Article
Journal of Medicinal Chemistry, 2010, Vol. 53, No. 21 7637
Lisboa” for providing FTICR-MS data, both in the National
Mass Spectrometry Network. J.F.S.C. thanks FCT for Grant
SFRH/BD/18263/2004.
Supporting Information Available: Experimental methods
and procedures for chemistry and biology and structural char-
acterization of compounds. This material is available free of
References
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Figure 2. General SAR of sterols for cytotoxicity based on the IC50
results on HT-29 cancer cells.
3, and 27 and ester 18 can be due to metabolic transforma-
tions.
The co-incubation of a low concentration of oxysterol 4
with Doxo highly favors its cytotoxic potency toward the
colon cancer cells HT-29, without affecting the normal ones.
Herein, we have explored and cemented the cytotoxic
profile of 30 ring-B oxygenated steroids in a broad array of
human cells. New insights on structural modifications favor-
ing the selective cytotoxicity of oxysterols and the disclosure
of their ability to increase Doxo’s potency toward cancer cells
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Experimental Section
For details, refer to the Supporting Information. The final
compounds 1, 2, 3, 7, 816 and 4, 9-16, 1814 were obtained as
described in the literature. The other compounds were obtained
asdescribedinthe Supporting Information. Puritywas confirmed
by HPLC to be g95% for all final compounds except for 3β,5R,
6β,16R-tetrahydroxypregnan-20-one, 16 (84%).
(9) Ishimaru, C.; Yonezawa, Y.; Kuriyama, I.; Nishida, M.; Yoshida,
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General Procedure for Synthesis of Sterol 6β-Hemiphthalates.
To a solution of Chol (250 mg, 0.646 mmol) in acetonitrile
(19 mL) under reflux, MMPP (351.5 mg, 0.711 mmol) was
added. The mixture was stirred at reflux temperature for 24 h
and then stopped by evaporation under vacuum. The resulting
white residue was washed with water, filtered, and evaporated to
dryness. Careful flash chromatography of the crude material
starting with chloroform and then in slow gradient with chloro-
form/ethanol (50:1 to 1:1) afforded the pure white solid 3β,
5R-dihydroxycholestan-6β-yl hemiphthalate (24, 143 mg, 39%).
Mp 190-192.5 °C (AcOEt). IR (film) 3403, 3064, 2939, 2867,
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Lasuncion, M. A. Cholesterol is essential for mitosis progression
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A.; Bessede, G.; Corcos, L.; Gambert, P.; Neel, D.; Lizard, G.
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1712, 1565, 1404, 1281, 1131, 1078, 1037, 958, 759 cm-1. H
1
recent reports. Steroids 1999, 64, 687–714.
NMR (400 MHz, DMSO-d6) δ ppm 0.59 (3H, s, 18-CH3), 0.82
and 0.83 (each 3H, 2d, J = 6.6 Hz, 26-CH3 and 27-CH3), 0.86
(3H, d, J = 6.5 Hz, 21-CH3), 1.02 (3H, s, 19-CH3), 3.84 (1H, m,
3R-H), 4.36 (1H, s, OH), 4.83 (1H, brs, 6R-H), 7.39 (3H, m, Ph),
7.74 (1H, d, J = 7.2 Hz, Ph). 13C NMR (101 MHz, DMSO-d6) δ
ppm 11.9, 16.1, 18.4, 20.6 (CH2), 22.3, 22.6, 23.2 (CH2), 23.7
(CH2), 27.3, 27.8 (CH2), 30.4, 30.7 (CH2), 30.8 (CH2), 31.7
(CH2), 35.2, 35.6 (CH2), 37.8 (C), 38.9 (CH2), 39.6 (CH2), 40.1
(CH2), 42.2 (C), 44.1, 55.6, 55.6, 65.4, 73.4 (C-5), 75.9, 126.2,
128.1, 128.9, 129.4, 133.0 (C), 139.2 (C), 167.8 (CdO), 171.0
(CdO). MS m/z (%): 567.3 (100) [M - H]þ, 361.5 (15). HRMS
(ESI), positive mode, m/z [M þ Na]þ calcd for C35H53O6Na,
591.3656; found, 591.3664.
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Acknowledgment. We thank Fundac-ao para a Ciencia e
Tecnologia (FCT), Portugal, through POCI for financial
support. We acknowledge “Lab. Espectrometria de Massa
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do Centro de Estudos Farmaceuticos, Universidade Coim-
bra” for providing LC-MS data (QITMS) and “Lab. FTICR
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e Proteomica Avanc-ada, Faculdade Ciencias, Universidade
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