Synthesis and investigation of glycosylated mono- and diarylporphyrins for photodynamic therapy

Article abstract of DOI:10.1016/S0968-0896(99)00133-9

The synthesis of a diaryl substituted porphyrin bearing a galactosyl and a cholesteryloxy substituent and of a galactosyl substituted monoaryl porphyrin is described. The spectroscopic and aggregation properties of both compounds were investigated. The ga

Full text of DOI:10.1016/S0968-0896(99)00133-9

Bioorganic & Medicinal Chemistry 7 (1999) 1857±1865
Synthesis and Investigation of Glycosylated Mono- and
Diarylporphyrins for Photodynamic Therapy
Christian Schell and Hermann K. Hombrecher*
Institut fur Chemie der Medizinischen Universitat zu Lubeck, Ratzeburger Allee 160, D-23538 Lubeck, Germany
È
È
È
È
Received 21 December 1998; accepted 5 March 1999
AbstractÐThe synthesis of a diaryl substituted porphyrin bearing a galactosyl and a cholesteryloxy substituent and of a galactosyl
substituted monoaryl porphyrin is described. The spectroscopic and aggregation properties of both compounds were investigated.
The galactosyl substituted monoaryl porphyrin (12) was eciently incorporated into liposomes and lipoproteins whereas the diaryl
porphyrin showed no interaction with these lipids. Furthermore the binding constants of compound 12 to HDL, LDL, VLDL, and
PE and DMPC liposomes were estimated. # 1999 Elsevier Science Ltd. All rights reserved.
Introduction
glycosyl substituent.11±18 We have recently reported in a
short communication about the synthesis and some
preliminary investigations of a diaryl substituted por-
phyrin bearing a galactosyl and a cholesteryloxy sub-
stituent.19 Here we report full experimental details of the
synthesis and some new investigations about the aggre-
gation behaviour and the interaction of this compound
and a galactosyl substituted monoaryl porphyrin with
lipoproteins and liposomes.
The development of new sensitizers for photodynamic
therapy of cancer, cardiovascular and ophtalmic dis-
eases is a very important and interesting ®eld of por-
phyrin chemistry today.1±6 Therefore, a large number of
di€erent porphyrin derivatives were synthesized and
tested in vitro and in vivo studies in the last decade.
Most promising results were obtained with amphiphilic
porphyrins which show high selectivity to neoplastic
tissue. Although the exact mechanism of sensitizer
uptake by tumour tissue is still unknown, there is strong
evidence from biological studies that hydrophobic and
amphiphilic porphyrins associate strongly to plasma
lipoproteins.7,8 Since cancer cells express elevated levels
of LDL receptors it is most likely that these sensitizers
were incorporated into the tumour cell via receptor
mediated endocytosis of low density lipoproteins.9 Fur-
thermore, amphiphilic porphyrinic sensitizers may also
be more eciently incorporated into cell membranes.
This leads to a high quantum yield of cell destruction.10
Therefore, to enhance selectivity of porphyrins to
tumour cells the sensitizers should have a high binding
anity to LDL. Unfortunately, amphiphilic and
hydrophobic porphyrins tend to aggregate in water
solution. Aggregation within the cells lead to a decrease
in singlet oxygen production. Therefore a number of
di€erent carbohydrate substituted porphyrins were syn-
thesized that show enhanced water solubility due to the
Synthesis
Diarylsubstituted porphyrins are classically synthesized
by using the MacDonald procedure.20 In this method a
bis-formyl substituted dipyrrylmethane is reacted with a
dipyrrylimethane unsubstituted in position 5. The start-
ing dipyrrylimethanes are synthesized by a condensation
reaction of benzaldehyde derivatives with protected
pyrroles. We have already reported about a modi®ca-
tion of this methodology that proceeds under very mild
reaction conditions.21 Using this method the carbo-
hydrate substituted compounds were synthesized in
acceptable yield (Schemes 1 and 2). The starting glyco-
sylated benzaldehyde dimethylacetal (1) was synthesized
by reaction of 4-brommethylbenzaldehyde dimethyl-
acetal with 1,2:3,4-di-isopropylidene-a-d-galactose in
DMF/NaH. The crude reaction product was puri®ed by
column chromatography on silica gel using hexane/
ether (3/1) as eluent. Compound 2 was synthesized by
reaction of the same benzaldehyde derivative with cho-
lesterol in THF/NaH and puri®ed by column chroma-
tography on silica gel (hexane/ether, 3/1). Reaction of
Key words: Porphyrins; carbohydrates; ¯uorescence; photodynamic
therapy.
* Corresponding author.
0968-0896/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved.
PII: S0968-0896(99)00133-9

1858
C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
Coupling of compounds 6 and 7 was done by reaction
with imminium salt 8 in CH2Cl2/CH3CN (1/1) and
subsequent oxidation of the intermediately formed por-
phyrinogene with K3[Fe(CN)6].22 Besides some small
amounts of an etioporphyrin (<1%) two monoaryl
substituted porphyrins 9 (2.4%) and 10 (3.2%) and the
diaryl substituted compound 11 (3.9%) were isolated by
chromatography on silica gel (CH2Cl2). It is important
to notice that neither the bis galactosyl nor the bis cho-
lesteryloxy substituted porphyrin was formed under
these reaction conditions. Formation of monoaryl sub-
stituted porphyrins 9 and 10 is due to an acid induced
fragmentation of the intermediately formed porphyr-
inogene.21 Furthermore, if DDQ was used instead of
K3[Fe(CN)6] as oxidising agent the total porphyrin yield
was increased (15%) and 10 was formed in 11% yield
but 11 was only formed in 1.7% yield. Deprotection of
the carbohydrate moiety of compounds 10 and 11 was
achieved by treatment with CF3COOH/H2O (9/1) in
very good yield. All new compounds were fully char-
Scheme 1. Synthesis of dipyrylmethanes.
1
acterized by H NMR, 13C NMR, mass spectroscopy,
and microanalysts and were found to be analytical pure
as indicated by HPLC and TLC analysis.
Spectroscopic Properties and Aggregation Behaviour
The carbohydrate substituted porphyrins 12 and 13
were soluble in CH2Cl2/CH3OH (1/1) or DMSO and
exhibit strong Soret-absorptions at 402 (e=2.23Â105
1
M
M
cm 1, CH2Cl2/CH3OH) and 409 (e=2.11Â105
1
cm 1, CH2Cl2/CH3OH) nm, respectively. Further-
more four Q-bands were detected in the region between
505 and 630 mn. The half width of the Soret-band was
42 nm for 12 and 45 nm for 13. Thus, the Soret-band is
signi®cantly broadened compared to that of the fully
acetylated compounds 10 (fwhm: 30 nm) and 11 (fwhm:
38 nm). These ®ndings suggest that some aggregation
occurs even in organic solvents. In micellar solution
(CHAPS or SDS) the UV±vis spectra of compound 12
were comparable with the spectrum obtained in
CH2Cl2/CH3OH. For porphyrin 13 a signi®cant broad-
ening of the Soret-absorption was observed and two
new but less intensive absorptions appeared at the red
and blue end of the Soret-band. In CH2Cl2/CH3OH
(1/1) porphyrin 12 exhibits two emission bands at 624
and 688 respectively. For compound 13 these emissions
were found at 630 and 694 nm respectively. The excita-
tion spectra for both compounds were comparable with
the absorption spectra. We furthermore investigated the
aggregation behaviour of compounds 12 and 13 in
water solution. Injection of a DMSO solution of 13 into
water (dilution 1:1000 and 1:5000) led to the formation
of aggregates. The absorption spectrum in water exhi-
bits a split and less intensive Soret-band with peaks
centered at 375 and 436 mn. Thus the blue shift (2025
cm 1) of the Soret-absorption is larger than the red shift
(1640 cm 1). It is important to notice, that both Soret-
absorptions have a di€erent half-width of 5000 and
4700 cm 1, respectively. We furthermore added 13 to a
micellar solution of CHAPS in phosphate bu€ered sal-
ine (PBS) at pH 7 and incubated the solution for 24 h.
Then the surfactant was removed by dialysis and the
Scheme 2. Synthesis of porphyrins.
compounds 1 and 2 with pyrrole 3 was performed in
ethanol/water (90/10) in presence of 2 mL, H2SO4
(concd). The products 4 and 5 separated from the reac-
tion mixture and were isolated by ®ltration in nearly
quantitative yield and high purity. It is interesting to
notice, that the carbohydrate substituted compound 4 is
stable under these very acidic reaction conditions.
Decarboxylation of 4 and 5 was performed in boiling
ethylene glycol under strongly basic conditions. Dipyr-
rylmethanes 6 and 7 were obtained in 99 and 86% yield,
respectively, and used without further puri®cation.

C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
1859
solution was treated with ultrasound to promote the
formation of self-assembling structures. A clear por-
phyrin solution was obtained using this procedure. We
have already reported, that under these conditions por-
phyrinic vesicle like structures were formed as indicated
by light scattering experiments and electron micro-
scopy.19 The optical spectrum of this solution exhibits a
split Soret-band with peaks centred at 386 and 441 nm
(Fig. 1). Thus, the red shift (2250 cm 1) of the Soret-
absorption is larger than the blue shift (1335 cm 1).
Furthermore, both Soret-absorptions have approxi-
mately the same half-width of 5000 cm 1 indicating that
both absorptions were formed by only one type of por-
phyrin aggregate. Thus, the di€erences observed for
wavelength-shift and half-width of the Soret-band indi-
cate, that di€erent forms of aggregates were formed by
using the dilution technique or the ultrasound metho-
dology. Thus, the dilution technique leads to unde®ned
mixtures of aggregates whereas dialysis and ultrasound
treatment leads to de®ned self-assembled structures.
the porphyrin monomer Soret-band (402 nm) was
observed and the two Soret-absorptions of the aggre-
gated system appeared at a methanol concentration of
70% (Fig. 2). Furthermore, two isosbestic points were
detected in the absorption spectrum (Fig. 3). This ®nd-
ing indicates, that the aggregation process is a de®ned
self-assembling process and that formation of di€erent
types of aggregates is not likely. Furthermore, all por-
phyrinic aggregates exhibit no ¯uorescence in water
solution.
Interaction with Liposomes and Lipoproteins
Liposomes were often used as cell membrane models for
the investigation of photophysical and biochemical
properties that are important for the in vivo properties
of new photosensitizers.23 We, therefore, incubated
solutions of 12 and 13 (2.5 mg/mL, see Experimental
for solution preparation) with phosphatidylethanol-
amine (PE) and dimyristoylphosphatidylcholine (DMPC)
liposomes for 24 h at 37ꢀC. The liposome concentration
was varied between 5 and 300 mg/mL. The uptake of the
sensitizers was detected by ¯uorescence spectroscopy.
Whereas no uptake of 13 was observed for both types of
liposomes, compound 12 was eciently incorporated
into the liposomes as indicated by a strong increase in
¯uorescence intensity. The ¯uorescence spectra exhibit
two strong emissions at 625 and 688 nm (Fig. 4). These
emissions are due to the monomer emission of that
porphyrin. Furthermore, the excitation spectrum regis-
tered at 625 and 688 is comparable to the absorption
spectrum produced by porphyrin monomer. Especially
at low liposome concentration a less intensive emission
appeared at 660 nm that is due to porphyrin dimer
formation.24 We also estimated an analytical binding
constant Kb of porphyrin 12 to the two types of lipo-
somes by using the method described by Ehrenberg.25
From a plot of 1/FO versus 1/[Lipid], Kb was found
If compound 12 was added to a CHAPS/PBS-solution,
dialysed and treated with ultrasound also clear por-
phyrinic solutions were obtained. The optical spectrum
shows a split Soret-band with peaks centred at 365
1
(e=0.9Â104 M 1 cm 1) and 447 (e=1.1Â104 M 1 cm
)
nm. Furthermore, three less intensive Q-bands were
observed at 526, 486 and 631 nm. Thus, a signi®cant
exciton splitting of the Soret-absorption is observed also
for this compound. The blue shift (2525 cm 1) is only
slightly larger than the red shift (2505 cm 1). Further-
more, the two Soret-bands have approximately the same
half-width of 5200 cm 1. We also investigated the
aggregation behaviour of compound 12 in methanol/
water mixtures at ®xed porphyrin concentration (2.5 mg/
mL) by recording the absorption spectra. In 100%
methanol, 12 gave a typical porphyrin-type spectrum
with a Soret-band at 402 mn and four Q-bands. If the
proportion of water in the methanol/water mixtures was
increased, a decrease in intensity and a broadening of
1
to be 35.6‹2.1 (mg/mL) for DMPC liposomes and
Figure 2. Aggregation curve of 12 in rnethanol/water mixtures.
Absorbance was detected at 398 nm and corrected for density and
compression changes.
Figure 1. Optical spectra of porphyrin 13 in CHCl3 (a) and PBS-solu-
tion (b).

1860
C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
Figure 5. Plot of 1/Fo versus 1/cLipid for 12 incorporated in PE lipo-
somes at a lipid concentration varied between 5 and 300mg/mL.
Figure 3. Optical spectra of 12 in methanol/water mixtures. Two iso-
sbestic points were detected at 355 and 413 nm.
liposome-porphyrin interaction. Interestingly the stron-
gest binding was observed to VLDL (Kb=64.1‹8.1
(mg/mL) 1. For LDL and HDL, Kb values of 22.6‹0.6
1
1
(mg/mL)
and 5.3‹1.1 (mg/mL)
were observed.
This is an important ®nding because high binding to
LDL and VLDL may cause high selectivity to cancer
cells.
Conclusions
The two investigated glycosylated porphyrins show very
interesting and di€erent self-assembling properties.
Compound 13 bearing a galactosyl and a cholesteryloxy
moiety tends to form very stable vesicle like structures
in aqueous solution. From aggregation studies it is evi-
dent, that the method of aggregate formation is impor-
tant for the formation of porphyrinic vesicles. The
dilution technique leads to a mixture of di€erent aggre-
gates whereas the dialysis and ultrasound treatment led
to vesicle formation. Furthermore, no incorporation of
compound 13 into liposomes and lipoproteins was
observed due to the very high stability of the aggregates.
In marked contrast to this, compound 12, that is less
hydrophobic, shows high binding constants to lipo-
somes and VLDL and LDL. This indicates, that the
structure of the photosensitizer (i.e. the balance between
hydrophilic and hydrophobic moieties) is of consider-
able importance for the uptake into lipoproteins and
cells. Furthermore we can conclude, that compound 12
formed a di€erent type of aggregate than porphyrin 13.
Work is underway in our laboratories to elucidate the
structure of the aggregates by electron micoscopy and
spectroscopic studies.
Figure 4. Fluorescence spectra of 12 in PE liposomes. The liposome
concentration was varied from 5 (lowest curve) to 300 mg/mL (upper
curve). Porphyrin concentration 2.5 mg/mL. Emissions at 625 and 688
are due to porphyrin monomer ¯uorescence, emission at 660 nm is due
to ¯uorescence of porphyrin dimers incorporated in the liposomes.
1
89.4‹5.7 (mg/mL) for PE liposomes (Fig. 5). These
values are signi®cantly higher than those observed for
hematoporphyrin binding to PE liposomes (11.5 (mg/
mL) 1).26 As already mentioned, the interaction of
porphyrinic sensitizers with lipoproteins is of great
importance for cell uptake by receptormediated endo-
cytosis. We, therefore, estimated the binding constants
of 12 to low density lipoproteins (LDL), very low den-
sity lipoproteins (VLDL) and high density lipoproteins
(HDL) by using the same methodology as described for
Experimental
General
Melting points were detected at a Buchi 510 apparatus
and are uncorrected. Column chromatography was
carried out with silica gel 60 mesh size 0.060±0.2 mm

C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
1861
1
(Merck). H NMR und 13C NMR spectra were recor-
Here, FO is the observed ¯uorescence intensity in pre-
sence of lipid, F is the ¯uorescence at full binding and
ded on a Bruker DRX 500 MHz spectrometer or on a
Varian 200 MHz spectrometer in CDCl3 or [D5]-pyri-
dine. Chemical shift values are reported in ppm with
TMS as internal standard. UV±vis spectra were mea-
sured on a Kontron Uvikon 860 spectrometer. Fluores-
cence spectra were measured on a Spex Fluoromax 1
spectro¯uorometer. Mass spectra were obtained from a
VG Analytical VG70:250E spectrometer. Pulse sonica-
tion was done with a Bandelin Sonoplus HD 200
sonicator with a TT 13 Pt-sonotrode. l-a-Dimyristoyl-
phosphatidylcholine (DMPC) was purchased from
Sigma (P6392, 99+%) and E. coli total lipid extract
(PE, Sigma, type IX) was used for preparation of PE
liposomes according to a procedure given in the litera-
ture.27,28 Human lipoproteins (VLDL, LDL and HDL)
were purchased from Sigma and used without further
puri®cation.
1
[Lipid] is the lipid concentration expressed in mg/mL.
4-((1,2:3,4-Di-O-isopropyliden-ꢀ-D-galactopyranos-6-oxy)-
methyl)benzaldehyde dimethylacetal (1). In a dry round
bottom ¯ask 0.4 g (10 mmol) of NaH (60%) were
added under nitrogen to 20 mL of dry DMF. Then 1.16
g (4.46 mmol) 1,2:3,4-di-O-isopropylidene-a-d-galacto-
pyranose dissolved in 2 mL DMF were added. After
5 min 1 g (4.46 mmol) 4-(brommethyl)benzaldehyde
dimethylacetal was added. The reaction mixture was
stirred for 20 h at room temperature. Then the reaction
mixture was carefully poured into 200 mL, water and
extracted with ether (3Â50 mL). The combined organic
phases were washed with water (5Â50 mL), dried
(Na2SO4) and the solvent was evaporated. The residue
was chromatographed on a silica gel column using hex-
ane/ether (3/1) as eluent yielding 0.86 g (45%) of oily 1.
52:00ꢀ (c 1, CHCl3). 1H NMR (200 MHz,
CDCl3, 300 K) d 1.34 (s, 6H, iPr-CH3), 1.44, 1.55 (2 s,
6H, iPr-CH3),3.32 (s, 6H, -CH(OCH3)2), 3.62 (dd, 1H,
J5/6b=6.8, J6a/6b=10.4 Hz, Gal-6b), 3.68 (dd, 1H,
20
d
‰aŠ
Formation of porphyrin aggregates
Porphyrins 12 or 13 (1 mg), respectively, and 100 mg
CHAPS was dissolved in 10 mL PBS solution at pH 7
and stirred for 24 h at 40ꢀC. The solution was ®ltered
through a 400 nm ®lter and dialysed 10 times in a 3±15
mL Slide-A-Lyser cassette (Pierce) against a 1000-fold
volume of PBS solution. The solution was removed
from the cassette and diluted to 100 mL, with PBS
solution and pulse sonicated (50% pulse, 40% intensity)
until clear solutions were obtained. These solutions were
used for measurements of the binding constants.
J5/6a=5.4, J6/6b=10.4 Hz, Gal-6a), 4.02 (m, 1H, J4/5
2.0, J5/6a=5.4, J5/6b=6.8 Hz, Gal-5), 4.26 (dd, 1H, J3/4
=
=
8.1, J4/5=2.0 Hz, Gal-4), 4.30 (dd, 1H, J1/2=4.9,
J2/3=2.5 Hz, Gal-2), 4.54 (d, 1H, J=12.2 Hz, Aryl-CH2-
O-), 4.60 (dd, 1H, J2/3=2.5, J3/4=8.1 Hz, Gal-3), 4.63
(d, 1H, J=12.2 Hz, Aryl-CH2-O-), 5.39 (s, 1H,
-CH(OCH3)2), 5.55 (d, 1H, J1/2=4.9 Hz, Gal-1), 7.35
(d, 2H, J=8.3 Hz, Aryl), 7.42 (d, 2H, J=8.3 Hz, Aryl).
13C NMR (50 MHz, CDCl3, 300 K) d 24.42, 24.93,
25.97, 26.09 (4 q, -C(CH3)2), 52.63 (q, -CH(OCH3)2),
66.86 (d, Gal-5), 68.88 (t, Gal-6), 70.55 (d, Gal-3,4),
70.62 (d, Gal-3,4), 71.15 (d, Gal-2), 72.98 (t Aryl-CH2-
O), 96.33 (d, Gal-1), 102.96 (d, -CH(OCH3)2), 108.54,
109.20 (2 s, -C(CH3)2), 126.69 (d, Aryl), 127.51 (d,
Aryl), 137.32 (s, Aryl), 138.58 (s, Aryl). MS (70 eV) m/z
424 (M+, 5), 393 (M+-CH3O+, 50), 335 (15), 227 (15),
223 (20), 181 (15), 165 (M+-Aryl-CH(OCH3)2+, 100),
149 (35), 134 (35), 119 (30), 105 (30), 91 (C7H+7 , 55), 85
(25), 71 (40), 59 (45). IR (KBr) n 2971, 1450, 1369, 1250,
1164, 1080, 997, 887 cm 1. Anal. calcd for C22H32O8
(424.5): C, 62.25; H, 7.60. Found: C, 62.18; H, 7.63.
Liposome preparation
To a PBS solution (2 mL, pH 7) E. coli lipid (50 mg) or
DMPC (50 mg) was added. After incubation for 24 h
the suspension was dialysed ®ve times in a 0.5±3 mL
Slide-A-Lyser-cassette against a 500-fold volume of PBS
solution. The solution was removed from the cassette
and diluted with PBS solution to a total volume of 10
mL. This liposome stock solution was stored in liquid
nitrogen until use. Before use the solutions were care-
fully warmed to room temperature and pulse sonicated.
From this solution aliquots were taken for incubation
with porphyrin aggregate solution.
4-(Cholesteryloxymethyl)benzaldehyde dimethylacetal (2).
In a 100 mL, round bottom ¯ask 0.3 g (7.5 mmol) NaH
(60%) were added under nitrogen to 25 mL, of dry
THF. Then 1.48 g (4.10 mmol) cholesterol was added
and the mixture was heated to 80ꢀC for 2 h. Then 1 g
(4.46 mmol) 4-(brommethyl)benzaldehyde dimethylace-
tal was added and the mixture stirred at 80ꢀC for 20 h.
Then the mixture was poured carefully into 200 mL, of
water and extracted with ether (3Â50 mL). The organic
layer was washed with water (3Â50 mL) and dried
(Na2SO4). The solvent was removed and the residue
chromatographed on a silica gel column (3Â30 cm)
using hexane/ether (3/1) as eluent yielding 3.03 g (46%)
Measurement of analytical binding constants
The measurement of the analytical binding constant for
liposomes, LDL, VLDL and HDL followed always the
same procedure. The lipid concentration was varied
between 5 and 300 mg/mL. Incubation of the lipid
solution with porphyrinic aggregates was performed in
the dark for at least 24 h at 37ꢀC. The initial porphyrin
concentration in the aggregate solutions was 10 mg/mL.
This solution (500 mL) was diluted with lipid solution
and PBS solution to a total volume of 2 mL. The
increase of ¯uorescence intensity was registered and an
analytical binding constant was estimated from the fol-
20
ꢀ
2. Fp: 117±120ꢀC. ‰aŠ
19.1 (c 1, CHCl3). H NMR
1
d
lowing equation by a plot of 1/FO versus 1/[Lipid] and
1 25
(200 MHz, CDCl3, 300 K) d 0.67±1.61 (m, 20H, Chol),
overlapped by 0.67 (s, 3H, Chol-10-CH3), 0.86 (d, 6H,
J=6.3 Hz, Chol-22-(CH3)2), 0.91 (d, 3H, J=6.3 Hz,
Chol-18-CH3), 1.01 (s, 3H, Chol-13-CH3), 1.80±2.17
expressed in (mg/mL)
.
1=FO ˆ 1=ꢀKbF ‰LipidŠ† ‡ 1=F
1
1

1862
C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
(m, 5H, Chol), 2.26±2.40 (m, 4H, Chol), 3.31 (s, 6H,
-CH(OCH3)2),4.56 (s, 2H, Aryl-CH2-O-), 5.33 (d, 1H,
J=6 Hz, Chol-4), 5.39 (s, 1H, -CH(OCH3)2), 7.31 (d,
2H, J=8.3 Hz, Aryl) 7.42 (d, 2H, J=8.3 Hz, Aryl). 13C
NMR (50 MHz, CDCl3, 300 K) d 11.86 (q, Chol-18),
18.71 (q, Chol-21), 19.41 (q, Chol-19), 21.05 (t, Chol-
11), 22.56 (q, Chol-26), 22.84 (q, Chol-27), 23.82 (t,
Chol-23), 24.30 (t, Chol-15), 28.02 (d, Chol-25), 28.24 (t,
Chol-12), 28.43 (t, Chol-2), 31.87 (d, Chol-8), 31.93 (t,
Chol-7), 35.78 (d, Chol-20), 36.16 (t, Chol-22), 36.89 (s,
Chol-10), 37.20 (t, Chol-1), 39.13 (t, Chol-4), 39.50 (t,
Chol-24), 39.76 (t, C-16), 42.31 (s, Chol-13), 50.14 (d,
Chol-9), 52.60 (q, -CH(OCH3)2), 56.10 (d, C-17), 56.76
(d, Chol-14), 69.64 (t, Aryl-CH2-O-), 78.60 (d, Chol-3),
102.96 (d, CH(OCH3)2), 121.61 (d, Chol-6), 126.72 (d,
Aryl), 127.38 (d, Aryl), 137.16 (s, 7-7 Aryl), 139.31 (s,
Aryl), 140.88 (s, Chol-5). MS (FAB) m/z 550 (M+, 15)
520 (M+-CH2O, 100), 369 (M+-O-Aryl-CH(OCH3)+2 ,
50). IR (KBr) n 2926, 1458, 1358, 1193, 1086, 1044, 805
cm 1. UV (CH2Cl2) lmax 229 (3.345), 249 (3.159) nm.
Anal. calcd for C37H58O3 (550.9): C, 80.67; H, 10.6.
Found: C, 80.44; H, 10.41.
1091, 1065, 1000 cm 1. UV (CH2Cl2) lmax 228 (4.188),
276 (4.516), 282 (4.515) run. Anal. calcd for
C40H54O10N2 (722.9): C, 66.46; H, 7.53; N, 3.87. Found:
C, 66.40; H, 7.42; N, 3.81.
4-(Cholesteryloxymethyl)phenyl-bis-(5-ethoxycarbonyl-4-
ethyl-3-methyl-2-pyrryl)methane (5). Benzaldehyde deri-
vative 2 (0.78 g, 1.42 mmol) was dissolved in 20 mL
ethanol (90%). Then pyrrole 3 (0.52g, 2.84 mmol) and 2
mL H2SO4 (concd.) were added. The mixture was stir-
red at room temperature for 24 h. The product sepa-
rated and was isolated by ®ltration, washed with water
(100 mL) and with cold ether and pentane. Recrystalli-
sation (hexane/ether) a€orded 1.03 g (86%) of 5. Fp
20
d
168±169ꢀC. ‰aŠ
10.00ꢀ (c 1, CHCl3). H NMR (200
1
MHz, CDl3, 300 K) d 0.60±2.40 (m, 29H, Chol), over-
lapped by: 0.61 (s, 3H, Chol-10-CH3), 0.79 (d, 6H,
J=7.3 Hz, Chol-22-(CH3)2), 0.84 (d, 3H, J=6.4 Hz,
Chol-18-CH3), 0.94 (s, 3H, Chol-13-CH3), 1.03 (t, 6H,
J=7.9 Hz, Pyrr-CH2-CH3), 1.23 (t, 6H, J=7.2 Hz,
-CO2-CH2-CH3), 1.71 (s, 6H, Pyrr-CH3), 2.65 (q, 4H,
J=7.9 Hz, Pyrr-CH2-CH3), 4.16 (q, 4H, J=7.2 Hz,
-CO2-CH2-CH3), 4.47 (s, 2H, Aryl-CH2-O-), 5.29 (d, 1H,
J=6.0 Hz, Chol-4), 5.41 (s, 1H, -CH(Pyrr)2), 6.99 (d,
2H, JAryl=8.3 Hz, Aryl) 7.24 (d, 2H, JAryl=8.3 Hz,
8.23 (br s, 2H, NH). 13C NMR (50 MHz, CDCl3, 300
K) d 8.56 (q, Pyrr-CH2-CH3), 11.84 (q, Chol-18), 14.43
(q, Pyrr-CH3), 15.09 (q, -CO2-CH2-CH3), 18.44 (t, Pyrr-
CH2-CH3), 18.69 (q, Chol-21), 19.39 (q, Chol-19), 21.03
(t, Chol-11), 22.54 (q, Chol-26), 22.82 (q, Chol-27),
23.80 (t, Chol-23), 24.27 (t, Chol-15), 28.00 (d, Chol-25),
28.22 (t, Chol-12), 28.41 (t, Chol-2), 31.85 (d, Chol-8),
31.91 (t, Chol-7), 35.76 (d, Chol-20), 36.17 (t, Chol-22),
36.86 (s, Chol-10), 37.18 (t, Chol-1), 39.11 (t, Chol-4),
39.48 (t, Chol-24), 39.73 (t, Chol-16), 40.84 (d, -CH
(Pyrr)2), 42.29 (s, Chol-13), 50.11 (d, Chol-9), 56.11 (d,
Chol-17), 56.74 (d, Chol-14), 59.74 (t, -CO2-CH2-CH3),
69.52 (t, Aryl-CH2-O-), 78.89 (d, Chol-3), 117.01 (s,
Pyrr), 117.10 (s, Pyrr), 121.64 (d, Chol-6), 128.21 (d,
Aryl), 128.27 (d, Aryl), 131.68 (s, Pyrr), 134.30 (s, Aryl),
137.99 (s, Aryl), 138.31 (s), 140.83 (s, Chol-5), 161.47 (s,
CO2-CH2-CH3). MS (70 eV) m/z 849 (M+, 15), 668
(M+-C10H15O2N, 20), 464 (M+C27-H45O, 60), 373 (40),
327 (100). IR (KBr) n 3318, 2923, 1689, 1646, 1456,
1371, 1267, 1235, 1141, 1084, 1016, 772 cm 1. Anal.
calcd for C55H80N2O5 (849.3): C, 77.79; H, 9.50; N,
3.30. Found: C, 77.68; H, 9.38; N 3.48.
[4-((1,2:3,4-Di-O-isopropylidene-ꢀ-D-galactopyranos-6-
oxy)methyl)phenyl]-bis-(5-ethoxycarbonyl-4-ethyl-3-meth-
yl-2-pyrryl)methane (4). Benzaldehyde derivative 1 (0.86
g, 2.03 mmol) was dissolved in 20 mL ethanol (95%).
Then pyrrole 3 (0.73g, 4.05 mmol) and 2 mL H2SO4
(conc.) were added. The mixture was stirred at room
temperature for 24 h. Then 100 mL CH2Cl2 was added
and the mixture was washed with NaHCO3-solution
and water. The organic layer was separated and dried
(Na2SO4). The solvent was evaporated and the residue
was chromatographed on a silica gel column (3Â30 cm)
using CH2Cl2 as eluent. Yield 1.08 g (74%) of 4. Fp 71±
20
d
ꢀ
73ꢀC. ‰aŠ
12.8 (c 1, CHCl3). H NMR (200 MHz,
1
CDCl3, 300 K) d 1.07 (t, 6H, J=7.3 Hz, Pyrr-CH2-
CH3),130 (t, 6H, J=7.1 HZ, -CO2-CH2-CH3), 1.33 (s,
6H, iPr-CH3), 1.45, 1.54 (2 s, 6H, iPr-CH3), 1.79 (s, 6 H,
Pyrr-CH3), 2.73 (q, 4H, J=7.3 Hz, Pyrr-CH2-CH3),
3.65 (dd, 1H, J5/6b=6.4, J6a/6b=10.1 Hz, Gal-6b) 3.72
(dd, 1H, J5/6a=5.9, J6a/6b=10.1 Hz, Gal-6a), 4.03 (m,
1H, J4/5=2.0, J5/6a=5.9, J5/6b=6.4 Hz, Gal-5), 4.23 (q,
4H, J=7.1 Hz, -CO2-CH2-CH3), 4.28 (dd, 1H, J3/4
7.6, J4/5=2.0 Hz, Gal-4), 4.32 (dd, 1H, J1/2=4.9, J2/3
=
=
2.0 Hz, Gal-2), 4.53 (d, 1H, J=11.1 Hz, Aryl-CH2-O-),
4.60 (dd, 1H, J2/3=2.0, J3/4=7.6 Hz, Gal-3), 4.62 (d,
1H, J=11.1 Hz, Aryl-CH2-O-), 5.49 (s, 1H, -CH
(Pyrr)2), 5.55 (d, 1H, J1/2=4.9 Hz, Gal-1), 7.06 (d, 2H,
JAryl=7.8 Hz, Aryl), 7.31 (d, 2H, JAryl=7.8 Hz, Aryl),
8.35 (br s, 2H, NH). 13C NMR (50 MHz, CDCl3, 300
K) d 8.61 (q, Pyrr-CH2-CH3), 14.36 (q, Pyrr-CH3),
15.08 (q, -CO2-CH2-CH3), 18.45 (t, Pyrr-CH2-CH3),
24.42, 24.89, 25.96, 26.09(4 q, -C(CH3)2), 40.51 (d, -CH
(Pyrr)2), 59.72 (t, CO-CH2-CH3), 66.86 (d, Gal-5), 69.10
(t, Gal-6), 70.55 (d, Gal-3,4), 70.61 (d, Gal-3,4), 71.15
(d, Gal-2), 72.85 (t, Aryl-CH2O-), 96.36 (d, Gal-1),
108.51, 109.20 (2 s, -C(CH3)2), 117.06 (s, Pyrr), 117.22
(s, Pyrr), 128.16 (d, Aryl), 131.92 (s, Pyrr), 134.19 (s,
Aryl), 137.47 (s, Aryl), 138.54 (s, Pyrr), 161.61 (s, CO2-
CH2-CH3). MS (FAB) m/z 723 (M+, 100), 543 (M+
-C10H14O2N, 50), 463 (M+-C12H20O6, 90), 327 (45). IR
(KBr) n 3421, 2960, 1683, 1646, 1447, 1377, 1240, 1162,
4-(1,2:3,4)-Di-O-isopropyliden-ꢀ-D-galactopyrons-6-oxy-
methyl)phenyl-bis-(4-ethyl-3-methyl-2-pyrryl)methane
(6). Compound 4 (0.93 g, 1.29 mmol) and NaOH (2 g)
was dissolved by heating in 40 mL ethylene glycol and
re¯uxed for 20 min. The reaction mixture was cooled
down and poured into 200 mL water. Then 150 mL
ether was added and the organic layer separated and
dried (Na2SO4) and the solvent evaporated. Yield 0.74 g
1
(99%). H NMR (200 MHz, CDCl3, 300 K) d 1.16 (t,
6H, J=7.5 Hz, Pyrr-CH2-CH3), 1.33 (s, 6H, iPr-CH3),
1.44, 1.53 (2 s, 6H, iPr-CH3), 1.79 (s, 6H, Pyrr-CH3),
2.42 (q, 4H, J=7.5 Hz, Pyrr-CH2-CH3), 3.65 (dd, 1H,
J5/6b=6.4, J6a/6b=9.6 Hz, Gal-6b), 3.68 (dd, 1H, J5/6a
5.1, J6a/6b=9.6 Hz, Gal-6a), 4.02 (m, 1H, J4/5=1.9,
J5/6a=5.1, J5/6b=6.4 Hz, Gal-5), 4.26 (dd, 1H, J3/4
=
=

C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
1863
7.9, J4/5=2.0 Hz, Gal-4), 4.30 (dd, 1H, J1/2=5.0, J2/3
=
was added. After 10 min 10 g of K3[Fe(CN)6] were
added and the reaction mixture was re¯uxed for 6 h.
The solution was cooled down and K3[Fe(CN)6] was
removed by ®ltration. The solution was washed with
water (3Â50 mL) and dried (Na2SO4). The solvent was
evaporated and the residue chromatographed on a silica
gel column (5Â60) using CH2Cl2 as eluent. Four por-
phyrinic fractions were collected. The ®rst one was
etioporphyrin IV, the second was porphyrin 9 followed
by 10 and 11.
2.5 Hz, Gal-2), 4.53 (d, 1H, J=11.7 Hz, Aryl-CH2-O-),
4.57 (d, 1H, J=11.7 Hz, Aryl-CH2-O-), 4.60 (dd, 1H,
J2/3=2.5, J3/4=7.9 Hz, Gal-3), 5.48 (s, 1H, -CH
(Pyrr)2), 5.54 (d, 1H, J1/2=5.0 Hz, Gal-1), 6.34, (d, 2H,
J=1.8 Hz, -C=CH-NH-), 7.08 (d, 2H, JAryl=8.1 Hz,
Aryl), 7.28 (d, 2H, JAryl=8.1 Hz, Aryl), 7.33 (br, 2H,
NH). 13C NMR (50 MHz, CDCl3, 300 K) d 8.96 (q,
Pyrr-CH2-CH3), 14.19 (q, Pyrr-CH3), 18.77 (t, Pyrr-
CH2-CH3), 24.45, 24.93, 26.00, 26.12 (4 q, -C(CH3)2),
40.70 (d, -CH(Pyrr)2), 66.86 (d, Gal-5), 69.04 (t, Gal-6),
70.55 (d, Gal-3,4), 70.65 (d, Gal-3,4), 71.18 (d, Gal-2),
73.13 (t, Aryl-CH2O-), 96.36 (d, Gal-1), 108.57, 109.24
(2 s, -C(CH3)2), 112.01 (d, -C=CH-NH-), 113.59 (s,
Pyrr), 125.99 (s, Pyrr), 127.66 (s, Pyrr) 128.17 (d, Aryl),
128.35 (d, Aryl), 136.62 (s, Aryl), 141.29 (s, Aryl). MS
(FAB) m/z 578 (M+, 45), 470 (M+-C7H10N, 100), 319
Etioporphyrin-IV. Yield: 9.5 mg (0.6%). Fp >270ꢀC. 1H
NMR (500 MHz, CDCl3, 300 K) d 3.727 (br s, 2H,
NH), 1.937 (t, 12H, J=7.33 Hz, Por-CH2-CH3), 3.682
(s, 12H, Por-CH3), 4.152 (q, 8H, J=7.33 Hz, Por-CH2-
CH3), 10.124 (s, 4H, Por-5, Por-10, Por-15, Por-20). 13
C
NMR (125 MHz, CDCl3, 300 K) d 11.630 (q, Por-CH3),
11.675 (q, Por-CH3), 17.823 (q, Por-CH2-CH3), 19.949
(t, Por-CH2-CH3), 19.996 (t, Por-CH2-CH3), 96.234 (d,
Por), 96.316 (d, Por), 96.436 (d, Por), 135.076 (s, Por),
142.177 (s, Por), 144.165 (s, Por), 144.354 (s, Por). MS
(FAB) m/z 479 (M++1). IR (KBr) 3407, 2952, 1446,
1256, 1216, 1184, 1090, 1052, 951, 829, 797, 738, 674
cm 1. UV (CH2Cl2) lmax 396 (5.136), 496 (4.027), 529
(3.873), 565 (3.659), 618 (3.501).
(M+-C12H20O6, 20), 210 (40). IR (KBr) n 3368, 2951,
1707, 1452, 1377, 1251, 1163, 1064, 998, 906, 728 cm
Anal. calcd for C34H46O6N2 (578.7): C, 70.56; H, 8.01;
N, 4.84. Found: C, 60.28; H, 6.86; N, 4.35
1
.
Synthesis of 4-(cholesteryloxymethyl)phenyl-bis-(4-ethyl-
3-methyl-2-pyrryl)methane (7). As described for the
synthesis of 6, 0.79 g (0.93 mmol) ꢀof 5 were reacted.
1
Yield 0.64 g (86%) of 7. Fp 75±82 C. H NMR (200
MHz, CDCl3, 300 K) d 0.60±2.40 (m, 29H, Chol),
overlapped by 0.67 (s, 3H, Chol-10-CH3), 0.78 (d, 6H,
J=7.3 Hz, Chol-22-(CH3)2), 0.84 (d, 3H, J=6.4 Hz,
Chol-18-CH3), 0.93 (s, 3H, Chol-13-CH3), 1.00 (t, 6H,
J=8.6 Hz, Pyrr-CH2-CH3), 1.79 (s, 6H, Pyrr-CH3), 2.72
(q, 4H, J=7.3 Hz, Pyrr-CH2-CH3), 4.51 (s, 2H, Aryl-
CH2-O-), 5.35 (d, 1H, J=6 Hz, Chol-4), 5.47 (s, 1H,
-CH(Pyrr)2), 6.35 (d, 2H, J=1.5 Hz, -C=CH-NH-),
7.09 (d, 2H, JAryl=7.8 Hz, Aryl), 7.2 (d, 2H, JAryl=7.8
Hz, Aryl), 7.30 (br s, 2H, NH). 13C NMR (50 MHz,
CDCl3, 300 K) d 8.92 (q, Pyrr-CH2-CH3), 11.86 (q,
Chol-18), 14.16 (q, Pyrr-CH3), 18.52 (t, Pyrr-CH2-CH3),
18.71 (q, Chol-21), 19.37 (q, Chol-19), 21.07 (t, Chol-
11), 22.56 (q, Chol-26), 22.81 (q, Chol-27), 23.82 (t,
Chol-23), 24.30 (t, Chol-15), 28.02 (d, Chol-25), 28.24 (t,
Chol-12), 28.42 (t, Chol-2), 31.90 (d, Chol-8), 31.96 (t,
Chol-7), 35.78 (d, Chol-20), 36.19 (t, Chol-22), 36.89 (s,
Chol-10), 37.23 (t, Chol-1), 39.12 (t, Chol-4), 39.50 (t,
Chol-24), 39.79 (t, Chol-16), 40.74 (d, -CH(Pyrr)2),
42.31 (s, Chol-13), 50.20 (d, Chol-9), 56.16 (d, Chol-17),
56.79 (d, Chol-14), 69.70 (t, Aryl-CH2-O-), 78.91 (d,
Chol-3), 111.95 (d, -CˆCH-NH-), 113.56 (s, Pyrr)
121.67 (d, Chol-6), 126.02 (s, Pyrr), 127.66 (s, Pyrr)
128.07 (d, Aryl), 128.39 (d, Aryl), 134.38 (s, Aryl),
137.79 (s, Aryl), 138.31 (s), 140.83 (s, Chol-5). MS (70
eV) m/z 704 (M+, 20), 596 (M+-C7H10N, 100), 319
(M+-C27H45O, 35). IR (KBr) n 3415, 2921, 1678, 1454,
1266, 1075 cm 1. Anal. calcd for C49H72O (705.1): C,
70.29; H, 10.29; N, 3.97. Found: C, 70.11; H, 9.98; N,
4.01.
5-(4-Cholesteryloxybenzyl)-2,8,13,17-tetraethyl-3,7,12,18-
tetramethyl-porphyrin (9). Yield: 57.2 mg (2.4%). Fp
228±242ꢀC. 1H NMR (500 MHz, CDCl3, 300 K) d
3.091 (br s, 2H, NH), 0.850±1.800 (m, 22H, Chol),
overlapped by: 0.726 (s, 3H, Chol-18), 0.983 (d, 6H,
J=7.58 Hz, Chol-26 u. Chol-27), 0.996 (d, 3H, J=6.51
Hz, Chol-21),1.106 (s, 3H, Chol-19), 1.845 (t, 6H,
J=7.37 Hz, Por-CH2-CH3), 1.957 (t, 6H, J=7.37 Hz,
Por-CH2-CH3), 2.037±2.175 (m, 2H, Chol-2-H) 2.424±
2.628 (m, 2H, Chol-24), 2.554 (s, 6H, Por-CH3), 3.507±
3.515 (m, 1H, Chol-3), 3.701 (s, 6H, Por-CH3), 4.084±
4.173 (m, 8H, Por-CH2-CH3), 4.993 (s, 2H, Aryl-CH2-
O-), 5.435 (m, 1H, Chol-4), 7.778 (d, 2H, JAryl=7.62
Hz, Aryl), 8.106 (d, 2H, JAryl=7.62 Hz, Aryl), 10.006 (s,
1H, Por-H-15), 10.225 (s, 2H, Por-10, Por-20). 13C
NMR (125 MHz, CDCl3, 300 K) d 11.495 (q, Por-CH3),
11.724 (q, Chol-18), 14.675 (q, Por-CH3), 17.482 (q,
Por-CH2-CH3), 17.603 (cl, Por-CH2-CH3), 18.628 (q,
Chol-21), 19.309 (q, Chol-19),19.738 (t, Por-CH2-CH3),
19.831 (t, Por-CH2-CH3), 20.944 (t, Chol-11), 22.508 (q,
Chol-26), 22.759 (q, Chol-27), 23.821 (t, Chol-23),
24.154 (t, Chol-15), 27.962 (d, Chol-25), 28.120 (t, Chol-
12), 28.584 (t, Chol-2), 31.764 (d, Chol-8), 31.798 (t,
Chol-7), 35.702 (d, Chol-20), 36.114 (t, Chol-22), 36.814
(s, Chol-10), 37.240 (t, Chol-1), 39.303 (t, Chol-4), 39.466
(t, Chol-24), 39.644 Chol-16), 42.182 (s, Chol-13),
50.048 (d, Chol-9), 56.053 (d, Chol-17), 56.590 (d, Chol-
14), 70.035 (t, Aryl-CH2-O-), 78.880 (d, Chol-3), 95.118
(d, Por-15), 96.293 (d, Por-10, Por-20), 118.869 (s, Por-
5), 121.516 (d, Chol-6), 126.419 (d, Aryl), 132.878 (d,
Aryl) 132.921 (s, Por), 134.360 (s, Por), 135.538 (s, Por),
136.176 (s, Aryl), 139.407 (s, Aryl), 139.503 (s, Por),
140.852 (s, Chol-5), 141.522 (s, Por), 141.705 (s, Por),
141.791 (s, Por), 142.605 (s, Por), 142.932 (s, Por),
143.791 (s, Por), 144.050 (s, Por), 144.187 (s, Por),
144.351 (s, Por), 144.458 (s, Por), 145.346 (s, Por). MS
(70 eV) m/z 955 (M++1, 100), 584 (M+-C27H47, 20).
Synthesis of porphyrins
Imminiumion 8 (0.61 g, 5 mmol) was dissolved in a
mixture of CH3CN and CH2Cl2 (1/1). Then 1.45 g (2.5
mmol) of 6 was added and the mixture was stirred for 5
min at room temperature. Then 1.76 g (2.5 mmol) of 7

1864
C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
IR (KBr) n 3418, 2945, 1601, 1461, 1442, 1363, 1079,
1054, 948, 824, 737 cm 1. UV (CH2Cl2) lmax 404
(5.261), 503 (4.169), 536 (3.822), 570 (3.803), 622 (3.351).
Anal. calcd for: C66H88N4OÂH2O (971.6): C, 81.60; H,
9.34; N, 5.76. Found: C, 81.79; H, 9.23; N, 5.67.
7.752 (d, 2H, JAry12=7.47 Hz, Aryl), 8.061 (d, 2H,
JAryl2=7.47 Hz, Aryl), 8.069 (d, 2H, JAryl1=7.53 Hz,
Aryl), 10.263 (s, 2H, Por-10, Por-20). 13C NMR (125
MHz, CDCl3, 300 K) d 11.853 (q, Chol-18), 14.527 (q,
Por-CH3), 14.576 (q, Por-CH3), 17.570 (q, Por-CH2-
CH3), 18.721 (q, Chol-21), 19.454 (q, Chol-19), 19.936
(t, Por-CH2-CH3), 21.086 (t, Chol-11), 22.581 (q, Chol-
26), 22.837 (q, Chol-27), 23.865 (t, Chol-23), 24.288 (t,
Chol-15), 24.569 (q, iPr-C-(CH3)2), 24.995 (q, iPr-C-
(CH3)2), 26.096 (q, iPr-C-(CH3)2), 26.197 (q, iPr-C-
(CH3)2), 28.030 (d, Chol-25), 28.234 (t, Chol-12), 28.702
(t, Chol-2), 31.909 (d, Chol-8), 31.972 (t, Chol-7), 35.793
(d, Chol-20), 36.191 (t, Chol-22), 36.958 (s, Chol-10),
37.388 (t, Chol-1), 39.409 (t, Chol-4), 39.532 Cho-24),
39.783 (t, Chol-16), 42.313 (s, Chol-13), 50.212 (d, Chol-
9), 56.155 (d, Chol-17), 56.760 (d, Chol-14), 67.131 (d,
Gal-5), 69.003 (t, Gal-6), 70.158 (t, Aryl-CH2-O-Chol),
70.685 u. 70.785 (d, Gal-3 u. Gal-4), 71.409 (d Gal-2),
73.285 (t, Aryl-CH2-O-Gal), 79.005 (d, Chol-3), 96.405
(d, Por-10 u. Por-20), 96.504 (d, Gal-1), 108.655 (s, iPr-
C-(CH3)2), 109.363 (s, iPr-C-(CH3)2), 117.769 (s, Por),
117.832 (s, Por), 121.658 (d, Chol-6), 126.525 (d, Aryl),
126.690 (d, Aryl), 132.827 (d, Aryl), 135.899 (s, Aryl),
138.446 (s, Aryl), 139.429 (s, Aryl), 141.005 (s, Chol-5),
141.005 (s, Por), 144.547 (s, Por), 145.177 (s, Por),
145.209 (s, Por). MS (FAB) m/z 1300 (M++1, 100). IR
(KBr) n 3399, 2947, 1462, 1440, 1369, 1249, 1204, 1065,
995, 760 cm 1. UV (CH2Cl2) lmax 408 (5.329), 506
(4.217), 539 (3.690), 573 (3.820), 625 (2.954). Anal. calcd
for C85H112N4O7ÂH2O (1319.9): C, 77.35; H, 8.71; N,
4.24. Found: C, 76.99; H, 8.79; N, 4.06.
5-[4-(1,2;3,4-Di-O-isopropyliden-ꢀ-D-galactopyranos-6-
oxy)benzyl]-2,8,13,17-tetraethyl-3,7,12,18-tetramethyl-
porphyrin (10). Yield: 66.1 mg (3.2%). Fp 159±162ꢀC
1H NMR (500 MHz, CDCl3, 300 K) d 3.2 (br s, 2H,
NH), 1.39, 1.43, 1.55, 1.65 (4 s, 12H, iPr-CH3), 1.75 (t,
6H, J=7.6 Hz, Por-CH2-CH3), 1.87 (t, 6H, J=7.3 Hz,
Por-CH2-CH3), 2.46, (s, 6H, Por-CH3), 3.64 (s, 6H, Por-
CH3), 3.90 (dd, 1H, J5/6b=6.4, J6a/6b=11.2 Hz, Gal-6b),
3.92 (dd, 1H, J5/6a=5.8, J6a/6b 11.2 Hz, Gal-6a), 3.99±
4.12 (m, 8H, Por-CH2-CH3), 4.19 (m, 1H, J4/5=2.0,
J5/6a=5.8, J5/6b=6.4 Hz, Gal-5), 4.39 (dd, 1H, J1/2=4.9,
J2/3=2.4 Hz, Gal-2), 4.44 (dd, 1H, J3/4=7.8, J4/5=2.0
Hz, Gal-4), 4.71 (dd, 1H, J2/3=2.4, J3/4=7.8 Hz, Gal-
3), 4.97 (d, 1H, J=12.5 Hz, Aryl-CH2-O-), 5.00 (d, 1H,
J=12.5 Hz, Aryl-CH2-O-), 5.66 (d, 1H, J1/2=4.9 Hz,
Gal-1), 7.72 (d, 2H, J=7.3 Hz, Aryl), 8.03 (d, 2H,
J=7.3 Hz, Aryl), 9.94 (s, 1H, Por-15), 10.15 (s, 2H, Por-
10, Por-20). 13C NMR (125 MHz, CDCl3, 300 K) d
11.62 (q, Por-CH3), 14.75 (q, Por-CH3), 17.62 (q, Por-
CH2-CH3), 19.92 (t, Por-CH2-CH3), 24.56, 25.00, 26.11,
26.20 (4 q, iPr-(CH3)2), 67.12 (d, Gal-5), 68.95 (t, Gal-
6), 70.65 u. 70.75 (d, Gal-3 u. Gal-4), 71.38 (d, Gal-2),
73.28 (t, Aryl-CH2-O-), 95.24 (d, Por-15), 96.41 (d, Gal-
1), 96.50 (d, Por-10 u. Por-20), 108.68, 109.37 (2 s, iPr-
C(CH3)2), 118.90 (S, Por), 126.19 (d, Aryl), 126.70 (d,
Aryl), 132.98 (d, Aryl), 134.49 (s, Por), 135.66 (s, Por),
136.26 (s, Aryl), 138.43 (s, Aryl), 141.62 (s, Por), 141.84
(s, Por), 141.97 (s, Por), 144.14 (s, Por). MS (FAB) m/z
828 (M++1, 100). IR (KBr) n 3410, 2948, 1687, 1626,
1447, 1367, 1250, 1205, 1158, 1088, 1061, 994, 893, 825,
778, 671 cm 1. UV (CH2Cl2) lmax 402 (5.218), 501
(4.130), 535 (3.771), 570 (3.756), 622 (3.230). Anal. calcd
for C51H62N4O6 (827.1): C, 74.06; H, 7.56; N, 6.78.
Found: C, 73.97; H, 7.87; N, 5.91.
5-[4-ꢀ/ꢁ-D-Galactopyranos-6-oxy)benzyl]-2,8,13,17-tetra-
ethyl-3,7,12,18-tetramethyl-porphyrin (12). Porphyrin 10
(55 mg, 0.066 mmol) was dissolved in 5 mL TFA (90%)
and stirred for 20 min at room temperature. Then the
mixture was neutralized with 2 M NaOH solution. The
separated porphyrin was collected by ®ltration and
washed several times with water. Analytically pure 12
was obtained by TLC chromatography on silica gel
plates (20Â20 cm, 0.5 mm, Merck) using CH2Cl2/
MeOH (9/1) as eluent. Yield: 43 mg (87%). Fp 209±
213ꢀC 1H NMR (500 MHz, [D5]-Pyridin, 300 K) d
2.56 (br m, 2H, NH), 1.741±1.841 (m, 12H, Por-CH2-
CH3), 2.538 (s, 6H, Por-CH3), 3.503 (s, 6H, Por-CH3),
3.945±4.010 (m, 8H, Por-CH2-CH3), 4.352±4.514 (m,
2H, Gal-6b, Gal-3), 4.673±4.708 (m, 2H, Gal-2, Gal-4),
4.795±4.855 (m, 1.5H, Gal-6a), 4.974±5.042 (m, 2H,
Aryl-CH2O-), 5.189 (m, 1H, Gal-5), 5.424 (d, 0.5H,
J1/2=7.56 Hz, Gal-1-b), 6.105 (d, 0.5H, J1/2=1.12 Hz,
Gal-1-a), 7.803 (d, 2H, JAryl=7.86 Hz, Aryl), 8.006 (d,
2H, JAryl=7.86 Hz, Aryl), 10.188 (m, 1H, Por-15),
10.403 (s, 2H, Por-10, Por-20). 13C NMR (125 MHz,
pyridine-d5, 300 K) d 11.004 (q, Por-CH3), 14.551 (q,
Por-CH3), 17.449 (q, Por-CH2-CH3), 17.512, (q, Por-
CH2-CH3), 19.502 (t, Por-CH2CH3), 19.684, (t, Por-
CH2-CH3), 69.955 (d, Gal-5), 70.371 (d, Gal-4), 70.870
(d, Gal-4), 70.993 (t, Gal-6), 71.070 (d, Gal-2), 71.088 (t,
Gal-6), 71.166 (d, Gal-2), 72.931, 72.994 (t, Aryl-CH2-)
74.000 (d, Gal-2), 74.654 (d, Gal-3), 75.195 (d, Gal-3),
94.305 (d, Gal-1-a), 95.684 (d, Por-15), 96.704 (d, Por-
10, Por-20), 99.263 (d, Gal-1-b), 103.929, 119.387 (s,
Por), 126.740 (d, Aryl), 132.792 (d, Aryl), 132.887 (s,
5-(4-Cholesteryloxybenzyl)-2,8,12,18-tetraethyl-3,7,13,17-
tetramethyl-15-[4-(1,2;3,4-di-O-isopropyliden-ꢀ-D-galacto-
pyranos-6-oxy)benzyl]-porphyrin (11). Yield: 117.2 mg
(3.9%). Fp 223±227ꢀC. H NMR (500 MHz, CDCl3,
1
300 K) d 2.344 (br s, 2H, NH), 0.671±2.141 (m, 29H,
Chol), overlapped by 0.714 (s, 3H, Chol-19), 0.918 (d,
3H, J=6.57 Hz, Chol-26), 0.922 (d, 3H, J=6.58 Hz,
Chol-27), 0.960 (d, 3H, J=6.44 Hz, Chol-18-CH3),1.108
(s, 3H, Chol-18), 1.415 (s, 3H, Gal-CH3),1.458 (s, 3H,
Gal-CH3), 1.586 (s, 3H, Gal-CH3), 1.685 (s, 3H, Gal-
CH3), 1.804 (t, 12H, J=7.54 Hz, Por-CH2-CH3), 2.528
(s, 12H, Por-CH3), 3.925 (dd, 1H, J5/6b=6.86, J6a/6b
10.16 Hz, Gal-6b), 3.975 (dd, 1H, J5/6a=5.58, J6a/6b
=
=
10.16 Hz, Gal-6a), 4.049 (q, 8H, J=7.54 Hz, Por-CH2-
CH3), 4.260 (m, 1H, J4/5=2.27, J5/6a=5.58, J5/6b=6.86
Hz, Gal-5), 4.428 (dd, 1H, J1/2=5.06, J2/3=2.39 Hz,
Gal-2), 4.480 (dd, 1H, J3/4=7.91, J4/5=2.27 Hz, Gal-4),
4.737 (dd, 1H, J2/3=2.39, J3/4=7.91 Hz, Gal-3), 4.961
(s, 2H, Aryl-CH2-O-Chol), 4.977 (d, 1H, J=12.45 Hz,
Aryl-CH2-O-Gal), 5.033 (d, 1H, J=12.45 Hz, Aryl-
CH2-O-Gal), 5.455 (m, 1H, Chol-4), 5.696 (d, 1H, J1/2=
5.06 Hz, Gal-1), 7.737 (d, 2H, JAryl1=7.53 Hz, Aryl),

C. Schell, H. K. Hombrecher / Bioorg. Med. Chem. 7 (1999) 1857±1865
1865
Por), 135.019 (s, Por), 136.048 (s, Por), 136.066 (s, Por),
136.469 (s, Aryl), 139.397 (s, Por), 139.450 (s, Por),
141.275 (s, Aryl), 141.528 (s, Por), 141.552(s, Por),
141.890 (s, Por), 141.956 (s, Por), 142.992 (s, Por),
143.152 (s, Por), 144.458 (s, Por), 144.506 (s, Por),
144.546 (s, Por), 145.569 (s, Por), 145.704 (s, Por). MS
(FAB) m/z 748 (M++1, 15), 584 (M++1-C6H12O5,
95), 568 (M++1-C6H12O6, 75), 414 (100). IR (KBr) n
3379, 2949, 1670, 1440, 1367, 1256, 1194, 1078, 1050,
795, 738, 674 cm 1. UV (CH2Cl2/CH3OH) lmax 402
(5.348), 501 (4.253), 534 (3.921), 567 (3.899), 620 (3.429).
Anal. calcd. for: C45H54N4O6Â3 H2O (801.3): C, 67.45;
H, 7.55; N, 7.00. Found: C, 67.34; H, 7.48; N 6.89.
Â3H2O (1275.7): C, 74.38; H, 8.69; N, 4.39. Found: C,
74.20; H, 8.32; N, 4.40.
Acknowledgements
Financial support of this work by the Deutsche For-
schungsgemeinschaft and the Fonds der Chemischen
Industrie is gratefully acknowledged.
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5-(4-Cholesteryloxybenzyl)-2,8,12,18-tetraethyl-3,7,13,17-
tetramethyl-15-[4-ꢀ/ꢁ-D-galactopyranos-6-oxy)benzyl]-
porphyrin (13). According to the procedure described
for the synthesis of porphyrin 12, 40 mg (0.031 mmol)
of 11 were reacted. Yield: 31 mg (82%). Fp 102±109ꢀC.
1H NMR (500 MHz, pyridine-d5, 300 K) d 1.710 (br s,
2H, NH), 0.672±1.996 (m, 29H, Chol), overlapped by:
0.680 (s, 3H, Chol-19), 0.917 (d, 3H, J=6.61 Hz, Chol-
26), 0.918 (d, 3H, J=6.58 Hz, Chol-27), 0.990 (d, 3H,
J=6.53 Hz, Chol-18-CH3), 1.091 (s, 3H, Chol-18),
1.774±1.817 (m, 12H, Por-CH2-CH3), 2.599, 2.605,
2.662 (3 s, 12H, Por-CH3), 4.024±4.115 (q, 8H, J=7.54
Hz, Por-CH2-CH3), 4.309±4.526 (m, 2H, Gal-6b, Gal-
3), 4.642±4.769 (m, 2H, Gal-2, Gal-4), 4.799±4.837 (m,
1H, Gal-6a), 5.013±5.084 (m, 4H, Aryl-CH2O-), 5.142±
5.181 (m, 1H, Chol-4), 5.396 (d, 0.5H, J1/2=7.54 Hz,
Gal-1-b), 5.523±5.548 (m, 1H, Gal-5), 6.105 (d, 0.5H,
J1/2=2.5 Hz, Gal-1-a), 7.882 (d, 2H, JAryl=8.05 Hz,
Aryl), 7.979 (d, 2H, JAryl=7.77 Hz, Aryl), 8.105 (d, 2H,
JAryl=8.05 Hz, Aryl), 8.182 (d, 2H, JAryl=7.77 Hz,
Aryl), 10.546 (s, 2H, Por-10, Por-20). 13C NMR (125
MHz, CDCl3, 300 K) d 12.011 (q, Chol-18), 14.743 (q,
Por-CH3), 14.808 (q, Por-CH3), 17.911 (q, Por-CH2-
CH3), 18.959 (q, Chol-21), 19.553 (q, Chol-19), 20.123
(t, Por-CH2-CH3), 21.374 (t, Chol-11), 22.713 (q, Chol-
26), 22.963 (q, Chol-27), 24.203 (t, Chol-23), 24.517 (t,
Chol-15), 28.267 (d, Chol-25), 28.520 (t, Chol-12),
29.117 (t, Chol-2), 32.134 (d, Chol-8), 32.258 (t, Chol-7),
36.062 (d, Chol-20), 36.495 (t, Chol-22), 37.186 (s, Chol-
10), 37.592 (t, Chol-1), 39.753 (t, Chol-4), 39.873 (t,
Chol-24), 39.993 (t, Chol-16), 42.506 (s, Chol-13),
50.436 (d, Chol-9), 56.393 (d, Chol-17), 56.848 (d, Chol-
14), 70.299 (t, Aryl-CH2-O-Chol), 70.726 (d, Gal-5),
71.204 (d, Gal-4), 71.387 (d, Gal-4), 71.645 (d, Gal-6),
73.324 (t, Aryl-CH2-O-Gal), 74.341 (t, Aryl-CH2-O-
Gal), 74.999 (d, Gal-2), 75.542 (d, Gal-3), 79.383 (d,
Chol-3), 94.655 (d, Gal-1-a) 96.579 (d, Por-10, Por-20),
99.611 (d, Gal-1-b), 118.727 (s, Por), 118.782 (s, Por),
121.968 (d, Chol-6), 127.187 (d, Aryl), 133.073 (d, Aryl),
136.527 (s, Aryl), 139.822 (s, Aryl), 141.213 (s, Aryl),
141.343 (s, Chol-5), 141.430 (s, Por), 145.355 (s, Por),
145.863 (s, Por). MS (FAB) m/z 1221 (M++1, 75), 1058
(M++1-C6H11O5, 15), 837 (M++1-C27H45O, 10), 685
(60), 460 (85), 392 (100). IR (KBr) n 3390, 2941, 1620,
1440, 1380, 1081, 1054, 760 cm 1. UV (CH2Cl2/
CH3OH) lmax 409 (5.325), 507 (4.218), 541 (3.730), 573
(3.848), 624 (3.136). Anal. calcd for C79H104N4O7
26. Regev, A.; Ehrenberg, B.; Nitzan, Y.; Kral, V.; Sessler, J.
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Koback, H. R. Methods Enzymol. 1986, 125, 429.
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