A novel sunscreen agent having antimelanoma activity

Article abstract of DOI:10.1016/S0014-827X(03)00195-2

A novel series of eight dibenzoylmethane derivatives having both sunscreen and cytotoxic activity has been obtained by derivatizing commercial dibenzoyl methanes. Four human cancer cell lines (MCF 7 (breast), NCI ADR (breast expressing the multidrug resis

Full text of DOI:10.1016/S0014-827X(03)00195-2

Il Farmaco 58 (2003) 1163ꢀ1169
/
www.elsevier.com/locate/farmac
A novel sunscreen agent having antimelanoma activityꢀ
a,1
Marisa A. Nogueira , Eva G. Magalh a˜ es , Aderbal F. Magalh a˜ es ,
a
a
a
D e´ bora N. Biloti , Antonio Laverde, Jr. , Francisco B.T. Pessine ,
a
a
b
b
b
a,
Jo a˜ o E. Carvalho , Luciana K. Kohn , M a´ rcia A. Ant oˆ nio , Anita J. Marsaioli *
a
Instituto de Qu ´ı mica, Universidade Estadual de Campinas, CP 6154, 13083-970 Campinas, SP, Brazil
Centro Pluridisciplinar de Pesquisas Qu ´ı micas, Biol o´ gicas e Agr ´ı colas, Universidade Estadual de Campinas, CP 6171, 13083-970 Campinas, SP, Brazil
Received 14 February 2003; accepted 10 July 2003
b
Abstract
A novel series of eight dibenzoylmethane derivatives having both sunscreen and cytotoxic activity has been obtained by
derivatizing commercial dibenzoyl methanes. Four human cancer cell lines (MCF 7 (breast), NCI ADR (breast expressing the
multidrug resistance phenotype), NCI 460 (lung) and UACC 62 (melanoma)) were used for the cytotoxic assay. Eight among the 19
dibenzoylmethane derivatives showed cytotoxicity against these four cell lines. Absorption spectroscopies revealed that these
compounds can be used as sunscreens against UV radiation.
´
#
2003 Editions scientifiques et m e´ dicales Elsevier SAS. All rights reserved.
Keywords: Dibenzoylmethane derivatives; UV sunscreen; Cancer; Melanoma
1
. Introduction
anti-tumor activities. In female rats, DBM was an
effective inhibitor of in vivo mammary tumors pro-
moted by 7,12-dimethylbenz[a]anthracene and of 7,12-
tetradenoylphorbol-13-acetate-induced skin tumors in
mice [2]. Recently, the effect of DBM on prostate cancer
cell growth has been reported [3]. The sunscreen
Skin cancer is one of the common malignancies in
man, showing increasing occurrence in Europe and in
the United States. There are three recognized types of
skin cancer: basal cell carcinoma, squamous carcinoma,
and melanoma. There is evidence from analytical studies
that the increase in melanoma incidence is the result of
intermittent recreational sun exposure and severe sun-
burns, which are particularly harmful in childhood [1].
These cancers frequently occur on the sun-exposed areas
†
†
derivatives from DBM, Eusolex 8020 and Parsol
1789, are more efficient in the UVA range because they
prevent the penetration of the radiation to vital cell
components and block over production of oxygen-
derived free radicals [4]. The use of sunscreen products
has been recommended by many health care organiza-
tions as a means to reduce skin damage produced by UV
radiation from sunlight [1].
(
face, ears, scalp, etc.). Consequently, broad-spectrum
sunscreens displaying appropriate UVA (320ꢀ400 nm),
UVB (280ꢀ320 nm) and UVC (200ꢀ280 nm) protection
/
/
/
and novel mechanisms of action are in demand to
combat this disease [1].
Dibenzoylmethane (DBM, 1,3-diphenyl-propane-
dione), shown in Fig. 1, is a small b-diketone compound
and sunscreen, which display anti-inflammatory and
In the natural products realm, DBM and its deriva-
tives have been found as constituents of some plants
belonging to the Leguminosae family, as minor consti-
tuent of licorice [5], and are classified as a rare kind of
flavonoid. The natural DBM 4 was reported for the first
time in Lonchocarpus latifolius (Wild) DC and showed
biological activity [6,7].
Compounds protecting human cells against UV
radiation (sunscreen) and against skin cancer would
certainly find application in both medicine and cos-
metics. This prompted us to search for 2-alkyl-1,3-
ꢀ
Patent request: INPI 6583-8 (Brazil).
*
Corresponding author.
E-mail address: anita@iqm.unicamp.br (A.J. Marsaioli).
1
Present address: Faculdade de Farm a´ cia, Universidade Estadual
do Oeste do Paran a´ , 85814-110 Cascavel, PR, Brazil.
´
0
014-827X/03/$ - see front matter # 2003 Editions scientifiques et m e´ dicales Elsevier SAS. All rights reserved.
doi:10.1016/S0014-827X(03)00195-2

1164
M.A. Nogueira et al. / Il Farmaco 58 (2003) 1163ꢀ1169
/
compounds. The products were characterized by high-
13
1
resolution mass spectrometry (HRMS) and H and
C
NMR spectroscopies. Alkylation of the DBMs 1ꢀ
/
3
drastically inhibited the keto-enolic equilibrium present
in these compounds. The major spectroscopic evidences
are the lack of a chelated enol hydrogen at d 12ꢀ17 in
/
1
the H NMR spectra and the hypsochromic shift of the
UV maximum absorption bands, which shifted from
lmax
:
/
350 nm (for 1ꢀ
/
3) to lmax
:
/
250 nm (for 5ꢀ13).
/
This phenomenon was assigned to the steric strain of the
enolic form that now has two substituents located on the
double bond, as shown in Fig. 3, thereby diminishing
the enol contribution in the keto-enolic equilibrium,
which is physically evident in the hypsochromic shift in
the UV. This effect limited the application of com-
pounds (5, 6, 7, 10, 13) to UVB/UVC sunscreen agents
while maintaining their potentiality as cytotoxic com-
pounds.
Fig. 1. Chemical structures of DBM (1) and derivatives.
diphenyl-propanedione derivatives (DBM derivatives)
with chemopreventive and photoprotection effects
against skin cancer (melanoma) and UVB/UVC radia-
tion, respectively. This paper describes the synthesis of
A second series of derivatives was obtained by
reducing the diketones 5ꢀ
/
13 with NaBH at ꢁ
/
10 8C
4
various DBM derivatives (5ꢀ
/
22), shown in Fig. 2, and
in methanol producing ketols (14ꢀ
The H NMR spectra of all derivatives showed absorp-
tion at ca. d 4.00 corresponding to the carbinolic
/
19) and diols (20ꢀ22).
/
the evaluation of their anticancer activity.
1
protons. The ketols (14ꢀ19) were produced as syn and
/
anti mixtures with variable diastereomeric ratios, with a
predominance of the anti isomer. The relative stereo-
2
. Chemistry
Compounds 5ꢀ
1
3
/
13 were obtained by alkylation of
chemistry of the major diol 22 was determined by
NMR as 1,2-syn and 2,3-anti. DBM asymmetric reduc-
C
†
†
DBM (1), Eusolex 8020 (2) and Parsol 1789 (3) using
potassium carbonate in acetone (Ara u´ jo, 1996). These
conditions were chosen viewing future scale up of active
1
tion, relative stereochemistry and full H NMR and
13
C
NMR details will be published elsewhere.
3
Fig. 2. Obtention of DBM derivatives. [Reaction conditions: (a) R Br, K
2
CO
3
, (CH
3
)
2
CO; (b) NaBH
4
(1 equiv.), MeOH, ꢁ10 8C; (c) NaBH
4
/
(excess), MeOH, ta.].

M.A. Nogueira et al. / Il Farmaco 58 (2003) 1163ꢀ
/1169
1165
J 17.1, 1.5 and 1.3, H-3aƒ), 5.30 (1H, t, J 6.7, H-2), 5.87
1H, ddt, J 17.1, 10.1 and 6.7, H-2ƒ), 7.45 (4H, tt, 7.8
and 1.3, H-3? and H-5?), 7.57 (2H, tt, 7.5 and 1.3, H-4?),
(
1
3
7
.96 (4H, dd, J 8.5 and 1.3, H-2? and H-6?); C NMR:
d (125.8 MHz; CDCl ; TMS) 33.57 (CH , C-1ƒ), 56.76
C
3
2
Fig. 3. The steric strain of the enolic form that now has two
substituents located on the double bond.
(CH, C-2), 117.26 (CH , C-3ƒ), 128.61 (4CH, C-3? and
2
C-5?), 128.91 (4CH, C-2? and C-6?), 133.57 (2CH, C-4?),
1
35.08 (2C , C-1?), 135.98 (CH, C-2ƒ), 195.55 (2C , C-1
o
o
3
. Experimental
and C-3); MS [m/z (% rel. int.)]: 159.07 (12), 142.70 (6),
105.02 (100); HRMS: Calc. for C H O 264.1150,
observed 264.1153.
18 16 2
1
13
H and C NMR spectra were obtained on a Varian
Inova-500 spectrometer (11.74 T) with standard pulse
(
9
/
)-1,3-Diphenyl-2-benzyl-1,3-propanedione (6) was
obtained as a colorless solid in 85% yield; m.p.: 58.3ꢀ
8.7; R ꢂ0.74 (n-hexane:ethyl acetate 8:2); IR (KBr,
1
sequences operating at 499.88 and 125.7 MHz for H
/
1
and C, respectively. The chemical shifts (d) are
3
5
/
f
ꢁ
1
1
reported in ppm using TMS (d 0) and residual CHCl
13
3
cm ): 3031.33, 1694.20, 1664.60, 999.3; H NMR: d
(500 MHz; CDCl ; TMS) 3.45 (2H, d, J 6.7, CH2 Bz),
5
H
1
d 77.00) signals as internal references for H and
(
NMR, respectively. The coupling constant (J) are in
C
3
.52 (1H, t, J 6.7, H-2), 7.16 (1H, tt, 6.6 and 2.0, H-4ƒ),
.24 (4H, m, H-2ƒ, H-3ƒ, H-5ƒ and H-6ƒ), 7.40 (4H, tt, J
hertz. All NMR samples (0.6 ml) were prepared in
CDCl . IR data were measured on a PerkinꢀElmer
model 1600 (FTIR) spectrometer using KBr pellets or
film. Mass spectra (HRMS) were recorded on a VG
Auto Spec (10 000) instrument using a 70 eV ionizing
potential.
7
/
3
7.9 and 1.3, H-3? and H-5?), 7.53 (2H, tt, 7.5 and 1.3, H-
4
NMR: dC (125.8 MHz; CDCl ; TMS) 35.21 (CH2 Bz),
13
?), 7.89 (4H, dd, J 8.5 and 1.3, H-2? and H-6?);
C
3
5
8.99 (CH, C-2), 126.63 (CH, C-4ƒ), 128.60 (4CH, C-3?
and C-5?), 128.84 (4CH, C-2ƒ, C-3ƒ, C-5ƒ and C-6ƒ),
1
28.98 (4CH, C-2? and C-6?), 133.51 (C , C-1ƒ), 135.98
o
3.1. Synthesis of the DBM derivatives: general
procedures
(2CH, C-4?), 139.05 (2C , C-1?), 195.58 (2C , C-1 and C-
o
o
3
); MS [m/z (% rel. int.)]: 209.09 (100), 131.05 (7), 105.03
(90); HRMS: Calc. for C H O 314.1307, observed
314.1306.
22 18 2
3
.1.1. Alkylation of DBM derivatives (1ꢀ
/
3) [8]
Potassium carbonate (3.0 equiv.) and DBM (1.0
(9
was obtained as a yellow solid in 82% yield; m.p.:
95.2ꢀ95.9; R ꢂ0.47 (n-hexane:ethyl acetate 8:2); IR
/
)-1,3-Diphenyl-2-propargyl-1,3-propanedione (7)
equiv.) were suspended in acetone (20 ml) and stirred
for 30 min at room temperature (r.t.). To this mixture
the alkylating reagent (alkyl bromide or benzyl bromide
or propargyl bromide, 1.0 equiv.) was added and the
mixture was stirred at r.t. overnight. The mixture was
filtered, the solvent was evaporated and the product was
/
/
f
ꢁ
1
1
(KBr, cm ): 3300.0, 1685.40, 1655.60, 977.8; H NMR:
dH (500 MHz; CDCl ; TMS) 1.98 (1H, t, J 2.7, H-3ƒ),
3
3.01 (2H, dd, J 7.0 and 2.7, H-1ƒ), 6.49 (1H, t, J 7.0, H-
2), 7.45 (4H, tt, 7.8 and 1.3, H-3? and H-5?), 7.58 (2H, tt,
7.5 and 1.3, H-4?), 7.98 (4H, dd, J 8.5 and 1.3, H-2? and
purified by preparative TLC (SiO ) using n-hexane/
2
1
3
AcOEt 80:20 v/v as eluent.
H-6?); C NMR: d (125.8 MHz, CDCl ; TMS) 19.05
C
3
(
CH , C-1ƒ), 55.56 (CH, C-2), 70.90 (CH, C-3ƒ), 81.02
o
2
3
.1.2. Reduction of DBM derivatives (5ꢀ
/
13)
(C , C-2ƒ), 128.78 (4CH, C-3? and C-5?), 128.92 (4CH,
C-2? and C-6?), 133.80 (2CH, C-4?), 135.75 (2C , C-1?),
DBM derivatives 5ꢀ13 (1.0 equiv.) were suspended in
/
o
MeOH (3 ml). To this mixture, NaBH (1.0 equiv. for
monoreduction or excess amounts for total reduction)
194.43 (2C , C-1 and C-3); MS [m/z (% rel. int.)]: 262.10
(26), 105.03 (100), 77.03 (43); HRMS: Calc. for
C H O 262.0994, observed 262.0999.
4
o
was added and it was stirred at ꢁ
/
10 8C for 30 min. The
1
8
14
2
mixture was monitored by TLC (CH Cl ), evaporated
and purified by preparative TLC using CH Cl as
eluent.
(9
panedione (8) was obtained as a colorless oil in 80%
yield; R ꢂ0.59 (n-hexane:ethyl acetate 8:2); IR (Film,
/
)-1-[(4-Isopropyl)phenyl]-2-allyl-3-phenyl-1,3 pro-
2
2
2
2
/
f
ꢁ
1
1
cm ): 1693.64, 1668.49, 1000.72; H NMR: d (500
MHz; CDCl ; TMS) 1.25 (6H, d, J 7.0, H-8?), 2.87 (2H,
H
3.1.3. Spectroscopic data of the eight compounds (Fig. 4)
that showed cytotoxicity against the human cancer cell
lines evaluated
3
m, H-1ƒ?), 2.95 (1H, hept., J 7.0, H-7?), 5.02 (1H, dtt, J
10.1, 1.7 and 1.3, H-3bƒ?), 5.10 (1H, dtt, J 17.1, 1.7 and
1.3, H-3aƒ?), 5.28 (1H, t, J 6.7, H-2), 5.88 (1H, ddt, J
17.1, 10.1 and 6.7, H-2ƒ?), 7.31 (2H, d, J 8.4, H-3? and
H-5?), 7.46 (2H, t, J 7.7, H-3ƒ and H-5ƒ), 7.58 (1H, tt, J
7.5 and 1.3, H-4ƒ), 7.92 (2H, d, J 8.4, H-2? and H-6?),
(
9
/
)-1,3-Diphenyl-2-allyl-1,3-propanedione (5) was
obtained as a colorless solid in 76% yield; m.p.: 64.9ꢀ
5.7; R ꢂ0.55 (n-hexane:ethyl acetate 8:2); IR (KBr,
/
6
/
f
ꢁ
1
1
cm ): 1694.8, 1670.2, 1007.7, 962.2; H NMR: d (500
MHz; CDCl ; TMS) 2.88 (2H, tt, J 6.7 and 1.3, H-1ƒ),
H
1
3
7.98 (2H, dd, J 8.5 and 1.3, H-2ƒ and H-6ƒ); C NMR:
d (125.8 MHz, CDCl ; TMS) 23.58 (CH , C-8?), 33.58
3
5
.03 (1H, dtt, J 10.1, 1.5 and 1.3, H-3bƒ), 5.10 (1H, dtt,
C
3
3

1166
M.A. Nogueira et al. / Il Farmaco 58 (2003) 1163ꢀ1169
/
(
(
CH , C-1ƒ?), 34.23 (CH, C-7?), 56.63 (CH, C-2), 117.11
dH (500 MHz; CDCl ; TMS) 1.99 (1H, dt, J 13.5, 5.8
3
2
CH , C-3ƒ?), 127.03 (2CH, C-3? and C-5?), 128.59 (2CH,
and 1.7, H-1aƒ?), 2.03 (1H, ddd, J 9.3, 5.0 and 1.7, H-2),
2.30 (1H, dt, J 13.5 and 8.3, H-1aƒ?), 5.02 (1H, dd, J
10.1 and 1.5, H-3bƒ?), 5.04 (1H, dt, J 17.1 and 1.5, H-
3aƒ?), 5.68 (1H, dddd, J 17.1, 10.1, 8.1 and 5.8, H-2ƒ?),
7.19 (4H, t, 7.8, H-3?, H-5?, H-3ƒ and H-5ƒ), 7.28 (2H, t,
7.5, H-4? and H-4ƒ), 7.38 (4H, d, J 8.5, H-2?, H-6?, H-2ƒ
2
C-2ƒ and C-6ƒ), 128.86 (2CH, C-3ƒ and C-5ƒ), 128.89
(
1
1
int.)]: 147.07 (100), 105.03 (35), 77.03 (16); HRMS: Calc.
for C H O 306.1619, observed 306.1620.
2CH, C-2? and C-6?), 133.49 (CH, C-4ƒ), 133.74 (C , C-
o
?), 135.22 (C-2ƒ?), 136.03 (C , C-1ƒ), 155.18 (C , C-4?),
o
o
95.13 (C , C-1), 195.65 (C , C-3); MS [m/z (% rel.
o
o
1
3
and H-6ƒ); C NMR: dC (125.8 MHz, CDCl ; TMS)
2
1
22
2
3
(
9
/
)-1-[(4-Isopropyl)phenyl]-2-propargyl-3-phenyl-
,3-propanedione (10) was obtained as a colorless oil in
0% yield; R ꢂ0.49 (n-hexane:ethyl acetate 8:2); IR
28.96 (CH , C-1ƒ?), 51.09 (CH, C-2), 72.72 (CH, C-3),
74.90 (CH, C-1), 116.89 (CH , C-3ƒ?), 125.74 (2CH, C-3ƒ
2
1
6
(
8
(
2
/
and C-5ƒ), 125.80 (2CH, C-3? and C-5?), 128.06 (2CH,
C-2ƒ and C-6ƒ), 128.51 (2CH, C-2? and C-6?), 126.94
(CH, C-4ƒ), 127.40 (CH, C-4?), 137.14 (CH, C-2?ƒ),
142.52 (C , C-1ƒ), 143.55 (C , C-1?); MS [m/z (% rel.
f
ꢁ
1
Film, cm ): 3297.22, 1693.99, 1666.24, 1323.57,
1
36.60; H NMR: dH (500 MHz; CDCl ; TMS) 1.25
3
6H, d, J 7.0, H-8?), 1.98 (1H, t, J 2.7, H-3ƒ?), 2.95 (1H,
o
o
hept., J 7.0, H-7?), 3.00 (2H, dd, J 7.0 and 2.7, H-1ƒ?),
5
5
tt, J 7.5 and 1.3, H-4ƒ), 7.92 (2H, d, J 8.4, H-2? and H-
6
NMR: d (125.8 MHz, CDCl ; TMS) 19.05 (CH , C-
1
2
3
int.)]: 209.09 (23), 143.09 (26), 129.07 (100), 107.05 (28),
.46 (1H, t, J 7.0, H-2), 7.30 (2H, d, J 8.4, H-3? and H-
?), 7.45 (2H, tt, J 7.7 and 1.3, H-3ƒ and H-5ƒ), 7.57 (1H,
77.04 (30); HRMS: Calc. for C H O 107.04969, ob-
7
5
served 107.04944.
(9)-1-(4-Methoxyphenyl)-2-benzyl-3-[(4-tertbu-
tyl)phenyl]-1,3-propanediol (23) was obtained as a
colourless oil in 90% yield; R ꢂ0.34 (n-hexane:ethyl
/
1
3
?), 7.99 (2H, dd, J 8.5 and 1.3, H-2ƒ and H-6ƒ);
C
/
C
3
2
f
ꢁ
1
ƒ?), 23.57 (CH , C-8?), 34.26 (CH , C-7?), 55.53 (CH, C-
acetate 8:2); IR (KBr, cm ): 3443.89, 2961.70, 2923.17,
2866.57, 1655.14, 1601.69, 1571.48, 1455.05, 1250.71,
3
3
), 70.79 (CH, C-3ƒ?), 81.15 (C , C-2ƒ?), 127.05 (2CH, C-
o
1
1175.96, 1033.17, 944.48; H NMR: dH (500 MHz;
? and C-5?), 128.78 (2CH, C-3ƒ and C-5ƒ), 128.88 (2CH,
C-2ƒ and C-6ƒ), 129.07 (2CH, C-2? and C-6?), 133.46
CDCl ; TMS) 1.31 (9H, s, H-8ƒ), 2.23 (1H, dtd, J 10.2;
3
(
(
(
C , C-1?), 133.72 (C , C-4ƒ), 135.79 (C , C-1ƒ), 155.49
4.5 and 2.7, H-2), 2.54 (1H, dd, J 13.6 and 4.5, H-7aƒ?),
2.82 (1H, dd, J 13.6 and 10.2, H-7bƒ?), 3.24 (1H, d, J
4.5, OH-3), 3.80 (3H, s, H-7?), 3.96* (1H, d, J 2.7, H-3),
4.75* (1H, t, J 4.5, H-1), 4.96 (1H, sl, OH-1), 6.86 (2H,
d, J 9.0, H-3? and H-5?), 7.06 (2H, d, J 7.5, H-2ƒ? and H-
6ƒ?), 7.15 (1H, t, J 7.5, H-4ƒ?), 7.18 (2H, d, J 8.6, H-3ƒ
and H-5ƒ), 7.22 (2H, d, J 8.6, H-2ƒ and H-6ƒ), 7.23 (2H,
t, J 7.5, H-3?ƒ and H-5ƒ?), 7.34 (2H, d, J 9.0, H-2? and
o
o
o
C , C-4?), 193.95 (C , C-1), 194.55 (C , C-3); MS [m/z
o
o
o
% rel. int.)]: 147.08 (100), 105.03 (48) 304.14 (6);
HRMS: Calc. for C H O 304.1463, observed
2
1
20
2
3
04.1463.
)-1-(4-Methoxyphenyl)-2-propargyl-3-[(4-tertbu-
tyl)phenyl]-1,3-propanedione (13) was obtained as a
yellow solid in 61% yield; m.p.: 79.3ꢀ79.7; R ꢂ0.53
n-hexane:ethyl acetate 8:2); IR (KBr, cm ): 1604.78,
(
9
/
/
/
f
ꢁ
1
13
(
1
H-6?); C NMR: d (125.8 MHz, CDCl ; TMS) 31.36
C
3
1
508.01, 1024.50, 843ꢀ
/
795; H NMR: dH (500 MHz;
(3CH , C-8ƒ), 30.44 (C , C-7ƒ), 53.19 (CH, C-2), 55.25
3
o
CDCl ; TMS) 1.31 (9H, s, H-8ƒ), 1.97 (1H, t, J 2.7, H-
3
(
(CH , C-7?), 72.43* (CH, C-3), 74.29* (CH, C-1), 113.49
3
3
ƒ?), 2.97 (1H, ddd, J 17.1; 7.0 and 2.7, H-1aƒ?), 3.01
1H, ddd, J 17.1; 7.0 and 2.7, H-1bƒ?), 3.85 (3H, s, H-7?),
(2CH, C-3? and C-5?), 125.31** (2CH, C-3ƒ and C-5ƒ),
125.34** (2CH, C-3ƒ? and C-5ƒ?), 126.89 (2CH, C-2ƒ and
C-6ƒ), 128.36 (2CH, C-2ƒ? and C-6ƒ?), 129.02 (2CH, C-2?
5
5
8
.39 (1H, t, J 7.0, H-2), 6.93 (2H, d, J 9.0, H-3? and H-
?), 7.45 (2H, d, J 8.6, H-3ƒ and H-5ƒ), 7.91 (2H, d, J
.6, H-2ƒ and H-6ƒ), 8.00 (2H, d, J 9.0, H-2? and H-6?);
C NMR: d (125.8 MHz, CDCl ; TMS) 19.11 (CH ,
#
#
and C-6?), 134.73 (C , C-1ƒ?), 140.38 (C , C-1?), 140.72
o
o
(C , C-1ƒ), 150.19 (C , C-4ƒ), 158.51 (C , C-4?); MS [m/z
o
o
o
1
3
(% rel. int.)]: 241.12 (15), 209.10 (13), 161.09 (27), 135.05
(100); HRMS: Calc. for C H O 241.12285, observed
241.12291.
C
3
2
C-1ƒ?), 31.00 (CH , C-8ƒ), 35.17 (C , C-7ƒ), 55.49 (CH,
3
o
18 18
2
C-2), 55.54 (CH , C-7?), 70.67 (CH, C-3ƒ?), 81.36 (C , C-
3
o
2
ƒ?), 114.11 (2CH, C-3? and C-5?), 125.86 (2CH, C-3ƒ
and C-5ƒ), 128.72 (2CH, C-2ƒ and C-6ƒ), 128.78 (C , C-
3.2. Cytotoxic activity
o
1
1
1
2
?), 131.27 (2CH, C-2? and C-6?), 133.16 (C , C-1ƒ),
o
57.55 (C , C-4ƒ), 164.05 (C , C-4?), 193.09 (C , C-1),
3.2.1. Cell culture
o
o
o
94.03 (C , C-3); MS [m/z (% rel. int.)]: 310.15 (100),
53.08 (10), 135.03 (95), 161.08 (49), 108.04 (27);
The experiments were performed using the following
human cancer cell lines: MCF 7 (breast), NCI ADR
(breast expressing the multidrug resistance phenotype),
NCI 460 (lung) and UACC 62 (melanoma). The
National Cancer Institute, Washington, USA (NCI),
kindly donated these cell lines; and stock cultures were
kept in liquid nitrogen.
o
HRMS: Calc. for C H O 348.1725, observed
3
2
3
24
3
48.1725.
,3-Diphenyl-2-allyl-1,3-propanediol (20) was ob-
tained as colorless crystal in 70% yield; m.p.: 118.6ꢀ
20.3; R ꢂ0.47 (n-hexane:ethyl acetate 8:2); IR (KBr,
cm ): 3286.49, 3026.05, 2904.39, 1638.23, 1599.08,
1
/
1
/
f
ꢁ
1
2
Cells were cultured in 25-cm flasks (Nunc Brand
Products) containing 5 ml of RPMI 1640 (Gibco BRL,
1
1
305.53, 1197.31, 1082.99, 1059.28, 997.71. H NMR:

M.A. Nogueira et al. / Il Farmaco 58 (2003) 1163ꢀ
/1169
1167
Fig. 4. Compounds that showed activity against human cancer cell line K 562 (leukemia), MCF 7 (breast), NCI ADR (breast expressing the
multidrug resistance phenotype), NCI 460 (lung) and UACC 62 (melanoma).
Fig. 5. Growth inhibitory effects of DMB derivative 22 against human cancer cell line MCF 7 (breast), NCI ADR (breast expressing the multidrug
resistance phenotype), NCI 460 (lung) and UACC 62 (melanoma) as a function of increasing concentration. Viable cells were measured using an
MTT assay and expressed as corrected units at 590 nm (nꢂ3).
/

1168
M.A. Nogueira et al. / Il Farmaco 58 (2003) 1163ꢀ1169
/
Table 1
IC50 of 1,3-propanedione and 1,3-propanediol derivatives against human cancer cells
Comp.
MCF 7 mama cancer
cells
NCI 460 lung cancer
cells
UACC 62 melanome cancer
cells
NCI ADR multidrug resistant breast cancer
cells
8
7
55.2
198.2
37.66
68.19
241.7
446.4
74.9
1
2
5
6
2
0
207.0
197.7
222.3
665.4
103.9
171.4
179.3
0
132.9
231.9
9.126
6.25
2
11.82
6.75
5.8
7.01
8.66
6.14
Doxorubicine
4
Life Technologies) with 5% fetal bovine serum (Gibco
BRL, Life Technologies). Cells were diluted once a
week, discarded after 20 consecutive dilutions, and then
replaced by newly thawed stock from the liquid nitro-
gen.
(NCI 460) and 3ꢃ10 (UACC 62) cells per ml.
/
Microtiter plates containing cells were pre-incubated
for ca. 24 h at 37 8C in order to allow stabilization prior
to the addition of 100 ml of the test substances in cell
culture solutions having concentrations of 0.25, 2.5, 25.0
ꢁ
1
and 250 mg ml . The plates were incubated with the
test substance for 48 h at 37 8C and 5% CO2.
3
.2.2. Biological assays
All the adherent cell lines were detached from the
culture flasks by addition of 0.5 ml of trypsin (Nutricell
Cell Nutrient). Trypsin was inactivated by addition of 5
ml of 5% fetal bovine serum containing RPMI 1640
medium. Cells were separated into single-cell suspen-
sions by a gentle pipetting. After counting and dilution
into appropriate seeding densities, the cells were inocu-
lated into 96-wells microtiter plates (Nunc Brand
Products). The cells plating volume was 100 ml per
well. Seeding densities varied among the cell lines as
3
.2.3. Photochemical study
A Germetec UVA lamp (Cosmetex UVA-Plus), 100
W, was used as light source. Solutions with a concen-
ꢁ
5
ꢁ3
tration of 1.00ꢃ
/
10
mol dm
of each DBM
derivative in 50% v/v ethanol were placed in quartz
cells of 1 cm pathlength at 25 8C. UV absorption spectra
were recorded on a Hewlett-Packard Spectrophotometer
4
4
4
(8452A), with diode array detection, for 540 min [9].
follows: 6.5ꢃ
/
10 (MCF 7), 5ꢃ
/
10 (NCI ADR), 4ꢃ10
/
Fig. 6. Photochemical behavior of compound 22 under UVB radiation at different time intervals over 9 h, with an initial concentration of 1.00ꢃ
/
ꢁ
5
ꢁ3
10
mol dm
in 50% (v/v) ethanol.

M.A. Nogueira et al. / Il Farmaco 58 (2003) 1163ꢀ
/1169
1169
4
. Results and discussions
Compounds 5ꢀ22 were submitted to cytotoxic assay
Acknowledgements
/
This work was supported by the Funda c¸ a˜ o de
Amparo a` Pesquisa do Estado de S a˜ o Paulo (FAPESP).
M.A.N. is grateful to this foundation for a post-doctoral
fellowship.
using four human cancer cell lines: MCF 7 (breast), NCI
ADR (breast expressing the multidrug resistance phe-
notype), NCI 460 (lung) and UACC 62 (melanoma).
The inhibitory effects of DBM derivatives were assessed
by varying the concentrations and the results were
obtained after 72 h using the MTT assay. All assays
were performed in triplicate. Among the 19 compounds
tested, only eight (Fig. 4) showed cytotoxicity against
these four cell lines. Of these we would like to focus on
the activity depicted by compound 22, which was
present against the four cell lines, as shown in Fig. 5
with an IC50 that is below doxorubicine for melanome
cells (Table 1). Notwithstanding these results we are
particularly interested in the antimelanoma results,
which indicate 22 as a good UVB/UVC sunscreen with
therapeutical action.
References
[1] J.C. van der Leun, UV radiation from sunlight: summary,
conclusions and recommendations, J. Photochem. Photobiol. B:
Biol. 35 (1996) 237ꢀ244.
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[2] K. Singletary, C. MacDonald, M. Iovinelli, C. Fisher, M. Wallig,
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[
[
[
[
/
are sunscreens
As photostability is a desired property for sunscreen
agents, the stabilities of compounds 5, 6, 7, 8, 10, 13, 20,
/
2
2 were further evaluated by ultraviolet absorption
exposure over 9 h. The photochemical behavior of the
eight candidates, measured at different time intervals,
indicated that only compound 22 was highly stable
under UV radiation for 9 h with a wide band near 280
nm (Fig. 6).
Thus 22 is a leading candidate for use as a UV
sunscreen agent, also having therapeutical activity
against melanoma cells. As far as we know, this is the
first report on the inhibitory effects of DBM derivatives
on cancer cell line growth as well as a photochemical
evaluation for their application as UVB/UVC radiation
sunscreens.
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6] A.F. Magalh a˜ es, A.M.A. Tozzi, G.E. Magalh a˜ es, I.S. Blanco,
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tano aislado, Rev. Ceres 45 (1998) 351ꢀ358.
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[
[
8] A.C.V. Ara u´ jo, F.V. Almeida, L.W. Bieber, The synthesis of
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9] D.N. Biloti, M.M. Reis, M.M.C. Ferreira, F.B.T. Pessine, Photo-
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†
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4
81 (1999) 557ꢀ561.
/