Synthesis of some novel 1,2,3-triazole derivatives containing kojic acid moiety and evaluation for their antioxidant activity

5-Aminoisophthalate-based kojic acid-appended bis-1,2,3-triazole: a fluorescent chemosensor for Cu2+ sensing and in silico study

A new, easy-to-prepare, and highly selective fluorescent chemosensor, i.e., 5-aminoisophthalate-based kojic acid-appended bis-1,2,3-triazole, was synthesized from an alkyne of 5-aminoisophthalic acid and azido-kojic acid using Cu(i)-catalyzed click chemistry and then successfully characterized. The alkyne structure of 5-aminoisophthalic acid, 1, was supported by the single-crystal X-ray crystallographic data. The fluorescent probe 3 was found to be highly selective for Cu2+ ions supported by the Job's plot with a stoichiometric ligand : metal ratio of 2 : 1, exhibiting almost a two-fold enhancement in the emission intensity upon the addition of Cu2+ ions (0-25 μM) with a detection limit of 8.82 μM. A comparison with LODs from previously developed chemosensors for Cu2+ ions was also conducted. Reversibility analysis indicated that probe 3 could be used as both a reusable sensor and as a scavenger of copper ions. DFT calculations with the basis sets B3LYP/6-311G(d,p) and LanL2DZ were employed for geometrical optimizations of structures of the alkyne 1, azide 2, probe 3, and complex 3.Cu2+. Hirshfeld surface analysis revealed significant intermolecular interactions in compound 1. Additionally, molecular docking for the antimicrobial activity showed the better antibacterial efficacy of probe 3.

Combining high energy ball milling and liquid crystal templating method to prepare magnetic ordered mesoporous silica. A physico-chemical investigation

The physico-chemical investigation of superparamagnetic MCM41 like materials prepared by the novel combination of high energy ball milling and a liquid crystal templating method is presented. Structural, morphological, textural, thermal, and preliminary magnetic characterization demonstrated the successful combination of the two synthesis techniques, avoiding the problems associated with the current methods used for the preparation of magnetic ordered mesoporous silica. MCM41 like materials with high specific surface area values (625-720 m2 g-1) and high mesopore volumes in the range 1-0.7 cm3 g-1 were obtained. The ordered mesoporous structure and accessible pores were maintained after the inclusion of increasing amounts of the magnetic component in the silica structure. All the samples showed superparamagnetic behaviour.

Emerging Aspects of Triazole in Organic Synthesis: Exploring its Potential as a Gelator

Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) - commonly known as the "click reaction" - serves as the most effective and highly reliable tool for facile construction of simple to complex designs at the molecular level. It relates to the formation of carbon heteroatomic systems by joining or clicking small molecular pieces together with the help of various organic reactions such as cycloaddition, conjugate addition, ring-opening, etc. Such dynamic strategy results in the generation of triazole and its derivatives from azides and alkynes with three nitrogen atoms in the five-membered aromatic azole ring that often forms gel-assembled structures having gelating properties. These scaffolds have led to prominent applications in designing advanced soft materials, 3D printing, ion sensing, drug delivery, photonics, separation, and purification. In this review, we mainly emphasize the different mechanistic aspects of triazole formation, which includes the synthesis of sugar-based and non-sugar-based triazoles, and their gel applications reported in the literature for the past ten years, as well as the upcoming scope in different branches of applied sciences.

Ultrasound-assisted synthesis of kojic acid-1,2,3-triazole based dihydropyrano[3,2-b]pyran derivatives using Fe3O4@CQD@CuI as a novel nanomagnetic catalyst

The magnetic nanoparticles coated with carbon quantum dot and copper (I) iodide (Fe₃O₄@CQD@CuI) were used as eco-friendly heterogeneous Lewis / Brønsted acid sites and Cu (I) nanocatalysts. In the first step, it was applied in the synthesis of kojic acid-based dihydropyrano[3,2-b]pyran derivatives in a three-component reaction and in the second step, as a recyclable catalyst for the synthesis of kojic acid-1,2,3-triazole based dihydropyrano[3,2-b]pyran derivatives in the CuI-catalyzed azide/alkyne cycloaddition (CuAAC) reaction. The catalyst was characterized fully by using the different techniques including fourier transform infrared spectroscopy (FT-IR), elemental mapping analysis, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermal gravimetric (TG) and value-stream mapping (VSM) methods. The final synthesized derivatives were identified by ¹H- and ¹³C-NMR spectroscopy.

Design and microwave-assisted synthesis of a novel Mannich base and conazole derivatives and their biological assessment

4-Amino-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (1) was converted to the corresponding Schiff base (2) by treatment with salicylaldehyde. 1,2,4-Triazoles were then converted to the corresponding Mannich bases containing fluroquinolone core using a one-pot three-component procedure. Moreover, the synthesis of six compounds, which can be considered as conazole analogues, was performed starting from 1,2,4-triazole-3-one compounds via three steps by either conventional or microwave-mediated conditions. All the newly synthesized compounds were screened for their antimicrobial activities. Most exhibited good to moderate antibacterial and/or antifungal activity. The structural assignments of the new compounds were based on elemental analysis and spectral (IR, 1H NMR, 13C NMR, and LC-MS) data.

An overview of hydroxypyranone and hydroxypyridinone as privileged scaffolds for novel drug discovery

Hydroxypyranone and hydroxypyridinone are important oxygen-containing or nitrogen-containing heterocyclic nucleus and attracted increasing attention in medicinal chemistry and drug discovery over the past decade. Previous literature reports revealed that hydroxypyranone and hydroxypyridinone derivatives exhibit a wide range of pharmacological activities such as antibacterial, antifungal, antiviral, anticancer, anti-inflammatory, antioxidant, anticonvulsant, and anti-diabetic activities. In this review, we systematically summarized the literature reported biological activities of hydroxypyranone and hydroxypyridinone derivatives. In particular, we focus on their biological activity, structure-activity relationship (SAR), mechanism of action, and interaction mechanisms with the target. The collected information is expected to provide rational guidance for the development of clinically useful agents from these pharmacophores.

Cu-Kojic Acid Complex Anchored to Functionalized Silica-MCM-41: A Promising Regioselective and Reusable Nanocatalyst for Click Reaction

Cu-Kojic acid (KA) complex anchored to functionalized silica-MCM-41 was synthesized via the process of postgrafting and introduced as an effective, new, reusable, and thermally resistant heterogeneous nanocatalyst for the clean synthesis of 1H-1,2,3-triazoles from Click reaction of 2-(azidomethyl)-5-benzyloxy-4-pyrone and azido Kojic acid with a variety of terminal alkynes in excellent yields. The structure of nanocatalyst was analyzed by ICP, BET, XRD, EDS, SEM, TGA, TEM, and FT-IR techniques.

Design, synthesis and anticancer activity of novel pyrimidine and pyrimidine-thiadiazole hybrid glycosides

New 1,3,4-thiadiazole thioglycosides linked to substituted pyrimidines were synthesized via glycosylation of 1,3,4-thiadiazole thiol compounds. Also, novel 1,2,3-triazole derivatives linked to carbohydrate units were prepared using the standard click chemistry conditions employing the Cu(I)-catalyzed azide-alkyne cycloaddition of substituted-aryl-azides with a selection of alkyne-functionalized sugars. The chemical structures of the new derivatives were verified using various spectroscopic techniques, such as IR, ¹H NMR, ¹³C NMR and elemental analyses. The cytotoxic activities of the prepared compounds were investigated in vitro against human liver cancer (HepG-2) and human breast adenocarcinoma (MCF7) cell lines. In addition, the biological evaluation of the new compounds involved the investigation of their effects on a human normal retinal pigmented epithelial cell line (RPE1) using the MTT assay.

Design, Synthesis, and Antimicrobial Activities of 1,2,3-Triazole Glycoside Clickamers

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.

Copper(i)-catalysed azide–alkyne cycloaddition and antiproliferative activity of mono- and bis-1,2,3-triazole derivatives

A series of mono- and bis-1,2,3-triazole derivatives were prepared via the copper(i)-catalysed azide–alkyne cycloaddition between substituted aromatic derivatives, comprising one or two terminal alkyne groups and a selection of aromatic azides.

Synthesis and optical properties of novel 1,2,3-triazole derivatives possessing highly substituted imidazoles

Reactions of 1,4,5-triaryl-2-(4-bromomethyl)phenyl-imidazoles with sodium azide in acetone give the corresponding azidomethyl derivatives, which on 1,3-dipolar cycloaddition with various terminal alkynes in the presence of CuI afford novel 1,2,3-triazole products. On the other hand, treatment of 2,4,5-triaryl-1-(4-hydroxyphenyl)-imidazoles with propargyl chloride in the presence of a base gives the corresponding propargyl ether derivatives, which under CuI-catalyzed 1,3-dipolar cycloaddition with benzyl azide produce 1,2,3-triazole derivatives. All the products are characterized from their spectroscopic data and most are evaluated for fluorescence emission. The optical parameters of the studied products are also reported.

Synthesis, In Vitro α-Glucosidase Inhibitory Activity and Molecular Docking Studies of Novel Benzothiazole-Triazole Derivatives

Benzothiazole-triazole derivatives 6a–6s have been synthesized and characterized by ¹H-NMR and ¹³C-NMR. All synthetic compounds were screened for their in vitro α-glucosidase inhibitory activity by using Baker’s yeast α-glucosidase enzyme. The majority of compounds exhibited a varying degree of α-glucosidase inhibitory activity with IC₅₀ values between 20.7 and 61.1 μM when compared with standard acarbose (IC₅₀ = 817.38 μM). Among the series, compound 6s (IC₅₀ = 20.7 μM) bearing a chlorine group at the 5-position of the benzothiazole ring and a tert-butyl group at the para position of the phenyl ring, was found to be the most active compound. Preliminary structure-activity relationships were established. Molecular docking studies were performed to predict the binding interaction of the compounds in the binding pocket of the enzyme.