Chemistry Reference
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R
2
H
H
N
N
N
N
N
N
R
1
M
R
3
R
1
R
1
N
N-C
O
N
C-N
R
2
O
R
2
FF
F
N-CH
3
M = Mn(III)
MnDMPyFPC
R
1
= R
3
=
R
2
=
+
19
R
1
= R
2
= (CH
2
)
3
OH
F
F
R
1
= (CH
2
)
3
O(CH
2
)
2
O(CH
2
)
2
NH
2
R
2
= H
20
MnTMPyPC
N-CH
3
R
1
= R
2
= R
3
=
M = Mn(III)
+
21
R
1
= (CH
2
)
3
NH(CH
2
)
2
NH
2
R
2
= H
TMPyP
N-CH
3
M = H
R
1
= R
2
= R
3
=
+
22
R
1
= (CH
2
)
3
N[(CH
2
)
2
NH
2
]
2
R
2
= H
Fig. 14 Polyamine-conjugated sapphyrins and molecular structure of corroles
3.2 Porphyrinoid Derivatives with Different Composition
of the Core Ring
Modifications in the macrocycle ring of the porphyrinoids cause variation in the
photophysical proprieties of the macrocycle, i.e., red shift of the Soret band. This
effect increases the photocleavage capabilities of chromophores, when irradiated at
red-shifted wavelengths (
600 nm) [
142
,
143
]. This region is preferable, as it is here
that the bodily tissues are most transparent [
144
]. In the context of this program
Sessler reported that sapphyrin 19 (a pentapyrrolic “expanded” porphyrin) is capable
of photocleaving DNA when irradiated at wavelengths above 620 nm [
142
-
145
]. In
an attempt to increase the efficiency as photosensitizer of the sapphyrins, Sessler
synthetized three sapphyrin derivatives, with polyamine conjugates 20, 21, and 22
(Fig.
14
) comparing results with non-conjugate sapphyrin compound [
146
,
147
].
Having the inner cavity larger and more basic than normal porphyrins [
148
],
sapphyrin derivatives are protonated and positively charged at neutral pH. This
characteristic allows to chelate the anionic phosphate backbone of DNA in a precise,
rigid fashion [
149
]. They found that amino-functionalized sapphyrin derivatives
20, 21, and 22 showed significantly more effective cleavage than compound 19.
On the contrary corroles have a smaller ring than porphyrin, however they show a
better efficacy in inhibiting tumor progression and metastasis in animal models than
analogous porphyrins. Gross synthetized manganese(III) corrole with two
pyridinium groups, MnDMPyFPP (Fig.
14
), to study the interactions with DNA
and then compared these with analogue porphyrin. By CD experiments, he observed
that although the spectrum of MnDMPyFPC is composed of both negative and
positive components, that of the analogous porphyrin derivative displays only a
positive CD band that is also of much lower ellipticity. He suggests that the corrole
is capable of both intercalate and outside binding with DNA, whereas the analogous
porphyrin is only capable of outside binding [
150
]. Moreover, cationic manganese
corrole has been proved catalytic activity for the oxidative cleavage DNA [
150
,
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