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Metastatic prostate cancer (mPCa) relapses after a short period of androgen deprivation therapy and becomes the castration-resistant prostate cancer (CR PCa); to which the treatment is limited. Hence, it is imperative to identify novel therapeutic agents towards this patient population. In the present study, antiproliferative activities of novel imidazopyridines were compared. Among three derivatives, PHE, AMD and AMN, examined, AMD showed the highest inhibitory activity on LNCaP C-81 cell proliferation, following dose- and time-dependent manner. Additionally, AMD exhibited significant antiproliferative effect against a panel of PCa cells, but not normal prostate epithelial cells. Further, when compared to AMD, its derivative DME showed higher inhibitory activities on PCa cell proliferation, clonogenic potential and in vitro tumorigenicity. The inhibitory activity was apparently in part due to the induction of apoptosis. Mechanistic studies indicate that AMD and DME treatments inhibited both AR and PI3K/Akt signaling. The results suggest that better understanding of inhibitory mechanisms of AMD and DME could help design novel therapeutic agents for improving the treatment of CR PCa.

Poly[4-(4-vinylbenzyloxy)-2-hydroxylbenzaldehyde] was evaluated for removing low concentrations of lead(II) in ppb levels from aqueous media. The effects of the pH condition and the initial lead concentrations on removal were examined. It was found that the metal absorption is best described with the Langmuir model. The RL values obtained between 0.01 and 0.23 indicate that favorable absorption occurs in the studied concentration ranges. The kinetic study revealed that the metal removal proceeds at a very fast pace—less than 30 s—to reach the maximum capacity. The data fit the description of pseudo–second-order rate. The dynamic column study for real-time practical absorption also was investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Two new ternary Tb 3+ complexes, Tb(MAA) 3 phen and Tb(AA) 3 phen have been synthesized that possess polymer precursors. Each complex consists of two different ligands: one is carboxylate which is derived from methacrylic acid (MAA) or acrylic acid (AA) to serve not only as a ligand but also as a functional group for polymer precursor, the other is 1,10-phenanthroline which is found to be a critical component to make the complex exhibit desirable photophysical properties. The fluorescence of the complexes shows the characteristic emission of Tb 3+ ion in both solid state and liquid solution. The fluorescence intensity is found to be concentration-dependent in solution up to 0.02 M. Afterwards, the emission property of Tb(AA) 3 phen shows to be fairly stable all the way up to 0.1 M.

This work reports the degenerate two-photon absorption spectrum for a series of Salen complexes possessing two azo dye units. The observed spectra peak at 1000 nm, twice the wavelength of the linear absorption peak, and increase monotonically to the blue due to resonant enhancement of the non linearity. The two-photon absorption properties of these molecules were found to be an additive effect of chromophores and independent of the metal ions. The two-photon absorption spectra were described with a sum-over-states model, from which the transition dipole moment and dipole moment change were determined and compared with quantum chemistry calculation.

Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

In this paper, we present the one- and two-photon optically induced birefringence in cast films of amorphous poly(methyl methacrylate) (PMMA), containing a new series of organometallic azoaromatic compounds, referred to as Salen dyes, which may be used in optical storage applications. For the one-photon optically induced birefringence, longer writing times were required for the organometallic compounds in comparison with the nonmetal one, probably due to the higher degree of aggregation in the azoaromatic moieties that precludes molecular orientation. Furthermore, as a novelty concerning optical storage, two-photon optically induced birefringence could be achieved in the Salen dyes guest-host films, which allows their application in three-dimensional optical memories.

A new series of Schiff base complexes [Fe(III), VO(II), Pd(II), Cu(II), and Ni(II)] has been developed. The ligand possesses bulky t -pentyl groups at the 3- and 5-positions. The iron (III) complex is obtained in monomeric form with a square-pyramidal configuration while the copper complex is with square-planar configuration.

An imidazole-based ligand has been evaluated for a potential fluorescent Hg(II) sensing probe. In water–acetonitrile solvent system, the ligand exhibits a unique selectivity towards Hg(II), which not only modulates fluorescence intensity but also shifts the emission band. The fluorescence reduction and the emission shift correlate with Hg(II) concentrations.

Two- and three-photon excited fluorescence and its optimization via pulse shaping was studied in a novel classes of Y-shaped chromophores with large nonlinear absorption cross section

The steric effect from aromatic species at the 2-position has been evaluated in 2,4,5-trisubstituted imidazole system. The steric interaction from the 2-position has a direct impact on the fluorescent properties. There is a correlation between the twist and fluorescence quantum yield. The larger the twist is, and the more reduction of quantum yield it will have. The use of thiazole at the 2-position almost eliminates the interaction and retains the coplanarity. As a result, the substitution at the 1-position does not compromise the quantum yield.

A series of chiral bimetallic complexes have been prepared containing both Cu(II) and Hg(II) metal centers. The complexes possess chiral salen ligands which host Cu(II) in the center of the cis-N2O2 chromophore and Hg(II) via two oxygen atoms of the chromophore. Halogen and acetate groups from mercury salts interact with the Cu(II) center. The X-ray crystallographic data of 11 reveals a short distance of Cl⋯Cu (3.22–3.26 A). EPR study also discloses a strong interaction, in particular, of acetate group with Cu.

The tert -pentyl group has been found to produce a pronounced stereodirecting effect, which is manifested in a study on Salen–Mn(III) complexes bearing such groups.

A chiral vanadyl complex prepared from a chiral Salen ligand possessing branched bulky groups at 3- and 5-positions showed two independent molecules in solid state in which the core conformations are significantly different.

Ultrasound has been found to enhance N-substitution against elimination in the reaction of carbazole-containing bromides 3 with a Disperse Orange 3 derivative 2 under PTC condition. Upon using combined PTC and ultrasound conditions, a series of bifunctional molecules 1 have been prepared to possess charge-transporting agents and nonlinear optical chromophores in 2:1 ratio.

Crystalline TiO2 nanoparticles with different phase compositions were fabricated on carbon fibers. The fabrication is achieved at low temperature. The process includes the treatment of Ti(OH)4 with hydrogen peroxide in the presence of carbon fibers. Neither additional acids nor bases, or additives are used during the process. Carbon fibers prior to and after TiO2 loading are characterized by FE-SEM, XRD, and UV-vis absorption spectroscopy. The photocatalytic activity was assessed via photocatalytic degradation of methyl orange solution, and found to be phase composition-dependent & pH dependent. Carbon fibers loaded with mixed-phase TiO2 led to the best photocatalytic performance. HRTEM reveals the anatase/rutile heterojunction which helps explain the high efficiency of photocatalysis. They have been demonstrated to be re-usable in the continuous photocatalytic degradation process.

A new series of thermally stable heterocyclic imidazole-based nonlinear optical chromophores has been developed. These chromophores possess a thiophene based stilbene conjugation pathway with a nitro acceptor group attached to the phenyl end. This feature leads to robust chromophores with high thermal stability and enhanced molecular nonlinearity

Potentially photorefractive molecules, which possess both a charge transfer component and a nonlinear optical chromophore, were prepared by the direct N -monoalkylation of Disperse Orange 3 ( 1 ) with a carbazole alkyl bromide ( 2 ) utilizing phase transfer catalysis. Further N -alkylation of the remaining active N–H with alkyl halides with various chain lengths allowed the thermal properties of the Disperse Orange 3 derivatives to be fine-tuned.

An efficient and facile synthesis of a new class of novel chiral Salen Schiff base ligands has been developed via a stepwise approach. An important feature of these new Salen ligands is that they possess two different salicylaldehyde units, therefore, while steric factor or electronic factor can be fixed on one side, electronic or/and steric factors can be tuned from the other side with different substituents.

Five new tetradentate unsymmetrical ligands, ethylene-N-(acetylacetoneimine)-N′-(ortho-hydroxyl arylaldimine) (aryl = 3,5-dibromophenyl, 3-methylphenyl, 3,6-dimethylphenyl, 3,5-dichlorophenyl, 3,5-dibromoacetophenone), have been prepared and characterized for studies of the general structure of their copper(II) complexes and assessment of the substituent effects on central metal ions. Upon reaction with copper(II) ions, the ligands derived from aryls, where aryls are 3,5-dibromophenyl, 3-methylphenyl, 3,6-dimethylphenyl and 3,5-dibromoacetophenone, give the corresponding copper(II) complexes while the ligand derived from 3,5dichlorophenyl undergoes partial hydrolysis leading to the cleavage of an acetylacetone moiety. The general coordination configuration has been revealed by an X-ray crystallographic study of one of the complexes, ethylene-N-(acetylacetoneiminato)-N′-(o-hydroxy-3,5-dibromoacetophenoneiminato)copper(II), which exhibits an approximately square-planar geometry with a slight tetrahedron distortion. An ESR study of the copper(II) complexes in solution indicates electronic effects from substituents influence the reactivity of central metal ions. In addition, a key step in preparation of the unsymmetrical ligands has been dramatically improved to ensure synthetic reproducibility and eliminate the decomposition of an intermediate, 7-amino-4-methyl-5azo-3-heptene-2-one, AMAHO. Thermal stability of the complexes has been also evaluated to assess the compatibility of the two donating moieties.

A new synthetic method for tricyanovinylation has been developed to prepare a series of novel NLO imidazole chromophores containing a tricyanovinyl acceptor coupled with thiophene spacer.

Eight new vanadyl complexes utilizing unsymmetrical bis-Schiff base ligands [VOL, H 2 L = o -HOArC(R)NCH 2 CH 2 NHC(CH) 3 )CHC(O)CH 3 ], prepared from ethylene-diamine, acetylacetone and a salicylaldehyde derivative have been synthesized and characterized. A 0 and g 0 values determined by ESR were found to be solvent-independent. Substituents on the phenyl ring of the ligand strongly effect A 0 , with strongly electron-withdrawing groups giving rise to higher A 0 values, however, g 0 was only slightly effected by ring substituents. VO[2-O-3,5-Br 2 C 6 H 2 C(CH 3 )NCH 2 CH 2 NC(CH 3 )CHC(O)CH 3 (VOL 8 ) was characterized by single-crystal X-ray crystallography and the vanadium was found to be displaced above the basal plane by 0.612 A. This large displacement of the vanadium from the basal plane may contribute to solvent-independence of A 0 and g 0 values determined by ESR.

Two new classes of two-photon absorbing Y-shaped molecules have been developed to possess an imidazole-thiazole core and a stilbene-type conjugation pathway with either nitro or sulfonyl as terminal electron-accepting group.

A modified method for the synthesis of o-hydroxyaryl aldehydes in moderate yields has been developed by treating aryloxymagnesium bromides with formaldehyde using triethylamine in place of hexamethylphosphoric triamide (HMPA).

tert-Pentyl groups are recognized to be highly effective steric groups that can enhance enantioselectivity of salen titanium complexes when they are used in asymmetrical cyanation of aromatic aldehydes. High ee (92-97%) has been obtained with several aldehyde substrates. Compared to its tert-butyl analogue, the tert-pentyl group has been found to improve enantioselectivity and in some cases quite dramatically.

This work demonstrates that the detuning of the fs-laser spectrum from the two-photon absorption band of organic materials can be used to reach further control of the two-photon absorption by pulse spectral phase manipulation. We investigate the coherent control of the two-photon absorption in imidazole–thiophene core compounds presenting distinct two-photon absorption spectra. The coherent control, performed using pulse phase shaping and genetic algorithm, exhibited different growth rates for each sample. Such distinct trends were explained by calculating the two-photon absorption probability considering the intrapulse interference mechanism, taking into account the two-photon absorption spectrum of the samples. Our results indicate that tuning the relative position between the nonlinear absorption and the pulse spectrum can be used as a novel strategy to optimize the two-photon absorption in broadband molecular systems.

A modified method for the synthesis of o-hydroxyaryl aldehydes in moderate yields has been developed by treating aryloxymagnesium bromides with formaldehyde using triethylamine in place of hexamethylphosphoric triamide (HMPA).

An efficient and facile synthesis of a new class of novel chiral Salen Schiff base ligands has been developed via a stepwise approach. An important feature of these new Salen ligands is that they possess two different salicylaldehyde units, therefore, while steric factor or electronic factor can be fixed on one side, electronic or/and steric factors can be tuned from the other side with different substituents.

A new class of novel chiral Schiff base ligands has been developed using a stepwise approach. The key feature of these new ligands is that they possess two different donor units, one of them is aromatic while the other is non-aromatic.

Ultrasound has been found to enhance N -substitution against elimination in the reaction of carbazole-containing bromide with disperse orange 3 derivative under PTC conditions.

tert-Pentyl groups are recognized to be highly effective steric groups that can enhance enantioselectivity of salen titanium complexes when they are used in asymmetrical cyanation of aromatic aldehydes. High ee (92-97%) has been obtained with several aldehyde substrates. Compared to its tert-butyl analogue, the tert-pentyl group has been found to improve enantioselectivity and in some cases quite dramatically.

Ultrasound has been found to enhance N -substitution against elimination in the reaction of carbazole-containing bromide with disperse orange 3 derivative under PTC conditions.

Schiff base compounds have been prepared possessing azo dye units. The two-photon absorption properties are evaluated, which reveals the additive property as a result of non-detrimental dipole-dipole interaction between dye chromophores.

New salen compounds have been developed to possess two pendant azo dye chromophores. The two-photon absorption properties have been observed which result from the chromophores. The additive property has been found to exist as a result of no detrimental dipole–dipole interaction between chromophores.

Poly[4-(4-vinylbenzyloxy)-2-hydrobenzaldehyde], PVBH, a salicylaldehyde chelating functional group-based polymer has been found to be capable of the removal of low concentration of cadmium metal ion in ppb level from aqueous media. The adsorption fits best with the Langmuir model, indicating the monolayer coverage of the metal ion on the surface of chelating polymer. The R(L) values have indicated the favorable adsorption in the range of all the ppb concentrations studied. The kinetic study has revealed a very fast adsorption process with the rate following the pseudo-second-order.

This work reports the degenerate (2PA) spectrum for a series of Salen complexes possessing two azo dye units. The 2PA properties of these molecules were found to be additive effect of chromophores.

[reaction: see text] Reaction of various aromatic aldehydes with 2,2'-dipyridyl ketone and ammonium acetate in hot acetic acid provides ready access to a series of substituted 1-pyridylimidazo[1,5-a]pyridines, a class of ligands possessing an N,N-bidentate feature, in good yields.

A facile and one-pot straightforward methodology has been developed to prepare a novel class of imidazo[1,5-a]pyridines. A key role played by ammonium acetate in chemoselectivity has been examined.

A nonlinear optical chromophore, 4,5-bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole, was investigated by X-ray crystallography. The study focused on coplanarity among several aromatic rings, including phenyls and imidazole. Two phenyl rings with NMe2 groups are twisted by 46.39(3) degrees from each other. However, they are twisted by 23.05(5) degrees and 46.84(3) degrees from the imidazole, respectively. These unequal twists were elucidated by different conjugation pathways from the donors to the acceptor. The phenyl ring with the NO2 group is twisted by only 6.76(6) degrees from the imidazole.