New 1-(Spiro[chroman-2,1′-cycloalkan]-4-yl)-1H-1,2,3-Triazoles: Synthesis, QTAIM/MEP analyses, and DNA/HSA-binding assays

Unveiling the ion sensing capabailities of 'click' derived chalcone-tailored 1,2,3-triazolic isomers for Pb(ii) and Cu(ii) ions: DFT analysis

In this study, two novel chalcone-derived 1,2,3-triazole-appended positional isomers (probe 6 and probe 9) were synthesized via the 'CuAAC' (Cu(i) - catalysed alkyne azide cycloaddition) methodology for the purpose of metal ion detection. The synthesized probes underwent characterization utilizing standard spectroscopic methodologies including FTIR, NMR (1H and 13C), and mass spectrometry. Subsequently, the sensing capabilities of these probes were explored using UV-Vis and fluorescence spectroscopy, wherein their selective recognition potential was established for Pb(ii) and Cu(ii), both of which can pose serious health hazards when prevalent in the environment above permissible limits. Both the probes exhibited fairly low limits of detection (LoD), determined as 5.69 μM and 6.55 μM in the case of probe 6 for Pb(ii) and Cu(ii) respectively; whereas the probe 9 exhibited an LoD of 5.06 μM and 7.52 μM for Pb(ii) and Cu(ii), respectively. The job's plot for the probe demonstrates the formation of a 1 : 1 complex between the metal and ligand. Furthermore, the interaction of the free probes with the metal ions in the metal-ligand complex was elucidated through 1H NMR analysis and validated theoretically using Density Functional Theory (DFT) simulations with the B3LYP/6-311G++(d,p) and B3LYP/LANL2DZ basis sets for geometry optimization of the probes and their corresponding metal complexes. These findings offer a reliable approach to Cu(ii) and Pb(ii) ion detection and can be further used for the potential applications in environmental monitoring and analytical chemistry.

Organocatalytic Synthesis and DNA Interactive Studies of New 1,2,3-triazolyl-thiazolidines Hybrids

An organocatalytic [3+2] cycloaddition reaction between thiazolidine-containing β-ketoester 1 and aryl azides 2 was employed to synthesize new 1,2,3-triazolyl-thiazolidine hybrids 3. In this metal-free approach, twelve compounds were isolated in yields ranging from 23 % to 96 % by using diethylamine (10 mol%) and DMSO at 75 °C for 24 hours. DNA-binding assays were conducted through absorption, emission spectroscopy and viscosimetry analysis, to evaluate the interaction capacity of the studied derivatives with nucleic acids. All the synthesized compounds were evaluated for their interactions with a specific group of compounds containing the pharmacophoric groups triazole and thiazolidine through a molecular docking speculative study, aimed at identifying the interaction profile of these compounds with DNA. The obtained results suggest that 1,2,3-triazolyl-thiazolidine hybrids could be a promising approach in the development of novel therapeutic agents targeting DNA-related processes.

Cu(i)-catalysed 1,2,3-triazole stitched chalcomer assembly as Pb(ii) and Cu(ii) ion sensor: DFT and docking scrutiny

Herein, a 1,2,3-triazole derivative (CBT), synthesized using the Copper(i) catalyzed Alkyne Azide Cycloaddition (CuAAC) procedure, based on a chalcone skeleton has been reported, that was implemented as an effective sensor for Pb(ii) and Cu(ii) ions. The synthesized CBT was characterized using spectroscopic techniques such as FTIR, NMR (1H and 13C), and mass spectrometry. The sensing behaviour of CBT was analyzed using UV-Vis spectroscopy, demonstrating selective sensing for Pb(ii) and Cu(ii) ions, competitively. The correlation plot revealed the detection limit for Pb(ii) and Cu(ii) ions to be 100 μM and 110 μM respectively. In addition, DFT simulations and molecular electrostatic potential (MEP) studies scrutinized the binding strategy of the free CBT and its orientation towards the metal ions in the metal-ligand complex. The probe CBT was predicted via the online platform Way2drug for its pharmacological properties, investigating the possibility to inhibit early atherosclerosis. CBT was subsequently docked to the TRIB1 protein using AutoDock Vina and demonstrated a high binding affinity with a value of -6.2 kcal mol-1.

1,2,3-Triazolo[4,5-b]aminoquinolines: Design, synthesis, structure, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, and molecular docking of novel modified tacrines

An efficient [4 + 2] cyclization protocol to synthesize a series of twelve examples of 1,2,3-triazolo[4,5-b]aminoquinolines (5) as novel structurally modified tacrines was obtained by reacting readily accessible precursors (i.e., 3-alky(aryl)-5-amino-1,2,3-triazole-4-carbonitriles (3)) and selected cycloalkanones (4) of five-, six-, and seven-membered rings. We evaluated the AChE and BChE inhibitory activity of the novel modified tacrines 5, and the compound derivatives from cyclohexanone (4b) showed the best AChE and BChE inhibitory activities. Specifically, 1,2,3-triazolo[4,5-b]aminoquinolines 5bb obtained from 3-methyl-carbonitrile (3b) showed the highest AChE (IC50 = 12.01 μM), while 5ib from 3-sulfonamido-carbonitrile (3i) was the most significant inhibitor for BChE (IC50 = 1.78 μM). In general, the inhibitory potency of compound 5 was weaker than the pure tacrine reference, and our findings may help to design and develop novel anticholinesterase drugs based on modified tacrines.

Novel spiro[chromanone-2,4'-piperidine]-4-one derivatives as potential inhibitors of fatty acid synthesis in pathogens: Design, synthesis, and biological evaluation

Bacterial survival depends on membrane lipid homeostasis that enables to regulate lipid composition to adapt and optimize their growth in diverse environments. Therefore, the development of inhibitors that interfere with the bacterial fatty acid synthesis process is considered to be a promising tactic. In this study, 58 novel spirochromanone derivatives were prepared and their structure-activity relationship (SAR) was investigated. The bioassay results showed that all most of the compounds showed excellent biological activities, exampled by compounds B₁₄, C₁, B₁₅, and B₁₃, which had outstanding inhibitory activities toward various pathogenic bacteria with EC₅₀ values of 0.78 μg/mL ∼3.48 μg/mL. Preliminary antibacterial behavior was studied by a series of biochemical assays including, but not limited to, fluorescence imaging patterns, GC-MS analysis, TEM images, and fluorescence titration experiments. Notably, compound B₁₄ decreased the lipid content of the cell membrane, and increased cell membrane permeability, thereby destroying the integrity of the bacterial cell membrane. Further qRT-PCR results indicated that compound B₁₄ interfered with the mRNA expression levels of fatty acid synthesis process-related genes including ACC, ACP, and Fab family genes. Herein, we highlight the promising bactericidal skeleton based on the spiro[chromanone-2,4'-piperidine]-4-one as a potential inhibitor of fatty acid synthesis.

Hybridized 4-Trifluoromethyl-(1,2,3-triazol-1-yl)quinoline System: Synthesis, Photophysics, Selective DNA/HSA Bio-interactions and Molecular Docking

The synthesis, structural analysis, and evaluation of the photophysical properties of twelve novel 2-aryl(heteroaryl)-6-(4-alkyl(aryl)-1H-1,2,3-triazol-1-yl)-4-(trifluoromethyl)quinolines (6-8), where aryl(heteroaryl)=Ph, 4-Me-C₆ H₄ , 4-F-C₆ H₄ and 2- furyl; 4-alkyl(aryl)=-CH₂ OH, -(CH₂ )₅ CH₃ and Ph, are reported. Hybrid scaffolds 6-8 were synthesized at 77-95 % yields by regioselective copper-catalysed azide-alkyne cycloaddition (CuAAC) reaction of unpublished 6-azido-4-(trifluoromethyl)quinolines (2) with selected terminal alkynes (3-5). Azido intermediates 2 were obtained from the reaction of 6-amino-4-(trifluoromethyl)quinolines (1) and sodium azide at good yields (78-87 %). Compounds 6-8 were structurally fully characterized by ¹ H-, ¹³ C- and ¹⁹ F- and ¹ H-¹³ C 2D-NMR (HSQC, HMBC) spectroscopy, X-ray diffraction (SC-XRD) and HRMS analysis. Moreover, the photophysical properties, DNA- and HSA-binding experiments (bio-interactions), and molecular docking studies for compounds 6-8 were performed. These are discussed and compared with similar compounds from recent research.

Ultrasound-assisted synthesis of pyrimidines and their fused derivatives: A review

The pyrimidine scaffold is present in many bioactive drugs; therefore, efficient synthetic routes that provide shorter reaction times, higher yields, and site-selective reactions are constantly being sought. Ultrasound (US) irradiation has emerged as an alternative energy source in the synthesis of these heterocyclic scaffolds, and over the last ten years there has been a significant increase in the number of publications mentioning US in either the construction or derivatization of the pyrimidine core. This review presents a detailed summary (with 140 references) of the effects of US (synergic or not) on the construction and derivatization of the pyrimidine core through classical reactions (e.g., multicomponent, cyclocondensation, cycloaddition, and alkylation reactions). The main points that were taken into consideration are as follows: chemo- and regioselectivity issues, and the results of conventional heating methods compared to US and mechanistic insights that are also presented and discussed for key reactions.