Soluble tetraarylporphyrin-platinum conjugates as cytotoxic and phototoxic antitumor agents

Article abstract of DOI:10.1021/jm0110690

A series of asymmetric tetraarylporphyrins was synthesized from pyrrole, para-substituted oligo- or poly(ethylene glycol) monomethyl ether benzaldehyde and from 4-hydroxybenzaldehyde etherified with diethyl bromomalonate according to the Lindsey method. A

Full text of DOI:10.1021/jm0110690

J . Med. Chem. 2002, 45, 2079-2089
2079
Solu ble Tetr a a r ylp or p h yr in -P la tin u m Con ju ga tes a s Cytotoxic a n d P h ototoxic
An titu m or Agen ts
Christian Lottner,† Karl-Christian Bart,† Gu¨nther Bernhardt,‡ and Henri Brunner*,†
Institut fu¨r Anorganische Chemie and Institut fu¨r Pharmazie, Universita¨t Regensburg, 93040 Regensburg, Germany
Received October 22, 2001
A series of asymmetric tetraarylporphyrins was synthesized from pyrrole, para-substituted
oligo- or poly(ethylene glycol) monomethyl ether benzaldehyde and from 4-hydroxybenzaldehyde
etherified with diethyl bromomalonate according to the Lindsey method. After hydrolysis of
the tetraarylporphyrin esters, the resulting carboxylic acid groups were used to bind platinum
fragments. In comparison to analogous hematoporphyrin-platinum conjugates, the title
compounds are characterized by a 30 nm bathochromic shift of their absorption bands. The
antiproliferative activity of 18 platinum complexes (1, 5, and 10 µM) differing in solubility,
type of the platinum fragment, and the corresponding tetraarylporphyrin ligands were studied
on TCC-SUP transitional bladder cancer cells in the dark and after irradiation (λ ) 600-730
nm; 24 J /cm2). The most active compounds were among the tetraarylporphyrin-platinum
conjugates bearing the diammine and (RR/ SS)-trans-1,2-diaminocyclohexane ligands.
Sch em e 1a
In tr od u ction
As described in the preceding paper we tried to
combine the cytostatic therapy with platinum complexes
and the photodynamic therapy with porphyrins by
assembling platinum fragments and porphyrin systems
in the same molecule. The cytostatic effect of the
platinum component and, on irradiation, the additional
photodynamic effect of the porphyrin sensitizer were
proven for hematoporphyrin-platinum conjugates. The
crucial limitation of the photodynamic effect is the small
depth of light penetration into the tissue depending on
the wavelength of the absorption maximum of the
sensitizer, which corresponds to the irradiation wave-
length. Comparing hematoporphyrins with tetraarylpor-
phyrins, the maxima of tetraarylporphyrins show a
bathochromic shift of about 30 nm. Therefore, we
switched from hematoporphyrins to tetraarylporphyrins
expecting an increase in the penetration depth due to
the red-shift of the irradiation wavelength. In the
present paper, the synthesis, characterization, and
antitumor properties of 18 tetraarylporphyrin-plati-
num derivatives are described. Ethylene glycol units
solubilize the new compounds in DMF, DMSO, and, in
particular, water.
a
Reagents: (i) tosyl chloride, CH2Cl2, NaOH, benzyltriethyl-
ammonium chloride, phase-transfer catalysis, 20 °C, 20 h; (ii)
4-hydroxybenzaldehyde, DMF, K2CO3, reflux, 48 h.
Sch em e 2a
a
Reagents: (i) diethyl bromomalonate, NaOH, DMF, 20 °C, 24
h.
Ch em ica l Resu lts a n d Discu ssion
Syn th esis of th e Su bstitu ted Ben za ld eh yd es. For
the reaction with 4-hydroxybenzaldehyde, the respective
oligo- and poly(ethylene glycol) monomethyl ethers had
to be activated at their alcohol terminus with tosyl
chloride according to a literature procedure.1 The ether-
ification was performed by refluxing the tosylated
alcohols 1-3 and 4-hydroxybenzaldehyde together with
K2CO3 in DMF.2 The substituted benzaldehydes 4-6
were separated by filtration and purified by column
chromatography (Scheme 1).
For platinum coordination to the tetraarylporphyrins
to be synthesized it is necessary to introduce two
adjacent carboxylic acid groups in one of the substituted
benzaldehydes. Therefore, 4-hydroxybenzaldehyde was
etherified with diethyl bromomalonate under alkaline
conditions (Scheme 2). The diethyl 2-(4-formylphenoxy)-
malonate 7 was used together with the substituted
benzaldehydes 4-6 for the synthesis of asymmetric
tetraarylporphyrins.
Syn th esis of th e P or p h yr in Liga n d s. The synthe-
sis of the asymmetric tetraarylporphyrins was per-
formed using the Lindsey method.3 Pyrrole and the
respective benzaldehydes were reacted under Lewis acid
catalysis to porphyrinogens, which were oxidized with
p-chloranil to the corresponding porphyrins. The tetra-
* Corresponding author: Prof. Dr. Henri Brunner, Institut fu¨r
Anorganische Chemie, Universita¨t Regensburg, 93040 Regensburg,
Germany. Tel: 49-941-943-4440. Fax: 49-941-943-4439. E-mail:
henri.brunner@chemie.uni-regensburg.de.
† Institut fu¨r Anorganische Chemie.
‡ Institut fu¨r Pharmazie.
10.1021/jm0110690 CCC: $22.00 © 2002 American Chemical Society
Published on Web 04/17/2002

2080 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10
Lottner et al.
Sch em e 3a
a
Reagents: (i) CH2Cl2, N2, BF3‚Et2O, 20 °C, 1 h; (ii) triethyl orthoacetate, 20 °C, 15 min; (iii) BF3‚Et2O, 20 °C, 1 h; (iv) p-chloranil, 20
°C, 24 h; (v) CHCl3 (only for the synthesis of 11 and 12 necessary), 20% methanolic KOH solution, reflux, 3 h; (vi) 7% aqueous HCl
solution; (vii) diammine(diaqua)platinum(II) hydroxide, H2O, EtOH, CHCl3 (only for the synthesis of 21 and 22 necessary), >18 h.
arylporphyrin esters 8-10 were purified by several
column chromatographies. The carboxylic acids 11-13,
which were required for coordination to the platinum-
(II) fragments, were prepared by hydrolysis of the esters
8 and 9 with a mixture of CHCl3 and 20% methanolic
KOH solution. For the hydrolysis of 10, pure 20%
methanolic KOH solution was used (Scheme 3).
Syn th esis of th e P la tin u m P r ecu r sor s. 1,2-Diami-
noethane, 1,3-diaminopropane, (RR/SS)-trans-1,2-di-
aminocyclohexane, and 2,2′-bipyridine were commer-
cially available and used as ligands to prepare the
corresponding dichloroplatinum(II) complexes 14-17
according to literature procedures.4-6
Ethyl (R/ S)-2,3-diaminopropionate dihydrochloride,
ethyl (S)-2,4-diaminobutanoate dihydrochloride, and
diethyl meso-4,5-diaminosuberate dihydrochloride were
synthesized according to literature procedures7-10 and
used for the preparation of the corresponding diiodo-
platinum(II) complexes 18-20.11
the case of the water-soluble ligand 13, in pure water.
The complexes 24-29, 31, and 32 precipitated. To the
water-soluble complex 30 was added CH2Cl2 to remove
neutral impurities before the aqueous phase was evapo-
rated to obtain the product (Schemes 4 and 5).
For the reaction with the porphyrinmalonic acids it
was necessary to activate the diamine(diiodo)platinum-
(II) complexes 18-20 by conversion into diamine-
(dinitrato)platinum(II) species,13 which are water-
soluble. In this form they were reacted with an equimolar
amount of the porphyrin ligands 11 and 12, respectively,
in a mixture of CH2Cl2, ethanol, and water. The water-
insoluble complexes 33-38 precipitated after concen-
trating the solutions (Schemes 6 and 7).
The tetraarylporphyrin-platinum(II) conjugates 21-
38 are easily soluble in CH2Cl2 and CHCl3, but only
slightly soluble in DMF or DMSO. The complexes 23
and 30 can be dissolved in water because of their poly-
(ethylene glycol) monomethyl ether side chains.
Syn th esis of th e P la tin u m Com p lexes. For the
reaction with the porphyrincarboxylic acids 11-13,
cisplatin had to be activated by conversion into diam-
mine(diaqua)platinum(II) hydroxide.12 It was reacted
with an equimolar amount of the porphyrin ligand in a
mixture of CHCl3, ethanol, and water or, in the case of
the water-soluble ligand 10, in pure water. The resulting
diammine(malonato)platinum(II) complexes 21 and 22
precipitated. To the reaction mixture of the water-
soluble complex 23 was added CH2Cl2 to remove neutral
impurities. The aqueous phase was evaporated to obtain
the product (Scheme 3).
The diamine(dichloro)platinum(II) precursors 14-17
were activated by conversion into diamine(dihydroxy)-
platinum(II) species,13 which were reacted with an
equimolar amount of the respective porphyrinmalonic
acid in a mixture of CH2Cl2, ethanol, and water or, in
The spectral data for the individual compounds are
given in the Experimental Section. Most of the general
points discussed in the preceding paper apply. The
tetraarylporphyrin derivatives exhibit UV/vis spectra
with absorption maxima at 650, 590, 555, and 520 nm.
In comparison with the spectra of the hematoporphyrin
derivatives described in the preceding paper, the maxima
of the tetraarylporphyrins show a bathochromic shift
of about 30 nm. The malonate substituent renders the
tetraarylporphyrin backbone asymmetric. Thus, in the
1H NMR spectra, the methine protons of the porphyrin
system form two different AB spin systems. Some of
them coincide, resulting in singlets.14
Biologica l Resu lts a n d Discu ssion
The antiproliferative activity of the new tetraarylpor-
phyrin ligands and the corresponding platinum com-

Soluble Tetraarylporphyrin-Platinum Conjugates
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10 2081
Sch em e 4a
a
Reagents: (i) AgNO3, H2O, 7 d; (ii) ion exchanger; (iii) 11 and 12, CH2Cl2, EtOH, H2O.
Sch em e 5a
a
Reagents: (i) AgNO3, H2O, 7 d; (ii) ion exchanger; (iii) 11-13, CH2Cl2 (only for the synthesis of 28 and 29 necessary), EtOH, H2O; (iv)
11 and 12, CH2Cl2, EtOH, H2O.
Sch em e 6a
a
Reagents: (i) AgNO3, H2O, 7 d; (ii) 11 and 12, CH2Cl2, EtOH, H2O.
plexes with different amine nonleaving groups were
determined on TCC-SUP bladder cancer cells.15 The
evaluation of the sensitivity of the cancer cells with
respect to the test compounds was performed in a
computerized (kinetic) chemosensitivity assay.16,17 The
technical details of the chemosensitivity assay, the
irradiation, and the evaluation of the results have been
described in the preceding paper.
E n d -P oin t Ch em osen sit ivit y Assa y. TCC-SUP
cells were incubated for 4 days with 1, 5, and 10 µM
tetraarylporphyrin ligand, tetraarylporphyrin-plati-
num conjugate, and hematoporphyrin or cisplatin as
references.
and hematoporphyrin are comparatively shown in Fig-
ure 1. At a dosage of 1 µM and 5 µM (Figure 1) and 10
µM (data not shown) no statistically significant cyto-
toxicity was observed in the dark. In contrast to the
ethylene glycol substituted hematoporphyrins reported
in the preceding paper, a marked light-induced toxicity
of the tetraarylporphyrins 11 and 12 was observed at a
concentration of 1 µM (T/Ccorr. ) 37%), whereas the
photoactivation of 13 (n ) ∼17) was low.
At a dosage of 1 µM and 5 µM, both the dark- and
phototoxicity of the tetraarylporphyrin-platinum con-
jugates 21-38 were highly influenced by the type of the
nonleaving group, the results agreeing with those of the
hematoporphyrin-platinum complexes discussed in the
preceding paper. Compounds 23, 29, and 30 were the
most active tetraarylporphyrin-platinum conjugates
The dark and the light-induced effects of the tetra-
arylporphyrin ligands 11-13, the putative leaving
groups of the tetraarylporphyrin-platinum complexes,

2082 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10
Lottner et al.
Sch em e 7a
a
Reagents: (i) AgNO3, H2O, 7 d; (ii) 11 and 12, CH2Cl2, EtOH,
H2O.
F igu r e 2. Effect of the tetraarylporphyrin-platinum conju-
gates 21-38 and the reference cisplatin (stock solution in
DMF) at a concentration of 5 µM on the proliferation of TCC-
SUP cells (in passage 55 from origin) without (filled bars) and
with (open bars) irradiation (λ ) 600-730 nm; 10 min; 24 J
cm-2) as a function of the different nonleaving groups. The
cells were exposed to the substances for 96 h. Irradiation was
performed 48 h after the addition of the test compounds.
a
b
Stock solution of the complexes 23 and 30 in H2O. Stock
solution of complex 31 in DMSO.
to the hematoporphyrin-platinum complexes, the most
active of which were those with the diammine or
the (RR/ SS)-trans-1,2-diaminocyclohexane nonleaving
groups. At 1 µM concentration, there was only a slight
enhancement of the cytotoxicity of the tetraarylporphy-
rin-platinum conjugates with the side chain length n
) 2 and n ) 3 upon irradiation. On the average, the
light-induced T/Ccorr. values were approximately 20%
lower than the dark-only cytotoxicities (data not shown).
An increase in the concentration of the complexes to
5 µM enhanced the dark effects and the phototoxicities
as shown in Figure 2. Apart from cisplatin, the highest
antitumor activities were measured for the tetraarylpor-
phyrin-platinum conjugates bearing diammine (21-
23) and (RR/ SS)-trans-1,2-diaminocyclohexane (28-30)
nonleaving groups. The differences between dark and
light-induced toxicities were best for the tetraarylpor-
phyrin-platinum complexes 24, 27, 32-34, 36, and 38
with a side chain length of n ) 2 or n ) 3.
F igu r e 1. Effect of the tetraarylporphyrin ligands 11-13 and
the reference hematoporphyrin (stock solution in DMF) on the
proliferation of TCC-SUP cells (in passage 55 from origin)
without (filled bars) and with (open bars) irradiation (λ ) 600-
730 nm; 10 min; 24 J cm-2). The cells were exposed to the
substances for 96 h. Irradiation was performed 48 h after the
addition of the test compounds. aStock solution of ligand 13
in H2O.
Mu ltip le P oin t Ch em osen sitivitiy Assa y. The
antitumor activity of the tetraarylporphyrin-platinum
compound 22 was analyzed on the TCC-SUP bladder
cancer cell line in a kinetic assay,16,17 as 22 was one of
the most active tetraarylporphyrin-platinum conju-
with T/Ccorr. values of around 37%, 57%, and 63%,
respectively, at 1 µM concentration. This is analogous

Soluble Tetraarylporphyrin-Platinum Conjugates
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10 2083
for the dose-response relationship experiment (Figure
3) and at 5 µM for the study of the phototoxicity of the
complex (Figure 4). By analogy to the end-point experi-
ment, irradiation was performed 48 h after addition of
the substances for 10 min with a light dose of 24 J cm-2
as indicated by the arrow in Figure 4. For Figures 3
and 4, T/Ccorr. and the percent cytocidal effect (left
ordinate) for the test compound were plotted together
with the absorbances of the untreated solvent control
(right ordinate) vs the time of drug exposure. In these
plots of T/Ccorr. vs time of incubation, time zero indicates
the time at which the drug was added. In both plots,
the growth-curve data of the corresponding solvent
control are given by filled circles. In these experiments,
the drug containing culture medium was left unchanged
throughout the incubation period.
As obvious from Figure 3, the tetraarylporphyrin-
platinum complex 22 shows a classical dose-response
relationship. A clear antiproliferative effect is observed
as a function of time for all three concentrations
resulting in T/Ccorr. values of 26.2% and 2.8% for 1 µM
and 5 µM concentration, and a cytocidal effect of 17.1%
at 10 µM concentration after an incubation period of
144 h.
On irradiation, there is an increase in cytotoxicity
indicated by a steep drop of the T/Ccorr. curve. At the
end of the experiment, the number of the irradiated cells
is lower than the number at the beginning of the
experiment (C0) (Figure 4). Thus, photoactivation of the
tetraarylporphyrin-platinum complex 22 improved the
antitumor activity from the T/Ccorr. value of 4%, result-
ing from the platinum moiety to a cytocidal effect of
20%.
F igu r e 3. Dose-response relationship of the tetraarylpor-
phyrin-platinum conjugate 22 (stock solution in DMF) on the
proliferation of long-term incubated TCC-SUP bladder cancer
cells (in passage 56 from origin) at a concentration of 1 µM
(O), 5 µM (0), and 10 µM (4). Proliferation kinetics of the
corresponding control (absorbance at 578 nm) (b).
In summary, we synthesized tetraarylporphyrin-
based platinum derivatives bearing a phototoxic ligand
which increases the antitumor activity of the platinum
moiety by an additional light-induced toxicity, which is
improved compared to their hematoporphyrin analogues
due to the red-shift of the irradiation wavelength. In
contrast to the ethylene glycol substituted hematopor-
phyrin ligands discussed in the preceding paper, the
new tetraarylporphyrin ligands showed a phototoxic
effect already at 1 µM by irradiation of the tumor cells
for 10 min with a light dose of 24 J cm-2 (λ ) 600-730
nm), which is attributed to the bathochromic shift of
about 30 nm. The largest difference between dark and
light-induced antitumor activity was found for the
tetraarylporphyrin-platinum conjugates 22, 24, 27, 29,
32-34, 36, and 38 bearing the 1,4,7-trioxaoctyl and the
1,4,7,10-tetraoxaundecyl groups.
F igu r e 4. Effect of the tetraarylporphyrin-platinum conju-
gate 22 (stock solution in DMF) on the proliferation of long-
term incubated TCC-SUP bladder cancer cells (in passage 56
from origin) without (filled square) and with (open square)
irradiation (λ ) 600-730 nm; 10 min; 24 J cm-2) at a
concentration of 5 µM. Irradiation was performed 48 h after
the addition of the test compound. Proliferation kinetics of the
corresponding control (absorbance at 578 nm) (b).
Our ongoing studies will focus on a further improve-
ment of the photophysical properties of the platinum
conjugates by replacing the hematoporphyrin or the
tetraarylporphyrin system with chlorins, phthalocya-
nines, or naphthalocyanines to induce a further batho-
chromic shift of the absorption bands.
gates in the end-point chemosensitivity assay at 5 µM
concentration and the antiproliferative effect was clearly
improved by irradiation (Figure 2). Dose-response
relationship of the dark toxicity and enhancement of its
antitumor activity by irradiation is exemplarily shown
in Figures 3 and 4.
The TCC-SUP cells were seeded into microplates, and
the tetraarylporphyrin-platinum conjugate 22 was
added after 48 h at a concentration of 1, 5, and 10 µM
Exp er im en ta l Section
Ch em istr y. IR: Beckman spectrometer 4240. 1H NMR:
Bruker WM 250 (250 MHz); chemical shifts are given in parts
per million; tetramethylsilane was used as internal standard.
MS: Finnigan MAT 95 and MAT 112 S, ThermoQuest Finni-
gan TSQ 7000. The respective molecules are designated as M;
in complexes the porphyrin ligands are designated as L. Mp:
Bu¨chi SMP 20; the melting points are not corrected. UV/vis:
Kontron Instruments spectrophotometer UVIKON 922.

2084 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10
Lottner et al.
Solid reagents were used as obtained from commercial
suppliers without further purification; liquids were freshly
distilled before use. Column chromatographies were performed
using alumina 90 (63-200 µm). Reaction progress was deter-
mined by TLC analysis on alumina 60 F254 (Merck, Darmstadt,
Germany).
The nomenclature of the porphyrins and their complexes
was based on the recommendation of the IUPAC and the
International Union of Biochemistry (IUB).18
Gen er a l P r oced u r e 1 (GP 1). A total of 150 mmol of the
respective alcohol were dissolved in 150 mL of CH2Cl2. Next,
1.37 g (6.00 mmol) of benzyltriethylammonium chloride and
120 mL of a 30% aqueous NaOH solution were added. Then a
solution of 4-toluenesulfonyl chloride (30.1 g, 160 mmol) in 150
mL of CH2Cl2 was added dropwise, and the reaction mixture
was stirred for 20 h at 20 °C. The white precipitate, which
formed in the organic layer, was dissolved by adding 200 mL
of H2O. The organic phase was separated, washed with 3 ×
150 mL of water, and dried with Na2SO4. The solvent was
removed, and the residue was purified by chromatography over
SiO2 (15 × 10 cm).
4-(1,4,7-Tr ioxa octyl)ben za ld eh yd e (4). According to GP
2, 8.37 g (68.5 mmol) of 4-hydroxybenzaldehyde was reacted
with 20.7 g (75.3 mmol) of 3,6-dioxaheptyl 4-toluenesulfonate
1 and 28.5 g (206 mmol) of K2CO3. The crude product was
purified by column chromatography over SiO2 with CH2Cl2.
After the solvent was removed, a solid was obtained, which
was recrystallized from ether/petroleum ether (40/60). Yield:
13.2 g (58.9 mmol, 86%) fine, colorless needles, mp 41-42 °C.
1
IR (film): 1670 cm-1 (CdO). H NMR (CDCl3) δ (ppm): 9.89
(s, 1H, CHO), 7.83 (d, 3J ) 8.7 Hz, 2H, aryl-H2,6), 7.02 (d,
3J ) 8.7 Hz, 2H, aryl-H3,5), 4.23 (d, 2H, aryl-OCH2CH2), 3.90
(d, 2H, aryl-OCH2CH2), 3.73 (d, 2H, OCH2CH2), 3.59 (d, 2H,
OCH2CH2), 3.40 (s, 3H, OCH3). MS (EI) m/z (rel int.): 224 (M,
16); 121 (OHCC6H4O, 13); 59 (CH3OCH2CH2, 100). Anal.
(C12H16O4, 224.3) C, H.
4-(1,4,7,10-Tetr a oxa u n d ecyl)ben za ld eh yd e (5). Accord-
ing to GP 2, 8.34 g (68.3 mmol) of 4-hydroxybenzaldehyde was
reacted with 23.9 g (75.1 mmol) of 3,6,9-trioxadecyl 4-toluene-
sulfonate 2 and 28.3 g (205 mmol) of K2CO3. The crude product
was purified by column chromatography over SiO2 with CH2-
Cl2. Yield: 16.9 g (63.0 mmol, 92%) nearly colorless, viscous
oil. IR (film): 1680 cm-1 (CdO). 1H NMR (CDCl3) δ (ppm): 9.89
(s, 1H, CHO), 7.83 (d, 3J ) 8.7 Hz, 2H, aryl-H2,6), 7.02 (d,
3J ) 8.7 Hz, 2H, aryl-H3,5), 4.22 (d, 2H, aryl-OCH2CH2), 3.89
(d, 2H, aryl-OCH2CH2), 3.75 (d, 2H, OCH2CH2), 3.69 (d, 2H,
OCH2CH2), 3.65 (d, 2H, OCH2CH2OCH3), 3.56 (d, 2H, OCH2CH2-
OCH3), 3.38 (s, 3H, OCH3). MS (EI) m/z (rel int.): 268 (M, 9);
149 (M - O(CH2CH2O)2Me, 15); 121 (OHCC6H4O, 22). Anal.
(C14H20O5, 268.3) C: calcd, 62.67; found, 62.21. H.
3,6-Dioxa h ep tyl 4-Tolu en esu lfon a te (1). According to GP
1, 18.0 g (150 mmol, 17.5 mL) of diethylene glycol monomethyl
ether was reacted with 30.1 g (160 mmol) of 4-toluenesulfonyl
chloride. The resulting crude yellow product was purified by
column chromatography over SiO2 with CH2Cl2. The first
yellow bands were discarded before the colorless product
eluted. Yield: 22.1 g (80.6 mmol, 54%) colorless oil. IR (film):
1380, 1180 cm-1 (SdO). 1H NMR (CDCl3) δ (ppm): 7.80 (d,
3J ) 8.3 Hz, 2H, aryl-H2,6), 7.34 (d, 3J ) 8.3 Hz, 2H, aryl-
H3,5), 4.17 (d, 2H, aryl-SO3CH2CH2), 3.69 (d, 2H, aryl-SO3-
CH2CH2), 3.58 (d, 2H, OCH2CH2), 3.48 (d, 2H, OCH2CH2), 3.35
(s, 3H, OCH3), 2.45 (s, 3H, aryl-CH3). MS (EI) m/z (rel int.):
274 (M, 10); 242 (M - MeOH, 28); 229 (M - MeOCH2, 4); 199
(M - OCH2CH2OMe, 17); 155 (M - O(CH2CH2O)2Me, 42); 91
(C7H7, 100); 59 (MeOCH2CH2, 78); 45 (MeOCH2, 64); 31 (MeO,
14). Anal. (C12H18O5S, 274.3) C, H.
3,6,9-Tr ioxa d ecyl 4-Tolu en esu lfon a te (2). According to
GP 1, 24.6 g (150 mmol, 23.7 mL) of triethylene glycol mono-
methyl ether was reacted with 30.1 g (160 mmol) of 4-tolu-
enesulfonyl chloride. The yellow oil obtained was purified by
column chromatography over SiO2 with CH2Cl2/MeOH 40:1.
After yellow impurities were removed, the colorless product
eluted. Yield: 22.1 g (80.6 mmol, 54%) colorless oil. IR (film):
1345, 1160 cm-1 (SdO). 1H NMR (CDCl3) δ (ppm): 7.80 (d,
3J ) 8.3 Hz, 2H, aryl-H2,6), 7.34 (d, 3J ) 8.3 Hz, 2H, aryl-
H3,5), 4.16 (d, 2H, aryl-SO3CH2CH2), 3.69 (d, 2H, aryl-SO3-
CH2CH2), 3.61 (d, 2H, OCH2CH2), 3.59 (m, 4H, OCH2CH2-
OCH3), 3.53 (d, 2H, OCH2CH2), 3.37 (s, 3H, OCH3), 2.45 (s,
3H, aryl-CH3). MS (EI) m/z (rel int.): 318 (M, 2); 243 (M -
OCH2CH2OMe, 9); 199 (M - O(CH2CH2O)2Me, 92); 172
(TosOH, 2); 155 (Tos, 50). Anal. (C14H22O6S, 318.4) C, H.
P oly(eth ylen e glycol)-750-m on om eth yl eth er -1-yl 4-Tol-
u en esu lfon a te (3). According to GP 1, 113 g (150 mmol) of
poly(ethylene glycol)-750-monomethyl ether was reacted with
30.1 g (160 mmol) of 4-toluenesulfonyl chloride. The resulting
yellow, waxy product was purified by column chromatography
over SiO2 with CH2Cl2/MeOH 20:1. The first yellow bands were
discarded before the product eluted. Yield: 88.4 g (94.5 mmol,
63%) colorless wax. IR (film): 1355, 1180 cm-1 (SdO). 1H NMR
(CDCl3) δ (ppm): 7.80 (d, 3J ) 8.3 Hz, 2H, aryl-H2,6), 7.34 (d,
3J ) 8.3 Hz, 2H, aryl-H3,5), 4.16 (d, 2H, aryl-SO3CH2CH2),
3.69 (d, 2H, aryl-SO3CH2CH2), 3.68-3.53 (m, 64H, OCH2), 3.38
(s, 3H, OCH3), 2.45 (s, 3H, aryl-CH3). (C42H78O20S, 935.1).
Gen er a l P r oced u r e 2 (GP 2). A total of 8.33 g (68.2 mmol)
of 4-hydroxybenzaldehyde, 28.3 g (205 mmol) of K2CO3, and
75.0 mmol of the respective 4-toluenesulfonate were dissolved
in 200 mL of absolute DMF under N2 atmosphere and heated
to reflux. After a period of 48 h, the conversion was quantita-
tive, which was monitored by TLC. The mixture was filtered,
and the filtrate was evaporated. The residue was diluted with
CH2Cl2 and filtered once more to separate insoluble compo-
nents. The filtrate was evaporated and purified as described
below.
4-(P oly(eth ylen e glycol)-750-m on om eth yl eth er -1-yl)-
ben za ld eh yd e (6). According to GP 2, 8.33 g (68.2 mmol) of
4-hydroxybenzaldehyde was reacted with 70.1 g (75.0 mmol)
of poly(ethyleneglycol)-750-monomethyl ether-1-yl 4-toluene-
sulfonate 3 and 28.3 g (205 mmol) of K2CO3. The brown, waxy
crude product was purified by column chromatography over
SiO2 with CH2Cl2. Yield: 25.1 g (28.4 mmol, 42%) yellowish,
viscous oil. IR (film): 1680 cm-1 (CdO). 1H NMR (CDCl3) δ
(ppm): 9.88 (s, 1H, CHO), 7.83 (d, 3J ) 8.7 Hz, 2H, aryl-H2,6),
3
7.02 (d, J ) 8.7 Hz, 2H, aryl-H3,5), 4.22 (d, 2H, aryl-OCH2-
CH2), 3.89 (d, 2H, aryl-OCH2CH2), 3.76-3.53 (m, 64H, OCH2-
CH2), 3.38 (s, 3H, OCH3). MS (ESI) m/z (rel int.): 923 (MK,
38); 907 (MNa, 70); 902 (M + NH4, 40); 879 (MK - OCH2CH2,
36); 863 (MNa - OCH2CH2, 80). (C42H76O19, 885.0).
Dieth yl 2-(4-F or m ylp h en oxy)m a lon a te (7). A total of
12.2 g (100 mmol) of freshly sublimated 4-hydroxybenzalde-
hyde and 23.9 g (100 mmol, 16.8 mL) of diethyl bromomalonate
were dissolved under N2 atmosphere in 120 mL of absolute
DMF. A total of 4.00 g (100 mmol) of pulverized NaOH was
added, and the mixture was stirred for 24 h at room temper-
ature. The orange solution was diluted with 300 mL of water
and extracted with 3 × 200 mL of CH2Cl2. The combined
organic phases were washed with 3 × 200 mL of H2O and dried
with Na2SO4. After the solvent was removed and the mixture
was dried in a vacuum, a yellow oil was obtained, which was
purified by bulb tube distillation. At 70-75 °C in a vacuum,
excessive diethyl bromomalonate and DMF were distilled. At
90-130 °C in high vacuum, the product 49 condensed in the
first bulb. Yield: 20.0 g (71.4 mmol, 71%) colorless, viscous
oil. IR (film): 1755, 1730 (CdO, ester); 1680 cm-1 (CdO,
1
aldehyde). H NMR (CDCl3) δ (ppm): 9.91 (s, 1H, CHO), 7.86
3
3
(d, J ) 8.7 Hz, 2H, aryl-H2,6), 7.07 (d, J ) 8.7 Hz, 2H, aryl-
3
H3,5), 5.31 (s, 1H, CH), 4.34 (q, J ) 7.1 Hz, 4H, 2 CO2CH2-
CH3), 1.32 (t, 3J ) 7.1 Hz, 6H, 2 CO2CH2CH3). MS (EI) m/z
(rel int.): 280 (M, 70); 207 (M - CO2Et, 25); 135 (MH - CO2-
Et, 100). Anal. (C14H16O6, 280.3) C, H.
Gen er a l P r oced u r e 3 (GP 3). In a 2 L three-necked flask
with gas tap containing 1.2 L of dry CH2Cl2, 805 mg (12.0
mmol, 840 µL) of freshly distilled pyrrole and 12.0 mmol of
the respective substituted benzaldehydes were added under
N2 atmosphere. The resulting 10-2 M solution was stirred for
15 min before 170 mg (1.20 mmol, 150 µL) of BF3‚Et2O was
added and the solution was stirred for an additional 75 min
in the dark at room temperature. Then 1.95 g (12.0 mmol, 2.18
mL) of triethyl orthoacetate was added. After the mixture was

Soluble Tetraarylporphyrin-Platinum Conjugates
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10 2085
stirred for 15 min, 150 µL of BF3‚Et2O was added once more
and the mixture was stirred for 1 h. The resulting porphy-
rinogens were oxidized to the corresponding porphyrins with
the addition of 2.22 g (9.00 mmol) of p-chloranil. After being
stirred for 20 h at room temperature in the dark, the reaction
mixture was concentrated and 5-10 g of SiO2 were added. The
solvent was removed with a rotary evaporator, the resulting
powder was put on the top of a chromatography column, which
had been dry filled with SiO2, and eluted with 500 mL of CH2-
Cl2/petroleum ether (40/60) 1:1 and 500 mL of pure CH2Cl2 to
remove multicolored pigments. The porphyrin fraction eluted
with CH2Cl2/MeOH 20:1 in form of a thick, purple band. The
different substituted porphyrins could be separated by further
chromatographies.
Hz, 8H, 4 aryl-H2,6), 7.28 (d, 3J ) 8.7 Hz, 8H, 4 aryl-H3,5),
4.41 (d, 8H, 4 aryl-OCH2CH2), 4.04 (d, 8H, 4 aryl-OCH2CH2),
3.87 (d, 8H, 4 OCH2CH2), 3.79 (d, 8H, 4 OCH2CH2), 3.73 (d,
8H, 4 OCH2CH2OCH3), 3.62 (d, 8H, 4 OCH2CH2OCH3), 3.42
(s, 12H, OCH3), -2.76 (bs, 2H, dNH). MS (ESI) m/z (rel int.):
1264 (MH, 40); 632.5 (M + 2 H, dipositive cation, 100). Anal.
(C72H86N4O16, 1263.5) C, H, N.
Dieth yl 2-(4-{10,15,20-Tr is[4-(1,4,7,10-tetr aoxau n decyl)-
p h en yl]p or p h yr in -5-yl}p h en oxy)m a lon a te (9). The syn-
thesis and work up was carried out according to 5,10,15,20-
tetrakis[4-(1,4,7,10-tetraoxaundecyl)phenyl]porphyrin. The crude
product was purified by chromatography over SiO2 (40 × 3.5
cm) with CH2Cl2/MeOH 100:1. Yield: 478 mg (0.375 mmol,
4.2%) purple, shiny crystals, mp 130-131 °C. IR (KBr): 3300
(dNH); 1760, 1740 cm-1 (CdO). UV/vis (CH2Cl2) λmax (log ꢀ)
421 (5.50); 518 (4.13); 555 (3.97); 592 (3.70); 649 nm (3.69). 1H
NMR (CDCl3) δ (ppm): 8.86 (d, 3J ) 4.8 Hz, 2H, 2 dCH), 8.81
(d, 3J ) 4.8 Hz, 2H, 2 dCH), 8.86 (s, 4H, dCH pos. 12, 13, 17,
18), 8.14 (d, 3J ) 8.7 Hz, 2H, C6H4 pos. 5), 7.35 (d, 3J ) 8.7
5,10,15,20-Tetr a k is[4-(1,4,7-tr ioxa octyl)p h en yl]p or p h y-
r in . According to GP 3, 2.02 g (9.00 mmol) of 4-(1,4,7-
trioxaoctyl)benzaldehyde 4 and 841 mg (3.00 mmol) of diethyl
2-(4-formylphenoxy)malonate 7 were reacted with 805 mg (12.0
mmol, 840 µL) of pyrrole. After the first chromatography, the
crude product mixture was chromatographed over SiO2 (65 ×
3 cm) with CH2Cl2/MeOH 160:1 eluting two small red bands,
which contain porphyrins with more than one diethyl malonate
group. If the methanol concentration of the solvent was
increased up to CH2Cl2/MeOH 150:1, compound 8 eluted in
form of a thick, purple band. Using a mixture of CH2Cl2/MeOH
140:1, the product eluted, which was recrystallized from CH2-
Cl2/cyclohexane. Yield: 221 mg (0.203 mmol, 2.3%) purple
needles, mp > 250 °C. IR (KBr): 3330 cm-1 (dNH). UV/vis
(CH2Cl2) λmax (log ꢀ) 421 (5.56); 518 (4.22); 556 (4.07); 593
3
Hz, 2H, C6H4 pos. 5), 8.10 (d, J ) 8.7 Hz, 6H, C6H4 pos. 10,
15, 20), 7.30 (d, 3J ) 8.7 Hz, 6H, C6H4 pos. 10, 15, 20), 5.53 (s,
3
3
1H, CH), 4.47 (q, J ) 7.1 Hz, 2H, CO2CH2CH3), 4.46 (q, J )
7.1 Hz, 2H, CO2CH2CH3), 4.43 (d, 6H, 3 aryl-OCH2CH2), 4.06
(d, 6H, 3 aryl-OCH2CH2), 3.89 (d, 6H, 3 OCH2CH2), 3.80 (d,
6H, 3 OCH2CH2), 3.75 (d, 6H, 3 OCH2CH2OCH3), 3.62 (d, 6H,
3
3 OCH2CH2OCH3), 3.43 (s, 9H, 3 OCH3), 1.43 (t, J ) 7.1 Hz,
6H, 2 CO2CH2CH3), -2.78 (bs, 2H, dNH). MS (FAB) m/z (rel
int.): 1275 (MH, 100). Anal. (C72H82N4O17, 1275.4) C: calcd,
67.80; found, 67.31. H, N.
1
(3.79); 650 nm (3.79). H NMR (CDCl3) δ (ppm): 8.85 (s, 8H,
Diet h yl 2-(4-{10,15,20-Tr is[4-(p oly(et h ylen e glycol)-
750-m on om eth yl eth er -1-yl)p h en yl]p or p h yr in -5-yl}p h e-
n oxy)m a lon a te (10). According to GP 3, 7.97 g (9.00 mmol)
of 4-(poly(ethylene glycol)-750-monomethyl ether-1-yl)benzal-
dehyde 6 and 841 mg (3.00 mmol) of diethyl 2-(4-formylphe-
noxy)malonate 7 were reacted with 805 mg (12.0 mmol, 840
µL) of pyrrole. After the first chromatography the crude
product mixture was chromatographed over SiO2 (65 × 3 cm)
with CH2Cl2/MeOH 100:1 up to 30:1, eluting several small
bands, which contain porphyrins with more than one diethyl
malonate group. If the methanol concentration of the solvent
was increased up to CH2Cl2/MeOH 20:1, the product eluted
as a purple band. Yield: 800 mg (0.256 mmol, 2.8%) dark red
oil. IR (film): 3300 (dNH); 1765, 1740 cm-1 (CdO). UV/vis
(CH2Cl2) λmax (log ꢀ) 421 (5.54); 518 (4.17); 555 (3.99); 593
3
3
dCH), 8.10 (d, J ) 8.7 Hz, 8H, 4 aryl-H2,6), 7.29 (d, J ) 8.7
Hz, 8H, 4 aryl-H3,5), 4.44 (d, 8H, 4 aryl-OCH2CH2), 4.06 (d,
8H, 4 aryl-OCH2CH2), 3.87 (d, 8H, 4 OCH2CH2), 3.69 (d, 8H,
OCH2CH2), 3.47 (s, 12H, 4 OCH3), -2.77 (bs, 2H, dNH). MS
(FAB) m/z (rel int.): 1087 (MH, 100). Anal. (C64H70N4O12
,
1087.3) C: calcd, 70.70; found, 70.24. H, N.
Dieth yl 2-(4-{10,15,20-Tr is[4-(1,4,7-tr ioxa octyl)p h en yl]-
p or p h yr in -5-yl}p h en oxy)m a lon a te (8). The synthesis and
work up was carried out according to 5,10,15,20-tetrakis[4-
(1,4,7-trioxaoctyl)phenyl]porphyrin. The crude product was
purified by chromatography over SiO2 (30 × 3 cm) with CH2-
Cl2/MeOH 200:1. Yield: 455 mg (0.398 mmol, 4.4%) purple
powder, mp 192 °C. IR (KBr): 3300 (dNH); 1760, 1740 cm-1
(CdO). UV/vis (CH2Cl2) λmax (log ꢀ) 419 (5.59); 518 (4.25); 555
(4.05); 593 (3.63); 650 nm (3.68). 1H NMR (CDCl3) δ (ppm):
1
3
(3.68); 650 nm (3.65). H NMR (CDCl3) δ (ppm): 8.88 (d, J )
3
3
8.86 (d, J ) 4.8 Hz, 2H, 2 dCH), 8.81 (d, J ) 4.8 Hz, 2H, 2
4.8 Hz, 2H, 2 dCH), 8.81 (d, 3J ) 4.8 Hz, 2H, 2 dCH), 8.85 (s,
3
3
dCH), 8.85 (s, 4H, dCH pos. 12, 13, 17, 18), 8.14 (d, J ) 8.7
4H, dCH pos. 12, 13, 17, 18), 8.13 (d, J ) 8.7 Hz, 2H, C6H4
3
Hz, 2H, C6H4 pos. 5), 7.35 (d, J ) 8.7 Hz, 2H, C6H4 pos. 5),
pos. 5), 7.34 (d, 3J ) 8.7 Hz, 2H, C6H4 pos. 5), 8.10 (d, 3J ) 8.7
3
3
3
8.10 (d, J ) 8.7 Hz, 6H, C6H4 pos. 10, 15, 20), 7.29 (d, J )
8.7 Hz, 6H, C6H4 pos. 10, 15, 20), 5.53 (s, 1H, CH), 4.47 (q,
3J ) 7.1 Hz, 2H, CO2CH2CH3), 4.46 (q, 3J ) 7.1 Hz, 2H,
CO2CH2CH3), 4.44 (d, 6H, 3 aryl-OCH2CH2), 4.06 (d, 6H, 3
aryl-OCH2CH2), 3.86 (d, 6H, 3 OCH2CH2), 3.69 (d, 6H, 3
Hz, 4H, C6H4 pos. 10, 20), 7.30 (d, J ) 8.7 Hz, 4H, C6H4 pos.
3
3
10, 20), 8.09 (d, J ) 8.7 Hz, 2H, C6H4 pos. 15), 7.29 (d, J )
3
8.7 Hz, 2H, C6H4 pos. 15), 5.53 (s, 1H, CH), 4.47 (q, J ) 7.1
3
Hz, 2H, CO2CH2CH3), 4.46 (q, J ) 7.1 Hz, 2H, CO2CH2CH3),
4.43 (d, 6H, 3 aryl-OCH2CH2), 4.06 (d, 6H, 3 aryl-OCH2CH2),
3.87 (d, 6H, 3 aryl-OCH2CH2OCH2CH2), 3.80 (d, 6H, 3 aryl-
OCH2CH2OCH2CH2), 3.73-3.53 (m, 168H, OCH2CH2), 3.48 (s,
3
OCH2CH2), 3.47 (s, 9H, 3 OCH3), 1.43 (t, J ) 7.1 Hz, 6H, 2
CO2CH2CH3), -2.78 (bs, 2H, dNH). MS (ESI) m/z (rel int.):
1143 (MH, 20); 572 (M + 2 H, dipositive cation, 100). Anal.
(C66H70N4O14, 1143.3) C, H, N.
3
9H, 3 OCH3), 1.43 (t, J ) 7.1 Hz, 6H, 2 CO2CH2CH3), -2.78
(bs, 2H, dNH). MS (ESI) m/z (rel int.): 3125 (MH, 22); loss of
2 CO2CH3 units and 1-16 OCH2CH2 units; 2231 (MH - 2 CO2-
CH3 - 17 OCH2CH2, 100). (C156H250N4O59, 3125.6).
5,10,15,20-Tetr akis[4-(1,4,7,10-tetr aoxau n decyl)ph en yl]-
p or p h yr in . According to GP 3, 2.41 g (9.00 mmol) of 4-(1,4,7,-
10-tetraoxaundecyl)benzaldehyde 5 and 841 mg (3.00 mmol)
of diethyl 2-(4-formylphenoxy)malonate 7 were reacted with
805 mg (12.0 mmol, 840 µL) of pyrrole. After the first
chromatography the crude product mixture was chromato-
graphed over SiO2 (65 × 3 cm) with CH2Cl2/MeOH 200:1 up
to 180:1, eluting two small red bands, which contain porphy-
rins with more than one diethyl malonate group. If the
methanol concentration of the solvent was increased from CH2-
Cl2/MeOH 150:1 up to 80:1, compound 9 eluted in form of a
thick, purple band. Using a mixture of CH2Cl2/MeOH 60:1, the
product eluted, which was recrystallized from CH2Cl2/cyclo-
hexane. Yield: 258 mg (0.204 mmol, 2.3%) purple needles, mp
154 °C. IR (KBr): 3310 cm-1 (dNH). UV/vis (CH2Cl2) λmax (log
ꢀ) 419 (5.59); 518 (4.33); 555 (4.17); 593 (3.81); 650 nm (3.92).
1H NMR (CDCl3) δ (ppm): 8.85 (s, 8H, dCH), 8.10 (d, 3J ) 8.7
2-(4-{10,15,20-Tr is[4-(1,4,7-tr ioxa octyl)p h en yl]p or p h y-
r in -5-yl}p h en oxy)m a lon ic Acid (11). 310 mg (0.271 mmol)
of diethyl 2-(4-{10,15,20-tris[4-(1,4,7-trioxaoctyl)phenyl]por-
phyrin-5-yl}phenoxy)malonate 8 was dissolved in 85 mL of
CH2Cl2. 200 mL of a 20% methanolic KOH solution and 3 mL
of water were added. The mixture was heated to reflux for 3
h and stirred for 12 h at room temperature. After concentrating
the solution to ca. 50 mL, it was cooled with ice and acidified
with a 7% aqueous HCl solution (pH 4). The resulting green
precipitate was filtered off, dissolved in CH2Cl2, and washed
with H2O until the aqueous phase is neutral. The purple
organic phase was dried with Na2SO4, evaporated, and dried
in a vacuum. Yield: 295 mg (0.271 mmol, 100%) dark blue,
shiny solid, mp 202-203 °C. IR (KBr): 3310 (dNH); 1710 cm-1
(CdO). UV/vis (CH2Cl2) λmax (log ꢀ) 421 (5.52); 458 (4.75); 518

2086 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10
Lottner et al.
(4.17); 555 (4.03); 594 (3.78); 651 (3.91); 697 nm (4.13). 1H NMR
(CDCl3) δ (ppm): 8.86-8.61 (m, 8H, dCH), 8.48 (d, 2H, C6H4
pos. 5), 7.57 (d, 2H, C6H4 pos. 5), 8.11 (d, 6H, C6H4 pos. 10, 15,
20), 7.32 (d, 6H, C6H4 pos. 10, 15, 20), 5.42 (s, 1H, CH), 4.46
(d, 6H, 3 aryl-OCH2CH2), 4.08 (d, 6H, 3 aryl-OCH2CH2), 3.87
(d, 6H, 3 OCH2CH2), 3.69 (d, 6H, 3 OCH2CH2), 3.47 (s, 6H, 2
OCH3 pos. 10, 20), 3.37 (s, 3H, OCH3 pos. 15), -2.81 (bs, 2H,
dNH). The CO2H signals could not be detected. MS (ESI) m/z
(rel int.): 1087 (MH, 100); 1043 (MH - CO2, 60); 544 (M + 2
H, dipositive cation, 17); 522 (M - CO2 + 2 H, dipositive cation,
11). Anal. (C62H62N4O14, 1087.2) C, H, N: calcd, 5.15; found,
4.49.
Gen er a l P r oced u r e 4 (GP 4). Diammine(diaqua)platinu-
m(II) hydroxide was synthesized from diammine(dichloro)-
platinum(II) (cisplatin) as previously described. After removal
of the solvent, a glassy solid was obtained, which was dissolved
in a 1:1 mixture of water/ethanol just before reaction with the
respective porphyrindicarboxylic acid ligands. Compounds 11
and 12 were dissolved in a mixture of CHCl3 and EtOH, and
the water-soluble ligand 13 was dissolved in water before an
equimolar amount of diammine(diaqua)platinum(II) hydroxide
was added. The solution was stirred for at least 18 h at room
temperature. The precipitated complexes 21 and 22 were
filtered off, washed with water and ethanol, and dried in a
vacuum. In the case of the water-soluble complex 23, CH2Cl2
was added to the aqueous solution and the mixture was
extracted with water. The aqueous phase was evaporated to
obtain the product.
Dia m m in e[2-(4-{10,15,20-tr is[4-(1,4,7-tr ioxa octyl)p h en -
yl]p or p h yr in -5-yl}p h en oxy)m a lon a to]p la tin u m (II) (21).
According to GP 4, 11 (109 mg, 0.100 mmol) was dissolved in
10 mL of CHCl3 and 20 mL of EtOH, combined with 0.100
mmol of the aqueous diammine(diaqua)platinum(II) hydroxide
solution and stirred for 20 h. Yield: 81.0 mg (54.2 µmol, 54%)
purple powder, mp 213-214 °C. IR (KBr): 1680, 1660 cm-1
(CdO). UV/vis (CH2Cl2) λmax (log ꢀ) 424 (5.05); 520 (4.16); 556
(3.98); 593 (3.69); 650 nm (3.66). 1H NMR (CDCl3) δ (ppm):
8.52 (m, 8H, dCH), 7.94 (d, 8H, 4 aryl-H2,6), 7.19 (d, 8H, 4
aryl-H3,5), 4.34 (d, 6H, 3 aryl-OCH2CH2), 3.94 (d, 6H, 3 aryl-
OCH2CH2), 3.78 (d, 6H, 3 OCH2CH2), 3.62 (d, 6H, 3 OCH2CH2),
3.39 (s, 9H, 3 OCH3), -3.01 (bs, 2H, dNH). The NH3 and CH
signals could not be detected. MS (ESI) m/z (rel int.): 1315
(MH - 10 H2O, 23); 1087 (LH, 8); 1043 (LH - CO2, 7); 999
(LH - 2 CO2, 6); 658 (M - 10 H2O + 2 H, dipositive cation,
100). Anal. (C62H66N6O14Pt‚10 H2O, 1494.5) C: calcd, 49.83;
found, 49.19. H, N: calcd, 5,62; found, 6.09.
Dia m m in e[2-(4-{10,15,20-t r is[4-(1,4,7,10-t et r a oxa u n -
decyl)phenyl]porphyrin-5-yl}phenoxy)malonato]platinum-
(II) (22). According to GP 4, 12 (122 mg, 0.100 mmol) was
dissolved in 10 mL of CHCl3 and 30 mL of EtOH, combined
with 0.100 mmol of the aqueous diammine(diaqua)platinum-
(II) hydroxide solution, and stirred for 20 h. Yield: 54.4 mg
(37.6 µmol, 75%) purple powder, mp 197-198 °C. IR (KBr):
1640, 1625 cm-1 (CdO). UV/vis (CH2Cl2) λmax (log ꢀ) 421 (5.39);
518 (4.20); 557 (4.06); 594 (3.72); 651 nm (3.76). 1H NMR
(CDCl3) δ (ppm): 8.52 (m, 8H, dCH), 7.99 (d, 8H, 4 aryl-H2,6),
7.20 (d, 8H, 4 aryl-H3,5), 4.38 (d, 6H, 3 aryl-OCH2CH2), 4.05
(d, 6H, 3 aryl-OCH2CH2), 3.76 (d, 6H, 3 OCH2CH2), 3.62 (d,
6H, 3 OCH2CH2), 3.49 (d, 6H, 3 OCH2CH2OCH3), 3.41 (d, 6H,
3 OCH2CH2OCH3), 3.42 (s, 9H, OCH3), -2.99 (bs, 2H, dNH).
The NH3 and CH signals could not be detected. MS (ESI) m/z
(rel int.): 1447 (MH, 28); 1219 (LH, 100); 724 (M + 2 H,
dipositive cation, 42); 610 (L + 2 H, dipositive cation, 55). Anal.
(C68H78N6O17Pt, 1446.5) C: calcd, 56.46; found, 56.01. H, N.
2-(4-{10,15,20-Tr is[4-(1,4,7,10-tetr a oxa u n d ecyl)p h en yl]-
p or p h yr in -5-yl}p h en oxy)m a lon ic Acid (12). 400 mg (0.314
mmol) of diethyl 2-(4-{10,15,20-tris[4-(1,4,7,10-tetraoxaunde-
cyl)phenyl]porphyrin-5-yl}phenoxy)malonate 9 was dissolved
in 100 mL of CH2Cl2. 300 mL of a 20% methanolic KOH
solution and 5 mL of water were added. The mixture was
heated to reflux for 3 h and stirred 12 h at room temperature.
After concentrating the solution to ca. 50 mL, it was cooled
with ice and acidified with a 7% aqueous HCl solution (pH 4).
The resulting green precipitate was filtered off, dissolved in
CH2Cl2, and washed with H2O until the aqueous phase was
neutral. The purple organic phase was dried with Na2SO4,
evaporated, and dried in a vacuum. Yield: 383 mg (0.314
mmol, 100%) greenish blue solid, mp > 250 °C. IR (KBr): 3300
(dNH); 1740, 1730 cm-1 (CdO). UV/vis (CH2Cl2) λmax (log ꢀ)
421 (5.53); 518 (4.08); 555 (3.89); 593 (3.47); 650 nm (3.54). 1H
NMR (CDCl3) δ (ppm): 8.80-8.64 (m, 8H, dCH), 8.12 (d, 2H,
C6H4 pos. 5), 7.28 (d, 2H, C6H4 pos. 5), 7.89 (d, 6H, C6H4 pos.
10, 15, 20), 7.28 (d, 6H, C6H4 pos. 10, 15, 20), 5.42 (s, 1H, CH),
4.31-3.55 (m, 36H, OCH2CH2), 3.36 (s, 9H, 3 OCH3), -2.80
(bs, 2H, dNH). The CO2H signals could not be detected. MS
(ESI) m/z (rel int.): 1219 (MH, 8); 1175 (MH - CO2, 10); 610
(M + 2 H, dipositive cation, 100); 588 (M - CO2 + 2 H,
dipositive cation, 88). Anal. (C68H74N4O17, 1219.3) C: calcd,
66.98; found, 66.50. H: calcd, 6.12; found 5.54. N.
2-(4-{10,15,20-Tr is[4-(p oly(et h ylen eglycol)-750-m on o-
m et h yl et h er -1-yl)p h en yl]p or p h yr in -5-yl}p h en oxy)m a -
lon ic Acid (13). A total of 800 mg (0.256 mmol) of diethyl
2-(4-{10,15,20-tris[4-(poly(ethyleneglycol)-750-monomethyl ether-
1-yl)phenyl]porphyrin-5-yl}phenoxy)malonate 10 was dissolved
in 120 mL of a 20% methanolic KOH solution, heated to reflux
for 3 h, and stirred for 12 h at room temperature. After the
solution was concentrated to ca. 50 mL, it was cooled with ice,
acidified with a 7% aqueous HCl solution (pH 4), and extracted
with 250 mL of CH2Cl2. The organic layer was washed with 2
× 100 mL of water, dried with Na2SO4, and evaporated
obtaining a green oil. Now 100 g of a strong basic ion exchanger
(Fa. Merck, Ionenaustauscher III) was activated with 100 mL
of 2 M NaOH and eluted with water, until the eluate was
neutral. Then the crude product was dissolved in 10 mL of
H2O and put on the top of the ion exchanger. The porphy-
rindicarboxylic acid was immobilized on the ion exchanger
matrix so that the excessive poly(ethylene glycol) could be
eluted with 1 L of water. With 2 M aqueous HCl, the
immobilized porphyrin could be eluted, which was extracted
with CH2Cl2. After drying the organic layer with Na2SO4, the
solvent was removed and the product was dried in a vacuum.
Yield: 400 mg (0.130 mmol, 51%) red oil. IR (film): 3310
(dNH); 1745, 1730 cm-1 (CdO). UV/vis (CH2Cl2) λmax (log ꢀ)
424 (5.53); 519 (4.15); 558 (4.06); 594 (3.67); 652 nm (3.77). 1H
NMR (CDCl3) δ (ppm): 8.86-8.54 (m, 8H, dCH), 8.17-7.28
(m, 16H, C6H4), 4.56-3.54 (m, 204 H, OCH2CH2), 3.37 (s, 9H,
3 OCH3). The CO2H, dNH, and CH signals could not be
detected. MS (ESI) m/z (rel int.): 3068 (MH, 20); loss of CO2
and 1-16 OCH2CH2 units; 2320 (MH - CO2 - 16 OCH2CH2,
Dia m m in e[2-(4-{10,15,20-tr is[4-(p oly(eth ylen eglycol)-
750-m on om et h yl
et h er -1-yl)p h en yl]p or p h yr in -5-yl}-
p h en oxy)m a lon a to]p la tin u m (II) (23). According to GP 4,
13 (307 mg, 0.100 mmol) was dissolved in 10 mL of H2O,
combined with 0.100 mmol of the aqueous diammine(diaqua)-
platinum(II) hydroxide solution and stirred for 20 h. To the
resulting solution was added CH2Cl2, and the mixture was
extracted with H2O. The aqueous phase was evaporated to
obtain the product. Yield: 48.2 mg (14.6 µmol, 15%) brown,
sticky solid. IR (KBr): 1635, 1620 cm-1 (CdO). UV/vis (DMSO)
λmax (log ꢀ) 423 (5.56); 519 (4.26); 557 (4.17); 595 (3.78); 651
nm (3.88). MS (ESI) m/z (rel int.): 2357 (MH - CH3 - 21
OCH2CH2, 34); loss of CH3 and 22-25 OCH2CH2 units; 2181
(MH - CH3 - 25 OCH2CH2, 100); 2137 (MH - CH3 - 26
OCH2CH2, 100). (C152H246N6O59Pt, 3296.7).
Gen er a l P r oced u r e 5 (GP 5). About 0.100 mmol of the
respective diamine(dichloro)platinum(II) complex were sus-
pended in ca. 15 mL of water. After 10 min ultrasonic
treatment, the 2-fold amount of AgNO3 was added, and the
mixture was stirred for 7 d in the dark. The precipitated AgCl
was filtered off and washed with H2O. A total of 15 g of a
strongly basic ion exchanger (Merck, Ionenaustauscher III)
97); 2276 (MH - CO2 - 17 OCH2CH2, 100). (C152H242N4O59
,
3069.5).

Soluble Tetraarylporphyrin-Platinum Conjugates
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10 2087
was activated with 100 mL of 2 N NaOH and flushed with
water until the eluate was neutral. The filtrate was brought
onto the ion exchanger and eluted with water. The eluate was
evaporated. The residue was dissolved in 15 mL of water,
before it was combined with a solution of the respective
porphyrindicarboxylic acid (0.100 mmol) in H2O or CH2Cl2/
EtOH. After being stirred for 2 d in the dark at room
temperature, the reaction mixture was concentrated. The
precipitated product was filtered off, washed with water and
EtOH, and dried in a vacuum.
1,2-Dia m in oeth a n e[2-(4-{10,15,20-tr is[4-(1,4,7-tr ioxa oc-
tyl)p h en yl]p or p h yr in -5-yl}p h en oxy)m a lon a to]p la tin u m -
(II) (24). According to GP 5, 109 mg (0.100 mmol) of 11 in 10
mL of CH2Cl2 and 20 mL of EtOH was reacted with 0.100
mmol of activated 1,2-diaminoethane(dichloro)platinum(II).
Yield: 52.0 mg (38.8 µmol, 39%) purple powder, mp 252 °C.
IR (KBr): 1650, 1630 cm-1 (CdO). UV/vis (DMF) λmax (log ꢀ)
422 (5.48); 519 (4.12); 557 (4.05); 596 (3.67); 652 nm (3.74).
MS (ESI) m/z (rel int.): 1341 (MH, 1); 1087 (LH, 28); 544 (L +
2 H, 100). Anal. (C64H68N6O14Pt, 1340.3) C: calcd, 57.35; found,
56.83. H, N.
1,2-Dia m in oeth a n e[2-(4-{10,15,20-tr is[4-(1,4,7,10-tetr a -
oxa u n d ecyl)p h en yl]p or p h yr in -5-yl}p h en oxy)m a lon a to]-
p la tin u m (II) (25). According to GP 5, 122 mg (0.100 mmol)
of 12 in 10 mL of CH2Cl2 and 20 mL of EtOH was reacted
with 0.100 mmol of activated 1,2-diaminoethane(dichloro)-
platinum(II). Yield: 70.8 mg (48.0 µmol, 48%) purple powder,
mp 207-208 °C. IR (KBr): 1665, 1640 cm-1 (CdO). UV/vis
(DMSO) λmax (log ꢀ) 422 (5.53); 518 (4.19); 556 (4.10); 594 (3.75);
651 nm (3.82). MS (ESI) m/z (rel int.): 1473 (MH, 19); 737
(M + 2 H, dipositive cation, 100). Anal. (C70H80N6O17Pt, 1472.5)
C: calcd, 57.10; found, 56.57. H, N.
1,3-Dia m in op r op a n e[2-(4-{10,15,20-t r is[4-(1,4,7-t r iox-
a octyl)p h en yl]p or p h yr in -5-yl}p h en oxy)m a lon a to]p la ti-
n u m (II) (26). According to GP 5, 109 mg (0.100 mmol) of 11
in 10 mL of CH2Cl2 and 20 mL of EtOH was reacted with 0.100
mmol of activated 1,3-diaminopropane(dichloro)platinum(II).
Yield: 72.0 mg (53.2 µmol, 53%) light purple powder, mp 212
°C. IR (KBr): 1645, 1630 cm-1 (CdO). UV/vis (CH2Cl2) λmax
(log ꢀ) 422 (5.11); 441 (4.91); 521 (4.19); 556 (4.01); 595 (3.79);
651 nm (3.71). MS (ESI) m/z (rel int.): 1355 (MH, 7); 1087
(LH, 15); 678 (M + 2 H, dipositive cation, 100); 544 (L + 2 H,
dipositive cation, 70). Anal. (C65H70N6O14Pt, 1354.4) C, H, N.
1,3-Dia m in op r op a n e[2-(4-{10,15,20-tr is[4-(1,4,7,10-tet-
r aoxau n decyl)ph en yl]por ph yr in -5-yl}ph en oxy)m alon ato]-
p la tin u m (II) (27). According to GP 5, 122 mg (0.100 mmol)
of 12 in 10 mL of CH2Cl2 and 20 mL of EtOH was reacted
with 0.100 mmol of activated 1,3-diaminopropane(dichloro)-
platinum(II). Yield: 82.6 mg (55.6 µmol, 56%) purple solid, mp
202-203 °C. IR (KBr): 1650, 1630 cm-1 (CdO). UV/vis (CH2-
Cl2) λmax (log ꢀ) 386 (4.66); 422 (5.44); 442 (5.02); 520 (4.31);
556 (4.12); 595 (3.86); 651 nm (3.81). MS (ESI) m/z (rel int.):
1487 (MH, 64); 744 (M + 2 H, dipositive cation, 100). Anal.
(C71H82N6O17Pt, 1486.5) C, H, N.
(RR/SS)-tr a n s-1,2-Dia m in ocycloh exa n e[2-(4-{10,15,20-
tr is[4-(1,4,7-tr ioxaoctyl)ph en yl]por ph yr in -5-yl}ph en oxy)-
m a lon a to]p la tin u m (II) (28). According to GP 5, 109 mg
(0.100 mmol) of 11 in 10 mL of CH2Cl2 and 20 mL of EtOH
was reacted with 0.100 mmol of activated (RR/SS)-trans-1,2-
diaminocyclohexane(dichloro)platinum(II). Yield: 72.0 mg (50.3
µmol, 50%) purple powder, mp 238 °C. IR (KBr): 1660, 1645
cm-1 (CdO). UV/vis (DMF) λmax (log ꢀ) 422 (5.49); 519 (4.16);
556 (4.05); 594 (3.64); 651 nm (3.74). MS (ESI) m/z (rel int.):
1395 (MH - 2 H2O, 47); 698 (M - 2 H2O + 2 H, dipositive
cation, 100). Anal. (C68H74N6O14Pt‚2H2O, 1430.5) C, H, N.
(RR/SS)-tr a n s-1,2-Dia m in ocycloh exa n e[2-(4-{10,15,20-
tr is[4-(1,4,7,10-tetr a oxa u n d ecyl)p h en yl]p or p h yr in -5-yl}-
p h en oxy)m a lon a to]p la tin u m (II) (29). According to GP 5,
122 mg (0.100 mmol) of 12 in 10 mL of CH2Cl2 and 20 mL of
EtOH was reacted with 0.100 mmol of activated (RR/SS)-trans-
1,2-diaminocyclohexane(dichloro)platinum(II). Yield: 113 mg
(73.9 µmol, 74%) purple solid, mp 208 °C. IR (KBr): 1650, 1630
cm-1 (CdO). UV/vis (DMSO) λmax (log ꢀ) 423 (5.52); 520 (4.17);
555 (4.02); 595 (3.65); 650 nm (3.69). MS (ESI) m/z (rel int.):
1527 (MH, 57); 764 (M + 2 H, dipositive cation, 100). Anal.
(C74H86N6O17Pt, 1526.6) C, H, N.
(RR/SS)-tr a n s-1,2-Dia m in ocycloh exa n e[2-(4-{10,15,20-
tris[4-(poly(ethylene glycol)-750-monomethyl ether-1-yl)phen-
yl]p or p h yr in -5-yl}p h en oxy)m a lon a to]p la tin u m (II) (30).
According to GP 5, 307 mg (0.100 mmol) of 13 in 10 mL of
H2O was reacted with 0.100 mmol of activated (RR/SS)-trans-
1,2-diaminocyclohexane(dichloro)platinum(II). CH2Cl2 was added
to the reaction mixture, and it was extracted with water. The
aqueous phase was evaporated to obtain the product. Yield:
190 mg (56.3 µmol, 56%) purple, sticky solid. IR (KBr): 1655,
1640 cm-1 (CdO). UV/vis (DMSO) λmax (log ꢀ) 424 (5.57); 489
(3.71); 519 (4.18); 557 (4.09); 594 (3.68); 651 nm (3.79). MS
(ESI) m/z (rel int.): 3112 (MH - 6 OCH2CH2, 33); loss of 7-13
OCH2CH2 units; 2804 (MH - 13 OCH2CH2, 90). (C158H254N6O59-
Pt, 3376.8).
2,2′-Bip yr id yl[2-(4-{10,15,20-t r is[4-(1,4,7-t r ioxa oct yl)-
p h e n yl]p or p h yr in -5-yl}p h e n oxy)m a lon a t o]p la t in u m -
(II) (31). A total of 42.2 mg (0.100 mmol) of 2,2′-bipyridyl-
(dichloro)platinum(II) was suspended in 15 mL of H2O. After
a 10 min ultrasonic treatment, 34.0 mg (0.200 mmol) of AgNO3
was added, and the mixture was stirred for 7 d in the dark at
room temperature. The precipitated AgCl was filtered off and
washed with water. The filtrate containing the activated
platinum(II) complex was evaporated. The residue was dis-
solved in 5 mL of H2O and combined with a solution of 11 (109
mg, 0.100 mmol) in 10 mL of CHCl3 and 20 mL of EtOH. After
the mixture was stirred for 20 h at 50 °C and cooled to room
temperature, the precipitated solid was filtered, washed with
water and EtOH, and dried in a vacuum. Yield: 92.4 mg (64.3
µmol, 64%) purple powder, mp 235-236 °C. IR (KBr): 1690,
1660 cm-1 (CdO). UV/vis (DMSO) λmax (log ꢀ) 421 (5.54); 518
(4.11); 555 (3.96); 593 (3.60); 649 nm (3.64). MS (ESI) m/z (rel
int.): 1459 (MNa, 100); 1437 (MH, 17); 741 (M + 2 Na,
dipositive cation, 49); 730 (MH + Na, dipositive cation, 100);
719 (M + 2 H, dipositive cation, 35). Anal. (C72H68N6O14Pt,
1436.4) C, H, N.
2,2′-Bip yr id yl[2-(4-{10,15,20-tr is[4-(1,4,7,10-tetr a oxa u n -
d ecyl)p h en yl]p or p h yr in -5-yl}p h en oxy)m a lon a t o]p la t i-
n u m (II) (32). According to the synthesis of 31, 2,2′-bipyridyl-
(dichloro)platinum(II) (42.2 mg, 0.100 mmol) was reacted with
122 mg (0.100 mmol) of 12. The precipitated solid was filtered,
washed with water and EtOH, and dried in a vacuum. Yield:
67.9 mg (43.3 µmol, 43%) purple solid, mp 237 °C. IR (KBr):
1690, 1660 cm-1 (CdO). UV/vis (DMF) λmax (log ꢀ) 422 (5.54);
518 (4.20); 556 (4.11); 595 (3.78); 651 nm (3.84). 1H NMR
(CDCl3) δ (ppm): 8.85 (d, 3J ) 4.8 Hz, 2H, 2 dCH), 8.70 (d,
3
3J ) 4.8 Hz, 2H, 2 dCH), 8.81 (d, J ) 1.4 Hz, 2H, 2 dCH),
8.70 (d, 3J ) 1.4 Hz, 2H, 2 dCH), 8.13 (d, 3J ) 8.6 Hz, 2H,
C6H4 pos. 5), 8.79 (d, 3J ) 8.6 Hz, 2H, C6H4 pos. 5), 7.99 (d,
3
3J ) 8.6 Hz, 4H, C6H4 pos. 10, 20), 7.23 (d, J ) 8.6 Hz, 4H,
C6H4 pos. 10, 20), 7.99 (d, 3J ) 8.6 Hz, 2H, C6H4 pos. 15), 7.17
(d, 3J ) 8.6 Hz, 2H, C6H4 pos. 15), 7.80 (m, 2H, bipy), 7.05 (m,
2H, bipy), 6.84 (m, 2H, bipy), 5.77 (m, 2H, bipy), 5.09 (s, 1H,
CH), 4.43 (d, 2H, aryl-OCH2CH2 pos. 15), 4.04 (d, 2H, aryl-
OCH2CH2 pos. 15), 4.32 (d, 4H, 2 aryl-OCH2CH2 pos. 10, 20),
3.94 (d, 4H, 2 aryl-OCH2CH2 pos. 10, 20), 3.86 (d, 2H, OCH2-
CH2 pos. 15), 3.60 (d, 2H, OCH2CH2 pos. 15), 3.77 (d, 4H, 2
OCH2CH2 pos. 10, 20), 3.53 (d, 4H, 2 OCH2CH2 pos. 10, 20),
3.71 (d, 6H, 3 OCH2CH2OCH3), 3.62 (d, 6H, 3 OCH2CH2OCH3),
3.41 (s, 3H, OCH3 pos. 15), 3.34 (s, 6H, 2 OCH3 pos. 10, 20),
-3.29 (bs, 2H, dNH). MS (FAB) m/z (rel int.): 1569 (MH, 100).
Anal. (C78H80N6O17Pt, 1568.6) C: calcd, 59.73; found, 59.27.
H: calcd, 5.14; found, 4.59. N: calcd, 5.36; found, 4.90.
Gen er a l P r oced u r e 6 (GP 6). The respective diamine-
(diiodo)platinum(II) complex (0.100 mmol) was suspended in
10 mL of water. After a 3 h ultrasonic treatment, 34.0 mg
(0.200 mmol) of AgNO3 was added and the mixture was stirred
for 7 d in the dark. The precipitated AgI was filtered off and
washed with H2O. The filtrate was evaporated. The glassy
residue was dissolved in 10 mL of water, before it was
combined with a solution of the respective porphyrindicar-
boxylic acid (0.100 mmol) in a mixture of 10 mL of CH2Cl2
and 40 mL of EtOH. The pH of the solution was adjusted to 6

2088 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 10
Lottner et al.
with 0.1 M NaOH, and the reaction mixture was stirred for 2
d in the dark at room temperature. After the solution was
concentrated, the precipitated product was filtered off, washed
with water and the solvent used above, and dried in a vacuum.
(MH, 100); 837 (M + 2 H, dipositive cation, 75). Anal.
(C80H96N6O21Pt, 1672.7) C, H: calcd, 5.78; found, 5.31. N.
Cell Cu ltu r e. The human TCC-SUP bladder cancer cell
line15 was obtained from the American Type Culture Collection
(ATCC) (Rockville, MD). Cell line banking and quality control
were performed according to the “seed stock concept” reviewed
by Hay.19 The maintenance and the routine treatment of the
TCC-SUP (ATCC No.: HTB-5) cells is described in the
preceding paper.
Dr u gs. Cisplatin (gold label) was obtained from Sigma-
Aldrich (Steinheim, Germany) and hematoporphyrin from
Fluka (Neu-Ulm, Germany). Both substances were dissolved
in DMF. As the complexes, with the exception of 23 and 30,
were not soluble in water or PBS, they were dissolved in DMF
or DMSO. For all drugs, 10 mM stock solutions were prepared.
After appropriate dilution, feed solutions were made. The
drugs (feed solutions) were added to the culture medium such
that the final DMF, DMSO, or water concentration was 0.1%
(v/v).
Eth yl (R/S)-2,3-Dia m in op r op ion a te[2-(4-{10,15,20-tr is-
[4-(1,4,7-t r ioxa oct yl)p h en yl]p or p h yr in -5-yl}p h en oxy)-
m a lon a to]p la tin u m (II) (33). According to GP 6, ethyl (R/
S)-2,3-diaminopropionate(diiodo)platinum(II) (58.1 mg, 0.100
mmol) was reacted with 109 mg (0.100 mmol) of 11. Yield: 67.0
mg (47.4 µmol, 47%) purple powder, mp 210-215 °C. IR
(KBr): 1725 (CdO, ester); 1655, 1630 cm-1 (CdO, carboxylate).
UV/vis (CH2Cl2) λmax (log ꢀ) 421 (5.25); 519 (4.00); 557 (3.85);
594 (3.48); 651 nm (3.52). MS (ESI) m/z (rel int.): 1413 (MH,
6); 1087 (LH, 28); 544 (L + 2 H, dipositive cation, 100). Anal.
(C67H72N6O16Pt, 1412.4) C: calcd, 56.98; found, 56.54. H, N.
Eth yl (R/S)-2,3-Dia m in op r op ion a te[2-(4-{10,15,20-tr is-
[4-(1,4,7,10-tetr a oxa u n d ecyl)p h en yl]p or p h yr in -5-yl}p h e-
n oxy)m a lon a to]p la tin u m (II) (34). According to GP 6, ethyl
(R/ S)-2,3-diaminopropionate(diiodo)platinum(II) (58.1 mg, 0.100
mmol) was reacted with 122 mg (0.100 mmol) of 12. Yield: 76.9
mg (49.8 µmol, 50%) purple solid, mp 170 °C. IR (KBr): 1730
(CdO, ester); 1640, 1630 cm-1 (CdO, carboxylate). UV/vis
(CH2Cl2) λmax (log ꢀ) 421 (5.55); 519 (4.32); 555 (4.16); 594
(3.86); 650 nm (3.88). MS (ESI) m/z (rel int.): 1545 (MH, 24);
773 (M + 2 H, dipositive cation, 100). Anal. (C73H84N6O19Pt,
1544.6) C, H, N.
Ch em osen sit ivit y Assa y. The general procedure for
chemosensitivity testing is described in the preceding paper.
Drug effects were expressed as corrected T/C values for each
group according to
T - C0
C - C0
T/Ccorr. [%] )
‚ 100 [%]
Eth yl (S)-2,4-Dia m in obu ta n oa te[2-(4-{10,15,20-tr is[4-
(1,4,7-tr ioxa octyl)p h en yl]p or p h yr in -5-yl}p h en oxy)m a lo-
n a to]p la tin u m (II) (35). According to GP 6, ethyl (S)-2,4-
diaminobutanoate(diiodo)platinum(II) (59.5 mg, 0.100 mmol)
was reacted with 109 mg (0.100 mmol) of 11. Yield: 95.0 mg
(56.6 µmol, 57%) purple powder, mp 234-235 °C. IR (KBr):
1725 (CdO, ester); 1655, 1630 cm-1 (CdO, carboxylate). 1H
NMR (CDCl3, 5 drops CD3OD) δ (ppm): 8.73 (m, 8H, dCH),
8.02 (d, 8H, 4 aryl-H2,6), 7.24 (d, 8H, 4 aryl-H3,5), 4.36 (d,
6H, 3 aryl-OCH2CH2), 3.99 (d, 6H, 3 aryl-OCH2CH2), 3.79 (d,
6H, 3 OCH2CH2), 3.63 (d, 6H, 3 OCH2CH2), 3.40 (s, 9H, OCH3),
-2.86 (bs, 2H, dNH). The CH signal and the signals of the
nonnucleofuge could not be detected. MS (ESI) m/z (rel int.):
where T is the mean absorbance of the treated cells, C the
mean absorbance of the controls, and C0 the mean absorbance
of the cells at the time (t ) 0), when the drug was added.
When the absorbance of treated cells T is less than that of
the culture at t ) 0 (C0), the extent of cell killing must be
calculated as
C0 - T
C0
cytocidal effect [%] )
‚ 100 [%]
The relationship between growth kinetics of a drug-treated
cell population and the plot of corrected T/C values versus time
is discussed elsewhere.16,17
1427 (MH - 14 H2O, 13); 1087 (LH, 100). Anal. (C68H74N6O16
-
Pt ‚ 14 H2O, 1678.6) C, H, N.
Eth yl (S)-2,4-Dia m in obu ta n oa te[2-(4-{10,15,20-tr is[4-
(1,4,7,10-t et r a oxa u n d ecyl)p h en yl]p or p h yr in -5-yl}p h e-
n oxy)m a lon a to]p la tin u m (II) (36). According to GP 6, ethyl
(S)-2,4-diaminobutanoate(diiodo)platinum(II) (59.5 mg, 0.100
mmol) was reacted with 122 mg (0.100 mmol) of 12. Yield: 61.8
mg (39.7 µmol, 40%) purple solid, mp 201-203 °C. IR (KBr):
1730 (CdO, ester); 1650, 1620 cm-1 (CdO, carboxylate). UV/
vis (CH2Cl2) λmax (log ꢀ) 421 (5.54); 519 (4.26); 556 (4.12); 594
(3.81); 650 nm (3.83). MS (ESI) m/z (rel int.): 1559 (MH, 84);
780 (M + 2 H, dipositive cation, 100). Anal. (C74H86N6O19Pt,
1558.6) C, H, N: calcd, 5.39; found, 4.94.
Ir r a d ia tion of th e Cells. In brief, irradiation occurred for
10 min with an incoherent light source, namely a Waldmann
PDT 700 lamp (Waldmann-Medizintechnik, Villingen-Schwen-
nigen, Germany). The wavelength range was between 600 and
730 nm. The distance from lamp to irradiated microplate was
0.5 m corresponding to a fluence rate of 40 mW cm-2 and a
light dose of 24 J cm-2
.
En d -P oin t Ch em osen sitivity Assa y. To obtain both the
cytotoxic and the phototoxic effect, two microplates were
prepared in duplicate for the same substances. After an
incubation time of 2 d, one batch of plates was irradiated with
the Waldmann PDT 700 lamp. After irradiation, the irradiated
and the nonirradiated plates were incubated for another 2 d
at 37 °C. The drug-containing culture medium was left
unchanged throughout the incubation period.
Mu ltip le P oin t Ch em osen sitivity Assa y. The culture and
the seeding of the TCC-SUP cells, the preparation of the stock
solutions of the tetraarylporphyrin-platinum conjugates, cis-
platin, and hematoporphyrin, and the preparation of the wells
of the microplates were carried out as described in the
preceding paper. For the dose-response relationship experi-
ment, the compounds were tested at 1, 5, and 10 µM concen-
tration. For studying the dark and light-induced toxicity, the
test compounds were used at 5 µM concentration. At 48 h after
incubation with the tetraarylporphyrin-platinum conjugates
corresponding to t ) 0 (the time zero indicates the time at
which the drug was added), one series of the plates was
irradiated. The data of the first time point of the kinetics were
obtained immediately after the irradiation. The drug-contain-
ing culture medium was left unchanged throughout the
incubation period. In both series, one additional plate was used
to determine the initial cell density.
Dieth yl m eso-4,5-Dia m in osu ber a te[2-(4-{10,15,20-tr is-
[4-(1,4,7-t r ioxa oct yl)p h en yl]p or p h yr in -5-yl}p h en oxy)-
m a lon a to]p la tin u m (II) (37). According to GP 6, diethyl
meso-4,5-diaminosuberate(diiodo)platinum(II) (70.9 mg, 0.100
mmol) was reacted with 122 mg (0.100 mmol) of 11. Yield: 65.3
mg (42.4 µmol, 42%) dark purple powder, mp 206 °C. IR
(KBr): 1720, 1705 (CdO, ester); 1640, 1625 cm-1 (CdO,
carboxylate). UV/vis (DMSO) λmax (log ꢀ) 423 (5.57); 519 (4.24);
557 (4.16); 594 (3.75); 651 nm (3.86). MS (ESI) m/z (rel int.):
1540 (MH, 25); 1087 (LH, 80); 770.5 (M + 2 H, dipositive
cation, 60); 544 (L + 2 H, dipositive cation, 100). Anal.
(C74H84N6O18Pt, 1540.6) C, H. N: calcd, 5.46; found, 6.03.
Dieth yl m eso-4,5-Dia m in osu ber a te[2-(4-{10,15,20-tr is-
[4-(1,4,7,10-tetr a oxa u n d ecyl)p h en yl]p or p h yr in -5-yl}p h e-
n oxy)m a lon a to]p la tin u m (II) (38). According to GP 6, di-
ethyl meso-4,5-diaminosuberate(diiodo)platinum(II) (70.9 mg,
0.100 mmol) was reacted with 122 mg (0.100 mmol) of 12.
Yield: 87.2 mg (52.1 µmol, 52%) purple solid, mp 191-192 °C.
IR (KBr): 1730 (CdO, ester); 1650, 1630 cm-1 (CdO, carbox-
ylate). UV/vis (CH2Cl2) λmax (log ꢀ) 421 (5.55); 518 (4.21); 556
(4.04); 593 (3.64); 650 nm (3.72). MS (ESI) m/z (rel int.): 1673

Soluble Tetraarylporphyrin-Platinum Conjugates
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