ω,ω′-Appended nucleo-base derivatives of hypericin

Article abstract of DOI:10.1007/s00706-008-0898-0

ω,ω′-Disubstituted hypericin derivatives with the nucleo-bases thymine, cytosine, and adenine in these positions were prepared starting from tri-O-methyl-ω-bromoemodin. The most promising derivative proved to be that with a thymine moiety. It displayed the best solubility of the three products together with a potency to produce singlet oxygen and/or reactive oxygen species comparable to the parent compound hypericin. In addition, although no specific interaction with DNA or poly(2′- deoxyadenylic acid) could be detected, it proved to be significantly better accumulating in the nucleus of prostatic cancer LNCaP cells than hypericin making it a promising candidate for a second-generation photodynamic hypericin agent.

Full text of DOI:10.1007/s00706-008-0898-0

Monatsh Chem 139, 1127–1136 (2008)
DOI 10.1007/s00706-008-0898-0
Printed in The Netherlands
x,x0-Appended nucleo-base derivatives of hypericin
David Geißlmeir, Heinz Falk
Institute of Organic Chemistry, Johannes Kepler University, Linz, Austria, Europe
Received 16 January 2008; Accepted 16 January 2008; Published online 18 February 2008
# Springer-Verlag 2008
Abstract !,!0-Disubstituted hypericin derivatives
with the nucleo-bases thymine, cytosine, and adenine
in these positions were prepared starting from tri-
O-methyl-!-bromoemodin. The most promising de-
rivative proved to be that with a thymine moiety. It
displayed the best solubility of the three products
together with a potency to produce singlet oxygen
and=or reactive oxygen species comparable to the
parent compound hypericin. In addition, although no
specific interaction with DNA or poly(20-deoxyade-
nylic acid) could be detected, it proved to be signifi-
cantly better accumulating in the nucleus of prostatic
cancer LNCaP cells than hypericin making it a prom-
ising candidate for a second-generation photodynamic
hypericin agent.
bases to get a first access to hypericin derivatives
potentially interacting with the complementary
nucleo-bases of DNA or RNA by Watson-Crick pair-
ing, or intercalation, or with other constituents of the
cell nucleus.
Keywords Hypericin; Thymine; Oxidizing species; Prostatic
cancer cells.
Results and discussion
Introduction
Derivatization of hypericin (1; 1,3,4,6,8,13-hexahy-
droxy-10,11-dimethyl-phenanthro[1,10,9,8-opqra]-
perylene-7,14-dione) is a major aim in the search for
second-generation photodynamic agents [1]. This
could be done either targeting a shift to absorption
at longer wavelengths or with specific interaction
functionality in mind. Here we present an investi-
gation of the possibility to hybridize 1 with nucleo-
Syntheses
To guarantee the extensively unperturbed photo-
chemical properties of the hypericin residue deriva-
tization with the nucleo-bases could be optimally
undertaken at the !,!0-methyl groups of 1. For this
purpose, the appropriately modified emodin deriva-
tives had to be prepared first in order to dimerize
them in the next steps. This derivatization was en-
visaged to proceed best starting from the tri-O-meth-
yl protected emodin bromomethyl derivative 2. For
the nucleo-base synthons we used the NH or NH2
benzoyl-protected derivatives. Thus, 2 reacted with
Correspondence: Heinz Falk, Institute of Organic Chemistry,
Johannes Kepler University, Altenbergerstraße 69, 4040 Linz,
Austria, Europe. E-mail: heinz.falk@jku.at

1128
D. Geißlmeir, H. Falk
Scheme 1
3-benzoylthymine (prepared according to Ref. [2])
in presence of an excess of K2CO3 in DMF as the
solvent to provide 69% of the corresponding emodin
derivative 3 (Scheme 1). The latter could be depro-
tected and reduced in the common one-pot way [3]
to the anthrone 4 with Sn(II) chloride in glacial
acetic acid=HBr in 92% yield. The dimerization to
the corresponding protohypericin derivative 5 with
Fe(II) sulfate=pyridine-N-oxide in analogy to Ref.
[4] was achieved with a yield of 88%. Photocycliza-
tion of this latter derivative 5 in acetone according to
Ref. [4] then produced the targeted !,!0-thymine-di-
substituted hypericin derivative 6 in 77% yield, thus
providing an overall yield of 6 based on 2 of 43%.
Along the route described above for 6 the cytosine
derivative 10 starting from 2 and N-benzoylcytosine
[5] could be synthesized via 7, 8, and 9 (Scheme 2),
although the reaction time in the first step had to be
prolonged slightly. In the same way the adenine de-
rivative 14 was advanced from 2 and N-benzoylade-
nine [6] via 11, 12, and 13 (Scheme 3) – both target
compounds were obtained in yields comparable to
the one of 6. However, in the latter case the reaction
time had to be prolonged considerably in the first
step and KI had to be added as a catalyst to achieve
the transformation. In addition, the photocyclizations
were somewhat hampered by the low solubilities of
the protohypericin derivatives and thus some added
base or DMSO=DMF was necessary. Unfortunately,
the guanineemodin derivative 15, produced from 2
and N-benzoylguanine [7] (Scheme 4) under pro-
longed reaction time and addition of KI, could not
be reduced to the anthrone derivative without exces-
sive destruction.

Nucleo-base derivatives of hypericin
1129
Scheme 2
Properties
than hypericin (1) itself, but they are obviously (as
judged from the irradiation time dependent decrease
of the ‘‘hypericin’’-band absorption) slightly photo-
destructed themselves in the course of irradiation.
The interactions of the derivatives 6, 10, and 14
with calf thymus DNA and single strand poly(20-
deoxyadenylic acid) sodium salt (poly(dA)) were in-
vestigated according to Refs. [9, 10]. However, (cf.
Exp. part) no changes in the absorption spectra of
the hypericin derivatives, which would indicate a
specific interaction like intercalation with DNA or
Watson-Crick pairing of the thymine derivative 6
with poly(dA), could be observed. A possible expla-
nation might be sought in the relatively high steric
hindrance at the respective sites of the molecule as
advanced by means of a MM2 force field calculation
of the structure of 6 as shown in Fig. 2.
As expected for non-conjugated hybrids of hypericin
(1) with other chromophores, the long wavelength
absorption bands and fluorescence properties of the
three compounds 6, 10, and 14 were very similar to
the corresponding spectra of the parent compound 1.
However, the solubilities of these derivatives in com-
mon solvents were significantly reduced compared
to 1, with 6 as the most soluble one.
The light-induced production of singlet oxygen
and oxidizing species as tested by the destruction
of bilirubin-IXꢀ according to Ref. [8] (Fig. 1) proved
to be slightly lowered as compared to 1, but is nev-
ertheless appreciable. It might be stressed that in
contrast to the thymine derivative 6 the cytosine
and the adenine derivatives 10 and 14 initially pro-
vided a superior photo-destruction of bilirubin-IXꢀ

1130
D. Geißlmeir, H. Falk
Scheme 3
distribution between healthy tissue and tumor, but
also on the subcellular distribution in malignant
cells. The penetration of the photosensitizer into var-
ious cell compartments, especially the nucleus, plays
an important role in its cytotoxic activity. Hypericin
(1), which is usually accumulated in the cytoplasmic
membrane, can penetrate these membranes and ac-
tually reach the inside of the nucleus after long
term incubation, as it has been shown by Miskovsky
et al. [11].
We decided to investigate the subcellular distribu-
tion of the thymine substituted hypericin derivative 6
compared to 1 in the prostatic carcinoma cell line
LNCaP by means of fluorescence microscopy. The
LNCaP cells were grown according to Ref. [12] and
incubated in the dark with DMSO solutions of 6 or
1. The final concentrations of 6 and 1 were set to
Scheme 4
Distribution of 6 in prostatic cancer cells
The efficiency of a photosensitizer is not only depen-
dent on its photochemical properties and its relative

Nucleo-base derivatives of hypericin
1131
Fig. 1 Light-induced photodestruction of bilirubin-IXꢀ sen-
sitized by hypericin (1, —) and the nucleo-base substituted
derivatives 6 (– –), 10 (– ꢀ ), and 14 (– ꢀ ꢀ )
Fig. 3 LNCaP after 4 h incubation with 6
The relative accumulation of 6 and 1 in the nucle-
us compared to the cytoplasmic membrane of the
LNCaP cells was determined by measuring the in-
tensity of fluorescence in the relevant regions. After
4 h incubation 6 was found in the nucleus with the
median relative accumulation significantly higher
compared to 1. However, while the amount of 1 in
the nucleus barely changed between the two incuba-
tion times, 6 showed a much higher accumulation in
the nucleus after short-term incubation (cf. Fig. 4).
Due to the higher concentration of 6 in the vital parts
of the cell (like the nucleus) we also expect an in-
creased cytotoxicity upon light irradiation compared
to 1, keeping in mind the almost equivalent photo-
sensitizing properties of 6 and 1 as probed by the
photodestruction of bilirubinate IXꢀ.
Fig. 2 Steric requirements by molecules of 6 as advanced by
means of a MM2 force field calculation
1 ꢁg=cm3 and DMSO concentrations ranged from
0.1 to 1% (v=v) in the culture medium. During
the incubation period light irradiation was strictly
avoided to prevent a preliminary destruction of the
cells or cell ingredients, and the dark toxicity of
6 and 1 is low enough for long incubation times.
Measurements were taken after 4 and 24 h with
a confocal fluorescence microscope – Fig. 3 pro-
vides an impression of the localization of 6 in the
LNCaP cells.
Fig. 4 Relative accumulation of 6 (grey) and 1 (black) in the
nucleus of LNCaP cells after 4 and 24 h incubation

1132
D. Geißlmeir, H. Falk
calf thymus DNA was expressed in nucleotide=dm3, deter-
mined spectrophotometrically by using an average molecular
weight of 338 for a nucleotide and an extinction coefficient of
Conclusion
The synthesis of three of the four possible bis-!,!0-
nucleo-base-hypericin derivatives 6, 10, and 14
substituted with the nucleo-bases thymine, cytosine,
and adenine could be accomplished. The thymine
derivative 6 proved to be the best soluble one and
displayed photoproduction of singlet oxygen and=or
reactive oxygen species comparable to the one of
hypericin (1). Although no specific interaction with
DNA or Watson-Crick base pairing with poly(20-
deoxyadenylic acid) could be detected it accumu-
lated in the nucleus of prostatic cancer cells even
better than 1. Thus, it may constitute a novel poten-
tial second-generation hypericin derivative for pho-
todynamic therapy.
"
¼ 6600 Mꢂ1 cmꢂ1. Ratios of 1:40, 1:200, and 1:400 and
260
measurements after 30 min, 2 and 24h with stirring at 4ꢁC in
between were used. No change of the hypericin chromophore
absorption spectra of 6, 10, and 14 as compared to a blind
sample without DNA could be detected. The concentration for
poly(dA) was expressed in nucleotide=dm3 and determined
spectrophotometrically by using an extinction coefficient of
"
¼ 9100 Mꢂ1 cmꢂ1 [9, 10]. In this case the relation be-
260
tween 6 and poly(dA) was 1:3 and 1:6 with measurements
after 30min, 2 and 24h. Again, no change in the absorption
spectrum of 6 could be detected.
6-(Bromomethyl)-1,3,8-trimethoxyanthracene-9,10-dione
(2, C18H15BrO5)
A mixture of 500 mg 1,3,8-trimethoxy-6-methyl-9,10-anthra-
quinone (1.85 mmol) [14], 317 mg 1,3-dibromo-5,5-dimethyl-
hydantoin (1.11 mmol) (Aldrich), 10mg dibenzoylperoxide
(0.041mmol), and 80cm3 CCl4 was refluxed under Ar for
36h. The reaction progress was controlled by means of NMR.
The reaction mixture was evaporated, and the residue was
washed with CCl4 and hot H2O. After purification by means of
recrystallization from toluene=EtOAc¼ 2=1 and column chro-
matography(toluene=EtOAc ¼ 1=1),440 mg(1.12 mmol)2were
obtained (61% yield). Mp 218–220ꢁC; Rf ¼ 0.33 (CHCl3=
EtOAc¼ 3=1), Rf ¼ 0.34 (toluene=EtOAc¼ 1=1); 1H NMR
(500MHz, DMSO-d6, 30ꢁC): ꢂ ¼ 7.76 (s, ar-H5), 7.61 (s, ar-
H7), 7.17 (d, J ¼ 2.3 Hz, ar-H4), 6.98 (d, J ¼ 2.3Hz, ar-H2),
4.82 (s, 6-CH2Br), 3.94 (s, 3-OCH3), 3.91 (s, 8-OCH3), 3.90
(s, 1-OCH3) ppm; NOESY (DMSO-d6): 1-OCH3 $ ar-H2, 3-
OCH3 $ ar-H2 and ar-H4, 8-OCH3 $ ar-H7, 6-CH2Br $ ar-
Experimental
The products were characterized by means of mp (Kofler
microscope, Reichert), NMR (Bruker Avance DPX 200MHz
or a Bruker Avance 500 MHz spectrometer using a TXI cryo-
probe with z-gradient coil using standard pulse sequences as
provided by the manufacturer. Typical 90ꢁ hard pulse dura-
tions were 8.2 ꢁs (1H) and 16.6ꢁs (13C), 90ꢁ pulses in decou-
pling experiments were set to 67ꢁs. HSQC and HMBC
experiments were optimized for decoupling constants of
145 Hz for single quantum correlations and 10Hz for multi-
bond correlations. The NOESY mixing time was set to
400 ms), IR (Bruker Tensor 27, KBr), MS (Thermofinnigan
LCQ Deca XP Plus or Hewlett Packard 59987 quadrupole
instrument), fluorescence (Varian Carey Eclipse fluores-
cence instrument), and UV-Vis data (Varian Cary 100 Bio).
Fluorescence quantum yields were calculated according to the
comparative method of Williams et al. [13] using hypericin (1)
as standard sample. Fluorescence microscopy was carried out
on a LSM 510 Laser Module Axiovert 200 M fluorescence
microscope.
Photocyclizations were carried out using a 700 W Hg high-
pressure lamp with fluorescence screen (Philips). For the irra-
diation experiments a 300 W tungsten lamp (Philips) and a
long-pass cut-off filter (lcut-off>570 nm) were used. Thin lay-
er chromatography (TLC) was performed on silica gel 60 F254
aluminum sheets (Merck). Column chromatography was car-
ried out on silica gel (0.060–0.200 mm, pore diameter 6 nm),
unless stated otherwise.
13
H5 and ar-H7; C NMR (125MHz, DMSO-d6, 30ꢁC):
ꢂ ¼ 182.8 (C10), 179.6 (C9), 163.5 (C3), 161.1 (C1), 159.0
(C8), 144.0 (C6), 135.5 (C4a), 134.3 (C10a), 122.9 (C8a),
119.4 (C7), 118.8 (C5), 117.5 (C9a), 105.1 (C2), 102.4
(C4), 56.43 (1-OCH3 or 8-OCH3), 56.36 (8-OCH3 or 1-
OCH3), 55.90 (3-OCH3), 32.72 (6-CH2Br) ppm; HMBC
(DMSO-d6): C1$ 1-OCH3, ar-H2 and ar-H4, C2 $ ar-H4,
C3$ 3-OCH3, ar-H2 and ar-H4, C4 $ ar-H2, C5$ ar-H7
and 6-CH2Br, C6 $ ar-H7 and 6-CH2Br, C7 $ ar-H5 and 6-
CH2Br, C8$ 8-OCH3 and ar-H7, C10$ ar-H4 and ar-H5,
C4a $ ar-H4, C8a$ ar-H5 and ar-H7, C9a $ ar-H2 and ar-
H4, 6-CH2Br $ ar-H5 and ar-H7; HSQC data were according
to structure; ESI-MS (CH3OHþ 1 vol% HCOOH, positive
ion mode): m=z ¼ 392 ([M þ H]þ); IR (KBr): ꢃꢀ¼ 3088,
2941, 2840, 1774, 1708, 1663, 1597, 1566, 1464, 1426,
1349, 1324, 1252, 1220, 1206, 1163, 1135, 1071, 1020, 943,
849, 755 cmꢂ1; UV-Vis (CHCl3): lmax ¼ 280 (100), 403 (28)
nm (rel. int.)
The production of singlet oxygen=oxidizing species by 1, 2,
and 3 was monitored by bilirubin-IXꢀ-degradation according
to Ref. [8]. The long-wavelength absorption band intensities
of the three compounds were made equal by adjusting con-
centrations to provide comparable light absorptions for all
compounds.
DNA interaction experiments were carried out with calf
thymus DNA (Sigma) and poly(20-deoxyadenylic acid) sodium
salt (poly(dA), Sigma) according to Refs. [9, 10] using H2O
(MilliQ 18 MO) þ 10% DMSO (v=v). The concentration of
3-Benzoyl-5-methyl-1-((4,5,7-trimethoxy-9,10-dioxo-9,10-
dihydroanthracen-2-yl)methyl)pyrimidine-2,4(1H,3H)-dione
(3, C30H24N2O2)
A mixture of 63mg 2 (0.163mmol), 56mg 3-benzoylthymine
(0.244mmol) [2], and 67mg dried K2CO3 (0.489 mmol) was
dissolved in 15cm3 DMF. After heating to 80ꢁC under Ar

Nucleo-base derivatives of hypericin
1133
atmosphere the reaction mixture was stirred for 16h. The
solvent was evaporated and the residue was dissolved in
CHCl3. The organic layer was washed with water several
times, dried (MgSO4), and evaporated. The crude product
was purified by means of column chromatography (CHCl3=
MeOH ¼ 30=1) yielding 60.53 mg (69%) 3. Mp 216–
219ꢁC; Rf ¼ 0.41 (CHCl3=MeOH¼ 9=1); 1H NMR (500MHz,
DMSO-d6, 30ꢁC; note that here and throughout the descrip-
tions we follow the numbering scheme of emodin and not the
IUPAC enumeration as given with the name for the NMR
assignments due to better comparison possibilities): ꢂ ¼ 1.96
(s, 50-CH3), 3.95 (s, 8-OCH3), 3.96 (s, 1-OCH3), 3.97 (s, 3-
OCH3), 4.98 (s, 6-CH2), 6.79 (d, J ¼ 1.9 Hz, ar-H2), 7.14 (s,
60-H), 7.28 (s, ar-H7), 7.33 (d, J ¼ 1.9 Hz, ar-H4), 7.51 (m, ar-
H400), 7.64 (m, ar-H300, ar-H500), 7.73 (s, ar-H5), 7.93–7.94
(m, ar-H200, ar-H600) ppm; 13C NMR (125 MHz, DMSO-d6,
30ꢁC): ꢂ ¼ 11.3 (50-CH3), 50.2 (6-CH2), 54.8 (3-OCH3),
55.4 (1-OCH3) 55.6 (8-OCH3), 101.1 (C4) 104.3 (C2), 110.8
(C50), 116.4 (C5), 116.6 (C7), 117.0 (C9a), 122.9 (C8a), 128.0
(C100), 129.3 (C200) 130.4 (C500), 133.9 (C600), 134.1 (C10a),
135.0 (C4a), 138.0 (C60), 140.0 (C6), 149.0 (C20), 159.3 (C8),
160.7 (C1), 161.6 (C40), 162.9 (C3), 167.4 (Bz-C¼ O), 180.0
(C9), 182.6 (C10) ppm; NOESY (DMSO-d6, 30ꢁC): ar-
H2$ 1-OCH3 and 3-OCH3, 60-H$ 6-CH2- and 50-CH3,
ar-H4 $ 3-OCH3, ar-H7 $ 6-CH2- and 8-OCH3, ar-H5 $ 6-
CH2-; HMBC (DMSO-d6, 30ꢁC): 50-CH3 $ C60. C50 and
C40, 8-OCH3$ C8, 1-OCH3 $ C1, 3-OCH3 $ C3, 6-CH2-$
C5, C6, C7 and C60, ar-H2 $ C9a and C9, 60-H$ C50and
C20, ar-H7 $ C8 and C8a, ar-H4 $ C4a and C10, ar-
H200 $ Bz-C ¼ O, ar-H5 $ C10a and C10; HSQC data were
according to structure; ESI-MS (MeOH=CHCl3 ¼ 9=1 þ 1
vol% HCOOH, positive ion mode): m=z ¼ 541 ([M þ H]þ);
IR (KBr): ꢃꢀ¼ 2925, 2852, 1749, 1694, 1657, 1598, 1437,
1351, 1316, 1247, 1202, 1159, 1126, 1068, 1020, 997, 946,
910, 872, 817, 782, 752, 710 cmꢂ1; UV-Vis (CHCl3):
lmax ¼ 402 (100) nm (rel. int.).
60-H$ 6-CH2- and 50-CH3, ar-H5$ 6-CH2-, ar-H7 $ 6-CH2;
HMBC (DMSO-d6, 30ꢁC): 8-OH $ C8, 1-OH $ C1, 3-
OH $ C3, 60-H$ C20, C40, C50 and 6-CH2-, ar-H5 $ C10,
C10a, C6 and 6-CH2-, ar-H7 $ C6, C8 and C8a, ar-H4 $
C3, C4a and C10, ar-H2 $ C1, C3 and C9a, 6-CH2- $ C5,
C6, C7, C20 and C60, 4a-CH2- $ C4, C4a, C5 and C10a,
50-CH3 $ C40, C50 and C60; HSQC data were according to
structure; ESI-MS (MeOH=CHCl3 ¼ 3=1 þ 1 vol% NH3, neg-
ative ion mode): m=z ¼ 379 ([M ꢂ H]þ); IR (KBr): ꢃꢀ¼ 3179,
3033, 2926, 1687, 1624, 1601, 1478, 1435, 1379, 1244, 1171,
1064, 958, 911, 835, 798, 763, 723, 643 cmꢂ1; UV-Vis
(DMF): lmax ¼ 389 (100), 371 (63) nm (rel. int.).
1,10-(1,3,4,6,8,15-Hexahydroxy-7,16-dioxo-7,16-dihydrodi-
benzo[a,o]perylene-10,13-diyl)bis(methylene)bis(5-methyl-
pyrimidine-2,4(1H,3H)-dione) (5, C40H26N4O12)
A light-protected mixture of 33mg 4 (0.086 mmol), 1.2 mg
FeSO4 ꢀ 7H2O (0.0043mmol), and 45mg pyridine-N-oxide
(0.475mmol) in 2.5 cm3 dry pyridine and 0.2 cm3 dry piperi-
dine was stirred under Ar at 115ꢁC for 1 h. After cooling to
room temperature the mixture was poured into 16 cm3 2 N HCl
and stirred for another 30min. The precipitate was centrifuged
and washed three times with HCl (3%) and three times with
H2O. The residue was dried over P2O5 in vacuum and 29mg 5
were obtained (88% yield). Due to its light-sensitivity isola-
tion was only possible as a mixture with the light-induced
sequel product 6. Thus, characterization could only be
achieved by mass spectrometry and UV-Vis spectrometry.
Mp >350ꢁC; ESI-MS (acetoneþ 1 vol% NH3, negative ion
mode): m=z ¼ 753 ([M ꢂ H]þ); UV-Vis (acetone): lmax ¼ 371
(100), 555 (91), 590 (88) nm (rel. int.).
1,10-(1,6,8,10,11,13-Hexahydroxy-7,14-dioxo-7,14-dihydro-
phenanthro[1,10,9,8-opqra]perylene-3,4-diyl)bis(methylene)-
bis(5-methylpyrimidine-2,4(1H,3H)-dione) (6, C40H24N4O12)
A vigorously stirred solution of 147mg 5 (0.195 mmol)
in 2250 cm3 acetone was irradiated for 150 min by means of
a 700W Hg high-pressure lamp with fluorescence screen.
After evaporation of the solvent the residue was purified by
means of column chromatography (Sephadex LH20 MeOH)
and 113 mg 6 were obtained (77% yield). Due to its low
solubility a complete structure determination by means of
NMR experiments was not possible. Data for 13C NMR
are partly derived from 2D NMR experiments. Mp >350ꢁC;
Rf ¼ 0.80 (CHCl3=MeOH¼ 1=1), Rf ¼ 0.66 (THF=petrol
ether=MeOH ¼ 7=1=1); 1H NMR (500 MHz, DMSO-d6,
30ꢁC; note that hypericin enumeration is retained for NMR
assignments for the hypericinoid compounds, instead of the
IUPAC numbering): ꢂ ¼ 18.65 (bs, 3-OH, 4-OH), 14.74 (s,
1-OH, 6-OH), 14.13 (s, 8-OH, 13-OH), 11.08 (s, 30-NH,
300-NH), 7.42 (s, ar-H9, ar-H12), 7.29 (s, 60-H, 600-H), 6.62
(s, ar-H2, ar-H5), 5.73 (d, J ¼ 15Hz, 10-CH2-, 11-CH2-),
4.98 (d, J ¼ 15Hz, 10-CH2-, 11-CH2-), 1.57 (s, 50-CH3, 500-
CH3) ppm; 13C NMR (125MHz, DMSO-d6, 30ꢁC): ꢂ ¼ 184.8
(C7, C14), 175.7 (C3, C4), 168.8 (C1, C6), 163.9 (C40, C400),
163.6 (C20, C200), 161.5 (C8, C13), 150.9 (C50, C500), 142.5
(C60, C600), 141.7 (C10, C11), 119.7 (C10a, C10b), 117.6 (C9,
C12), 109.6 (C7a, C13a), 106.9 (C2, C5), 102.0 (C6a, C14a),
3-Benzoyl-5-methyl-1-((4,5,7-trihydroxy-10-oxo-9,10-
dihydroanthracen-2-yl)methyl)pyrimidine-2,4(1H,3H)-dione
(4, C20H16N2O2)
An argon-flushed solution of 61 mg 3 (0.113 mmol) in 10cm3
glacial acetic acid was heated to reflux. Then 203 mg
SnCl2 ꢀ 2H2O (0.9 mmol) in 4 cm3 HBr (47%) were added
drop-wise and refluxed for 90min. The reaction mixture was
poured into 15cm3 ice=water, the precipitate was separated by
centrifugation, and washed with H2O several times. The prod-
uct was dried in vacuum and 40 mg 4 were isolated (92%
yield). Mp 275ꢁC (dec); Rf ¼ 0.45 (CHCl3=MeOH¼ 9=1);
1H NMR (500 MHz, DMSO-d6, 30ꢁC): ꢂ ¼ 12.31 (s, 8-OH),
12.29 (s, 1-OH), 11.35 (s, 30-H), 10.85 (s, 3-OH), 7.63 (s, 60-
H), 6.83 (s, ar-H5), 6.74 (s, ar-H7), 6.43 (s, ar-H4), 6.24 (s, ar-
H2), 4.86 (s, 6-CH2), 4.36 (s, 4a-CH2). 1.78 (s, 50-CH3) ppm;
13C NMR (125MHz, DMSO-d6, 30ꢁC): ꢂ ¼ 190.9 (C9), 164.4
(C3), 164.2 (C1), 163.7 (C40), 161.7 (C8), 151.0 (C20), 144.6
(C6), 141.2 (C60), 117.2 (C8a), 116.7 (C5), 113.2 (C7), 109.2
(C9a), 108.4 (C50), 107.4 (C4), 100.5 (C2), 49.8 (6-CH2-),
32.4 (C10), 11.9 (50-CH3) ppm; NOESY (DMSO-d6, 30ꢁC):
8-OH$ ar-H7, 1-OH$ ar-H2, 3-OH $ ar-H4 and ar-H2,

1134
D. Geißlmeir, H. Falk
50.8 (10-CH2-, 11-CH2-), 12.9 (50-CH3, 500-CH3) ppm – C3a,
C3b, C6b, C7b, C7c, C13b, C14b and C14c not visible;
NOESY (DMSO-d6, 30ꢁC): 10-CH2- and 11-CH2- $ 60-H
and 600-H, 50-CH3 and 500-CH3 $ 60-H and 600-H; COSY
(DMSO-d6): 10-CH2- and 11-CH2- $ 10-CH2- and 11-CH2-;
HMBC (DMSO-d6): 1-OH and 6-OH$ C1 and C6, C6a
and C14a, C2 and C5, 8-OH and 13-OH $ C8 and C13,
C12 and C9, C7a and C13a, ar-H9 and ar-H12 $ C8 and
C13, C10a and C10b, C7a and C13a, 60-H and 600-H$ C40
and C400, C50and C500, ar-H2 and ar-H5 $ C1 and C6, C6a
and C14a, 10-CH2- and 11-CH2- $ C50 and C500, C10 and
C11, C10a and C10b, 50-CH3 and 500-CH3 $ C20 and C200,
C60 and C600; HSQC data were according to structure; ESI-
MS (acetone=MeOH¼ 1=1, 1 vol% HCOOH, positive ion
mode): m=z ¼ 753 ([M þ H]þ); IR (KBr): ꢃꢀ¼ 3501, 3064,
2925, 2854, 1684, 1586, 1550, 1497, 1430, 1374, 1244,
1186, 1114, 859, 785, 721 cmꢂ1; UV-Vis (DMSO, c ¼ 1.812ꢀ
10ꢂ5 mol dmꢂ3): lmax (") ¼ 603 (18433), 557 (8278), 345
(9437) nm (dm3 molꢂ1 cmꢂ1); UV-Vis (acetone, c ¼ 3.986 ꢀ
10ꢂ5 mol dmꢂ3): lmax (") ¼ 600 (24561), 555 (12017) nm
(dm3 molꢂ1 cmꢂ1); UV-Vis (THF, c ¼ 3.986 ꢀ 10ꢂ5 mol dmꢂ3):
lmax (") ¼ 605 (17612), 559 (9107) nm (dm3 molꢂ1 cmꢂ1);
UV-Vis (EtOH (80%), c ¼ 3.986ꢀ 10ꢂ5 mol dmꢂ3): lmax (") ¼
595 (17410), 551 (9057) nm (dm3 molꢂ1 cmꢂ1); fluorescence
(DMSO, c ¼ 3.98 ꢀ 10ꢂ8 mol dmꢂ3, lex ¼ 550 nm): lem (rel.
int.) ¼ 607 (100), 658 (30) nm, Ff ¼ 0.11; fluorescence (ace-
tone, c ¼ 7.9 ꢀ 10ꢂ8 mol dmꢂ3, lex ¼ 550 nm): lem (rel. int.) ¼
605(100), 657 (29) nm; fluorescence (THF, c ¼ 3.98ꢀ
10ꢂ8 mol dmꢂ3, lex ¼ 550 nm): lem (rel. int.) ¼ 609 (100), 655
ble; NOESY (DMSO-d6, 30ꢁC): NH$ ar-H200 and ar-H600,
60-H$ 50-H and 6-CH2-, ar-H5 and ar-H7 $ 6-CH2-, 8-
OCH3 $ ar-H7, 1-OCH3 ar-H2, 3-OCH3 $ ar-H2 and ar-H4;
HMBC (DMSO-d6): NH$ Bz-C¼ O, 60-H$ C20and 6-CH2,
ar-H200 and ar-H600 $ C100, C300 and C500, ar-H5 and ar-H7 $
C6, C10a, C8, C8a and 6-CH2-, ar-H300 and ar-H500 $ C600,
C200 and C400, 50-H$ C60 and C40, ar-H4$ C10, C3 and C4a,
ar-H2 $ C9, C1, C3 and C9a, 8-OCH3 $ C8, 1-OCH3 $ C1,
3-OCH3 $ C3; HSQC data were according to structure;
ESI-MS (MeOH þ 1 vol% HCOOH, positive ion mode):
m=z ¼ 526 ([M þ H]þ); IR (KBr): ꢃꢀ¼ 3527, 2941, 2840,
1669, 1599, 1565, 1487, 1458, 1353, 1323, 1248, 1070,
1018, 945, 753, 704 cmꢂ1; UV-Vis (CHCl3): lmax ¼ 400 (16),
265 (100) nm (rel. int.).
4-Amino-1-((4,5,7-trihydroxy-10-oxo-9,10-dihydroanthracen-
2-yl)methyl)pyrimidin-2(1H)-one (8, C29H23N3O7)
An Ar-flushed solution of 81mg 7 (0.154mmol) in 15cm3
glacial acetic acid was heated to reflux under vigorous stirring.
Then 278mg SnCl2 ꢀ 2H2O (1.23 mmol) dissolved in 10cm3
HBr (47%) was added dropwise. After 45min the reaction
mixture was poured into ice=water, stirred for another 30 min,
and extracted with EtOAc three times. The organic layer was
evaporated, the residue was suspended in water, and centri-
fuged. After the product was washed with H2O two times and
dried over P2O5 in vacuum 50mg 8 were obtained (89%
yield). According to NMR data 8 underwent tautomerization.
Mp 243ꢁC (dec); Rf ¼ 0.29 (CHCl3=MeOH¼ 15=1); 1H NMR
(500MHz, DMSO-d6, 30ꢁC): ꢂ ¼ 12.30 (s, 8-OH), 12.28 (s,
1-OH), 10.87 (s, 3-OH), 9.09 (bs, ¼NH), 8.05 (bs, 30-H), 8.03
(d, 60-H, J ¼ 7.75Hz), 6.87 (s, ar-H5), 6.78 (s, ar-H7), 6.43 (s,
ar-H4), 6.24 (s, ar-H2), 6.03 (d, 50-H, J ¼ 7.75Hz), 4.99 (s,
6-CH2-), 4.35 (s, 2H, 10-H2) ppm; 13C NMR (125 MHz,
DMSO-d6, 30ꢁC): ꢂ ¼ 191.0 (C9), 165.3 (C3), 164.7 (C1),
161.8 (C8), 160.3 (C40), 149.4 (C60), 148.9 (C20), 145.0
(C4a), 144.2 (C6), 142.6 (C10a), 117.4 (C5), 114.5 (C8a),
113.2 (C7), 108.5 (C9a), 107.5 (C4), 101.0 (C2), 94.1 (C50)
51.4 (6-CH2-), 32.5 (C10) ppm; NOESY (DMSO-d6, 30ꢁC):
8-OH$ ar-H7, 1-OH$ ar-H2, 3-OH$ ar-H2 and ar-H4,
N¼H $ 50-H, 60H $ 50H and 6-CH2-, ar-H5 $ 10-H2 and
6-CH2-, ar-H7$ 6-CH2-; HMBC (DMSO-d6): 8-OH$ C8,
1-OH$ C1, 3-OH$ C3, 60-H$ C40C50and 6-CH2-, ar-
H5$ C6, C10a, C10 and 6-CH2-, ar-H7 $ C8, C8a and C6,
ar-H4 $ C3, C4a and C10, ar-H2 $ C1, C3 and C9a, 6-
CH2- $ C6, C5, C7 and C60, 10H2 $ C8a, C9a, C10a, C4a,
C4 and C5; HSQC data were according to structure; ESI-
MS (MeOHþ 1 vol% NH3, negative ion mode): m=z ¼ 364
([M ꢂ H]þ).
(31) nm; fluorescence (EtOH 80%, c ¼ 3.98ꢀ 10ꢂ8 mol dmꢂ3
lex ¼ 550 nm): lem (rel. int.) ¼ 600 (100), 653 (34) nm.
,
N-(2-Oxo-1-((4,5,7-trimethoxy-10-oxo-9,10-dihydroan-
thracen-2-yl)methyl)-1,2-dihydropyrimidin-4-yl)benzamide
(7, C29H23N3O7)
A mixture of 114 mg 2 (0.291 mmol), 88 mg benzoylcytosine
[5] (0.408mmol), and 100 mg K2CO3 (0.72 mmol) was dis-
solved in 60 cm3 DMF. The Ar-flushed solution was heated
to 80ꢁC and stirred for 18 h. The solvent was evaporated,
the residue was dissolved in CHCl3, and washed with H2O
several times. The organic layer was dried (MgSO4) and
CHCl3 was evaporated. The crude product was purified by
column chromatography (silica gel, CHCl3=MeOH¼ 15=1)
and 127 mg 7 were obtained (83% yield). Mp 226–228ꢁC;
Rf ¼ 0.39 (CHCl3=MeOH ¼ 15=1); 1H NMR (500 MHz,
DMSO-d6, 30ꢁC): ꢂ ¼ 11.21 (bs, NH), 8.39 (d, 60-H, J ¼
7 Hz), 8.01 (m, ar-H200, ar-H600), 7.63 (m, ar-H400), 7.56 (s,
ar-H5, ar-H7), 7.52 (m, ar-H300, ar-H500), 7.39 (d, 50-H,
J ¼ 7 Hz), 7.16 (d, ar-H4, J ¼ 3 Hz), 6.99 (d, ar-H2, J ¼
3 Hz), 5.17 (s, 6-CH2-), 3.93 (s, 8-OCH3), 3.91 (s, 1-OCH3),
3.90 (s, 3-OCH3) ppm; 13C NMR (125 MHz, DMSO-d6,
30ꢁC): ꢂ ¼ 183.4 (C10), 182.9 (C9), 179.7 (C40), 167.3
(Bz-C ¼ O), 163.4 (C3), 161.1 (C1), 159.0 (C8), 155.3 (C20),
150.5 (C60), 142.9 (C6), 135.6 (C4a), 134.1 (C10a), 132.7
(C100), 132.6 (C400), 128.6 (C200), 128.5 (C300), 124.6 (C600),
122.8 (C8a), 118.5 (C7 or C5), 117.5 (C9a), 116.8 (C7 or C5),
104.4 (C2), 102.5 (C4), 96.5 (C50), 56.4 (8-OCH3) 56.3
(1-OCH3), 55.9 (3-OCH3), 52.5 (6-CH2-) ppm; C500 not visi-
10,13-Bis((4-amino-2-oxopyrimidin-1(2H)-yl)methyl)-
1,3,4,6,8,15-hexahydroxydibenzo[a,o]perylene-7,16-dione
(9, C38H24N6O10)
An Ar-flushed, light protected mixture of 60 mg
8
(0.164mmol), 2.3 mg FeSO4 ꢀ 7H2O (0.008mmol), and 86mg
pyridine-N-oxide (0.903mmol) in 3.5 cm3 dry pyridine and
0.3 cm3 dry piperidine was heated to reflux and stirred for
1 h. Then the reaction mixture was cooled to room tempera-
ture, poured into 30 cm3 2 N HCl, and stirred for 30min. The

Nucleo-base derivatives of hypericin
1135
precipitate was centrifuged, washed three times with HCl
(3%) and three times with H2O. The residue was dried over
P2O5 in vacuum and 28.4mg 9 were obtained (48% yield).
Due to its light sensitivity isolation was only possible as
a mixture with the light induced following product 10.
Characterization could only be achieved by mass spectrometry
and UV-Vis spectrometry. Mp >350ꢁC; ESI-MS (MeOHþ 1
vol% NH3, negative ion mode): m=z ¼ 723 ([M ꢂ H]þ); UV-
Vis (acetone=MeOH ¼ 3=1): lmax ¼ 585 (100), 550 (95) nm
(rel. int.).
(C70), 145.3 (C40), 142.3 (C6), 132.9 (C100) 132.4 (C200,
C600), 132.2 (C400), 128.8 (C300, C500), 127.8 (C4a), 125.4
(C60), 122.7 (C10a), 121.8 (C8a), 118.8 (C5), 117.5 (C9a),
117.1 (C7), 105.4 (C2), 102.8 (C4), 56.2 (1-OCH3), 56.0 (8-
OCH3), 55.8 (3-OCH3), 46.5 (6-CH2–) ppm; NOESY
(DMSO-d6, 30ꢁC): 6-CH2– $ 90-H, ar-H5 and ar-H7, ar-
H2$ 1-OCH3 and 3-OCH3, ar-H4 $ 3-OCH3, ar-H7 $ 8-
OCH3; HMBC (DMSO-d6): 90-H$ C20 and C70, 40-H$
C20, C40 and C60, Bz-H200 and Bz-H600 $ Bz-C¼ O, C100,
C600, C300 and C500, Bz-H400 $ C300 and C500, ar-H5 $ C10,
C6, C10a, C7 and 6-CH2-, ar-H7 $ C9, C6, C8a and
6-CH2–, ar-H4 $ C3, C4a, C9a and C2, ar-H2 $ C1, C3,
C9a, 6-CH2- $ cC90 and C2, 1-OCH3 $ C1, 8-OCH3 $ C8,
3-OCH3 $ C3; HSQC data were according to structure; ESI-
MS (MeOHþ 1 vol% HCOOH, positive ion mode): m=z ¼
550 ([M þ H]þ); IR (KBr): ꢃꢀ¼ 3503, 3090, 2924, 2851,
1670, 1597, 1507, 1457, 1323, 1247, 1204, 1162, 1070,
1018, 946, 876, 799, 753 cmꢂ1; UV-Vis (CHCl3): lmax ¼ 403
403 (8), 281 (100) nm (rel. int.).
3,4-Bis((4-amino-2-oxopyrimidin-1(2H)-yl)methyl)-
1,6,8,10,11,13-hexahydroxyphenanthro[1,10,9,8-opqra]-
perylene-7,14-dione (10, C38H22N6O10)
A vigorously stirred solution of 25mg 9 (0.0345 mmol) in
2000 cm3 acetone=ethanol ¼ 3=1 was irradiated for 120 min
by means of a 700 W Hg high pressure lamp with fluorescence
screen. The solvent was evaporated and the residue was dried
over P2O5 in vacuum. The crude product was washed several
times with CHCl3 and 22 mg 10 were obtained (88% yield).
Due to low solubility no 13C and 2D NMR experiments were
possible. Mp >350ꢁC; 1H NMR (500 MHz, DMSO-d6, 30ꢁC):
ꢂ ¼ 18.63 (bs, 3-OH, 4-OH), 14.72 (s, 1-OH, 6-OH), 14.10
(s, 8-OH, 13-OH), 7.78 (d, J ¼ 10Hz, 60-H, 600-H), 7.69
(d, J ¼ 10 Hz, 50-H, 500-H), 7.36 (s, ar-H9, ar-H12), 6.62
(s, ar-H2, ar-H5), 4.92 (s, 10-CH2-, 11-CH2-) ppm, NH2
not visible; ESI-MS (MeOHþ 1 vol% NH3, negative
ion mode): m=z ¼ 721 ([M ꢂ H]þ); IR (KBr): ꢃꢀ¼ 3567,
2925, 2854, 1733, 1684, 1653, 1457, 1374, 1271, 1176, 951,
776 cmꢂ1; UV-Vis (acetone=EtOH ¼ 3=1): lmax ¼ 600 (100),
550 (25) nm (rel. int.); UV-Vis (DMSO, c ¼ 1.26 ꢀ
10ꢂ4 mol dmꢂ3): lmax (") ¼ 602 (1968), 557 (1413) nm
(dm3 molꢂ1 cmꢂ1); UV-Vis (EtOH 80% þ1 vol% 50mM
NaOH, c ¼ 6.7 ꢀ 10ꢂ6 mol dmꢂ3): lmax (") ¼ 595 (671), 551
(358) nm (dm3 molꢂ1 cmꢂ1); fluorescence (DMSO, c ¼ 1.25 ꢀ
10ꢂ6 mol dmꢂ3, lex ¼ 550 nm): lem (rel. int.) ¼ 607 (100), 656
(26) nm.
N-(9-((4,5,7-Trihydroxy-10-oxo-9,10-dihydroanthracen-2-
yl)methyl)-9H-purin-6-yl)benzamide (12, C20H15N5O4)
An Ar-flushed solution of 42 mg 11 (0.0766 mmol) in 15cm3
glacial acetic acid and 5 cm3 HBr (47%) was heated to reflux.
Then 138 mg SnCl2 ꢀ 2H2O (0.612 mmol) in 5 cm3 HBr (47%)
was added and the reaction mixture was stirred for 90min.
After cooling to room temperature the reaction mixture was
poured into ice=H2O, stirred for another 30 min, and extracted
with EtOAc several times. The organic layer was washed with
1 N NaOH and H2O, dried (MgSO4), and EtOAc was evapo-
rated. The residue was dried in vacuum over P2O5 and 17 mg
12 were obtained (57% yield). Due to its rapid decomposition
in DMSO-d6, characterization by means of 13C and 2D NMR
experiments was not possible. Mp 272ꢁC (dec); Rf ¼ 0.16
(CHCl3=MeOH¼ 15=1); 1H NMR (500MHz, DMSO-d6,
30ꢁC): ꢂ ¼ 12.89 (bs, NH2), 12.28 (s, 8-OH), 12.26 (s,
1-OH), 10.85 (s, 3-OH), 8.41 (s, 20-H), 7.93 (s, 70-H), 6.83
(s, ar-H5), 6.73 (s, ar-H7), 6.42 (s, ar-H4), 6.23 (s, ar-H2), 5.59
(s, 6-CH2–), 4.32 (s, 10-H2) ppm; ESI-MS (MeOH þ 1 vol%
NH3, negative ion mode): m=z ¼ 388 ([M ꢂ H]þ).
N-(9-((4,5,7-Trimethoxy-9,10-dioxo-9,10-dihydroanthracen-
2-yl)methyl)-9H-purin-6-yl)benzamide (11, C30H23N5O6)
A mixture of 50mg 2 (0.128 mmol), 86mg benzoyladenine
[6] (0.358mmol), 35mg K2CO3 (0.256mmol), and 5 mg KI
was dissolved in 50 cm3 DMF. The Ar-flushed reaction mix-
ture was heated to 80ꢁC and stirred for 24h. Then DMF was
evaporated and the residue was dissolved in CHCl3. The or-
ganic layer was washed with H2O several times and dried
(MgSO4). After evaporation of the solvent and purification
by means of column chromatography (CHCl3=MeOH¼
15=1) 38 mg 11 were obtained (54% yield). Mp 214–216ꢁC;
Rf ¼ 0.20 (CHCl3=MeOH ¼ 15=1); 1H NMR (500MHz,
DMSO-d6, 30ꢁC): ꢂ ¼ 11.16 (bs, –NH–), 8.76 (s, 90-H), 8.69
(s, 40-H), 8.05 (m, Bz-H200, Bz-H600), 7.67 (s, ar-H5), 7.64
(m, Bz-H400), 7.56 (m, Bz-H300, Bz-H500), 7.53 (s, ar-H7),
7.14, d, J ¼ 2.3Hz, ar-H4), 6.98 (d, J ¼ 2.3Hz, ar-H2), 5.65
(s, 6-CH2–), 3.92 (s, 1-OCH3), 3.91 (s, 8-OCH3), 3.89 (s,
N,N0-(9,90-(1,3,4,6,8,15-Hexahydroxy-7,16-dioxo-7,16-
dihydrodibenzo[a,o]perylene-10,13-diyl)bis(methylene)bis-
(9H-purine-9,6-diyl))dibenzamide (13, C40H24N10O8)
An Ar-flushed mixture of 17mg 12 (0.0432 mmol), 0.6 mg
FeSO4 ꢀ 7H2O (0.002 mmol), and 22.6mg pyridine-N-oxide
(0.238mmol) in 2 cm3 pyridine and 0.2cm3 piperidine was
heated to reflux and stirred for 1 h. The reaction mixture
was cooled to room temperature, poured into 20cm3 3 N
HCl and stirred for another 30min. The precipitate was cen-
trifuged, washed three times with HCl (3%) and two times
with H2O. The product was dried in vacuum over P2O5 and
15mg 13 were obtained (89% yield). Due to its light-sensitiv-
ity isolation was only possible as a mixture with the light-
induced following product 14. Characterization could only
be achieved by mass spectrometry and UV-Vis spectrometry.
Mp >350ꢁC; ESI-MS (MeOH þ 1 vol% NH3, negative ion
mode): m=z ¼ 771 ([Mꢂ H]þ); UV-Vis (acetone=MeOH¼
13
3-OCH3) ppm; C NMR (125MHz, DMSO-d6, 30ꢁC):
ꢂ ¼ 182.9 (C10), 181.3 (C9), 165.3 (Bz-C ¼ O), 163.5 (C1),
161.0 (C3), 159.1 (C8), 152.8 (C90), 152.5 (C20), 150.2

1136
D. Geißlmeir, H. Falk
3=1 þ 0.15 vol% NH3 32%): lmax ¼ 578 (94), 548 (100) nm
ppm, C3a0, C40and C60 could not be resolved; NOESY
(DMSO-d6, 30ꢁC): 60-NH $ Bz-H200 and Bz-H600, ar-H7 $ 8-
OCH3, ar-H4 $ 3-OCH3, ar-H2 $ 1-OCH3 and 3-OCH3, 6-
CH2- $ 20-H, ar-H5 and ar-H7; HMBC (DMSO-d6, 30ꢁC):
20-H$ C7a0, Bz-H200 and Bz-H600 $ Bz-C¼ O, C100, C300
and C500, ar-H5 $ C10a and C7, ar-H7 $ C9, C6, C8 and
C8a, ar-H4 $ C10, C3 and C4a, ar-H2 $ C1, C3 and C9a,
6-CH2- $ C6, C20, C5 and C7, 1-OCH3 $ C1, 8-OCH3 $ C8,
3-OCH3 $ C3; HSQC data were according to structure;
ESI-MS (MeOH þ 1 vol% HCOOH, positive ion mode):
m=z ¼ 566 ([M þ H]þ); IR (KBr): ꢃꢀ¼ 3567, 2924, 2848,
1918, 1705, 1664, 1597, 1560, 1507, 1458, 1380, 1251,
1068, 946, 874, 821, 755 cmꢂ1; UV-Vis (CHCl3): lmax ¼ 405
405 (24), 276 (100) nm (rel. int.).
(rel. int.).
3,4-Bis((6-amino-9H-purin-9-yl)methyl)-1,6,8,10,11,13-hexa-
hydroxyphenanthro[1,10,9,8-opqra]perylene-7,14-dione
(14, C40H22N10O8)
A vigorously stirred solution of 14mg 13 (0.018mmol) in
2000 cm3 acetone=MeOH¼ 1=1 and 3 cm3 NH3 (32%) was
irradiated for 45 min by means of a 700 W Hg high pressure
lamp with fluorescence screen. The solvent was evaporated
and the residue was dried in vacuum over P2O5. After purifi-
cation by washing the crude product several times with CHCl3
5 mg 14 were obtained (36% yield). Due to the instability and
low solubility of the product a characterization by NMR
experiments was not possible. Mp >350ꢁC; Rf ¼ 0.0 (CHCl3=
MeOH ¼ 1=1); ESI-MS (MeOHþ 1 vol% NH3, negative ion
mode): m=z ¼ 769 ([M ꢂ H]þ); IR (KBr): ꢃꢀ¼ 3447, 2925,
Acknowledgement
2853, 1700, 1684, 1594, 1521, 1378, 1244, 847, 778 cmꢂ1
;
We are grateful to Dr. G. Kada and DI T. Gattringer of the
Institute of Biophysics, Johannes Kepler University Linz, for
granting access to the fluorescence microscope and recording
data.
UV-Vis (acetone=MeOH ¼ 1=1 þ 0.15 vol% NH3): lmax
¼
596 (100), 552 (70) 457 (84) nm (rel. int.); UV-Vis (DMSO,
c ¼ 5.19ꢀ 10ꢂ5 mol dmꢂ3): lmax (") ¼ 602 (3892), 557 (3102)
nm (dm3 molꢂ1 cmꢂ1); UV-Vis (EtOH 80% þ1 vol% 50mM
NaOH, c ¼ 5.6 ꢀ 10ꢂ5 mol dmꢂ3): lmax (") ¼ 595 (3143), 551
(1946) 468 (2304) nm (dm3 molꢂ1 cmꢂ1); fluorescence
(DMSO, c ¼ 7.67 10ꢂ7 mol dmꢂ3, lex ¼ 550 nm): lem (rel.
int.) ¼ 606 (100), 651 (31) nm.
References
1. For reviews see: Falk H (1999) Angew Chem 111:3306,
Angew Chem Int Ed Engl 38:3116; Waser M, Falk H
(2007) Curr Org Chem 11:547
2. Frieden M, Giraud M, Reese CB, Song Q (1998) J Chem
Soc Perkin Trans 1:2827
N-(6-Oxo-9-((4,5,7-trimethoxy-9,10-dioxo-9,10-dihydro-
anthracen-2-yl)methyl)-6,9-dihydro-1H-purin-2-yl)-
benzamide (15, C30H23N5O7)
3. Obermu¨ller RA, Falk H (2001) Monatsh Chem 132:1519
4. Falk H, Meyer J, Oberreiter M (1993) Monatsh Chem
124:339
5. Lagoja IM, Pochet S, Boudou V, Little R, Lescrinier E,
Rozenski J, Herdewijn P (2003) J Org Chem 68:1867
6. Bullock MW, Hand JJ, Stokstad ELR (1957) J Org Chem
22:568
7. Zikan V, Radl S (1988) CS 252622
8. Hagenbuchner K, Falk H (1999) Monatsh Chem
130:1075
9. Zeng Z, Qiao R, Zhou J, Xia S, Zhang Y, Liu Y, Chen J,
Wang X, Zhang B (2007) J Phys Chem B 111:3742
10. Pasternack RF, Brigandi RA, Abrams MJ, Williams AP,
Gibbs EJ (1990) Inorg Chem 29:4483
11. Miskovsky P, Sureau F, Chinsky L, Turpin PY (1995)
Photochem Photobiol 62:546
12. Colasanti A, Kisslinger A, Liuzzi R, Quarto M, Riccio P,
Roberti G, Tramontano D, Villani F (2000) J Photochem
Photbiol B 54:103
13. Williams ATR, Winfield SA, Miller JN (1983) Analyst
108:1067
14. Tran TNH, Falk H (1996) Monatsh Chem 127:717
An Ar-flushed mixture of 100 mg 2 (0.256 mmol), 131 mg ben-
zoylguanine [7] (0.513 mmol), 30mg K2CO3 (0.217mmol),
and 5 mg KI in 50 cm3 DMF was heated to 80ꢁC and stirred
for 24 h. After cooling to room temperature DMF was evapo-
rated and the residue was dissolved in CHCl3. The organic
layer was washed with HCl (1%) and H2O, dried (MgSO4),
and CHCl3 was evaporated. The crude product was purified
by column chromatography (CHCl3=MeOH¼ 15=1) and
58mg 15 were obtained (40% yield). Mp >350ꢁC; Rf ¼ 0.47
(CHCl3=MeOH ¼ 9=1); 1H NMR (500MHz, DMSO-d6,
30ꢁC): ꢂ ¼ 12.41 (s, 50-H), 11.91 (s, 60-NH), 8.50 (s, 20-H),
8.04 (m, Bz-H200, Bz-H600), 7.66 (m, ar-H5, Bz-H400), 7.56
(m, Bz-H300, Bz-H500), 7.53 (s, ar-H7), 7.13 (s, ar-H4), 6.98
(s, arꢀ H2), 5.66 (s, 6-CH2-), 3.91 (s, 1-OCH3), 3.90 (s, 8-
OCH3), 3.89 (s, 3-OCH3) ppm; 13C NMR (125MHz,
DMSO-d6, 30ꢁC): ꢂ ¼ 185.0 (C9), 184.8 (C10), 170.2 (Bz-
C ¼ O) 165.4 (C1), 163.0 (C3), 160.9 (C8), 146.4 (C20),
145.0 (C6), 135.4 (C100), 135.1 (C400), 134.4 (C300 or C500),
130.5 (C300 or C500), 130.3 (C200 or C600), 129.2 (C200 or
C600), 128.6 (C10a), 127.9 (C4a), 124.8 (C8a), 119.2 (C9a),
118.5 (C7), 117.4 (C5), 113.3 (C7a0), 106.6 (C2), 104.3 (C4),
57.5 (1-OCH3), 57.2 (8-OCH3), 56.7 (3-OCH3), 50.6 (6-CH2-)
¨
Verleger: Springer-Verlag GmbH, Sachsenplatz 4–6, 1201 Wien, Austria. – Herausgeber: Osterreichische Akademie der Wissenschaften, Dr.-Ignaz-Seipel-Platz 2,
¨
1010 Wien, und Gesellschaft Osterreichischer Chemiker, Eschenbachgasse 9, 1010 Wien, Austria. – Redaktion: Getreidemarkt 9=163-OC, 1060 Wien, Austria. –
Satz und Umbruch: Thomson Press Ltd., Chennai, India. – Offsetdruck: Krips bv, Kaapweg 6, 7944 HV Meppel, The Netherlands. – Verlagsort: Wien. –
Herstellungsort: Meppel. – Printed in The Netherlands.