A series of benzofuran-based chalconoids 6a-v were designed and synthesized as new potential AChE inhibitors. The in vitro assay of synthesized compounds 6a-v showed that most compounds had significant anti-AChE activity at micromolar or sub-micromolar levels. Among the tested compounds, 3-pyridinium derivative 6m bearing N-(2-bromobenzyl) moiety and 7-methoxy substituent on the benzofuran ring exhibited superior activity. This compound with IC₅₀ value of 0.027 μM was as potent as standard drug donepezil.

The emergence of multidrug-resistant bacteria causes an urgent need for new generation of antibiotics, which may have a different mechanism of inhibition or killing action from the existing. Targeting at the inhibition of bacterial cell division via the control of FtsZ function is one of the effective and promising approaches. Some natural extracts from plants such as sanguinarine and berberine (analogs of pyridinium compounds) are known to alter FtsZ function. In this study, a series of novel quaternary pyridinium compounds was constructed based on the N-methylbenzofuro[3,2-b]quinoline and N-methylbenzoindolo[3,2-b]-quinoline derivatives and their antibacterial activity against nine significant pathogens was investigated using broth microdilution method. In the in vitro assay, the compounds showed strong antibacterial activities against various testing strains, which include some drug-resistant strains such as methicillin-resistant S. aureus and vancomycin-resistant E. faecium. Our results of morphology change of B. subtilis cells and molecular docking proved that the compounds functioned as an effective inhibitor to suppress FtsZ polymerization and FtsZ GTPase activity and thus the compound stops cell division and cause cell death through interacting with C-terminal interdomain cleft of FtsZ.

A series of new uncharged functional acetylcholinesterase (AChE) reactivators including heterodimers of tetrahydroacridine with 3-hydroxy-2-pyridine aldoximes and amidoximes has been synthesized. These novel molecules display in vitro reactivation potencies towards VX-, tabun- and paraoxon-inhibited human AChE that are superior to those of the mono- and bis-pyridinium aldoximes currently used against nerve agent and pesticide poisoning. Furthermore, these uncharged compounds exhibit a broader reactivity spectrum compared to currently approved remediation drugs.

In this study, we have carried out a combined experimental and computational investigation to elucidate several bred-in-the-bone ideas standing out in rational design of novel cationic surfactants as antibacterial agents. Five 3-hydroxypyridinium salts differing in the length of N-alkyl side chain have been synthesized, analyzed by high performance liquid chromatography, tested for in vitro activity against a panel of pathogenic bacterial and fungal strains, computationally modeled in water by a SCRF B3LYP/6-311++G(d,p) method, and evaluated by a systematic QSAR analysis. Given the results of this work, the hypothesis suggesting that higher positive charge of the quaternary nitrogen should increase antimicrobial efficacy can be rejected since 3-hydroxyl group does increase the positive charge on the nitrogen but, simultaneously, it significantly derogates the antimicrobial activity by lowering the lipophilicity and by escalating the desolvation energy of the compounds in comparison with non-hydroxylated analogues. Herein, the majority of the prepared 3-hydroxylated substances showed notably lower potency than the parent pyridinium structures, although compound 8 with C12 alkyl chain proved a distinctly better antimicrobial activity in submicromolar range. Focusing on this anomaly, we have made an effort to reveal the reason of the observed activity through a molecular dynamics simulation of the interaction between the bacterial membrane and compound 8 in GROMACS software.