Biological Activity Evaluation of Phenolic Isatin-3-Hydrazones Containing a Quaternary Ammonium Center of Various Structures.

A series of new isatin-3-hydrazones bearing different ammonium fragments was synthesized by a simple and easy work-up reaction of Girard's reagents analogs with 1-(3,5-di--butyl-4-hydroxybenzyl)isatin. All derivatives have been shown to have antioxidant properties. In terms of bactericidal activity against gram-positive bacteria, including methicillin-resistant strains of , the best compounds are , , and , bearing octyl, acetal, and brucine ammonium centers, respectively.

Hybrids of Sterically Hindered Phenols and Diaryl Ureas: Synthesis, Switch from Antioxidant Activity to ROS Generation and Induction of Apoptosis.

The utility of sterically hindered phenols (SHPs) in drug design is based on their chameleonic ability to switch from an antioxidant that can protect healthy tissues to highly cytotoxic species that can target tumor cells. This work explores the biological activity of a family of 45 new hybrid molecules that combine SHPs equipped with an activating phosphonate moiety at the benzylic position with additional urea/thiourea fragments. The target compounds were synthesized by reaction of iso(thio)cyanates with C-arylphosphorylated phenols containing pendant 2,6-diaminopyridine and 1,3-diaminobenzene moieties.

Diverse Biological Activity of Benzofuroxan/Sterically Hindered Phenols Hybrids.

Combining two pharmacophores in a molecule can lead to useful synergistic effects. Herein, we show hybrid systems that combine sterically hindered phenols with dinitrobenzofuroxan fragments exhibit a broad range of biological activities. The modular assembly of such phenol/benzofuroxan hybrids allows variations in the phenol/benzofuroxan ratio.

Bi-functional sterically hindered phenol lipid-based delivery systems as potential multi-target agents against Alzheimer's disease via an intranasal route.

New lipid-based nanomaterials and multi-target directed ligands (MTDLs) based on sterically hindered phenol, containing a quaternary ammonium moiety (SHP-s-R, with s = 2,3) of varying hydrophobicity (R = CH2Ph and CnH2n+1, with n = 8, 10, 12, 16), have been prepared as potential drugs against Alzheimer's disease (AD). SHP-s-R are inhibitors of human cholinesterases with antioxidant properties. The inhibitory potency of SHP-s-R and selectivity ratio of cholinesterase inhibition were found to significantly depend on the length of the methylene spacer (s) and alkyl chain length.

New 2,6-diaminopyridines containing a sterically hindered benzylphosphonate moiety in the aromatic core as potential antioxidant and anti-cancer drugs.

A series of 2,6-diaminopyridines was synthesized for the first time, containing phosphoryl sterically hindered phenolic fragments in the aromatic core. The antioxidant activity of these compounds was investigated, 2,6-diaminopyridine derivatives were shown to exhibit higher activity in comparison with their structural analogues. For dialkyl/diphenyl [(3,5-di-tert-butyl-4-hydroxyphenyl) (2,6-diaminopyridin-3-yl) methyl] phosphonates, their structural analogues based on meta-phenylenediamine, phosphorus-containing sterically hindered phenols and the corresponding cyclohexadienones cytotoxicity against tumor lines of epithelioid carcinoma of the cervix uteri (M-Hela) and breast adenocarcinoma (MCF-7) has been studied in vitro, as well as on normal human Chang liver cell lines.