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A series of novel bis-naphalenyl compounds with different diamine linkers were synthesized and characterized by H NMR, C NMR, and HR-MS. The DNA binding abilities of the compounds were studied by using flourescence titration, DNA thermal denaturation experiments, viscosity titration, and NMR studies. The DNA binding abilities of all the bis-naphalenyl compounds were on the same order of magnitude. Compared with the groove binding mode of the monomer, the bis-naphalenyl compounds exhibited partial intercalating binding mode. The cytotoxicity activities of the compounds were evaluated by MTT assay in vitro. According to the results of MTT assay, bis-naphalenyl compound 3c with hexamethylenediamine linker, and 3d with p-xylylenediamine linker were found to be more toxic against BGC823 cells. The IC values of the two compounds were similar to that of the control drug (5-Fluorouracil) on BGC823 cells. Compared with the results on BGC823 cells, better results were found on SW480 cells. Compounds 3c and 3d exhibited smaller IC values than that of control drug (5-Fluorouracil). The IC values of 3c, 3d, and 5-Fluorouracil were 52.01, 66.09, and 230.11 μM, respectively. [ABSTRACT FROM AUTHOR]

4 H-Chromene and 1,4-naphthoquinone systems are generally considered to be medicinally privileged scaffolds. We have designed novel conjugates that incorporated both these scaffolds, as such conjugates exhibit unique biological properties reflecting those due to individual units and collective presence. In this work, we have achieved facile, efficient, and high yielding synthesis of 19 such conjugates from readily available 2-alkylamino-4-methylsulfanyl-3-nitro-4 H-chromenes and 2-hydroxynaphthalene-1,4-dione. Highly polar nitroketene- O, N-acetal unit present in the conjugates is designed to prevent crossing blood brain barrier. We have conducted structure activity relationship (SAR) studies based on initial antimicrobial screening of a set of ten conjugates against three Gram positive bacteria [ Bacillus Subtilis, Staphylococcus aureus (MSSA), Staphylococcus aureus (MRSA)], one Gram negative bacteria ( Escherichia coli), and two fungi ( Aspergillus niger, Candida albicans). The SAR studies revealed that the conjugates with halogens at C(6) and C(8) positions of the 4 H-chromene ring having C(2)NMe group display impressive activity, almost equal to that of standard drugs. None of the conjugates, however, showed antimalarial activity, although they possess 2-hydroxy-1,4-naphthoquinone unit. [ABSTRACT FROM AUTHOR]

A novel brief process for the synthesis of nafoxidene has been developed. The epoxidation of 6-methoxy-1-{4-[2-(pyrrolin-1-yl)ethoxy)]phenyl}-3,4-dihydronaphthalene by m-CPBA directly gave the ketone 6-methoxy-1-[4-(2-(pyrrolidin-1-yl)ethoxy)phenyl]-3,4-dihydronaphthalen-2(1H)-one, which was subject to phenyl magnesium bromide/cerium chloride and subsequently treated with an acid to yield nafoxidene. In addition, the preparation of the starting naphthalene was also optimized by replacing the aromatic lithium at low temperature with its Grignard reagent at refluxing THF. This mild process, without the use of toxic or noble metals, was more cost-efficient and easily worked up. [ABSTRACT FROM AUTHOR]

An efficient and environmentally benign protocol for the synthesis of dibenzo [ b, i]xanthene-tetraones and fluorescent hydroxyl naphthalene-1,4-diones in the presence of a catalytic amount of ZrOCl·8HO as an inexpensive and eco-friendly catalyst with high catalytic activity under solvent-free conditions is reported. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel 4-(2-{[6-(1,1-dicyanoprop-1-en-2-yl)naphthalen-2-yl](methyl)amino} ethoxy)-4-oxobutanoic acid ( 5) fluorescent probe for β-amyloids was synthesized by catalytic acylation using 4-dimethylaminopyridine between succinic anhydride and (1-{6-[(2-hydroxyethyl)(methyl) amino]-2-naphthyl}ethylidene)malononitrile ( 4). The structures of all compounds were identified by proton nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry, and ultraviolet-visible (UV-Vis) spectroscopy. The UV-Vis and fluorescence spectra of 1-{6-[(2-hydroxyethyl)(methyl) amino]-2-naphthyl}ethan-1-one ( 3), 4, and 5 in solvents with different polarities were investigated, and the effects of solvent polarity on the optical properties of the three compounds were studied. The objective product 5 showed high binding affinities toward Aβ(1-40) aggregates in vitro ( K = 29.4 nmol/L) by fluorophotometry. This study provides a powerful fluorescent probe for the molecular diagnosis of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

The nitration selectivity of naphthalene was studied in different organic solvents with 95 % fuming nitric acid as nitration reagent. The yield of dinitronaphthalene can achieve 78 % in hexane. With nitrogen dioxide as nitration reagent in oxygen, the selectivity of dinitronaphthalene in different types of molecular sieve catalyst was studied. When HBEA zeolite catalyst was used, the yield of dinitronaphthalene was up to 61 %. This method is easy to carry out, environmentally benign, and economical. [ABSTRACT FROM AUTHOR]