Synthesis of new DOPO derivatives and investigation of their synergistic effect with APP-PEI on the flame retardancy of epoxy composite.

Epoxy resin has been extensively used in many industrial and daily applications due to its unique properties. However, the high flammability of epoxy has limited its further development. DOPO derivatives, which are organophosphorus compounds, are highly effective components of flame retardant epoxy composites due to their good compatibility with the resin and their lower toxicity compared to halogenated compounds. This study synthesized sixteen new DOPO derivatives, characterizing their chemical structures with NMR spectroscopy. The combination of synthesized DOPO derivatives and APP-PEI (ammonium polyphosphate-polyethyleneimine) has shown a synergistic effect on enhancing the flame retardancy of epoxy resin with the UL-94 V-0 rating and the LOI value of 28.6%. Moreover, the epoxy composites displayed relatively high mechanical performance with the impact strength of 26-28 kJ m-2.

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 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.

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

A convenient microwave-assisted one-pot four-component synthetic approach was developed en route to novel functionalized benzo[a]pyridazino[3,4-c]phenazine derivatives starting from 2-hydroxy-1,4-naphthoquinone, aromatic aldehydes, methyl hydrazine and o-phenylenediamine. Nine new derivatives were successfully synthesized and subsequently evaluated in terms of their biological profiles. The results revealed good cytotoxic activities of compounds 6a, 6h against KB, HepG2, Lu1 and MCF7 human cancer cell lines. Besides that, compound 6d exhibited promising antimicrobial activities toward Staphylococcuc aureus and Bacillus subtilis bacterial strains with IC50 < 6 µM.

Synthesis of novel potent cytotoxicy podophyllotoxin-naphthoquinone compounds via microwave-assited multicomponent domino reactions.

A series of novel podophyllotoxin-naphthoquinone compounds 5a-p were synthesized in good yields using microwave-assisted four-component reactions of 2-hydroxy-1,4-naphthoquinone, aromatic benzaldehydes, tetronic acid and ammonium acetate. All the synthesized compounds were fully characterized by spectral data and evaluated for their cytotoxicity activities against KB, HepG2, Lu1, MCF7, and non-cancerous Hek-293 cell lines. Among 16 new compounds screened, compounds 5a, 5d, 5h, and 5k displayed high potent inhibitory activities with IC50 < 40 nM against HepG2 and SK-Lu-1 cell lines, and showed lower toxicity for non-cancerous Hek-293 cell line, demonstrating the potential importance of these compounds in the development of potential anticancer agents.