Aliphatic amines containing N-heterocyclic fragments reacted with dialkyl [3,5-di-tert-butyl-4-oxo-2,5-cyclohexadienylidene)methyl] phosphonates to form 1,6-nucleophilic addition products. This approach was used to obtain α-aminophosphonates containing sterically hindered phenol and N-heterocyclic fragments in high yields. All the compounds were evaluated for their in vitro cytotoxicity with various cancer cell lines by MTT assay method. In the course of biological studies, it was found that the obtained compounds possess cytotoxic activity against some tumor cells.

This study describes synthesis and biological evaluation of a new phosphonamidate and a series of α-aminophosphonates, employing propargylamine as a key NH-nucleophilic synthon. Two synthetic approaches were successfully implemented: (i) the reaction with O-ethyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonоchloridate to form a P–N bond; (ii) a 1,6-aza-Michael addition to dialkyl/diphenyl [(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phosphonate, affording the α-aminophosphonate scaffold via C–N bond formation. Initial in vitro cytotoxicity screening against a panel of human cancer cell lines using the MTT assay revealed that the phosphonamidate derivative exhibited the highest activity within the synthesized series.

A modular approach for dual organelle targeting based on phenol–diaminopyridine–oxaazacyclononyne (SHP–DAP–OACN) thiourea-linked hybrids was developed.

A strategy to create highly effective antimicrobial agents was proposed based on the conjugation of three functional components: a cationic quaternary ammonium salt (QAS) that exerts a membrane-disrupting effect and promotes selective accumulation on bacterial surfaces; a phosphonamidate linker for controlled activation; and a sterically hindered phenol (SHP) fragment as a potential redox component. This approach enabled the preparation of 40 target phosphonamidate–SHP/QAS hybrids in high yields (88–98%). Evaluation of their antimicrobial activity against major pathogens and methicillin-resistant Staphylococcus aureus (MRSA) revealed high potency against Gram-positive bacteria. The lead compounds achieved minimum inhibitory concentration (MIC) values of 0.7–2.8 μM, which is up to 10 times lower than that of the reference drug, norfloxacin. Mechanistic studies confirmed that these hybrids disrupt the bacterial membrane. In addition, an increase in intracellular ROS levels was observed for the most active compound. The SHP/QAS hybrids retained high activity against S. aureus ATCC 209P after 17 passages and showed low cytotoxicity (SI = 62–92) and negligible hemolysis. These properties indicate that this approach may offer a useful strategy for developing antibacterial agents with a potentially lower risk of inducing conventional resistance mechanisms.

The convergence of ligand-based and structure-based computational strategies provides a robust foundation for hit optimization in anticancer drug discovery. We integrated ligand-based SAR with structure-based covalent docking to guide the optimization of haloacetamide-derived di(hetero)arylmethanes. SAR revealed that the 2-haloacetamide warhead is essential, while the di(hetero)aryl scaffold modulates activity, leading to submicromolar bis(pyrazolyl)methane hits. Rather than seeking to establish a definitive molecular target, we used GAPDH and GSTO1 as experimentally motivated target hypotheses to derive structural constraints for covalent scaffold design. Covalent docking was used to prioritize these hypotheses and guide the design of phosphorylated diarylmethane derivatives, leading to the identification of highly cytotoxic bromoacetamide compound, comparable to doxorubicin. In PANC-1 cells, this lead decreased LDH activity and increased PDH activity, suggesting a shift in cellular metabolism from glycolysis toward oxidative phosphorylation. The results demonstrate the utility of target-hypothesis-guided design under conditions in which molecular target identity remains unresolved.

A method was developed for the preparation of polychloroalkyl derivatives of diarylmethylphosphonates containing a sterically hindered phenol using 3-chloro-2,2-bis(chloromethyl)propanoyl chloride. Primary biological screening revealed low background cytotoxicity for most compounds, consistent with the profile of redox-activated prodrugs, while two derivatives exhibited moderate activity. The developed approach provides a basis for the targeted search for new selective anticancer agents based on modified sterically hindered phenols.