Indoleamine 2,3-Dioxygenase Inhibitory Activity
of Derivatives of Marine Alkaloid
Tsitsikammamine A
Dr. Eduard Dolušić
Drug Design and Discovery Center
Department of Pharmacy
University of Namur (FUNDP), Belgium
Indoleamine 2,3-Dioxygenase (IDO)
 other substrates:
serotonin, melatonin,
tryptamine…
 protoheme IX
prosthetic group
 monomeric (~45 kDa)
 extrahepatic
Dr. Eduard Dolušić
JFB 2011 Liège 2
R. Schwarcz, Curr. Opin. Pharmacol.
2004, 4, 12.
Interest in IDO as a drug target
 IDO expression in
placenta is required for
immune tolerance of
fetus by the mother
 cancer immunotherapy shows limited efficacy
in vivo; IDO plays a crucial role
Munn, D. H.; Mellor, A. L. J. Clin. Invest. 2007, 117, 1147.
Prendergast, G. C. Oncogene 2008, 27, 3889.
Munn, D. H. et al,
Science 1998, 281, 1191.
 many human tumors
constitutively express IDO
Uyttenhove, C. et al,
Nat Med 2003, 9, 1269.
Dr. Eduard Dolušić
JFB 2011 Liège 3
Katz, J. B. et al, Imm. Rev. 2008, 222, 206.
IDO inhibitors - background
 inhibitors (lit.):
IC50 = 4.8-7.7 mM
Kumar et al, JMC 2008,
51, 4968.
Ki = 61–70 nM
Sugimoto, H. et al,
PNAS 2006, 103, 2611.
Dr. Eduard Dolušić
JFB 2011 Liège 4
Ki = 200 nM
Kumar et al, JMC
2008,51, 1706.
Carr et al, JMC
2008,51, 2634.
IC50=59–86 nM
IC50 = 50 mM
Yue et al, JMC
2009,52, 7364.
Röhrig et al, JMC
2010, 53, 1172.
IC50~100 mM
clinical trials
IDO inhibitors discovered by
virtual screening
Dr. Eduard Dolušić
JFB 2011 Liège 5
Dolušić, E. et al; Bioorg.
Med. Chem. 2011, 19, 1550.
Dolušić, E. et al; EJMC
2011, doi:10.1016/j.ejmech.2011.02.049.
IDO inhibitors discovered by
virtual screening
Dr. Eduard Dolušić
JFB 2011 Liège 6
Dolušić, E. et al; Bioorg.
Med. Chem. 2011, 19, 1550.
Dolušić, E. et al; EJMC
2011, doi:10.1016/j.ejmech.2011.02.049.
Work on another
(HTS) series in
progress.
Marine pyrroloquinoline alkaloids:
wakayin and tsitsikammamines
 wakayin (1): isolated in 1991 from the
ascidian Clavelina species
 reported to have diverse bioactivities
including cytotoxicity and topoisomerase I
inhibition
 tsitsikammamines A (2) and B (3): isolated
in 1996 from a Latrunculiidae sponge
 similar bioactivity profile to wakayin
Legentil, L. et al;
JMC 2006, 49, 2979.
Delfourne, E.; Anti Canc.
Agents Med. Chem.
2008, 8, 910.
Dr. Eduard Dolušić
JFB 2011 Liège 7
 pyrazolic derivatives of general (a) and (b)
structures also exhibit topoisomerase I/II
inhibitory activity; some of them are cytotoxic
2010: two novel regioisomeric series of
tsitsikammamine A analogues - synthesis
 synthesized on the basis of the Michael addition chemistry
a) abs. EtOH, rt, 2h; b) TFA, CH2Cl2, rt, 4h;
c) MnO2, CH2Cl2, rt, overnight; d) abs. EtOH, 4Å MS, D, 3h
Dr. Eduard Dolušić
JFB 2011 Liège 8
a)
1M NaOH, dioxane, rt, overnight;
b) BBr3, CH2Cl2, N2, 4h
Rives, A. et al; Eur. J. Med. Chem. 2010, 45, 343.
2010: two novel regioisomeric series of
tsitsikammamine A analogues - synthesis
a) abs. EtOH, rt, 2h; b) TFA, CH2Cl2, rt, 4h;
c) MnO2, CH2Cl2, rt, overnight; d) 1M NaOH, dioxane, rt, overnight; e) BBr3, CH2Cl2, N2, 4h
Dr. Eduard Dolušić
JFB 2011 Liège 9
Rives, A. et al; Eur. J. Med. Chem. 2010, 45, 343.
2010: two novel regioisomeric series of
tsitsikammamine A analogues –
pharmacological evaluation
 products were
evaluated in an
MTT
colorimetric
antiproliferative
assay against
several cancer
and normal
(fibroblast) cell
lines
Dr. Eduard Dolušić
JFB 2011 Liège 10
 a cytotoxic
synthetic
intermediate 8b
with an unknown
mechanism of
action was
identified
Rives, A. et al; Eur. J. Med. Chem. 2010, 45, 343.
IDO inhibitory activity of tsitsikammamine
derivatives
Dr. Eduard
Dolušić
JFB 2011
Liège 11
Conclusion
 several tsitsikammamine A analogues display
(sub)micromolar potencies in an IDO enzymatic test
 a number of derivatives are also reasonably
active in an IDO cellular test without being toxic
 this class of compounds is a potential source of leads
for the development of new anticancer compounds with a
novel pharmacological profile (manuscript in preparation)
Dr. Eduard Dolušić
JFB 2011 Liège 12
Collaborators
D3C, FUNDP Namur
Eduard Dolušić
Raphaël Frédérick
Bernard Masereel
Sara Modaffari
Laurence Moineaux
Christelle Vancraeynest
Johan Wouters
Ludwig Institute
for Cancer Research
Brussels Branch
Didier Colau
Pierre Larrieu
Luc Pilotte
Vincent Stroobant
Benoît Van den Eynde
Université Paul Sabatier
Laboratoire SPMIB
Toulouse, France
Evelyne Delfourne
Arnaud Rives
Euroscreen SA
Sébastien Blanc
Delphine Colette
Graeme Fraser
ULB Brussels
Lab. de Toxicologie
Robert Kiss
Benjamin Le Calvé
€€€
FNRS (Belgium)
Biowin (CANTOL: convention n 5678)
Dr. Eduard Dolušić
JFB 2011 Liège 13
Thank you for your
attention!