg, 0.17 mmol) in 110.8 mg
(71%) yield. MS (ESI), m/z: 913.8 [MH]+. UVꢀVis, λ/nm
(Irel (%)): 668.0 (45), 610.5 (9), 539.5 (10), 509.0 (12), 473.0
1
(6), 414.0 (100). H NMR, δ: –1.69 (br.s, 1 H, N(I)H); 0.46
(br.s, 1 H, N(III)H); 0.94, 0.89, 0.86, 0.79, 0.77 (all s, 3 H,
3 H, 3 H, 6 H, С(8´)H3, С(8´´)H3, С(9´)H3, С(9´´)H3, С(10´)H3,
С(10´´)H3), 2.79—2.56, 2.45—2.06, 2.02—1.20 (all m, 2 H,
6 H, 16 H, С(3´)H2, С(3´´)H2, H(4´), H(4´´), С(5´)H2, С(5´´)H2,
С(6´)H2, С(6´´)H2, С(17(1))H2, С(17(2))H2, С(8(2))H3,
С(18(1))H3); 3.04 and 2.94 (both t, 1 H each, H(2´), H(2´´),
J = 8.3 Hz); 3.26 (s, 3 H, С(2(1))H3); 3.44 (s, 3 H, С(7(1))H3);
3.71 (s, 3 H, С(12(1))H3); 3.74 (q, 2 H, С(8(1))H2, J = 8.3
Hz); 4.30 (br.d, 1 H, H(17), J = 7.3 Hz), 4.49 (q, 1 H, H(18),
J = 6.4 Hz); 4.90 (s, 1 H, ArОH); 5.06 and 5.01 (both d, 1 H each,
С(17´)H2, J = 12.0 Hz); 5.25 and 5.08 (both d, 1 H each,
С(13(2))H2, J = 19.2 Hz); 6.20 (d, 1 H, H(3(2))cis, J = 11.0 Hz);
6.31 (d, 1 H, H(3(2))trans, J = 17.4 Hz); 7.13 and 7.11 (both s,
1 H each, H(14´), H(16´)); 8.03 (dd, 1 H, H(3(1)), J = 18.3 Hz,
J = 11.0 Hz); 8.68 (s, 1 H, H(20)); 9.39 (s, 1 H, H(5)); 9.50
(s, 1 H, H(10)). 13С NMR, δ: 11.26 (С(7(1))), 12.07 (С(2(1))),
12.11 (С(12(1))), 12.52 (С(10´), С(10´´)), 17.43 (С(8(2))),
19.50 (С(8(1))), 20.11 (С(9´), С(9´´)), 21.30 (С(8´), С(8´´)),
23.13 (С(18(1))), 29.71 (С(17(1))), 31.35 (С(17(2))), 33.98
(С(3´), С(3´´)), 40.00 (С(6´), С(6´´)), 46.07 (С(2´), С(2´´)),
45.38 (С(4´), С(4´´)), 48.12 (С(7´), С(7´´)), 48.12 (С(13(2))),
49.97 (С(18)), 49.97 (С(1´), С(1´´)), 51.68 (С(17)), 67.34
(С(17´)), 93.07 (С(20)), 97.20 (С(5)), 104.11 (С(10)), 106.09
(С(15)), 122.54 (С(3(2))), 126.29 (С(14´), С(16´), С(15´)),
128.31 (С(13)), 128.85 (С(11´), С(13´)), 128.91 (С(3(1))),
129.28 (С(12)), 130.60 (С(2)), 131.55 (С(15´)), 135.83 (С(7)),
136.11 (С(4)), 136.22 (С(3)), 137.92 (С(11)), 141.50 (С(1)),
144.07 (С(8)), 149.06 (С(14)), 150.78 (С(9)), 152.03 (С(12´)),
154.31 (С(6)), 160.44 (С(16)), 171.43 (С(19)), 172.99 (С(17(3)),
196.15 (С(13(1)).
Methyl 2ꢀ{Oꢀ[(4ꢀhydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀtrimethylꢀ
bicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀ{(1R,2S,4S)ꢀ1,7,7ꢀtrimethylbiꢀ
cyclo[2.2.1]heptanꢀ2ꢀyl}phenyl)methyl]carbamoylethyl}ꢀ18ꢀ
[(Nꢀmethyl)carbamoyl]chlorinꢀ20ꢀyl)acetate (8) was obtained
as a dark blue powder from compound 3 (189.0 mg, 0.30 mmol)
and compound 4 (87.9 mg, 0.22 mmol) in 134.1 mg (61%)
yield. MS (ESI), m/z: 1002.7 [MH]+. UVꢀVis, λ/nm (Irel (%)):
663.5 (21), 606.0 (3), 554.5 (2), 527.5 (4), 500.5 (10), 402.5
(100). 1H NMR, δ: –1.78 (br.s, 1 H, N(I)H); –1.58 (br.s, 1 H,
N(III)H); 0.79 and 0.78 (both s, 6 H, 12 H, С(8´)H3, С(8´´)H3,
С(9´)H3, С(9´´)H3, С(10´)H3, С(10´´)H3); 2.68—2.53, 2.29—2.09,
1.92—1.22 (all m, 1 H, 4 H, 19 H, С(3´)H2, С(3´´)H2, H(4´),
H(4´´), С(5´)H2, С(5´´)H2, С(6´)H2, С(6´´)H2, С(17(1))H2,
С(17(2))H2, С(8(2))H3, С(18(2))H3); 2.95 (t, 2 H, H(2´),
H(2´´), J = 8.2 Hz); 3.28 (d, 1 H, C(13(2))H3, J = 4.6 Hz); 3.34
(s, 3 H, С(2(1))H3); 3.52 (s, 3 H, С(7(1))H3); 3.57 (s, 3 H,
С(12(1))H3); 3.84 (s, 3 H, С(15(3))H3); 3.82 (q, 2 H,
С(8(1))H2, J = 6.5 Hz); 4.39 (br.d, 1 H, H(17), J = 10.1 Hz);
Synthesis of compounds 7—9, 11, 12 and 14 (general proceꢀ
dure). A solution of carboxychlorin 2 or 3 (0.25—0.30 mmol),
2ꢀchloroꢀNꢀmethylpyridinium iodide (equimolar amount to
carboxychlorin), terpene alcohol 4, 5 or 6 (0.15—0.20 mmol),
and DMAP (0.50—0.60 mmol) in dichloromethane (25 mL)
was refluxed for 30 min. Then the reaction mixture was cooled
down and diluted with dichloromethane (100 mL) and washed
with 5% aqueous HCl solution and distilled water until a neuꢀ
tral reaction of aqueous layer to remove the excess of DMAP
and the products of conversion of 2ꢀchloroꢀNꢀmethylpyridiniꢀ
um iodide. The organic layer was dried over anhydrous Na2SO4
and concentrated under reduced pressure at 40—50 °С. Then
the residue was purified by chromatography on silica gel (eluꢀ
* Hereinafter the symbol "/" indicates the signals from diasteꢀ
reomers differing by the chemical shift values.

2162
Russ. Chem. Bull., Int. Ed., Vol. 66, No. 11, November, 2017
Khudyaeva et al.
4.50 (q, 1 H, H(18), J = 7.3 Hz); 4.95 (s, 1 H, ArOH); 5.06 and
4.99 (both d, 1 H each, С(17´)H2, J = 11.9 Hz); 5.50 and 5.24
(both d, 1 H each, С(15(1))H2, J = 19.2 Hz); 6.17 (d, 1 H,
H(3(2))cis, J = 11.9 Hz); 6.36 (br.t, 1 H, С(13(1))NH, J = 4.6 Hz);
6.38 (d, 1 H, H(3(2))trans, J = 17.4 Hz); 7.09 (s, 2 H, H(14´),
H(16´)), 8.12 (dd, 1 H, H(3(1)), J = 17.1 Hz, J = 11.9 Hz);
8.84 (s, 1 H, H(20)); 9.66 (s, 1 H, H(5)); 9.71 (s, 1 H, H(10)).
13С NMR, δ: 11.34 (С(7(1))), 11.95 (С(2(1))), 12.17 (С(12(1))),
12.53 (С(10´), С(10´´)), 17.70 (С(8(2))), 19.70 (С(8(1))), 20.12
(С(9´), С(9´´)), 21.32 (С(8´), С(8´´)), 23.04 (С(18(1))), 27.25
(C(13(2))), 27.49 (С(5´), С(5´´)), 29.74 (С(17(2))), 31.55
(С(17(1))), 33.96 (С(3´), С(3´´)), 40.00 (С(6´), С(6´´)), 46.05
(С(2´), С(2´´)), 45.36 (С(4´), С(4´´)), 48.13 (С(7´), С(7´´)),
49.35 (С(18)), 49.98 (С(1´), С(1´´)), 52.10 (C(15(3))), 53.18
(С(17)), 67.25 (С(17´)), 93.76 (С(20)), 98.80 (С(5)), 101.45
(С(10)), 102.10 (С(15)), 121.66 (С(3(2))), 126.17 (С(14´),
С(16´), С(15´)), 128.09 (С(13)), 128.88 (С(11´), С(13´)),
129.51 (С(3(1))), 129.98 (С(12)), 130.21 (С(2)), 134.65 (С(7)),
134.85 (С(4)), 135.09 (С(3)), 136.00 (С(11)), 139.02 (С(1)),
144.67 (С(8)), 148.82 (С(14)), 148.80 (С(9)), 149.06 (С(12´)),
154.27 (С(6)), 166.86 (С(16)), 168.96 (С(19)), 170.03 (С(13(1))),
173.03 (С(17(3))), 174.23 (С(15(2))).
160.32 (С(16)), 171.38 (С(19)), 173.09 (С(17(3))), 196.13
(С(13(2))).
Methyl 2ꢀ(Oꢀ3ꢀ[(4ꢀhydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀtrimeꢀ
thylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀ{(1R,2S,4S)ꢀ1,7,7ꢀtrimethylꢀ
bicyclo[2.2.1]heptanꢀ2ꢀyl}phenyl)propyl]carbamoylethyl}ꢀ18ꢀ
[(Nꢀmethyl)carbamoyl]chlorinꢀ20ꢀyl)acetate (11) was obtained
as a dark blueꢀgreen powder from compound 3 (180.1 mg,
0.29 mmol) and compound 5 (94.5 mg, 0.22 mmol) in 128.8 mg
(57%) yield. MS (ESI), m/z: 1030.7 [MH]+. UVꢀVis, λ/nm
(Irel (%)): 663.5 (29), 607.5 (4), 557.0 (2), 528.5 (4), 500.0 (10),
403.0 (100). 1H NMR, δ: –1.76 (br.s, 1 H, N(I)H); –1.54 (br.s,
1 H, N(III)H); 0.84, 0.82, 0.79 (all s, 3 H, 12 H, 6 H, С(8´)H3,
С(8´´)H3, С(9´)H3, С(9´´)H3, С(10´)H3, С(10´´)H3); 2.62—2.49,
2.34—2.08, 1.92—1.21 (all m, 3 H, 5 H, 20 H, С(3´)H2,
С(3´)H2, H(4´), H(4´´), С(5´)H2, С(5´´)H2, С(6´)H2,
С(6´´)H2, С(17(1))H2, С(17(2))H2, С(17´)H2, С(18´)H2,
С(8(2))H3, С(18(1))H3); 3.03—2.91 (m, 2 H, H(2´), H(2´´));
3.28 (d, 1 H, C(13(2))H3, J = 4.6 Hz); 3.35 (s, 3 H, С(2(1))H3);
3.53 (s, 3 H, С(7(1))H3); 3.58 (s, 3 H, С(12(1))H3); 3.83 (s, 3 H,
С(15(3))H3); 3.82 (q, 2 H, С(8(1))H2, J = 7.3 Hz); 4.15—3.96
(m, 2 H, С(19´)H2), 4.41 (br.d, 1 H, H(17), J = 9.2 Hz); 4.53
(q, 1 H, H(18), J = 7.3 Hz); 4.75 (s, 1 H, ArОH); 5.54 and 5.28
(both d, 1 H each, С(15(1))H2, J = 19.2 Hz); 6.18 (d, 1 H,
H(3(2))cis, J = 11.9 Hz); 6.36 (br.t, 1 H, С(13(1))NH, J = 4.6 Hz);
6.39 (d, 1 H, H(3(2))trans, J = 18.3 Hz); 6.90 (s, 2 H, H(14´),
H(16´)), 8.12 (dd, 1 H, H(3(1)), J = 18.3 Hz, J = 11.9 Hz);
8.85 (s, 1 H, H(20)); 9.66 (s, 1 H, H(5)); 9.72 (s, 1 H, H(10)).
13С NMR, δ: 11.35 (С(7(1))), 11.98 (С(2(1))), 12.20 (С(12(1))),
12.51 (С(10´), С(10´´)), 17.74 (С(8(2))), 19.72 (С(8(1))), 20.13
(С(9´), С(9´´)), 21.32 (C(13(2))), 21.40 (С(8´), С(8´´)), 27.30
(С(5´), С(5´´)), 29.71 (С(17(2))), 30.44 (С(17(1))), 31.29
(С(17´)), 33.93 (С(3´), С(3´´)), 33.94 (С(18´)), 40.00 (С(6´),
С(6´´)), 45.41 (С(2´), С(2´´)), 45.41 (С(15(3))), 46.07 (С(4´),
С(4´´)), 48.11 (С(7´), С(7´´)), 49.31 (С(18)), 49.92 (С(1´),
С(1´´)), 52.12 (С(17)), 63.93 (С(19´)), 93.65 (С(20)), 98.85
(С(5)), 101.49 (С(10)), 102.02 (С(15)), 121.63 (С(13(2))),
125.26 (С(14´)H, С(16´)H), 128.40 (С(13)), 128.43 (С(11´),
С(13´)), 129.54 (С(3(1))), 129.92 (С(12)), 130.19 (С(2)), 130.98
(С(15´)), 134.60 (С(7)), 134.98 (С(4)), 136.09 (С(3)), 138.93
(С(11)), 142.10 (С(1)), 144.79 (С(8)), 149.10 (С(14)), 150.14
(С(9)), 152.26 (С(12´)), 155.50 (С(6)), 161.96 (С(16)), 168.93
(С(19)), 170.15 (С(13(1))), 173.11 (С(15(2))), 174.28 (С(17(3))).
3ꢀ{(3S,4S)ꢀ{Oꢀ[(4ꢀHydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀtrimeꢀ
thylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀmethyl}propyl]}ꢀ4,8,13,18ꢀ
tetramethylꢀ20ꢀoxoꢀ9ꢀethenylꢀ14ꢀethylphorbinꢀ3ꢀpropanoate
(12) was obtained as a dark blue powder from compound 2
(149.5 mg, 0.28 mmol) and compound 6 (72.1 mg, 0.23 mmol)
in 79.4 mg (42%) yield. MS (ESI), m/z: 819.5 [MH]+. UVꢀVis,
λ/nm (Irel (%)): 664.0 (31), 608.0 (3), 554.5 (2), 529.0 (4),
3ꢀ{(3S,4S)ꢀ{Oꢀ[(4ꢀHydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀtrimethꢀ
ylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀ{(1R,2S,4S)ꢀ1,7,7ꢀtrimethylꢀ
bicyclo[2.2.1]heptanꢀ2ꢀyl}phenyl)}propyl]}ꢀ4,8,13,18ꢀtetraꢀ
methylꢀ20ꢀoxoꢀ9ꢀethenylꢀ14ꢀethylphorbinꢀ3ꢀpropanoate (9) was
obtained as a dark blue powder from compound 2 (141.8 mg,
0.27 mmol) and compound 5 (70.1 mg, 0.17 mmol) in 60.1 mg
(38%) yield. MS (ESI), m/z: 941.6 [MH]+. UVꢀVis, λ/nm
(Irel (%)): 668.5 (42), 610.5 (8), 540.0 (10), 508.5 (11), 472.0
1
(6), 414.5 (100). H NMR, δ: –1.65 (br.s, 1 H, N(I)H); 0.50
(br.s, 1 H, N(III)H); 0.93, 0.88, 0.84, 0.79, 0.76 (all s, 3 H,
3 H, 3 H, 3 H, 6 H, С(8´)H3, С(8´´)H3, С(9´)H3, С(9´´)H3,
С(10´)H3, С(10´´)H3); 2.82—2.63, 2.43—2.09, 1.98—1.20 (all m,
2 H, 5 H, 17 H, С(3´)H2, С(3´´)H2, H(4´), H(4´´), С(5´)H2,
С(5´´)H2, С(6´)H2, С(6´´)H2, С(17(1))H2, С(17(2))H2,
С(17´)H2, С(8(2))H3, С(18(1))H3); 2.57—2.50 (m, 2 H,
С(18´)H2); 2.93 (t, 2 H, С(17´)H2, J = 8.2 Hz); 3.03 and 2.59
(both t, 1 H each, H(2´), H(2´´), J = 7.3 Hz); 3.28 (s, 3 H,
С(2(1))H3); 3.45 (s, 3 H, С(7(1))H3); 3.71 (s, 3 H, С(12(1))H3);
3.73 (q, 2 H, С(8(1))H2, J = 7.3 Hz); 4.14—3.97 (m, 2 H,
С(19´)H2); 4.35 (br.d, 1 H, H(17), J = 8.3 Hz); 4.54 (q, 1 H,
H(18), J = 6.4 Hz); 4.64 (s, 1 H, ArОH); 5.31 and 5.15 (both d,
1 H each, С(13(2))H2, J = 20.2 Hz); 6.21 (d, 1 H, H(3(2))cis
,
J = 11.9 Hz); 6.32 (d, 1 H, H(3(2))trans, J = 17.4 Hz);
6.87 (s, 2 H, H(14´), H(16´)); 8.05 (dd, 1 H, H(3(1)), J = 17.4 Hz,
J = 11.9 Hz); 8.60 (s, 1 H, H(20)); 9.42 (s, 1 H, H(5)); 9.54
(s, 1 H, H(10)). 13С NMR, δ: 11.23 (С(7(1)), 12.05 (С(2(1)), 12.12
(С(12(1)), 12.50/12.59 (С(10´), С(10´´)), 17.44 (С(8(2))), 19.46
(С(8(1))), 20.12/20.21 (С(9´), С(9´´)), 21.39/21.50 (С(8´),
С(8´´)), 23.18 (С(18(1))), 27.53 (С(5´), С(5´´)), 29.89 (С(17(2))),
30.52 (С(17(1))), 32.10 (С(17´)), 33.93 (С(3´), С(3´´)), 34.02
(С(18´)), 40.00 (С(6´), С(6´´)), 45.42 (С(2´), С(2´´)), 46.06
(С(4´), С(4´´)), 48.10 (С(7´), С(7´´), С(13(2)), 49.90 (С(1´),
С(1´´)), 50.00 (С(18)), 51.80 (С(17)), 64.02 (С(19´)),
92.99 (С(20)), 97.18 (С(5)), 104.05 (С(10)), 106.04 (С(15)),
122.51 (С(3(2))), 125.27 (С(14´), С(16´)), 128.31 (С(13)),
128.38 (С(11´), С(13´)), 129.24 (С(3(1))), 130.50 (С(12)),
130.97 (С(2)), 131.51 (С(15´)), 135.84 (С(7)), 136.04 (С(4)),
136.17 (С(3)), 137.86 (С(11)), 141.52 (С(1)), 144.96 (С(8)),
149.01 (С(14)), 150.76 (С(9)), 152.24 (С(12´)), 155.17 (С(6)),
1
501.5 (9), 403.0 (100). H NMR, δ: –1.66 (br.s, 1 H, N(I)H);
0.48 (br.s, 1 Н, N(III)H); 0.93/0.88, 0.81/0.79, 0.84, 0.74 (all s,
3 Н each, C(8´)H3, C(9´)H3, C(10´)H3), 2.40/2.27 (s, 3 H,
C(13(1´))H3); 2.82—2.68, 2.43—2.09, 1.98—1.20 (all m, 1 Н,
7 Н, 13 Н, С(3´)H2, H(4´), С(5´)H2, С(6´)H2, С(18´)H2,
С(17(1))Н2, С(17(2))Н2, С(8(2))Н3, С(18(1))Н3); 2.47 (t, 2 Н,
С(17´)H2, J = 8.2 Hz); 3.10/3.00 (t, 1 Н, H(2´), J = 8.3 Hz);
3.26 (s, 3 Н, С(2(1))Н3); 3.44 (s, 3 Н, С(7(1))Н3); 3.70 (s, 3 Н,
С(12(1))Н3); 3.76—3.66 (m, 2 Н, С(8(1))Н2); 4.11—3.98 (m, 2 Н,
С(19´)H2), 4.35 (br.d, 1 Н, Н(17), J = 8.3 Hz); 4.52 (q, 1 Н,
Н(18), J = 6.4 Hz); 4.60 (s, 1 Н, ArОН); 5.31 and 5.15 (both d,
1 Н each, С(13(2))Н2, J = 20.2 Hz); 6.21 (d, 1 Н, Н(3(2))cis
,

Conjugates of natural chlorins and isobornylphenols Russ. Chem. Bull., Int. Ed., Vol. 66, No. 11, November, 2017 2163
J = 12.0 Hz); 6.32 (d, 1 Н, Н(3(2))trans, J = 18.0 Hz); 6.88
(s, 2 Н, H(14´), H(16´)), 8.03 (dd, 1 Н, Н(3(1)), J = 18.0 Hz,
J = 12.0 Hz); 8.59 (s, 1 Н, Н(20)); 9.40 (s, 1 Н, Н(5)); 9.51
(s, 1 Н, Н(10)). 13С NMR, δ: 11.23 (С(7(1))), 12.02 (С(2(1))),
12.11 (С(12(1))Н3), 12.41/12.48 (C(10´)), 16.14/16.24
(C(13´(1))), 17.43 (С(8(2))), 19.47 (С(8(1))), 20.21 (C(9´)),
21.36 (C(8´)), 23.19 (С(18(1))), 27.49 (C(5´)), 29.85 (С(17(2))),
31.65 (C(17(1))), 34.17 (C(3´)), 34.64 (C(18´)), 40.06 (C(6´)),
45.50 (C(2´)), 45.76 (C(4´)), 47.99 (C(7´)), 49.63 (C(1´)), 50.01
(С(18)), 51.74 (С(17)), 62.46 (C(17´)), 64.09 (C(18´)), 68.00
(C(19´)), 93.01 (С(20)), 97.20 (С(5)), 104.07 (С(10)), 106.04
(С(15)), 122.53 (С(3(2))), 125.81 and 125.95 (C(14´), C(16´)),
128.25 (С(13)), 128.78/128.87 (C(11´), C(13´)), 129.06 (С(3(1))),
129.23 (С(12)), 130.49 (С(2)), 131.53/131.71 (C(15´)), 135.86
(С(7)), 136.06 (С(4)), 136.19 (С(3)), 137.86 (С(11)), 141.55
(С(1)), 144.98 (С(8)), 149.01 (С(14)), 150.77 (С(9)), 151.18
(C(12´)), 155.21 (С(6)), 160.29 (С(16)), 171.41 (С(19)), 173.12
(С(17(3))), 196.18 (С(13(1))).
the brain was homogenized (10%) in saline solution (pH 7.4)
and centrifuged for 10 min (centrifuge CMꢀ6M, 1600 g,
3000 rpm). Then the supernatant (S1)10,12 containing water,
proteins, DNA, RNA, and lipids (cholesterol, galactolipids,
individual phospholipids, and gangliosides) was taken. The
studied compounds were added to the supernatant as solutions
in acetone (the final concentration 50 and 500 μmol L–1). After
30 min, LPO was initiated by addition of a freshly prepared
solution of FeCl2 and ascorbic acid,13 and the test samples were
incubated for 1 h at 37 °C under slow stirring. The content of
the secondary products of LPO reacting with 2ꢀthiobarbituric
acid (TBAꢀreactive products) was determined11,14,18 using
a ThermoSpectromic Genesys 20 spectrophotometer (USA) at
λ = 532 nm, the extinction coefficient of 1.56•105 L mol–1 cm–1
was used in calculations. A series of four samples was used in
each experiment.
The effect of compounds on the viability of HEK293 and
SHꢀSY5Y cells was evaluated by staining cells with trypan blue.
The method is based on the ability of the dye to penetrate into
the interior of the cell through damaged membranes, while
living cells do not stain.19 Human embryonic kidney cells 293
(HEK293) and neuroblastoma cells (SHꢀSY5Y) (Russian Colꢀ
lection of Cell Cultures, Institute of Cytology of the
Russian Academy of Sciences, St. Petersburg) were seeded in
24ꢀwell plates (1.5•105 cells mL–1) in the DMEM (Biolot,
Russia) medium, containing 10% fetal bovine serum (Invitroꢀ
gen, USA), 2 mM of Lꢀglutamine, 50 μg mL–1 of gentamycin
sulfate (PanEko, Russia), and cultured under 5% CO2 atmoꢀ
sphere at 95% humidity. After 24 h from the reseeding, the test
compounds were added to the cells, and the cells were incubated
for 48 h. Immediately before the experiments, the stock soluꢀ
tions of test compounds (100 mmol L–1 in 100% DMSO) were
diluted with the complete culture medium to the final concenꢀ
trations of 0.5, 5, and 50 μg mL–1; the final concentration of
DMSO was 0.1%. When the incubation was finished, the cells
were trypsinized (0.25% trypsin solution, 0.02% Versene soluꢀ
tion, 3 min, 37 °C), and differential counting of live and dead
cells was performed using trypan blue (0.01%) in the Goryaev
chamber. The results were expressed as the percentage of living
cells relative to the total number of cells in the experimental
and control groups. The data obtained from two independent
experiments were presented as the mean values of three meaꢀ
Methyl 2ꢀ(Oꢀ3ꢀ[(4ꢀhydroxyꢀ3ꢀ{(1S,2R,4R)ꢀ1,7,7ꢀtrimethꢀ
ylbicyclo[2.2.1]heptanꢀ2ꢀyl}ꢀ5ꢀmethylphenyl)propyl]carbamoꢀ
ylethyl}ꢀ18ꢀ[(Nꢀmethyl)carbamoyl]chlorinꢀ20ꢀyl)acetate (14)
was obtained as a blueꢀgreen powder from compound 3
(184.6 mg, 0.30 mmol) and compound 6 (72.5 mg, 0.24 mmol)
in 88.7 mg (41%) yield. MS (ESI), m/z: 908.7 [MH]+. UVꢀVis,
λ/nm (Irel (%)): 663.5 (33), 608.0 (3), 557.5 (1), 529.5 (2),
1
501.5 (8), 403.0 (100). H NMR, δ: –1.76 (br.s, 1 Н, N(I)H);
–1.54 (br.s, 1 Н, N(III)H); 0.82, 0.83/0.80, 0.74 (all s, 3 Н each,
С(8´)H3, С(9´)H3, С(10´)H3); 2.17/2.14 (s, 3 H, С(13´(1)H3);
2.60—2.41, 2.34—2.08, 1.92—1.21 (all m, 3 Н, 5 Н, 20 Н,
С(3´)H2, H(4´), С(5´)H2, С(6´)H2, С(18´)Н2, С(17´)Н2,
С(17(1))Н2, С(17(2))Н2, С(8(2))Н3, С(18(1))Н3); 3.02/2.97
(t, 1 Н, H(2´), J = 8.3 Hz); 3.28 (d, 3 Н, C(13(2))H3,
J = 4.6 Hz); 3.35 (s, 3 Н, C(2(1))Н3); 3.53 (s, 3 Н, C(7(1))Н3);
3.58 (s, 3 Н, C(12(1))Н3); 3.83 (s, 3 Н, C(15(3))Н3); 3.88—3.76
(m, 2 Н, C(8(1))Н2); 4.12—3.95 (m, 2 Н, С(19´)Н2); 4.40 (br.d,
1 Н, Н(17), J = 9.2 Hz); 4.52 (q, 1 Н, Н(18), J = 7.3 Hz); 4.67/
4.58 (s, 1 Н, ArОН); 5.56/5.54 and 5.28/5.25 (both d, 1 Н
each, С(15(1))Н2, J = 19.2); 6.18 (d, 1 Н, Н(3(2))cis, J = 12.0 Hz);
6.36 (br.t, 1 Н, С(13(1))NH, J = 4.6 Hz); 6.40 (d, 1 Н,
Н(3(2))trans, J = 18.0 Hz); 6.88 (br.s, 1 Н, H(16´)); 6.68 (br.s,
1 Н, Н(14´)); 8.13 (dd, 1 Н, Н(3(1)), J = 18.0 Hz, J = 12.0 Hz);
8.85 (s, 1 Н, Н(20)); 9.67 (s, 1 Н, Н(5)); 9.72 (s, 1 Н, Н(10)).
13С NMR, δ: 11.37 (С(7(1))), 11.97 (С(2(1))), 12.20 (С(2(1))),
12.39 (C(10´)), 16.14/16.17 (C(13´(1))), 17.75 (С(8(2))), 19.72
(С(8(1))), 20.21 (C(9´)), 21.37 (C(9´)), 23.08 (С(18(1))), 27.27
(C(13(2))), 27.44/27.52 (C(5´)), 29.71 (С(17(2))), 30.29/30.38
(С(17(1))), 31.22/31.26 (C(17´)), 31.64/31.60 (C(3´)), 34.09/
34.16 (C(18´)), 37.81 (С(15(1))), 40.06/40.02 (C(3´)), 45.69
(C(2´)), 45.50/45.45 (С(15(3))), 45.75 (C(4´)), 48.00 (C(7´)),
49.34 (С(18)), 49.63 (C(1´)), 52.11 (С(17)), 63.96/64.02
(C(19´)), 93.64 (С(20)), 98.85 (С(5)), 101.49 (С(10)), 102.05
(С(15)), 121.65 (С(3(2))), 125.81 (C(14´), C(16´)), 128.00/128.06
(С(13)), 128.78/128.87 (C(11´), C(13´)), 129.51 (С(3(1))),
129.92 (С(12)), 130.19 (С(2)), 131.67/131.71 (C(15´)), 134.58
(С(3)), 134.96/135.01 (С(4)), 136.11 (С(3)), 134.86 (С(11)),
138.95 (С(1)), 144.79 (С(8)), 149.13 (С(14)), 151.18 (С(9)),
151.21 (C(12´)), 154.29 (С(6)), 161.96 (С(16)), 166.68 (С(19)),
168.88 (С(13(1))), 170.15 (С(15(2))), 173.17/174.25 (С(17(3))).
The antioxidant activity of porphyrin derivatives was evaluꢀ
ated in vitro by the ability to inhibit LPO in a substrate obtained
from the brain of laboratory mices.10,11 After the extraction,
surements for each concentration
standard deviation with
respect to the control values (0.1% DMSO), which were asꢀ
sumed as 100%. To calculate the IC50 values (the concentraꢀ
tion of a compound, which inhibits cell viability by 50%),
a nonꢀlinear regression of the logarithm of the compound conꢀ
centrations and normalized values for the inhibition percentꢀ
age of viability (GraphPad Prism v.5.0, GraphPad Software
Inc., USA) was performed.
This work was performed using the equipment of the
"Chemistry" Center for Collective Use at the Institute of
Chemistry of Komi Scientific Centre, Ural Branch of the
Russian Academy of Sciences and the "Molecular Biology"
Center for Collective Use at the Institute of Biology of
Komi Scientific Centre, Ural Branch of the Russian Acadꢀ
emy of Sciences. The used animals were obtained from
the scientific collection of experimental animals at the
Institute of Biology of Komi Scientific Centre, Ural

2164
Russ. Chem. Bull., Int. Ed., Vol. 66, No. 11, November, 2017
Khudyaeva et al.
9. E. S. Nyman, P. H. Hynninen, J. Photochem. Photobiol., B,
2004, 73, 1.
10. C. I. Acker, R. Brandão, A. R. Rosário, C. W. Nogueira,
Environ. Toxicol. Pharmacol., 2009, 28, 280.
11. S. T. Stefanello, A. S. Prestes, T. Ogunmoyole, S. M. Salꢀ
man, R. S. Schwab, C.R. Brender, L. Dornelles, J. B. T.
Rocha, F. A. A. Soares, Toxicol. In Vitro, 2013, 27, 1433.
12. N. A. V. Belle, G. D. Dalmolin, G. Fonini, M. A. Rubim,
J. B. T. Rocha, Brain Res., 2004, 1008, 245.
13. R. Chawla, R. Arora, R. Kumar, A. Sharma, J. Prasad,
S. Singh, R. Sagar, P. Chaudhary, S. Shukla, G. Kaur, R. K.
Sharma, S. C. Puri, K. L. Dhar, G. Handa, V. K. Gupta,
G. N. Qazi, Mol. Cell. Biochem., 2005, 273, 193.
14. T. Asakawa, S. Matsushita, Lipids, 1980, 15, 137.
15. I. Yu. Chukicheva, O. V. Sukrusheva, L. I. Mazaletskaya,
A. V. Kutchin, Russ. J. Org. Chem., 2016, 52, 813.
16. E. V. Buravlev, I. Yu. Chukicheva, I. A. Dvornikova, A. V.
Churakov, A. V. Kutchin, Russ. J. Org. Chem., 2012, 48, 938.
17. L. A. Tulaeva, D. V. Belykh, N. M. Yakovleva, I. A. Selkoꢀ
va, A. V. Rocheva, A. V. Kutchin, Izv. Vyssh. Uchebn. Zaved.
Khim. Khim. Tekhnol., 2006, 49, 82 (in Russian).
Branch of the Russian Academy of Sciences (http://
www.ckpꢀrf.ru/usu/471933/).
This work was financially supported by the Russian
Science Foundation (Project No. 16ꢀ13ꢀ10367).
References
1. M. V. Kamyshentsev, P. D. Shabanov, V. E. Stefanov, Obꢀ
zory po klinicheskoi farmakologii i ledarstvennoy terapii [Reꢀ
views on Clinical Pharmacology and Drug Therapy], 2002, 1,
No. 1, 29 (in Russian).
2. V. I. Kaledin, N. G. Kolosova, A. M. Gonchar, A. Yu.
Grishapova, A. E. Prosenko, Sibirskii ekologicheskii zhurnal
[Siberian Ecological Journal], 2004, No. 1, 19 (in Russian).
3. E. B. Burlakova, Russ. J. Gen. Chem., 2007, 77, 1983.
4. E. V. Buravlev, I. Yu. Chukicheva, O. G. Shevchenko,
K. Yu. Suponitsky, A. V. Kutchin, Russ. Chem. Bull., 2016,
65, 1232.
5. E. V. Buravlev, I. Yu. Chukicheva,O. G. Shevchenko, A. V.
Kutchin, Russ. Chem. Bull., 2017, 66, 297.
6. E. V. Buravlev, I. Yu. Chukicheva, O. G. Shevchenko,
K. Yu. Suponitskii, A. V. Kutchin, Russ. Chem. Bull., 2017,
66, 91.
18. J.ꢀS. Kim, Food Nutr. Sci., 2013, 4, 177.
19. K. S. Louis, A. C. Siegel, Methods Mol. Biol., 2011, 740, 7.
7. O. G. Shevchenko, S. N. Plyusnina, L. N. Shishkina, I. Y.
Chukicheva, I. V. Fedorova, A. V. Kuchin, Biochemistry
(Moscow) Suppl. Ser. A: Membr. Cell Biol., 2013, 7, 302.
8. M. O. Senge, Photodiagn. Photodyn. Ther., 2012, 9, 170.
Received April 28, 2017;
in revised form July 24, 2017