Polymerization of novel methacrylated anthraquinone dyes

Homogeneous Distribution of Polymerizable Coumarin Dyes for Active Few Mode POF

For most kinds of active polymer optical fibers, a homogeneous distribution of dye molecules over the entire fiber length and cross section is required. In this study, chemical bonding of dyes to poly(methyl methacrylate) (PMMA) by copolymerization is achieved within the polymerization process instead of dissolving the dyes in the monomers. In combination with an improved fabrication mechanism, this leads to homogeneous dye distribution within the preforms. A method for proving the integration of the dyes into the polymer chains has been developed using high-performance liquid chromatography (HPLC) and size exclusion chromatography (SEC). Prestructured core-cladding preforms with dye-doped poly(cylohexyl methacrylate-co-methyl methacrylate)-core have been prepared with the Teflon string technique and were heat-drawn to few mode fibers.

Evaluation of Compound Optical Interference in High-Content Screening

Compound optical interference remains an inherent problem in chemical screening and has been well documented for biochemical assays and less so for automated microscopy-based assays. It has also been the assumption that the latter should not suffer from such interference because of the washing steps involved in the process, thus eliminating the residual nonspecific compound effects. Instead, these compounds may have no relevance to the actual target, and as such, compound optical interference contributes to a number of false-positives, resulting in a high attrition rate during subsequent follow-up studies. In this report, we analyze the outcome of a high-content screen using enhanced green fluorescent protein as a reporter in a gain-of-function cell-based assay in search of modulators of the micro RNA (miRNA) biogenesis pathway. Using a previously validated image-based biosensor, we screened a diverse library collection of ~315,000 compounds covering natural and synthetic derivatives in which 1130 positives were identified to enhance green fluorescence expression. Lateral confirmation and dose-response studies revealed that all of these compounds were the result of optical interference and not specific inhibition of miRNA biogenesis. Here, we highlight the chemical classes that are susceptible to compound optical interference and discuss their implications in automated microscopy-based assays.

Regiodefined synthesis of brominated hydroxyanthraquinones related to proisocrinins

Dibromobenzoisofuranone 12, synthesized in six steps, was regiospecifically annulated with 5-substituted cyclohexenones 13/36 in the presence of LiOt-Bu to give brominated anthraquinones 14/38 in good yields. Darzens condensation of 30 was shown to give chain-elongated anthraquinone 32. Alkaline hydrolysis of 38 furnished 39 representing desulfoproisocrinin F.

Preparation and properties of a novel polymerizable amphiphilic anthraquinone derivative and its cationic colored copolymer latexes

Polymerizable amphiphilic dye was synthesized and used to prepare colored copolymer latexes. The amphiphilic structure overcomes the solubility limitation, dye conversion and color depth. The covalently colored film has enhanced light fastness.

Syntheses of 2-substituted 1-amino-4-bromoanthraquinones (bromaminic acid analogues) - precursors for dyes and drugs

Anthraquinone (AQ) derivatives play a prominent role in medicine and also in textile industry. Bromaminic acid (1-amino-4-bromoanthraquinone-2-sulfonic acid) is an important precursor for obtaining dyes as well as biologically active compounds through the replacement of the C4-bromo substituent with different (ar)alkylamino residues. Here we report methods for the synthesis of bromaminic acid analogues bearing different substituents at the 2-position of the anthraquinone core. 1-Aminoanthraquinone was converted to its 2-hydroxymethyl-substituted derivative which, under different reaction conditions, yielded the corresponding carbaldehyde, carboxylic acid, and nitrile derivatives. The latter was further reacted to obtain 1-amino-2-tetrazolylanthraquinone. Subsequent bromination using bromine in DMF led to the corresponding bromaminic acid derivatives in excellent isolated yields (>90%) and high purities. Alternatively, 1-amino-4-bromo-2-hydroxymethylanthraquinone could be directly converted to the desired 2-substituted bromaminic acid analogues in high yields (85-100%). We additionally report the preparation of bromaminic acid sodium salt and 1-amino-2,4-dibromoanthraquinone directly from 1-aminoanthraquinone in excellent yields (94-100%) and high purities. The synthesized brominated AQs are valuable precursors for the preparation of AQ drugs and dyes.

Bifurcated hydrogen bonding mediated planar 9,10-anthraquinone dyes: synthesis, structure and properties

By acylation of mono- and diamino-9,10-anthraquinones with o-alkoxylbenzene carbonyl chloride or o-alkoxylnaphthalene carbonyl chloride, a series of planar 9,10-anthraquinone dyes were designed and synthesized.