Synthesis and biological evaluation of novel naphthoquinone fused cyclic aminoalkylphosphonates and aminoalkylphosphonic monoester

Synthesis and Characterization of a Minophosphonate Containing Chitosan Polymer Derivatives: Investigations of Cytotoxic Activity and in Silico Study of SARS-CoV-19

Chitosan is broadly used as a biological material since of its excellent biological activities. This work describes investigations of chitosan interaction with SARS-CoV-2, which is occupied by human respiratory epithelial cells through communication with the human angiotension-converting enzyme II (ACE2). The β-chitosan derivatives are synthesized and characterized by FT-IR, nuclear magnetic resonance (¹H and ¹³C NMR), mass spectrometry, X-ray diffraction, TGA, DSC, and elemental analysis. The β-chitosan derivatives were screened for cytotoxic activity against the HepG2 and MCF-7 (breast) cancer cell lines. Compound 1h (GI₅₀ 0.02 µM) is moderately active against the HepG2 cancer cell line, and Compound 1c is highly active (GI₅₀ 0.01 µM) against the MCF-7 cancer cell line. In addition, chitosan derivatives (1a-1j) docking against the SARS coronavirus are found by in-silico docking analysis. The findings show that compound 1c exhibits notable inhibition ability compared with other compounds, with a binding energy value of -7.9 kcal/mol. Based on the molecular docking results, the chitosan analog is proposed to be an alternative antiviral agent for SARS-CoV2.

Octahydroquinoxalin-2(1H)-One-Based Aminophosphonic Acids and Their Derivatives-Biological Activity Towards Cancer Cells

In the search for new antitumor agents, aminophosphonic acids and their derivatives based on octahydroquinoxalin-2(1H)-one scaffold were obtained and their cytotoxic properties and a mechanism of action were evaluated. Phosphonic acid and phosphonate moieties increased the antiproliferative activity in comparison to phenolic Mannich bases previously reported. Most of the obtained compounds revealed a strong antiproliferative effect against leukemia cell line (MV-4-11) with simultaneous low cytotoxicity against normal cell line (mouse fibroblasts-BALB/3T3). The most active compound was diphenyl-[(1R,6R)-3-oxo-2,5-diazabicyclo[4.4.0]dec-4-yl]phosphonate. Preliminary evaluation of the mechanism of action showed the proapoptotic effect associated with caspase 3/7 induction.

New 2-Oxoindolin Phosphonates as Novel Agents to Treat Cancer: A Green Synthesis and Molecular Modeling

The work reports the facile synthesis of novel α-aminophosphonate derivatives coupled with indole-2,3-dione moieties, namely the diethyl(substituted phenyl/heteroaryl)(2-(2-oxoindolin-3-ylidene)hydrazinyl)methylphosphonates derivatives 4(a⁻n). One-pot three component Kabachnik-Fields reactions were used to synthesize these derivatives. The reaction was carried out at room temperature by stirring in presence of ceric ammonium nitrate (CAN) as a green catalyst. The structures of the synthesized compounds were established by spectral studies. The synthesized derivatives 4(a⁻n) were evaluated for their in vitro anticancer activity against six human cancer cell lines by the SRB assay method. The cancer cell lines used in this research work are SK-MEL-2 (melanoma), MCF-7 (breast cancer), IMR-32 (neuroblastoma) MG-63 (human osteosarcoma), HT-29 (human colon cancer) and Hep-G2 (human hepatoma). All the synthesized derivatives inhibited the cell proliferation. Importantly, all the target compounds showed no cytotoxicity towards normal tissue cells (GI₅₀ > 250 µM). A docking study was performed to predict the mode of action. Docking results indicate that the compounds have good binding with the enzyme tyrosine kinase as well as with microtubules, which makes them dual inhibitors. The result of in-silico bioavailability studies suggests that the compounds from the present series have good oral drug-like properties and are non-toxic in nature. In vivo acute oral toxicity study results indicate that the compounds can be considered safe, and therefore could be developed in the future as good anticancer agents or as leads for the design and synthesis of novel anticancer agents.

Proposal of Dual Inhibitor Targeting ATPase Domains of Topoisomerase II and Heat Shock Protein 90

There is a conserved ATPase domain in topoisomerase II (topo II) and heat shock protein 90 (Hsp90) which belong to the GHKL (gyrase, Hsp90, histidine kinase, and MutL) family. The inhibitors that target each of topo II and Hsp90 are intensively studied as anti-cancer drugs since they play very important roles in cell proliferation and survival. Therefore the development of dual targeting anti-cancer drugs for topo II and Hsp90 is suggested to be a promising area. The topo II and Hsp90 inhibitors, known to bind to their ATP binding site, were searched. All the inhibitors investigated were docked to both topo II and Hsp90. Four candidate compounds as possible dual inhibitors were selected by analyzing the molecular docking study. The pharmacophore model of dual inhibitors for topo II and Hsp90 were generated and the design of novel dual inhibitor was proposed.

Separation of AsV from aqueous solutions using chelating polymers containing FeIII -loaded phosphorus groups

As

Diphenyl (4′-(Aryldiazenyl)biphenyl-4-ylamino)(pyridin-3-yl)methylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

Diphenyl (4′-aminobiphenyl-4-ylamino)(pyridin-3-yl)methylphosphonate(1)was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of1gave the corresponding diazonium salt2which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes3–8in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

Integrating molecular docking, DFT and CoMFA/CoMSIA approaches for a series of naphthoquinone fused cyclic α-aminophosphonates that act as novel topoisomerase II inhibitors

Since they are potential topoisomerase II (Topo II) inhibitors, naphthoquinone fused cyclic α-aminophosphonates display anticancer activity. In order to explore the inhibitory mechanisms of these compounds, they were docked into the active site of Topo II structure, which allowed their probable binding modes to be predicted. Some meaningful results concerning their structure-activity relationships were obtained from density functional theory calculations. Models based on quantitative comparative molecular field analysis and comparative molecular similarity index analysis were derived for the steric, electrostatic, hydrophobic and H-bonding features of the compounds. The present study provides valuable results that enhance our understanding of the anticancer activities of these inhibitors and will aid the rational drug design of novel Topo II inhibitors in the future.