Synthesis and biological evaluation of novel benzo[a]pyridazino[3,4-c]phenazine derivatives

Improved synthesis, molecular modeling and anti-inflammatory activity of new fluorinated dihydrofurano-naphthoquinone compounds

A series of new fluorinated dihydrofurano-napthoquinone compounds were sucessfully synthesized in good yields using microwave-assisted multi-component reactions of 2-hydroxy-1,4-naphthoquinone, fluorinated aromatic aldehydes, and pyridinium bromide. The products were fully characterized using spectroscopic techniques and evaluated for their anti-inflammatory activity using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Among 12 new compounds, compounds 8b, 8d, and 8e showed high potent NO inhibitory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with IC50 values ranging from 1.54 to 3.92 µM. The levels of pro-inflammatory cytokines IL-1β and IL-6 in LPS-stimulated RAW264.7 macrophages were remarkably decreased after the application of 8b, 8d, 8e and 8k. Molecular docking simulations revealed structure-activity relationships of 8b, 8d, and 8e toward NO synthase, cyclooxygenase (COX-2 over COX-1), and prostaglandin E synthase-1 (mPGES-1). Further physicochemical and pharmacokinetic computations also demonstrated the drug-like characteristics of synthesized compounds. These findings demonstrated the importance of fluorinated dihydrofurano-napthoquinone moieties in the development of potential anti-inflammatory agents.

Synthesis, molecular docking analysis and in vitro evaluation of new heterocyclic hybrids of 4-aza-podophyllotoxin as potent cytotoxic agents

Two different synthetic approaches to novel heterocyclic hybrid compounds of 4-azapodophyllotoxin were investigated. The obtained products were characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution mass spectrometry. MTT protocol was then performed to examine the cytotoxic activity of these products against KB, HepG2, A549, MCF7, and Hek-293 cell lines. The cytotoxic assessment indicated that all products displayed moderate to high cytotoxicity against all tested cancer cell lines. The most active compound 13k containing the 2-methoxypyridin-4-yl group exhibited selective cytotoxicity against KB, A549, and HepG2 cell lines with the IC50 values ranging from 0.23 to 0.27 μM, which were between 5- to 10-fold more potent than the positive control ellipticine. Compounds 13a (HetAr = thiophen-3-yl) and 13d (HetAr = 5-bromofuran-2-yl) displayed high cytotoxic selectivity for A549 and HepG2 cancer cell lines when compared to the other cancer cell lines and low toxicity to the normal Hek-293 cell line. Molecular docking study was conducted to evaluate the interaction of new synthesized compounds with the colchicine-binding-site of tubulin. Besides that, physicochemical and pharmacokinetic properties of the most active compounds 13h,k were predicted.

Synthesis and Cytotoxic Evaluation of Fluoro and Trifluoromethyl Substituents Containing Novel Naphthoquinone-Fused Podophyllotoxins

A series of novel naphthoquinone-fused podophyllotoxins containing fluoro and trifluoromethyl substituents were synthesized in a medium with good yields using two different synthetic approaches: microwave-assisted four-component reactions of 2-hydroxy-1,4-naphthoquinone, tetronic acid, fluorinated arylaldehydes, and ammonium acetate, and microwave-assisted three-component reactions of 2-amino-1,4-naphthoquinone, tetronic acid, and fluorinated arylaldehydes. The structures of all products were confirmed by spectral analysis. Together, cytotoxicity assessment of the products against four human cancer cell lines (human carcinoma [KB], human hepatocellular carcinoma [HepG2], lung cancer [A549], breast carcinoma [MCF7], and human embryonic kidney [Hek-293]) was performed by MTT assay. Among the obtained compounds, compound 7f turned out to be the most potent anticancer agent with significant cytotoxic activity against KB, HepG2, and MCF cancer cell lines.

Synthesis and biological activity, and molecular modelling studies of potent cytotoxic podophyllotoxin-naphthoquinone compounds

A new approach for the synthesis of podophyllotoxin-naphthoquinone compounds using microwave-assisted three-component reactions is reported in this study. Novel podophyllotoxin-naphthoquinone derivatives with modification on ring E were synthesized. All the synthetic compounds were assessed in terms of their cytotoxicity profile against four cancer cell lines (KB, HepG2, A549, and MCF7), and noncancerous Hek-293 cell lines. Notably, treatment of SK-LU-1 cells with compounds 5a and 5b resulted in G2/M phase arrest of the cell cycle, caspase-3/7 activation, and apoptosis. Additionally, molecular docking studies were performed and showed important interaction of two compounds against residues in the colchicine-binding-site of tubulin as well. Taken together, compounds 5a and 5b were identified as potent anticancer agents.

A new approach for the synthesis of podophyllotoxin-naphthoquinone compounds using microwave-assisted three-component reactions is reported in this study.

Microwave-Assisted Three-Component Synthesis of Novel N-Arylated-Dihydrobenzo[g]quinoline-5,10-Diones and Their Potential Cytotoxic Activity

A convenient three-component synthetic approach was developed en route to new and significative N-arylated-dihydrobenzo[g]quinoline-5,10-diones using 2-hydroxy-1,4-naphthoquinone, a variety of aromatic aldehydes, and 4-(arylamino)furan-2(5H)-ones. A sequence of steps including Knoevenagel condensation, Michael addition, [1,3]-hydrogen shift, intramolecular cyclization and dehydration led to the formation of products. All the products were structurally characterized by spectroscopic techniques and assessed in terms of their cytotoxicity profile against four cancer cell lines (KB, HepG2, A549, and MCF7), and human embryonic kidney (Hek-293) cell lines.

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c']diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c']diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR (¹H and ¹³C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed.