Synthesis and Biological Evaluation of Tripartin, a Putative KDM4 Natural Product Inhibitor, and 1-Dichloromethylinden-1-ol Analogues

Article abstract of DOI:10.1002/cmdc.201800377

The natural product tripartin has been reported to inhibit the N-methyl-lysine histone demethylase KDM4A. A synthesis of tripartin starting from 3,5-dimethoxyphenylacrylic acid was developed, and the enantiomers were separated by chiral HPLC. We observed

Full text of DOI:10.1002/cmdc.201800377

Accepted Article
Title: Synthesis and biological evaluation of tripartin, a putative
KDM4 natural product inhibitor, and 1-dichloromethylinden-1-ol
analogues
Authors: Lucia Guillade, Federica Sarno, Hanna Tarhnskaya, Angela
Nebbioso, Susana Alvarez, Akane Kawamura, Christopher
Schofield, Lucia Altucci, and Angel R. de Lera
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FULL PAPER
DOI: 10.1002/cmdc.200((will be filled in by the editorial staff))
Synthesis and biological evaluation of tripartin, a putative KDM4
natural product inhibitor, and 1-dichloromethylinden-1-ol
analogues
Lucía Guillade,a Federica Sarno,b Hanna Tarhonskaya,c Angela Nebbioso,b Susana
Alvarez,a Akane Kawamura,c Christopher J. Schofield,c,* Lucia Altucci,b,* and
Ángel R. de Leraa,*
(a) Departamento de Química Orgánica, Facultade de Química, CINBIO and IBIV, Universidade de Vigo, Campus
As Lagoas-Marcosende, 36310 Vigo, Spain.
(b) Università degli Studi della Campania “Luigi Vanvitelli”, Vico L. De Crecchio 7, 80138 Napoli, Italy.
(c) Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1
3TA, United Kingdom.
Corresponding authors:
Prof. Dr. Angel R. de Lera qolera@uvigo.es; Prof. Lucia Altucci, lucia.altucci@unicampania.it; Prof. Chris J.
Schofield, christopher.schofield@chem.ox.ac.uk.
Abstract
The natural product tripartin has been reported to inhibit the
N-methyl lysine histone demethylase KDM4A. A synthesis of
tripartin starting from 3,5-dimethoxyphenylacrylic acid was
developed and the enantiomers were separated by chiral
HPLC. We observed that both tripartin enantiomers
manifested an apparent increase in the H3K9me3 levels when
dosed in cells, as measured by Western blot analysis. Thus,
there is no enantiomeric discrimination towards this natural
product in terms of its effects on cellular histone methylation
status. Interestingly, tripartin did not inhibit isolated KDM4A-E
under our assay conditions (IC50 > 100 μ M). Tripartin
analogues with a dichloromethylcarbinol group derived from
the indanone scaffold were synthesized and found to be
inactive against isolated recombinant KDM4 enzymes and in
cell-based assays. Although the precise cellular mode of
action of tripartin is unclear, our evidence suggests that it may
affect histone methylation status via a mechanism other than
direct inhibition of the KDM4 histone demethylases.
The The Jumonji C (Jmj-C) enzymes are the largest family of
KDMs and are non-heme iron (Fe(II))- and 2-oxoglutarate (2-
OG)-dependent oxygenases that catalyse demethylation of
Nε-methylated lysine residues on the histone tails, in
particular the N-terminal tail of histone H3. Their reaction
mechanism involves initial lysine methyl hydroxylation
followed by hydrolysis of the resultant hemiaminal
intermediate to release formaldehyde and the demethylated
product. The KDM4 (Jmj-D2) subfamily of histone KDMs has
four human members, KDM4A-D, and two likely pseudogenes
KDM4E/F, all of which showing a preference for tri- and di-Nε-
methylated H3K9 substrates (with KDM4A-C also acting on
Introduction
Histone methylation is an epigenetic modification that can be
modified from its normal status in diseases, including
leukemia, breast and prostate cancer, and inflammation.[1]
Histone methylation plays important roles in the regulation of
transcription and the maintenance of genomic integrity in
eukaryotes. The methylation status of specific lysine residues
is balanced through the competitive actions of two enzyme
families, i.e. the histone methyltransferases (HMTs)[2] and the
histone demethylases (KDMs)[3].
1
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10.1002/cmdc.201800377
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H3K36). The KDM4 enzymes are up-regulated in many
cancer cell types.[4] It has also been reported that they are
involved in regulating heterochromatin, replication timing and
chromosomal copy numbers.[5]
preparation of analogues with and without hydroxyl groups in
both racemic and enantiopure form. We were particularly
interested in investigating the structural reasons behind the
selectivity of 12 as a KDM4 inhibitor.
To date, few (partially) selective KDM inhibitors have been
6]
identified.[3b,
The search for more potent and selective
modulators of particular substrates is being pursued for
therapeutic benefit. Examples of reported KDM4 inhibitors
6b, 7]
are shown in Figure 1.[6a,
substrate binding site
Peptides targeting the
[8]
as well as analogues of the 2-OG
co-substrate, modified by incorporation of nitrogen-containing
functional groups (such as derivatives 1-3),[9] have been
developed. Pyridine carboxylic acids mimic binding of at least
one of the carboxylate groups of the co-susbtrate and have
been further modified,[10] as in the case of 3-(((3-
methylthiophene-2-yl)methyl)amino)pyridine
4-carboxylic
acid 4.[11] These compounds, as well as pyrido[3,4-
d]pyrimidin-4(3H)-one 6,[12] inhibit both KDM4 and KDM5
subfamily members. 5 showed higher potency (with Ki = 43
nM) and selectivity for KDM4C over other KDM subfamilies
tested and was discovered via docking of 600,000 fragments
into KDM4A structure, followed by linking other fragments to
the initial 5-aminosalicylate hit.[13]
The 8-hydroxyquinoline scaffold is known to chelate iron in
the active site of JmjC KDM members, and has been chosen
for diversification.[14] CCT1 (7), made by modified Betti
reaction of substituted 8-hydroxyquinolines,[15] showed
selectivity for KDM4 over other tested demethylases (and
other human 2-OG-dependent oxygenases). Inhibitor ML324
8 has been reported as a chemical probe for the KDM4
subfamily and to exhibit promising antiviral activity.[16]
Figure 1. Selected KDM4 inhibitors.
RESULTS AND DISCUSSION
From the synthetic perspective, a challenge posed by tripartin
12
is
associated
with
the
generation
of
the
dichloromethylcarbinol at the benzylic position. To address
this challenge, 1-indanone 13 (Scheme 1) was selected for
the model reactions. For the generation of the dichloromethyl
anion, the procedure of Kraus and co-workers[24] using n-BuLi
and tetramethylpiperidine was initially adopted. However, the
yields of 14 were lower than 40%, possibly due to anion
instability and lack of reactivity of the indanone. Degradation
of the anion was observed on use of CeCl3; however, we
found that if the organocerium intermediate was formed in a
reaction media stabilized with Et2O at temperatures below -
100 °C,[25] the yield of 14 improved to greater than 85%.
Oxidation of 14 at the benzylic position[26] using KMnO4 and
FeCl3 gave indanone 15 (60%) (Scheme 1).
The formation of the dichloromethyl carbinol using excess
reagent and its addition to the ketone were not feasible with
unprotected phenols, as shown with 7-hydroxyindanone 17[27]
which was prepared in 69% yield by acid-mediated
rearrangement of 4-chromanone 16 with neat AlCl3 (180 ºC, 5
min).[27] Use of the methyl ether derivative of 7-
hydroxyindanone (18),[27] obtained from 17 (42%), led to the
desired dichloromethylcarbinol 19 (49%).[28]
In view of the failure of unprotected hydroxyindanone to react
with the dichloromethyl anion, dihydroxyindanones were
prepared following demethylation of dimethoxyindanone 22
(vide infra).[29] The synthesis of 22 was carried out in two
steps, starting from 3,5-dimethoxyphenylacrylic acid 20.
Catalytic hydrogenation of 20 followed by intramolecular
Friedel-Crafts reaction with methanesulfonic acid at 96 ºC
provided 22 in a combined 82% yield.[29b] Dimethoxyindanone
22 underwent reaction with the dichloromethyl anion using
conditions developed for model system 18 to afford, in
addition to carbinol 23, a secondary product with the structure
of the ring expanded α-naphtol 24. This ‘thermodynamically
Other KDM4 inhibitors range in structure from 4-
hydroxypyrazoles[17] to more complex pyrazole derivatives
such as 9.[18] The latter, with a 8-substituted pyrido[3,4-
d]pyrimidin-4(3H)one core, are cell permeable dual KDM4
and KDM5 inhibitors that bind to the active site iron and, due
to substitution at the pyrazole ring, overlap with the peptide
binding site. Methylstat 10 (an ester prodrug that showed low
micromolar potency)[19] has been proposed to compete with
2OG and the peptide binding in the active site. Pyridine
hydrazone JIB-04 11 (the E is more potent than the Z
isomer) has been proposed to bind at the active site of
KDM4A.[20] It should be noted that most, if not all, of the
reported small molecule inhibitors of KDM4 bind in the active
site cavity and complex the Fe(II) cofactor. Since there are
∼60 human 2-OG--dependent oxygenases[21] there is a need
to develop new types of selective KDM inhibitors.
We are interested in the synthesis and evaluation of
epigenetic modulators that are inspired by natural
products.[22] Few natural product inhibitors of 2-OG-
dependent oxygenases, including the JmjC KDMs, have
been reported.[6a, 6b] Tripartin 12 is the only natural product
reported to act as a selective inhibitor of the KDM4 enzymes
in cells.[23] Tripartin 12 was isolated from a culture of
Streptomyces sp. associated with a larva of the dung beetle
Copris tripartitus Waterhouse.[23] Structurally, tripartin is a
dichloromethylcarbinol derivative of a dihydroxyindanodione,
a highly unusual motif in natural products. The (S) absolute
configuration for natural tripartin was determined by X-ray
crystallography.[23]
Tripartin 12 is of interest as “epigenetic regulator” because of
its unusual structure for biological compounds. We thus
targeted the synthesis of tripartin 12 to pave the way for
structure-activity
relationship
studies,
including
the
2
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10.1002/cmdc.201800377
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stable’ by-product is likely formed by the hydroxyl-assisted 1,2
migration/ring expansion and β-elimination. This result reveals
the sensitivity of the dichloromethyl carbinol group to basic
(and acidic) conditions; note that this reactivity maybe a
consideration in terms of the in vivo activity of the compounds
(see below).
carbanion to 27 afforded carbinol 28 (75%). Debenzylation
was effected by hydrogenation of dichloromethyl carbinol 28
using Pearlman’s catalyst (20% Pd(OH)2/C, EtOAc/Et3N).
Product 29 could only be isolated in DMF or MeOH solution;
otherwise, it underwent extensive degradation, precluding
assay / analysis.
Biological evaluation
KDM4 inhibition is reported to supress proliferation of many
cancer cells (including colon cancer cells HCT).[33] We thus
investigated the effects of tripartin and analogues on the
proliferation of a human colon cancer cell line. Specifically,
HCT-116 cells were stimulated with the selected compounds
at 10 µM for 24 hours and analyzed via FACS (Figs. 2A and
2B). Compared to control (DMSO), most of the compounds
did not alter the percentage of cells in cell cycle phases.
Compound 23, a dimethoxy analogue of reduced tripartin,
was able to induce a cell cycle arrest in G2/M phases (Fig.
2A) as well as cell death (Fig. 2B), as revealed by DNA
fragmentation percentage.
We then evaluated the effects of tripartin 12 on the
methylation status of H3K9 by treating HCT-116 cells with (S)-
12 or (R)-12 at 10 µM for 24 h. The results were compared
with those of PKF 118-310, an antagonist of Tcf4/β-catenin
signalling, also shown to inhibit KDM4A,[34] used at 1 µM
(Figs. 2C, 2D and 2E). Compared to DMSO and PKF 118-
310, both tripartin enantiomers caused moderate increase in
the H3K9me3 (Fig. 2C) and H3K9me2 (Fig. 2D) levels.
However, neither of the tripartin enantiomers altered the
H3K9me1 level within detection limits (Fig. 2E). Taken
together, these results suggest that (S)-12 and (R)-12 may be
KDM4 inhibitors with potential to be developed as anticancer
agents.
Scheme 1. Synthesis of rac-tripartin (rac-12) and analogues.
To investigate the structural elements of tripartin responsible
for KDM4 inhibition, we tested the activity of synthetic
intermediates. After treatment with compounds 14, 15, 19, 23,
25 at 10 µM for 24 h, HCT116 cells were evaluated for the
H3K9 methylation status. Compared to DMSO, all compounds
caused an increase in H3K9me2 levels to an extent similar
than PKF 118-310. Compounds 19, 23 and 25 also increased
the H3K9me3 and H3K9me1 levels and 14 apparently
increased H3K9me1, but not the H3K9me3, levels.
Oxidation at the benzylic position, using the same conditions
as for the model system (FeCl3 and KMnO4),[26] gave
indanone 25 (25%). Following an extensive survey of oxidants
(CrO3 in a 1:3 Ac2O/AcOH mixture, RuCl3, PhI and Oxone®),
we found that treatment with Pd(OAc)2, TBHP and K2CO3 at
room temperature for 6 days (adding reagents every 24 h)[30]
afforded the desired product in 80% yield after purification.
Demethylation of the methoxy groups at the indanone stage
was achieved using AlCl3 and
a thiol to dissolve the
These preliminary results suggest that the indanone scaffold
might play an important role in the activity of tripartin and
analogues as epigenetic modulators through KDM4 inhibition.
reagent.[31] HPLC purification gave tripartin rac-12 as a solid
(25%).
The tripartin enantiomers were separated by chiral HPLC. By
comparison of specific optical rotations with that described for
the natural product,[23] natural (S)-tripartin was assigned as
25
the enantiomer with the shorter tR and [α]D -100 (c 0.044,
MeOH).[23] The bis-benzyl derivative (S)-30 was prepared by
treatment of (S)-tripartin with benzyl bromide (76%). With the
aim of improving the overall yield of the route, indanone 22
[32]
was demethylated with BBr3
to give 26 in apparent
quantitative yield; the phenols of 26 were transformed into
several protected derivatives (-OBn, -OPMB, -OTBS, -OSEM,
-OAc, see S.I.). However, we found that these protecting
groups were incompatible with the ensuing steps of the
sequence (dichloromethyl anion addition, benzylic oxidation or
deprotection). The preparation of the analogue of tripartin
lacking a ketone was also attempted starting from the bis-
benzyl-protected indanone 27. Addition of dichloromethyl
3
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10.1002/cmdc.201800377
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FIH is related to the 2OG-dependent KDMs, as both belong to
the JmjC subfamily of 2OG oxygenases. Detailed kinetic
analysis revealed that (S)-30 does not inhibit FIH in a
competitive manner with respect to 2OG (Supplementary
Figure S3). Thus, it seems unlikely that the activity of tripartin
in cells results from ‘direct’ active site-mediated interactions.
Further work is required to define the mode of action of
tripartin. It is possible that tripartin inhibits the full length
KDM4s through binding at an allosteric site, which is absent in
the truncated recombinant KDM4s used in our assays (it
contains only JmjN-JmjC domains). It is also possible that
tripartin may undergo rearrangement
/ modifications to
produce compounds that inhibit the KDM4s in a cellular
context; the observed ring expansion leading to
hydroxynaphthalene 24 (Scheme 1) may be relevant to this,
since in the cellular assays, both (S)-12 and (R)-12
enantiomers were equipotent. It is interesting to note that
compound CCT1 7 was resolved into its enantiomers, but
these also displayed little difference in their KDM4
inhibition.[15] We have previously observed inhibition in a
cellular context with hydroxyquinoline-based inhibitors where
none was observed in assays with isolated enzymes (in that
case, 2-OG dependent prolyl-hydroxylases).[36] It may be that
an unidentified mechanism common to both tripartin and
related redox-sensitive compounds is operative for 2-OG
oxygenase inhibition in cells. It is also possible that the
observed H3K9me3 changes are a consequence of toxicity / a
stress response / apoptosis,[37] or that the activity of H3K9
HMTs is affected by the presence of tripartin.
Conclusions
Figure 2. Cellular effects of tripartin and analogues. HCT-116
cell cycle (A) and cell death induction (B) of (S)-12, (R)-12,
and analogues at 10 µM for 24 h are shown. Western blot
analyses for H3K9me3, H3K9me2 and H3K9me1 in HCT-116
cells treated with (S)-12, (R)-12 at 10 µM and PKF 118-310 at
1 µM for 24h (C, D, E) and with 14, 15, 19, 23 and 25 at 10
µM for 24h (F). Band quantifications in C, D and E were
performed using Image J software.
To conclude, tripartin has been prepared by a sequence
involving as key steps the reaction of dimethoxyindanone with
the dichloromethyl anion at -100 ºC assisted by CeCl3 to
afford the corresponding dichloromethylcarbinol, followed by
benzylic oxidation with Pd(OAc)2/TBHP and demethylation
using AlCl3 in t-BuSH. Separation of rac-tripartin provided the
natural product and its enantiomer. (S)-tripartin (and its
enantiomer) was confirmed to cause substantial increase in
H3K9me3 levels in HCT-116 cells by Western blot analysis.[23]
However, our biochemical evidence implies that the molecular
mechanism of action of tripartin remains to be defined. It may
be that tripartin is metabolised to an active KDM inhibitor, or
that it has an indirect effect on the H3K9 methylation status.
By contrast with the cell-based results, however, we
repeatedly observed either no inhibition or very mild inhibition
for tripartin (no inhibition) and analogues when tested at 100
µM against isolated KDM4A, B, C, D or E under standard
assay conditions. A control inhibitor (IOX1) was active under
these conditions (Table 1)[35]. A bisbenzyl derivative of natural
(S)-tripartin (S)-30 (Scheme 1) inhibited the human
asparaginyl hydroxylase FIH with moderate potency (Table 1).
Table 1. Screening of tripartin and analogues against recombinant KDM4 and FIH.i
% Inhibition at 100 µM (IC50, µM)
KDM4A
KDM4B
KDM4C
KDM4D
KDM4E
FIH
ref. IOX1 (for
KDM4); NOG
(for FIH)
(S)-12
(R)-12
28
49 ± 1
81 ± 8
57 ± 2
26 ± 0.3
75 ± 1
83 ± 0.5
NI
NI
NI
5 ± 1
NI
NI
NI
NI
NI
8 ± 1
NI
NI
NI
28 ± 4
NI
43 ± 3
32 ± 1
20 ± 3
33 ± 1
27 ± 1
2 ± 1
45 ± 1
(39)
(S)-30
NI
57 ± 2 (21)
iCompounds were tested against recombinant KDM4s (ref. IOX1) for their effect on H3K9me3 demethylation activity or against
FIH (ref. NOG) for ankyrin hydroxylation at 100 µM using a MALDI-TOF-MS assay.[36] IC50 values were determined for selected
compounds. NI – no inhibition at 100 µM.
4
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10.1002/cmdc.201800377
ChemMedChem
portion of Pd(OAc)2 and TBHP were added after 24 and 48 h.
The reaction mixture was then quenched with water (4 mL)
and the aqueous layer was extracted with EtOAc (3x). The
combined organic layers were washed with water (3x), brine
(2x), dried (Na2SO4) and the solvent was evaporated. The
residue was purified by column chromatography (silica gel
neutralized with 97:3 hexane/Et3N, 70:30 hexane/EtOAc) to
afford 0.05 g (80%) of a colorless oil identified as 25. MW:
Supporting Information
Detailed experimental procedures for the synthesis of tripartin
analogues, graphical representation of the inhibitory effects of
compound (S)-30 and copies of NMR spectra for all the
compounds.
EXPERIMENTAL SECTION
1
291.12 g/mol. H-NMR (400.13 MHz, CDCl3): δ 6.82 (d, J =
General procedures and preparation of compounds (see
S.I.)
2.0 Hz, 1H, ArH), 6.71 (d, J = 2.0 Hz, 1H, ArH), 6.47 (s, 1H,
CH), 3.94 (s, 3H, OCH3), 3.86 (s, 3H, OCH3), 3.42 (d, J = 19.0
Hz, 1H, CH2A), 2.82 (d, J = 19.0 Hz, 1H, CH2B) ppm. 13C-NMR
(100.16 MHz, CDCl3): δ 201.0 (s), 163.7 (s), 156.9 (s), 140.4
(s), 132.7 (s), 106.3 (d), 97.0 (d), 81.6 (s), 76.1 (d), 56.2 (q),
56.1 (q), 47.4 (t) ppm. HRMS (ESI+): Calcd. for C12H13Cl2O4
([M+H]+), 291.0185; found, 291.0184. IR (NaCl): ν 3600-3300
(br, O-H), 2924 (w, C-H), 2854 (w, C-H), 1720 (s, C=O), 1610
(s, C=C) cm-1. UV/Vis (MeOH): λmax 316, 264 nm.
rac-1-(Dichloromethyl)-5,7-dimethoxy-2,3-dihydro-1H-
inden-1-ol 23 and 6,8-dimethoxynaphthalen-1-ol 24.
Following the general procedure for the synthesis of
dichloromethylcarbinols by Method B (see S.I.) the treatment
of a solution of CH2Cl2 (5.5 mL, 156.6 mmol) in THF (6.7 mL)
with MeLi (9.2 mL, 1.6 M in Et2O, 14.7 mmol) at -100 °C,
followed by the addition of Et2O (39.2 mL) and anhydrous
CeCl3 (3.9 g, 15.6 mmol) and, one hour later, a solution of 5,7-
dimethoxy-2,3-dihydro-1H-inden-1-one 22 (0.2 g, 1.0 mmol) in
CH2Cl2 (11 mL) afforded, after purification by column
chromatography (silica gel, first 97:3 hexane/Et3N, then
gradient from 90:10 to 70:30 hexane/EtOAc), 0.22 g (76%) of
an orange solid identified as 1-(dichloromethyl)-5,7-
dimethoxy-2,3-dihydro-1H-inden-1-ol 23 and 0.06 g (28%) of
6,8-dimethoxynaphthalen-1-ol 24.
rac-3-(Dichloromethyl)-3,5,7-trihydroxy-2,3-dihydro-1H-
inden-1-one 12. In a Schlenk flask, AlCl3 (1.19 g, 8.93 mmol)
was placed and tert-butanethiol (43.5 mL) was added until a
clear solution was obtained. The mixture was cooled down to
0 °C and a solution of rac-3-(dichloromethyl)-3-hydroxy-5,7-
dimethoxy-2,3-dihydro-1H-inden-1-one 25 (0.13 g, 0.44 mmol)
in CH2Cl2 (20 mL) was added. After stirring the reaction
mixture overnight at room temperature, the solvent was
removed under reduced pressure and EtOAc (20 mL) and
NaH2PO4 (20 mL) were added stepwise. The reaction was
stirred under Ar until the solids were dissolved. The aqueous
layer was extracted with EtOAc (3x), the combined organic
layers were washed with brine (2x), dried (Na2SO4) and the
solvent was evaporated. The residue was purified by column
chromatography (LUNA column, 5 µm (PFP2) 100x10 mm,
eluting with a gradient from 30 to 70% H2O/MeOH, 217 nm
detection, tR = 16 min) to afford 0.03 g (25%) of a white solid
identified as the target compound. MW: 263.07 g/mol. 1H-
NMR (400.13 MHz, (CD3)2SO): δ 6.67 (s, 1H, CH), 6.56 (s,
1H, ArH), 6.39 (s, 1H, ArH), 3.16 (s, 1H, OH), 3.08 (d, J =
19.0 Hz, 1H, CH2A), 2.61 (d, J = 19.0 Hz, 1H, CH2B) ppm. 13C-
NMR (100.16 MHz, (CD3)2SO): δ 201.7 (s), 160.3 (s), 155.6
(s), 139.2 (s), 131.1 (s), 109.2 (d), 98.5 (d), 80.2 (s), 76.7 (d),
47.2 (t) ppm. MS (ESI+): m/z 261 (100), 263 (65), 265 (10). IR
(NaCl): ν 3450-3000 (br, O-H), 2917 (m, C-H), 2849 (w, C-H),
1697 (s, C=O) cm-1. UV/Vis (MeOH): λmax 329, 270 nm.
Data for 1-(dichloromethyl)-5,7-dimethoxy-2,3-dihydro-1H-
inden-1-ol 23. MW: 277.14 g/mol. M.p.: 73-76 °C (CH2Cl2).
1H-NMR (400.13 MHz, CDCl3): δ 6.45 (s, 1H, H1'), 6.37 (d, J =
2.0 Hz, 1H, ArH), 6.31 (d, J = 2.0 Hz, 1H, ArH), 3.85 (s, 3H,
OCH3), 3.80 (s, 3H, OCH3), 3.15–2.94 (m, 3H, 2H2 + OH),
2.95–2.79 (m, 1H, H3A), 2.21 (ddd, J = 14.5, 9.0, 5.5 Hz, 1H,
H3B) ppm. 13C-NMR (100.16 MHz, CDCl3): δ 162.9 (s), 156.6
(s), 148.2 (s), 121.6 (s), 101.2 (d), 97.4 (d), 88.5 (s), 77.7 (d),
55.7 (q), 55.5 (q), 34.8 (t), 31.0 (t) ppm. MS (ESI+): m/z 299
([M+Na]+, 100), 259 (84). HRMS (ESI+): Calcd. For
C12H14Cl2NaO3 ([M+Na]+), 299.0212; found, 299.0219. IR
(NaCl): ν 3600-3300 (br, O-H), 2943 (w, C-H), 2840 (w, C-H),
1601 (s, C=C) cm-1. UV/Vis (MeOH): λmax 280, 231 nm.
Data for 6,8-dimethoxynaphthalen-1-ol 24. MW: 204.23
g/mol. 1H-NMR (400.13 MHz, CDCl3): δ 9.11 (s, 1H, OH), 7.29
(t, J = 8.0 Hz, 1H, ArH, H3), 7.18 (d, J = 8.0 Hz, 1H, ArH), 6.74
-6.72 (m, 2H, ArH), 6.46 (d, J = 2.0 Hz, 1H, ArH), 4.03 (s, 3H,
OCH3), 3.89 (s, 3H, OCH3) ppm. 13C-NMR (100.16 MHz,
CDCl3): δ 157.7 (s), 157.4 (s), 154.7 (s), 137.6 (s), 128.4 (d),
118.1 (d), 111.0 (s), 108.7 (d), 99.6 (d), 97.8 (d), 56.3 (q),
55.5 (q) ppm. MS (ESI+): m/z 205 ([M+H]+, 57).
The enantiomers were separated by HPLC (Chiralpak IA, 5
µm, 25x1 cm, 60:40 H2O/MeOH, flow rate 2 mL/min, tR = 25
25
25
min, [α]D -100 (c 0.044, MeOH); tR = 36 min, [α]D +100 (c
0.044, MeOH). The spectroscopic data matched those
previously reported, including the same value of the optical
rotation described for the natural product of the enantiomer
with the shorter retention time.[23]
rac-3-(Dichloromethyl)-3-hydroxy-5,7-dimethoxy-2,3-
dihydro-1H-inden-1-one 25.
To an open-air solution of 1-
(dichloromethyl)-4,6-dimethoxy-2,3-dihydro-1H-inden-1-ol 23
(0.05 g, 0.18 mmol) in CH2Cl2 (9 mL), K2CO3 (0.90 g, 6.49
mmol), TBHP (4.5 mmol, 1.9 M in isooctane, 2.4 mL) and
Pd(OAc)2 (0.04 g, 0.18 mmol) were added. The reaction
mixture was stirred at room temperature for 24 h. The same
Cell lines
Human colon cancer HCT-116 (ATCC CCL247) cells were
propagated in McCoy’s 5A medium (Euroclone, Pero, MI,
5
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10.1002/cmdc.201800377
ChemMedChem
defined time point, in the linear range of the reaction (1 – 15
min depending on the enzyme). The final reaction conditions
were as follows: H3(1-15)K9me3 (25 µM, except for KDM4D
where 50 µM was used), Fe(II) (10 µM), ascorbate (500 µM),
2OG (10 µM), compound (100 µM, 1% DMSO), KDM4 (1 µM)
in 50 mM HEPES buffer and 50 mM NaCl (pH 7.5). For FIH,
the final reaction conditions were as follows: commercial 50
µM 1CA (1CA20-mer NLEVAEYLLEHGADVNAQDK), Fe(II) (50
µM), ascorbate (1 mM), 2OG (300 µM), compound (100 µM)
in 1% DMSO, FIH (0.5 µM) in 50 mM HEPES (pH 7.5) buffer.
The quenched reaction (1 µL) was mixed with α-cyano-4-
hydroxycinnamic acid (1 µL) and analysed by matrix-assisted
laser desorption / ionisation-time of flight (MALDI-TOF) mass
spectrometry. For detailed kinetic analysis of FIH, 2OG
concentrations were varied (2 – 100 µM) while the other
parameters were kept constant.
Italy) with 10% fetal bovine serum (FBS) (Euroclone), 2 mM L-
glutamine (Euroclone) and antibiotics (100 U/mL penicillin,
100 µg/mL streptomycin).[38]
Protein histone extraction
Cells were harvested and washed twice with ice-cold
Dulbecco’s phosphate-buffered saline (DPBS) and lysed in
Triton extraction buffer (TEB; PBS containing 0.5% Triton X
100 (v/v), 2 mM phenylmethanesulfonyl chloride (PMSF),
0.02% (w/v) NaN3) at a cell density of 107 cells/mL for 10 min
on ice, with gentle stirring. The samples were centrifuged
(2000 rpm, 4 °C, 10 min) and the supernatant was then
removed. The pellet was washed in half the volume of TEB
and centrifuged as before. The pellet was suspended in 0.2 N
HCl at a cell density of 4 × 107 cells/mL overnight at 4 °C on a
rolling table. The samples were then centrifuged at 2000 rpm
for 10 min at 4 °C, the supernatant was removed, and the
protein content was determined using a Bradford assay.
Acknowledgements
Work in ARdL laboratories was supported by the Spanish
MINECO (SAF2016-77620-R-FEDER), Xunta de Galicia
(Consolidación GRC 2013/007 from DXPCTSUG; ED-
431G/02-FEDER "Unha maneira de facer Europa" to CINBIO,
Western blotting
To quantify histone H3K9 modification, 5 µg of total histone
extracts were loaded on a 15% polyacrylamide gels and
transferred to nitrocellulose filters, which were blocked in dry
milk for 1 h at room temperature and then were incubated with
antibodies against H3K9me1, H3K9me2 and H3K9me3
(Diagenode). Histone H4 antibody (Abcam) was used to
normalize for equal loading. Semi-quantitative analysis was
performed using ImageJ software.[39]
a
Galician research center 2016-2019). Work in L.A.
laboratories was supported by EU project BLUEPRINT
(282510), the Italian flagship project EPIGEN, MIUR-Italian
Ministry of Education, Universities and Research Project of
National Significance 20152TE5PK, and the Italian
Association for Cancer Research (AIRC-17217). The financial
support of COST Action CM-1406 “Epigenetic Chemical
Biology” is gratefully acknowledeged. The Oxford team thanks
Cancer Research UK and the Wellcome Trust for funding.
Abbreviations
Cell cycle analyses
After the stimulation with compounds, 2 x 105 cells were
collected. The cells were centrifuged (1200 rpm for 5 min) and
suspended in 500 µL of a solution containing 1 x PBS, 0.1%
sodium citrate, 0.1% NP40 and 50 µg/mL propidium iodide.
Cells were incubated for 30 min at room temperature in the
dark. The samples were evaluated by fluorescence-activated
cell sorting (FACS) flow cytometer (FACSCalibur BD
Biosciences, San Jose, CA, USA) and analysed by ModFit v3
software (Verity Software House). Cell death was measured
by evaluation of the pre-G1 analyzed by FACS with Cell
Quest software (Becton Dickinson).[40] Experiments were
performed in biological duplicates and values expressed as
mean ± SD.
DPBS, Dulbecco’s phosphate-buffered saline; FACS:
fluorescence-activated cell sorter; FBS, fetal bovine serum;
KDM, histone demethylase; HMT, histone methyltransferase;
IR, infrared spectroscopy; Jmj: Jumonji domain; MALDI-TOF,
matrix-assisted laser desorption / ionisation-time of flight
mass spectrometry; mp, melting point; MS, mass
spectrometry; HRMS, high-resolution mass spectrometry;
MW, molecular weight; NMR, nuclear magnetic resonance
spectroscopy;
2-OG:
2-oxoglutarate;
PMSF;
phenylmethanesulfonyl chloride; TEB, Triton extraction buffer;
TLC, thin layer chromatography.
Keywords: Epigenetic modulator, natural product, tripartin
total synthesis, lysine demethylase inhibition.
MALDI-TOF MS assays for KDM4 and FIH
References and Notes
[1]
a) J. C. Black, C. Van Rechem, J. R. Whetstine, Mol. Cell 2012,
The catalytic domains of KDM4A-E and FIH were
recombinantly produced[41] and MALDI-TOF MS assays were
carried out as described[14, 42] with minor modifications. In brief,
enzymes were pre-incubated with inhibitors for 15 min prior to
the initiation of the reaction with substrates, co-factors and
assay components. Reactions were quenched with 1:1
volume of 3% for KDM4 or 10% FIH (v/v) formic acid at a
48, 491-507; b) L. Morera, M. Lübbert, M. Jung, Clin. Epigen. 2016, 8,
57.
[2]
1596-1629; b) M. Schapira, Cell Chem. Biol. 2016, 23, 1067-1076.
[3] a) S. M. Kooistra, K. Helin, Nat. Rev. Mol. Cell Biol. 2012, 13,
297-311; b) J. W. Hojfeldt, K. Agger, K. Helin, Nat. Rev. Drug Discov.
2013, 12, 917-930.
a) H. U. Kaniskan, K. D. Konze, J. Jin, J. Med. Chem. 2015, 58,
6
This article is protected by copyright. All rights reserved.

10.1002/cmdc.201800377
ChemMedChem
[4]
224.
[5]
G. Franci, A. Ciotta, L. Altucci, Biomol. Concepts 2014, 5, 209-
Szykowska, C. Gileadi, N. A. Burgess-Brown, F. von Delft, U.
Oppermann, Z. Walters, J. Shipley, F. I. Raynaud, S. M. Westaway, R.
K. Prinjha, O. Fedorov, R. Burke, C. J. Schofield, I. M. Westwood, C.
Bountra, S. Müller, R. L. M. van Montfort, P. E. Brennan, J. Blagg, J.
Med. Chem. 2016, 59, 1388-1409.
[19] X. Luo, Y. Liu, S. Kubicek, J. Myllyharju, A. Tumber, S. Ng, K.
H. Che, J. Podoll, T. D. Heightman, U. Oppermann, S. L. Schreiber, X.
Wang, J. Am. Chem. Soc. 2011, 133, 9451-9456.
[20] B. Cascella, S. G. Lee, S. Singh, J. M. Jez, L. M. Mirica, Chem.
Commun. 2017, 53, 2174-2177.
[21] C. Loenarz, C. J. Schofield, Trends Biochem. Sci. 2011, 36, 7-
18.
J. C. Black, E. Atabakhsh, J. Kim, K. M. Biette, C. Van Rechem,
B. Ladd, P. d. Burrowes, C. Donado, H. Mattoo, B. P. Kleinstiver, B.
Song, G. Andriani, J. K. Joung, O. Iliopoulos, C. Montagna, S. Pillai,
G. Getz, J. R. Whetstine, Genes Dev. 2015, 29, 1018-1031.
[6]
a) N. R. Rose, M. A. McDonough, O. N. F. King, A. Kawamura,
C. J. Schofield, Chem. Soc. Rev. 2011, 40, 4364-4397; b) T. E.
McAllister, K. S. England, R. J. Hopkinson, P. E. Brennan, A.
Kawamura, C. J. Schofield, J. Med. Chem. 2016, 59, 1308-1329; c. R.
A. Varier, H. T. M. Timmers, Biochim. Biophys. Acta (BBA) - Rev.
Cancer 2011, 1815, 75-89.
[7]
M. Gajhede, R. P. Clausen, Bioorg. Med. Chem. 2011, 19, 3625-3636.
[8] a) B. Lohse, A. L. Nielsen, J. B. L. Kristensen, C. Helgstrand, P.
B. Lohse, J. L. Kristensen, L. H. Kristensen, K. Agger, K. Helin,
[22] a) C. Pérez-Balado, P. Rodríguez-Graña, A. Nebiosso, A.
Minichiello, M. Miceli, L. Altucci, A. R. de Lera, J. Med. Chem. 2007,
50, 2497-2505; b) J. A. Souto, E. Vaz, I. Lepore, A.-C. Pöppler, G.
Franci, R. Álvarez, L. Altucci, Á. R. de Lera, J. Med. Chem. 2010, 53,
4654-4667; c) R. Pereira, R. Benedetti, S. Pérez-Rodríguez, A.
Nebbioso, J. García-Rodríguez, V. Carafa, M. Stuhldreier, M. Conte,
F. Rodríguez-Barrios, H. G. Stunnenberg, H. Gronemeyer, L. Altucci,
Å. R. de Lera, J. Med. Chem. 2012, 55, 9467-9491.
[23] S.-H. Kim, S. H. Kwon, S.-H. Park, J. K. Lee, H.-S. Bang, S.-J.
Nam, H. C. Kwon, J. Shin, D.-C. Oh, Org. Lett. 2013, 15, 1834-1837.
[24] G. A. Kraus, X. Wang, Tetrahedron Lett. 1999, 40, 8513-8514.
[25] D. E. Ward, Y. Gai, B. F. Kaller, J. Org. Chem 1996, 61, 5498-
5505.
A. C. Cloos, L. Olsen, M. Gajhede, R. P. Clausen, J. L. Kristensen,
Angew. Chem. Int. Ed. 2011, 50, 9100-9103; b) E. C. Y. Woon, A.
Tumber, A. Kawamura, L. Hillringhaus, W. Ge, N. R. Rose, J. H. Y.
Ma, M. C. Chan, L. J. Walport, K. H. Che, S. S. Ng, B. D. Marsden, U.
Oppermann, M. A. McDonough, C. J. Schofield, Angew. Chem. Int.
Ed. 2012, 51, 1631-1634; c) A. Kawamura, M. Münzel, T. Kojima, C.
Yapp, B. Bhushan, Y. Goto, A. Tumber, T. Katoh, O. N. F. King, T.
Passioura, L. J. Walport, S. B. Hatch, S. Madden, S. Müller, P. E.
Brennan, R. Chowdhury, R. J. Hopkinson, H. Suga, C. J. Schofield,
Nat. Commun. 2017, 8, 14773.
[9]
a) S. Hamada, T.-D. Kim, T. Suzuki, Y. Itoh, H. Tsumoto, H.
[26] S. Lai, D. G. Lee, Tetrahedron 2002, 58, 9879-9887.
[27] G. A. Parada, S. D. Glover, A. Orthaber, L. Hammarström, S.
Ott, Eur. J. Org. Chem. 2016, 3365-3372.
[28] D. L. J. Clive, Y. Tao, A. Khodabocus, Y.-J. Wu, A. G. Angoh,
S. M. Bennett, C. N. Boddy, L. Bordeleau, D. Kellner, J. Am. Chem.
Soc. 1994, 116, 11275-11286.
[29] a) E. Fillion, D. Fishlock, Org. Lett. 2003, 5, 4653-4656; b) H. M.
Sim, K. Y. Loh, W. K. Yeo, C. Y. Lee, M. L. Go, ChemMedChem 2011,
6, 713-724.
Nakagawa, R. Janknecht, N. Miyata, Bioorg. Med. Chem. Lett. 2009,
19, 2852-2855; b) S. Hamada, T. Suzuki, K. Mino, K. Koseki, F.
Oehme, I. Flamme, H. Ozasa, Y. Itoh, D. Ogasawara, H. Komaarashi,
A. Kato, H. Tsumoto, H. Nakagawa, M. Hasegawa, R. Sasaki, T.
Mizukami, N. Miyata, J. Med. Chem. 2010, 53, 5629-5638; c) N. R.
Rose, E. C. Y. Woon, G. L. Kingham, O. N. F. King, J. Mecinovic, I. J.
Clifton, S. S. Ng, J. Talib-Hardy, U. Oppermann, M. A. McDonough, C.
J. Schofield, J. Med. Chem. 2010, 53, 1810-1818.
[10] Y. K. Chen, T. Bonaldi, A. Cuomo, J. R. Del Rosario, D. J.
Hosfield, T. Kanouni, S.-c. Kao, C. Lai, N. A. Lobo, J. Matuszkiewicz,
A. McGeehan, S. M. O’Connell, L. Shi, J. A. Stafford, R. K. Stansfield,
J. M. Veal, M. S. Weiss, N. Y. Yuen, M. B. Wallace, ACS Med. Chem.
Lett. 2017, 8, 869-874.
[11] S. M. Westaway, A. G. S. Preston, M. D. Barker, F. Brown, J. A.
Brown, M. Campbell, C.-w. Chung, H. Diallo, C. Douault, G. Drewes,
R. Eagle, L. Gordon, C. Haslam, T. G. Hayhow, P. G. Humphreys, G.
Joberty, R. Katso, L. Kruidenier, M. Leveridge, J. Liddle, J. Mosley, M.
Muelbaier, R. Randle, I. Rioja, A. Rueger, G. A. Seal, R. J. Sheppard,
O. Singh, J. Taylor, P. Thomas, D. Thomson, D. M. Wilson, K. Lee, R.
K. Prinjha, J. Med. Chem. 2016, 59, 1357-1369.
[12] S. M. Westaway, A. G. S. Preston, M. D. Barker, F. Brown, J. A.
Brown, M. Campbell, C.-w. Chung, G. Drewes, R. Eagle, N. Garton, L.
Gordon, C. Haslam, T. G. Hayhow, P. G. Humphreys, G. Joberty, R.
Katso, L. Kruidenier, M. Leveridge, M. Pemberton, I. Rioja, G. A. Seal,
T. Shipley, O. Singh, C. J. Suckling, J. Taylor, P. Thomas, D. M.
Wilson, K. Lee, R. K. Prinjha, J. Med. Chem. 2016, 59, 1370-1387.
[13] M. Korczynska, D. D. Le, N. Younger, E. Gregori-Puigjané, A.
Tumber, T. Krojer, S. Velupillai, C. Gileadi, R. P. Nowak, E. Iwasa, S.
B. Pollock, I. Ortiz Torres, U. Oppermann, B. K. Shoichet, D. G.
Fujimori, J. Med. Chem. 2016, 59, 1580-1598.
[14] O. N. F. King, X. S. Li, M. Sakurai, A. Kawamura, N. R. Rose, S.
S. Ng, A. M. Quinn, G. Rai, B. T. Mott, P. Beswick, R. J. Klose, U.
Oppermann, A. Jadhav, T. D. Heightman, D. J. Maloney, C. J.
Schofield, A. Simeonov, PLoS ONE 2010, 5, e15535.
[15] C. C. Thinnes, A. Tumber, C. Yapp, G. Scozzafava, T. Yeh, M.
C. Chan, T. A. Tran, K. Hsu, H. Tarhonskaya, L. J. Walport, S. E.
Wilkins, E. D. Martinez, S. Muller, C. W. Pugh, P. J. Ratcliffe, P. E.
Brennan, A. Kawamura, C. J. Schofield, Chem. Commun. 2015, 51,
15458-15461.
[30] S. A. Snyder, T. C. Sherwood, A. G. Ross, Angew. Chem. Int.
Ed. 2010, 49, 5146-5150.
[31] Z. Fei, F. E. McDonald, Org. Lett. 2005, 7, 3617-3620.
[32] R. M. Garbaccio, S. J. Stachel, D. K. Baeschlin, S. J.
Danishefsky, J. Am. Chem. Soc. 2001, 123, 10903-10908.
[33] W. L. Berry, R. Janknecht, Cancer Res. 2013, 73, 2936-2942.
[34] G. Franci, F. Sarno, A. Nebbioso, L. Altucci, Epigenetics 2017,
12, 198-205.
[35] R. L. Hancock, N. Masson, K. Dunne, E. Flashman, A.
Kawamura, ACS Chem. Biol. 2017, 12, 1011-1019.
[36] R. J. Hopkinson, A. Tumber, C. Yapp, R. Chowdhury, W. Aik, K.
H. Che, X. S. Li, J. B. L. Kristensen, O. N. F. King, M. C. Chan, K. K.
Yeoh, H. Choi, L. J. Walport, C. C. Thinnes, J. T. Bush, C. Lejeune, A.
M. Rydzik, N. R. Rose, E. A. Bagg, M. A. McDonough, T. J. Krojer, W.
W. Yue, S. S. Ng, L. Olsen, P. E. Brennan, U. Oppermann, S. Muller,
R. J. Klose, P. J. Ratcliffe, C. J. Schofield, A. Kawamura, Chem. Sci.
2013, 4, 3110-3117.
[37] S. B. Hatch, C. Yapp, R. C. Montenegro, P. Savitsky, V.
Gamble, A. Tumber, G. F. Ruda, V. Bavetsias, O. Fedorov, B. Atrash,
F. Raynaud, R. Lanigan, L. Carmichael, K. Tomlin, R. Burke, S. M.
Westaway, J. A. Brown, R. K. Prinjha, E. D. Martinez, U. Oppermann,
C. J. Schofield, C. Bountra, A. Kawamura, J. Blagg, P. E. Brennan, O.
Rossanese, S. Müller, Epigen. Chrom. 2017, 10, 9.
[38] G. Ai, R. Dachineni, D. Kumar, L. F. Alfonso, S. Marimuthu, G.
Bhat, Mol. Med. Rep. 2016, 14, 1726-1732.
[39] C. A. Schneider, W. S. Rasband, K. W. Eliceiri, Nat. Meth. 2012,
9, 671-675.
[40] A. Nebbioso, N. Clarke, E. Voltz, E. Germain, C. Ambrosino, P.
Bontempo, R. Alvarez, E. M. Schiavone, F. Ferrara, F. Bresciani, A.
Weisz, A. R. de Lera, H. Gronemeyer, L. Altucci, Nat. Med. 2005, 11,
77-84.
[16] G. Rai, A. Kawamura, A. Tumber, Y. Liang, J. L. Vogel, J. H.
Arbuckle, N. R. Rose, T. S. Dexheimer, T. L. Foley, O. N. King, A.
Quinn, M. B. T., C. J. Schofield, U. Oppermann, A. Jadhav, A.
Simeonov, T. M. Kristie, D. J. Maloney, Probe Reports from the NIH
Molecular Libraries Program. National Center for Biotechnology
Information (US): Bethesda, MD, 2010 2012.
[41] a) L. Hillringhaus, W. W. Yue, N. R. Rose, S. S. Ng, C. Gileadi,
C. Loenarz, S. H. Bello, J. E. Bray, C. J. Schofield, U. Oppermann, J.
Biol. Chem. 2011, 286(48), 41616-41625; b) L. A. McNeill, E.
Flashman, M. R. G. Buck, K. S. Hewitson, I. J. Clifton, G. Jeschke, T.
D. W. Claridge, D. Ehrismann, N. J. Oldham, C. J. Schofield, Mol.
BioSyst. 2005, 1, 321-324.
[17] U. Leurs, R. P. Clausen, J. L. Kristensen, B. Lohse, Bioorg.
Med. Chem. Lett. 2012, 22, 5811-5813.
[42] H. Tarhonskaya, A. Tumber, A. Kawamura, C. J. Schofield,
Curr. Prot. Pharmacol. 2018, 80, 3.15.11-13.15.12.
[18] V. Bavetsias, R. M. Lanigan, G. F. Ruda, B. Atrash, M. G.
McLaughlin, A. Tumber, N. Y. Mok, Y.-V. Le Bihan, S. Dempster, K. J.
Boxall, F. Jeganathan, S. B. Hatch, P. Savitsky, S. Velupillai, T. Krojer,
K. S. England, J. Sejberg, C. Thai, A. Donovan, A. Pal, G.
Scozzafava, J. M. Bennett, A. Kawamura, C. Johansson, A.
7
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Entry for the Table of Contents
Lucía Guillade, Federica Sarno, Hanna
Tarhonskaya, Angela Nebbioso, Susana
Alvarez, Akane Kawamura, Christopher
J. Schofield,* Lucia Altucci,* and Ángel R.
de Lera
Page No. – Page No.
O
O
Synthesis and biological evaluation
of tripartin, a putative KDM4 natural
product inhibitor, and 1-
HO
HO
H3CO
COOH
S
+
R
OH
Cl
OH
Cl
HO
HO
Cl
OCH3
Cl
dichloromethylinden-1-ol analogues
natural tripartin
KDM4 inhibitors; no enantiomeric discrimination
(S)-tripartin does not inhibit neither isolated
KDM4A-E nor FIH
8
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