Bacterial resistance remains a significant threat and a leading cause of death worldwide, despite massive attempts to control infections. In an effort to develop biologically active antibacterial and antifungal agents, six novel aryl-substituted-1,2,3-triazoles linked to carbohydrate units were synthesized through the Cu(I)-catalyzed azide-alkyne cycloaddition CuAAC of substituted-arylazides with a selection of alkyne-functionalized sugars. The chemical structures of the new derivatives were verified using different spectroscopic techniques. The novel clicked 1,2,3-triazoles were evaluated for in vitro antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa, and the obtained results were compared with the activity of the reference antibiotic “Ampicillin”. Likewise, in vitro antifungal activity of the new 1,2,3-triazoles was investigated against Candida albicans and Aspergillus niger using “Nystatin” as a reference drug. The results of the biological evaluation pointed out that Staphylococcus aureus was more susceptible to all of the tested compounds than other examined microbes. In addition, some tested compounds exhibited promising antifungal activity.

Antibiotic-resistant bacteria are emerging at an alarming rate, posing a potential threat to human health. We synthesised alkyne-functionalised pyridines 3 and 4via alkylation of substituted 2-oxo-1,2-dihydropyridine derivatives 1 and 2 with propargyl bromide in alkaline DMF. The reactions afforded the O-propagylated compounds 3 and 4 as the main products. Copper(I)-catalysed azide–alkyne cycloaddition of compounds 3 and 4 with aromatic azides furnishes compounds 11–22. The chemical structures of the 1,2,3-triazole-pyridine hybrids 11–22 were fully verified using different spectroscopic tools, such as FT-IR, ¹H NMR, ¹³C NMR, and 2D NMR. We evaluated in vitro antibacterial and antibiofilm activities of the 1,2,3-triazole-pyridine hybrids 11–22 against methicillin-resistant Staphylococcus aureus (MRSA) in both planktonic and sessile cells. Compounds 17, 18, and 21 exhibited promising growth inhibition activity against planktonic and sessile MRSA cells with IC₅₀ = 34.94, 37.91, and 43.88 μM, respectively. The antibiofilm activities of the new compounds were evaluated using Vancomycin (Van) as a standard reference drug (IC₅₀ 186.0 μM).

A pyridinium-based design principle that leads to solution processable napthalimide-derived salts, which exhibit solid state fluorescence hydrochromism in response to changes in relative humidity.

Click chemistry has been utilised for the preparation of new tris(triazolyl)triazines containing aliphatic and polar side chains through coupling of 2,4,6-triethynyl-[1,3,5]triazines, which possess free terminal alkyne moieties with substituted aromatic azides. The cytotoxic activity and in vitro anticancer potential of the newly synthesised compounds have been evaluated against seven human cancer cell lines including liver HepG2, breast MCF-7, lung A549, acute myeloid leukemia HL-60, colon HCT116, and prostate PC3 cancer cell lines in addition to human normal melanocyte, HFB4. The results revealed that all the compounds did not exhibit any activity against A549, HL-60, and PC3. However compound G2 was effective against MCF-7 and HepG2 cancer cell lines. On the other hand, compound G1a exhibited higher potency against MCF-7 and HepG2 cells with no toxicity on normal cells in comparison with the standard drug doxorubicin.

A series of mono- and bis-1,2,3-triazole-based molecular architectures were prepared in excellent yields via the standard copper(I)-catalysed azide–alkyne cycloaddition (CuAAC) of substituted aromatic derivatives, comprising one or two terminal alkyne groups with a selection of aromatic azides. In vitro antiproliferative activities of the novel 1,2,3-triazoles were evaluated against four human cancer cell lines, including HepG-2, MCF-7, HCT-116, and A549 via the MTT assay. Among all the tested compounds, bis-1,2,3-triazole derivative 16 exhibited potent activity against HepG-2 compared to the standard reference anticancer drug doxorubicin. The mono-1,2,3-triazole 9, mono-1,2,3-triazole 13, and bis-1,2,3-triazole 17 showed comparable activities relative to doxorubicin in the case of the antiproliferative evaluation against MCF-7. With respect to HCT-116 biological activity screening, all the evaluated compounds except mono-1,2,3-triazole derivatives 10 and 11 showed potent antiproliferative activities relative to doxorubicin. Regarding the lung cancer cell line A549, mono-1,2,3-triazole 9, bis-1,2,3-triazole 15, bis-1,2,3-triazoles 21, and bis-1,2,3-triazoles 22 displayed slightly lower activities relative to doxorubicin, while the rest of the tested compounds exhibited moderate activities. Only compound 18 showed significant toxicity on the human healthy cells relative to both human lung and liver cancer types. The novel mono- and bis-1,2,3-triazoles developed in this work can ideally be utilised as potent candidates for pharmaceutical applications.