Dynamin plays a crucial role in mitosis, and dynamin inhibition broadly correlates with cytotoxicity. Dynole 34-2, dynamin inhibitor, is highly cytotoxic, but its poor drug-like properties limit its in vivo development. Three focused libraries of dynole-based dynamin inhibitors were synthesized enhance their druglike properties while maintaining their dynamin inhibition and cytotoxicity. Iterative modifications were undertaken to probe the effects of changes to the cyanoacrylamide linker amide, alkyl chain moieties, the N-propyl-N,N-dimethylamino moiety and the indole core. These compounds were screened against: HT29 and SW480 (colon), SMA (spontaneous murine astrocytoma), MCF-7 (breast), BE2-C (glioblastoma), SJ-G2 (neuroblastoma), MIA (pancreas), A2780 (ovarian), A431 (skin), H460 (lung), U87 (glioblastoma) and DU145 (prostate) cell lines to reveal a good correlation between dynamin inhibition and cytotoxicity. High potency against brain cancer cell lines was observed. The most dynamin active compounds returned average GI50 values of 2.26 and 1.5 mu M across the cell lines examined. The most active compound against 4 brain cancer cell lines averaged a GI50 value of 4.7 mu M; 10-fold improved over the gold standard for glioblastoma treatment; temozolomide. Importantly, this maintained a tPSA of 24.8 & Aring;2 and cLogP of 4.11; appropriate for blood brain barrier penetration. This active analogue in this series was (Z)-2-(3,4-dichlorophenyl)-3-(1-(3-(dimethylamino)propyl)-1H-pyrrol-3-yl)acrylonitrile (34).

Pancreatic cancer (PC) is a complex, heterogeneous disease with a dismal prognosis. Current therapies have failed to improve survival outcomes, urging the need for discovery of novel targeted treatments. Bispidinone derivatives have yet to be investigated as cytotoxic agents against PC cells. The cytotoxic effect of four bispidinone derivatives (BisP1: 1,5-diphenyl-3,7-bis(2-hydroxyethyl)-3,7-diazabicyclo[3.3.1]nonan-9-one; BisP2: 3,7-bis-(2-(S)-amino-4-methylsulfanylbutyryl)-1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonan-9-one dihydrochloride; BisP3: [2-{7-[2-(S)-tert-butoxycarbonylamino-3-(1H-indol-3-yl)-propionyl]-9-oxo-1,5-diphenyl-3,7-diazabicyclo[3.3.1]non-3-yl}-1-(S)-(1H-indol-3-ylmethyl)-2-oxoethyl]-carbamic acid tertbutyl ester; BisP4: 3,7-bis-[2-(S)-amino-3-(1H-indol-3-yl)-propionyl]-1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonan-9-one dihydrochloride) was assessed against PC cell lines (MiaPaca-2, CFPAC-1 and BxPC-3). Cell viability was assessed using a Cell Counting Kit-8 (CCK-8) colorimetric assay, while apoptotic cell death was confirmed using fluorescence microscopy and flow cytometry. Initial viability screening revealed significant cytotoxic activity from BisP4 treatment (1 µM–100 µM) on all three cell lines, with IC50 values for MiaPaca-2, BxPC-3, and CFPAC-1 16.9 µM, 23.7 µM, and 36.3 µM, respectively. Cytotoxic treatment time-response (4 h, 24 h, and 48 h) revealed a 24 h treatment time was sufficient to produce a cytotoxic effect on all cell lines. Light microscopy evaluation (DAPI staining) of BisP4 treated MiaPaca-2 PC cells revealed dose-dependent characteristic apoptotic morphological changes. In addition, flow cytometry confirmed BisP4 induced apoptotic cell death induction of activated caspase-3/-7. The bispidinone derivative BisP4 induced an apoptosis-mediated cytotoxic effect on MiaPaca-2 cell lines and significant cytotoxicity on CFPAC-1 and BxPC-3 cell lines. Further investigations into the precise cellular mechanisms of action of this class of compounds are necessary for potential development into pre-clinical trials.

Glioma stem cells (GSCs) play major roles in drug resistance, tumour maintenance and recurrence of glioblastoma. We investigated inhibition of the GTPase dynamin 2 as a therapy for glioblastoma. Glioma cell lines and patient-derived GSCs were treated with dynamin inhibitors, Dynole 34-2 and CyDyn 4-36. We studied about cell viability, and GSC neurosphere formation in vitro and orthotopic tumour growth in vivo. Dynamin inhibition reduced glioblastoma cell line viability and suppressed neurosphere formation and migration of GSCs. Tumour growth was reduced by CyDyn 4-36 treatment. Dynamin 2 inhibition therefore represents a novel approach for stem cell-directed Glioblastoma therapy.

We have previously reported the synthesis and breast cancer selectivity of (Z)-2-(3,4-dichlorophenyl)-3-(1H-pyrrol-2-yl)acrylonitrile (ANI-7) in cancer cell lines. To further evaluate the selectivity of ANI-7, we have expanded upon the initial cell line panel to now include the breast cancer cell lines (MCF7, MCF7/VP16, BT474, T47D, ZR-75-1, SKBR3, MDA-MB-468, BT20, MDA-MB-231); normal breast cells (MCF-10A); and cell lines derived from colon (HT29), ovarian (A2780), lung (H460), skin (A431), neuronal (BE2C), glial (U87, SJG2), and pancreatic (MIA) cancers. We now show that ANI-7 is up to 263-fold more potent at inhibiting the growth of breast cancer cell lines (MCF7, MCF7/VP16, BT474, T47D, ZR-75-1, SKBR3, MDA-MB-468) than normal breast cells (MCF-10A) or cell lines derived from other tumor types. Measures of growth inhibition, cell cycle analysis, morphologic assessment, Western blotting, receptor binding, gene expression, small interfering RNA technology, reporter activity, and enzyme inhibition assays were exploited to define the mechanism of action of ANI-7. In this work, we report that ANI-7 mediates its effects via the activation of the aryl hydrocarbon receptor (AhR) pathway and the subsequent induction of CYP1-metabolizing mono-oxygenases. The metabolic conversion of ANI-7 induces DNA damage, checkpoint activation, S-phase cell cycle arrest, and cell death in sensitive breast cancer cell lines. Basal expression of AhR, the AhR nuclear translocator, and the CYP1 family members do not predict for sensitivity; however, inherent expression of the phase II–metabolizing enzyme sulfur transferase 1A1 does. For the first time, we identify (Z)-2-(3,4-dichlorophenyl)-3-(1H-pyrrol-2-yl)acrylonitrile as a new AhR ligand.

Background: Multiple reaction monitoring (MRM) is an emerging branch of targeted mass spectrometry. It exploits the unique mass of a molecule to detect it in biological samples with immense specificity and sensitivity. MRM assays can be customised to monitor any number of cancer biomarkers and biochemical pathways, allowing biomarker detection in individual patients for diagnosis, prognosis, and therapy using blood or tumour samples.

Background: Multiple reaction monitoring (MRM) is an emerging branch of targeted mass spectrometry. It exploits the unique mass of a molecule to detect it in biological samples with immense specificity and sensitivity. MRM assays can be customised to monitor any number of cancer biomarkers and biochemical pathways, allowing biomarker detection in individual patients for diagnosis, prognosis, and therapy using blood or tumour samples.

Two libraries of highly decorated norcantharidin analogues were accessed via a series of sequential chemoselective flow hydrogenations and solvent-free transformations. Utilising a 10% Pd/C catalyst, modifications to reaction parameters (H-2 pressure, temperature and flow rate conditions) allowed facile access to effect selective direct reductive aminations and olefin reductions in the presence of furan, benzyl and nitrile moieties were established. The use of 20% Pd(OH)(2)/C; Pd tetrakis; 5% Pt/C (sulfided) gave mixtures of furan and olefin (both reduced) and olefin reduced products. RuO2; 0.5% Re/C and Re2O7 resulted in no reduction. Concurrent olefin and nitrile reduction was achieved in the presence of furan moieties by employing a RANEY (R) nickel catalyst. In total, 31 reaction conditions were examined using less than 200 mg of reagents allowing optimised conditions to be efficiently determined. These optimised hydrogenation conditions afforded desired analogues in near quantitative yields thus removing the requirements of reaction workup and chromatography.

AbstractTwo series (VI) and (XI) of norcantharidin analogues are synthesized using continuous flow hydrogenation in key steps.

We report the discovery of a series of acrylonitrile-containing molecules and alpha-amino amides which cause 99-100% lethality in H. contortus. Of the 22 acrylonitrile analogues investigated, the most active were 2-cyano-3-[1-(3-dimethylaminopropyl)-2-methyl-1H-indol-3-yl]-N-hexylacrylamide (13a), 2-cyano-3-[1(2-dimethylaminoethyl)-2-methyl-1H-indol-3-yl]-N-hexylacrylamide (13b), 2-cyano-3-{4-[3-(dimethylamino)-propoxy]phenyl}-N-octylacrylamide (21), and 2-cyano-3-{1-[3-(dimethylamino)propyl]-1H-pyrrol-2-yl}-N-octylacrylamide (22) with each displaying LD50 values <15 mu M whilst the alpha-amino amide methyl-2-[2-(2-benzoylphenylamino)-2-(4-methoxyphenyl) acetamido]acetate (12a) had an LD50 value of 10 mu M. A cytotoxicity screen of the acrylonitrile analogues (13a, 13b, 21 and 22) against nine cancer cell lines indicated modest to high cytotoxicity. In contrast, the alpha-amino amide 12a displayed very low cytotoxicity, with a maximum of similar to 30% cell death at 25 mu M (A2780, an ovarian carcinoma derived cell line) and with a mean of 11% cell death across all cell lines evaluated. Thus, 12a is considered a promising lead candidate for the development of a new anthelmintic.

With our lead compound (E)-3-(4-chlorophenyl)-2-(1H-pyrrole-2-carbonyl)acrylonitrile (1) inducing 50% growth inhibition of 11 cancer cell lines at 27–61μM, potency enhancements were rapidly established through the synthesis of a series of focused compound libraries. Six highly focused libraries (46 compounds in total) were synthesised. Each library allowed the identification of a new lead compound, viz Library A identified (E)-3-(pentafluorophenyl)-2-(1H-pyrrole-2-carbonyl)acrylonitrile (11) and (E)-3-(1H-indol-3-yl)-2-(1H-pyrrole-2-carbonyl)acrylonitrile (13) as inhibitors with improved cytotoxicity. Synthesis of discrete libraries of amidoacrylamide analogues (Ar–CC(CN)–Ar✠Ar–CC(CN)–C(O)NH)–Ar) resulted in a series of analogues significantly more potent that the lead, 1. Three furan three analogues: (E)-3-(5-chlorofuran-2-yl)-2-cyano-N-(4-methoxybenzyl)acrylamide (33), (E)-3-(5-bromofuran-2-yl)-2-cyano-N-(4-methoxybenzyl)acrylamide (34) and (E)-2-cyano-3-(furan-3-yl)-N-(4-methoxybenzyl)acrylamide (37) returned broad spectrum growth inhibition (GI50 values of 5–16μM). Replacement of the furan moiety with simple aromatics gave an additional three analogues: (E)-2-cyano-N-(4-methoxybenzyl)-3-phenylacrylamide (39), (E)-3-(4-chlorophenyl)-2-cyano-N-(4-methoxybenzyl)acrylamide (41) and (E)-2-cyano-N-(4-methoxyphenyl)-3-(naphthalen-1-yl)acrylamide (45) with GI50 values of 7–24μM. The final library retained the aromatic substituents but introduced a 3,4-dichlorbenzylamine moiety to afford the 1-naphthyl substituted 52, which was the most potent broad spectrum cytotoxic analogue produced here in with an average GI50=8.6μM. This represents a fivefold potency enhancement relative to 1 and a new cytotoxic scaffold suitable for further development.

AbstractSeveral norcantharidin derivatives (IV) are synthesized by substitution of the hydroxy group as well as further modifications in the side chain.

Cantharidin (1) and norcantharidin (2) display high levels of anticancer activity against a broad range of tumour cell lines. Synthetic manipulation of norcantharidin yields (3S,3aR,4S,7R,7aS)-3-hydroxyhexahydro-4,7-epoxyisobenzofuran-1(3H)-one (3), which also displays a high level of anticancer activity against tumour cells but interestingly, shows selectivity towards HT29 (colon; GI(50) = 14 μM) and SJ-G2 (glioblastoma; GI(50) = 15 μM) cell lines. Substitution at the hydroxyl group of the cyclic lactone within (3) produces a diasteromeric pair of products that have no difference in cytotoxicity over the cell lines tested. Incorporation of an isopropyl tail at this position (16) produced the most promising compound of this series to date, with strong selectivity towards HT29 (colon; GI(50) = 19 μM) and SJ-G2 (glioblastoma; GI(50) = 21 μM) cell lines but completely void of any activity against the remaining tumour cell lines (GI(50) > 100 μM), as per the parent molecule. We also discovered that the introduction of a terminal phosphate moiety (28) at the same position produced a different trend in cytotoxicity with strong activity in BE2-C (neuroblastoma; GI(50) = 9 μM) cells; suggestive of an alternate mode of action.

Crystal structures of two isomeric norcantharidin derivatives (3R,3aR,4S,7R,7aS)-3-(allyloxy)hexahydro-4,7-epoxyisobenzofuran-1(3H)-one (7b), and (3S,3aR,4S,7R,7aS)-3-((E)-but-2-en-1-yloxy)hexahydro-4,7-epoxyisobenzofuran-1(3H)-one (8a) have been determined. In both instances the equivalent enantiomer was also obtained. The crystal structures of these compounds clarify the stereochemistry inferred only by NMR analysis before.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

We previously reported the discovery of a simple conjugated cyano pharmacophore which had led to the development of (Z)-2-(3,4-dichlorophenyl)-3-(4-nitrophenyl)acrylonitrile (1), as a selective inhibitor of oestrogen receptor positive (ER+ve) human breast cancer cell line, MCF-7. Further exploration though modification of the acrylonitrile and aromatic substituents has highlighted key structural components necessary for broad spectrum cytotoxicity. The acrylic acid derivates (Z)-2-(3,4-dichlorophenyl)-3-(4-nitrophenyl)acrylic acid (8) and (Z)-2-(3,4-dichlorophenyl)-3-(4-methoxyphenyl)acrylic acid (9) were inactive; confirming the importance of the cyanide moiety. The most potent 2-phenylacrylonitriles synthesized were (Z)-2-(3,4-dichlorophenyl)-3-(1H-indo1-3-yl)acrylonitrile (3) and (Z)-2-(3,4-dichlorophenyl)-3-(1H-indol-5-yl)acrylonitrile (20) with an average GI(50) values of 1.4 and 0.53 mu M respectively. Five additional (Z)-2-(3,4-dichlorophenyl)-3-(indolyl)acrylonitriles also displayed average GI(50) values of <= 8.4 mu M. In the case of indole 20, this represents a 32-fold increase in broad spectrum cytotoxicity relative to the lead (1). Crown Copyright (C) 2012 Published by Elsevier Masson SAS. All rights reserved.

The Knoevenagel condensation of pyrrole-2-carboxaldehyde (1) with a range of substituted benzyl nitriles (2a–e) afforded rapid access to a family of α,β-unsaturated nitriles (3a–e) in good yields (67–78%). Flow hydrogenation (ThalesNano H-cube™) at 60°C, 50bar H2 pressure, 1.0mL/min through a 10% Pd-C catalyst selectively, and quantitatively, hydrogenated the olefin double bond (4a–e). Use of a Raney Nickel catalyst at 70°C, 70bar H2 pressure and flow rates of 0.5–1.0mL/min afforded quantitative conversion into the corresponding saturated amines with the reduction of both the olefin and nitrile bonds (5a–e). The versatility of this approach was further exemplified by reaction of 5a and 5c with norcantharidin to afford acid amide norcantharidin analogues 7 and 8 as novel protein phosphatase 1 and 2A inhibitors.