Synthesis and evaluation of a series of benzothiophene acrylonitrile analogs as anticancer agents.

A new library of small molecules with structural features resembling combretastatin analogs was synthesized and evaluated for anticancer activity against a panel of 60 human cancer cell lines. Three novel acrylonitrile analogs (5, 6 and 13) caused a significant reduction in cell growth in almost all the cell lines examined, with GI50 values generally in the range 10-100 nM. Based on the structural characteristics of similar drugs, we hypothesized that the cytotoxic activity was likely due to interaction with tubulin. Furthermore, these compounds appeared to overcome cell-associated P-glycoprotein (P-gp)-mediated resistance, since they were equipotent in inhibiting OVCAR8 and NCI/ADR-Res cell growth. Given that antitubulin drugs are among the most effective agents for the treatment of advanced prostate cancer we sought to validate the results from the 60 cell panel by studying the representative analog 6 utilizing prostate cancer cell lines, as well as exploring the molecular mechanism of the cytotoxic action of this analog.

Oxycodone N-oxide.

The title compound, (5R,9R,13S,14S,17R)-14-hydroxy-3-methoxy-17-methyl-4,5-epoxymorphinan-6-one N-oxide, C(18)H(21)NO(5), has been prepared in a diastereomerically pure form by the reaction of oxycodone with 3-chloroperbenzoic acid and subsequent crystallization of the product from chloroform. The crystal packing shows that the molecule exhibits intramolecular O-H···O [D···A = 2.482 (2) Å] hydrogen bonding. In addition, there are weak intermolecular C-H...O interactions which, along with van der Waals forces, stabilize the structure. The new chiral center at the 17-position is demonstrated to be R.

The effect of hydrogen bonding on the conformations of 2-(1H-indol-3-yl)-2-oxoacetamide and 2-(1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide.

In the title compounds, C(10)H(8)N(2)O(2), (I), and C(12)H(12)N(2)O(2), (II), the two carbonyl groups are oriented with torsion angles of -149.3 (3) and -88.55 (15)°, respectively. The single-bond distances linking the two carbonyl groups are 1.528 (4) and 1.5298 (17) Å, respectively. In (I), the molecules are linked by an elaborate system of N-H···O hydrogen bonds, which form adjacent R(2)(2)(8) and R(4)(2)(8) ring motifs to generate a ladder-like construct. Adjacent ladders are further linked by N-H···O hydrogen bonds to build a three-dimensional network. The hydrogen bonding in (II) is far simpler, consisting of helical chains of N-H···O-linked molecules that follow the 2(1) screw of the b axis. It is the presence of an elaborate hydrogen-bonding system in the crystal structure of (I) that leads to the different torsion angle for the orientation of the two adjacent carbonyl groups from that in (II).

Indolyl-quinuclidinols inhibit ENOX activity and endothelial cell morphogenesis while enhancing radiation-mediated control of tumor vasculature.

There is a need for novel strategies that target tumor vasculature, specifically those that synergize with cytotoxic therapy, in order to overcome resistance that can develop with current therapeutics. A chemistry-driven drug discovery screen was employed to identify novel compounds that inhibit endothelial cell tubule formation. Cell-based phenotypic screening revealed that noncytotoxic concentrations of (Z)-(+/-)-2-(1-benzenesulfonylindol-3-ylmethylene)-1-azabicyclo[2. 2.2]octan-3-ol (analog I) and (Z)-(+/-)-2-(1-benzylindol-3-ylmethylene)-1-azabicyclo[2.2.2]octan-3-ol (analog II) inhibited endothelial cell migration and the ability to form capillary-like structures in Matrigel by > or =70%. The ability to undergo neoangiogenesis, as measured in a window-chamber model, was also inhibited by 70%. Screening of biochemical pathways revealed that analog II inhibited the enzyme ENOX1 (EC(50) = 10 microM). Retroviral-mediated shRNA suppression of endothelial ENOX1 expression inhibited cell migration and tubule formation, recapitulating the effects observed with the small-molecule analogs. Genetic or chemical suppression of ENOX1 significantly increased radiation-mediated Caspase3-activated apoptosis, coincident with suppression of p70S6K1 phosphorylation. Administration of analog II prior to fractionated X-irradiation significantly diminished the number and density of tumor microvessels, as well as delayed syngeneic and xenograft tumor growth compared to results obtained with radiation alone. Analysis of necropsies suggests that the analog was well tolerated. These results suggest that targeting ENOX1 activity represents a novel therapeutic strategy for enhancing the radiation response of tumors.

Synthesis and antitubercular activity of a series of hydrazone and nitrovinyl analogs derived from heterocyclic aldehydes.

A series of hydrazone and 3-nitrovinyl analogs of indole-3-carboxaldehydes and related compounds were synthesized and screened for antitubercular activity against Mycobacterium tuberculosis H37R(V) in BACTEC 12B medium using the Microplate Alamar Blue Assay (MABA). Several compounds showed inhibitory activity against M. tuberculosis in primary screening assays at a concentration of 6.25 microg/mL; subsequent dose-response studies indicated that the most active compounds, 3d, 3e & 8b, had IC(50) values of 5.96, 5.4 & 1.6 microg/mL, respectively. These compounds represent potential leads for the further development of novel antitubercular agents.

(Z)-3-(Benzo[b]thiophen-2-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile and (E)-3-(benzo[b]thiophen-2-yl)-2-(3,4-dimethoxyphenyl)acrylonitrile. [corrected].

The title compounds, C20H17NO3S, (I), and C19H15NO2S, (II), were prepared by the reaction of benzo[b]thiophene-2-carbaldehyde with (3,4,5-trimethoxyphenyl)acetonitrile and (3,4-dimethoxyphenyl)acetonitrile, respectively, in the presence of methanolic potassium hydroxide. In (I), the C=C bond linking the benzo[b]thiophene and the 3,4,5-trimethoxyphenyl units has E geometry, with dihedral angles between the plane of the bridging unit and the planes of the two adjacent ring systems of 5.2 (3) and 13.1 (2) degrees, respectively. However, in (II), the C=C bond has Z geometry, with dihedral angles between the plane of the bridging unit and the planes of the adjacent benzo[b]thiophene and 3,4-dimethoxyphenyl units of 4.84 (17) and 76.09 (7) degrees, respectively. There are no significant intermolecular hydrogen-bonding interactions in the packing of (I) and (II). The packing is essentially stabilized via van der Waals forces.

Novel substituted (Z)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-one and (Z)-(+/-)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-ol derivatives as potent thermal sensitizing agents.

Use of ionizing radiation is essential for the management of many human cancers, and therapeutic hyperthermia has been identified as a potent radiosensitizer. Radiation therapy combined with adjuvant hyperthermia represents a potential tool to provide outstanding local-regional control for refractory disease. (Z)-(+/-)-2-(N-Benzylindol-3-ylmethylene)quinuclidin-3-ol (2) and (Z)-(+/-)-2-(N-benzenesulfonylindol-3-ylmethylene)quinuclidin-3-ol (4) were initially identified as potent thermal sensitizers that could lower the threshold needed for thermal sensitivity to radiation treatment. To define the structural requirements of the molecule that are essential for thermal sensitization, we have synthesized and evaluated a series of (Z)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-one (9), and (Z)-(+/-)-2-(N-benzylindol-3-ylmethylene)quinuclidin-3-ol (10) analogs that incorporate a variety of substituents in both the indole and N-benzyl moieties. These systematic structure-activity relationship (SAR) studies were designed to further the development and optimization of potential clinically useful thermal sensitizing agents. The most potent analog was compound 10 (R(1)=H, R(2)=4-Cl), which potently inhibited (93% inhibition at 50 microM) the growth of HT-29 cells after a 41 degrees C/2h exposure.

rac-(Z)-2-(2-Thienylmethylene)-1-azabicyclo[2.2.2]octan-3-ol.

The asymmetric unit of the racemic form of the title compound, C(12)H(15)NOS, contains four crystallographically independent molecules. The olefinic bond connecting the 2-thienyl and 1-azabicyclo[2.2.2]octan-3-ol moieties has Z geometry. Strong hydrogen bonding occurs in a directed co-operative O-H...O-H...O-H...O-H R(4)(4)(8) pattern that influences the conformation of the molecules. Co-operative C-H...pi interactions between thienyl rings are also present. The average dihedral angle between adjacent thienyl rings is 87.09 (4) degrees.

(Z)-2-[(1-Phenylsulfonyl-1H-indol-3-yl)methylene]-1-azabicyclo[2.2.2]octan-3-one semicarbazone.

In crystals of the title compound, C(23)H(23)N(5)O(3)S, the indole system is planar and the phenyl ring of the phenylsulfonyl group makes a dihedral angle with the best plane of the indole system of 77.18 (4) degrees. The olefinic bond connecting the azabicyclic and indole systems has Z geometry. The geometry adopted by the C=O bond with respect to the N-N bond is trans. The O atom of the carbonyl group of each molecule is hydrogen bonded to the hydrazidic H atom of an adjacent molecule to form an eight-membered-ring dimeric structure.

A pharmacokinetic study on Z-(+/-)-2-(1-benzylindole-3-yl-methylene)azabicyclo[2.2.2]octane-3-ol; a novel radio-sensitization agent.

PURPOSE: The purpose of this research was to characterize the pharmacokinetic parameters and to evaluate the absolute bioavailability of the targeted compound: Z-(+/-)-2-(1-benzylindole-3-yl-methylene)azabicyclo[2.2.2]octane-3-ol (BMABO), a novel radio-sensitization agent, after oral delivery. METHODS: Sprague-Dawley rats received a single oral dose of 20 mg/kg and this was compared with intravenous administration of the compound (1 mg/kg). Blood samples were collected at different time points, and plasma BMABO concentrations were determined using a new sensitive and specific LC/MS analytical method, which utilized electrospray ionization. RESULTS: The bioavailability of orally administered BMABO was determined by comparing plasma concentrations after oral gavage delivery with intravenous delivery. Following delivery of the oral dose, the average C (max) was 1,710 +/- 503 ng/ml, and the AUC-value was found to be 3,561 +/- 670 ng min kg/ml mg. Relative to the intravenous dose (100% bioavailability), the bioavailability was 6.2% after oral administration. CONCLUSION: As the current studies demonstrate the novel radio-sensitization agent BMABO may have potential therapeutic valuable in cancer treatment. Further evaluation of the efficacy and toxicity of BMABO will determine the feasibility of the oral route for future clinical studies.

Novel chemical enhancers of heat shock increase thermal radiosensitization through a mitotic catastrophe pathway.

Radiation therapy combined with adjuvant hyperthermia has the potential to provide outstanding local-regional control for refractory disease. However, achieving therapeutic thermal dose can be problematic. In the current investigation, we used a chemistry-driven approach with the goal of designing and synthesizing novel small molecules that could function as thermal radiosensitizers. (Z)-(+/-)-2-(1-Benzenesulfonylindol-3-ylmethylene)-1-azabicyclo[2.2.2]octan-3-ol was identified as a compound that could lower the threshold for Hsf1 activation and thermal sensitivity. Enhanced thermal sensitivity was associated with significant thermal radiosensitization. We established the structural requirements for activity: the presence of an N-benzenesulfonylindole or N-benzylindole moiety linked at the indolic 3-position to a 2-(1-azabicyclo[2.2.2]octan-3-ol) or 2-(1-azabicyclo[2.2.2]octan-3-one) moiety. These small molecules functioned by exploiting the underlying biophysical events responsible for thermal sensitization. Thermal radiosensitization was characterized biochemically and found to include loss of mitochondrial membrane potential, followed by mitotic catastrophe. These studies identified a novel series of small molecules that represent a promising tool for the treatment of recurrent tumors by ionizing radiation.

3-Ethyl-2-methyl-5-methyl-ene-6,7-di-hydroindol-4(5H)-one.

The title compound, C(12)H(15)NO, a degradation product of molindone hydro-chloride, was prepared by the reaction of molindone with methyl iodide and subsequent reaction of the resulting quaternary ammonium salt with 2N aqueous sodium hydroxide. The newly formed double bond is exocyclic in nature and the carbonyl group is conjugated with the π-electrons of the pyrrole ring. The six-membered ring is in the half-chair conformation. The H atom attached to the N atom is involved in an inter-molecular hydrogen bond with the O atom of a screw-related mol-ecule, thus forming a continuous chain.

1-(1H-Indol-3-ylcarbonyl)-N-(4-methoxybenzyl)formamide.

In the title compound, C18H16N2O3, the indole ring is planar and the two adjacent carbonyl groups are mutually trans oriented with a torsion angle of 144.8 (3) degrees. The single C-C bond linking the two carbonyl functionalities is 1.539 (4) A. Molecules are linked into a two-dimensional network by intermolecular N-H...O hydrogen bonds.

(Z)-2-(3-methoxybenzylidene)-1-azabicyclo[2.2.2]octan-3-one.

The crystal structure of the title compound, C(15)H(17)NO(2), contains two nearly identical but crystallographically independent molecules, each with a double bond connecting an azabicyclic ring system to a 3-methoxybenzylidene moiety. The space group is triclinic P-1. The benzene ring is twisted by 18.44 (5) and 22.35 (4) degrees with respect to the plane of the double bond connected to the azabicyclic ring system for the two molecules. In addition to C-H...pi interactions, molecules are held together in the solid state by van der Waals interactions.

(E)-2-Methyl-3-(2-methyl-2-nitrovinyl)-1H-indole and (E)-3-(2-methyl-2-nitrovinyl)-2-phenyl-1H-indole.

In the title compounds, C12H12N2O2, (I), and C17H14N2O2, (II), respectively, the indole rings are planar and the vinyl groups lie out of the indole planes, making dihedral angles of 33.48 (5) and 41.31 (8) degrees , respectively. In (II), the dihedral angle between the phenyl and indole ring planes is 32.06 (6) degrees . In both molecules, the double bond connecting the methylnitrovinyl group and the indole nucleus adopts an E configuration. Notwithstanding the differences in space group [C2/c for (I) and P2(1)2(1)2(1) for (II)], the mode of packing of compounds (I) and (II) is determined by similar intermolecular N-H...O hydrogen-bonding interactions, forming chains that run parallel to [101] in (I) and [001] in (II).

(Z)-3-(1H-Indol-3-yl)-2-(3-thienyl)acrylonitrile and (Z)-3-[1-(4-tert-butylbenzyl)-1H-indol-3-yl]-2-(3-thienyl)acrylonitrile.

(Z)-3-(1H-Indol-3-yl)-2-(3-thienyl)acrylonitrile, C15H10N2S, (I), and (Z)-3-[1-(4-tert-butylbenzyl)-1H-indol-3-yl]-2-(3-thienyl)acrylonitrile, C26H24N2S, (II), were prepared by base-catalyzed reactions of the corresponding indole-3-carboxaldehyde with thiophene-3-acetonitrile. 1H/13C NMR spectral data and X-ray crystal structures of compounds (I) and (II) are presented. The olefinic bond connecting the indole and thiophene moieties has Z geometry in both cases, and the molecules crystallize in space groups P2(1)/c and C2/c for (I) and (II), respectively. Slight thienyl ring-flip disorder (ca 5.6%) was observed and modeled for (I).

(Z)-2-(1-Phenylsulfonyl-1H-indol-3-ylmethylene)-1-azabicyclo[2.2.2]octan-3-one and (Z)-(S)-2-(1-phenylsulfonyl-1H-indol-3-ylmethylene)-1-azabicyclo[2.2.2]octan-3-ol.

The title compounds, C22H20N2O3S, (I), and C22H22N2O3S, (II), crystallize in space groups P-1 and P2(1)2(1)2(1), respectively. The indole rings are planar and the benzene ring of the phenylsulfonyl group makes a dihedral angle with the mean plane of the indole ring of 90.2 (2) degrees in (I) and 94.0 (2) degrees in (II). In both molecules, the double bond connecting the aza-bicyclic and indole moieties has a Z geometry. Compound (II) was obtained as an enantiomerically pure crystal and has the 3S configuration.