Search Results (6)

Six novel pyrazole-based carbohydrazone derivatives (3a–3f) bearing structurally diverse heteroaromatic substituents were synthesized and characterized by ATR-FTIR, ¹H NMR, APT-¹³C NMR, and HRMS analyses. Their multifunctional bioactivity was evaluated using antioxidant, photoprotective, CT-DNA-associated spectroscopic response, cytotoxicity, and scratch wound closure assays. Antioxidant activity was assessed by DPPH radical scavenging, Fe²⁺ chelation, and ferric thiocyanate (FTC) assays against appropriate reference standards, while photoprotective potential was determined by spectrophotometric SPF analysis using carrot seed oil as a reference. The benzothiazole-containing derivative (3f) showed the strongest DPPH scavenging activity, FTC antioxidant capacity, and photoprotective activity, while also producing one of the most pronounced CT-DNA-associated spectroscopic responses under the experimental conditions employed. In contrast, the benzimidazole derivative (3e) displayed the highest Fe²⁺ chelating activity among the synthesized compounds. In cell-based assays, the imidazole- and thiazole-containing derivatives (3b and 3c) showed the most favorable balance between growth-inhibitory potency and selectivity toward A431 epidermoid carcinoma cells relative to HaCaT keratinocytes. Scratch assay results did not support direct anti-migratory activity under the tested conditions but indicated compound-dependent modulation of wound-closure-associated cellular responses. Overall, these findings demonstrate that heteroaromatic substitution strongly modulates redox behavior, CT-DNA-associated spectroscopic behavior, photophysical properties, and cytotoxic selectivity in pyrazole-based carbohydrazones, identifying this scaffold as a structurally tunable platform for further bioactivity optimization. Full article

This study examines the influence of ligand design on the structural, optical, and electrical properties of copper-based coordination complexes. Ligands H₂L¹ and H₂L² were synthesized via the reaction of 5-nitrosalicylaldehyde with 2-hydroxy- or 4-hydroxybenzhydrazide. H₄L³ was obtained from the reaction of carbohydrazide and salicylaldehyde, while H₄L⁴ was prepared by condensing 4-methoxysalicylaldehyde with thiocarbohydrazide. The research focuses on two key design elements: (1) the effect of hydroxyl group positioning on the aroyl ring in hydrazide ligands (H₂L¹ vs. H₂L²) and (2) the impact of carbonyl versus thiocarbonyl groups and aldehyde substituents in hydrazone ligands (H₄L³ vs. H₄L⁴). The resulting complexes, [Cu₂(L¹)₂], [Cu₂(L²)₂(MeOH)₃], [Cu₂(L³)(H₂O)₂], and [Cu₂(L⁴)(H₂O)₂], were synthesized and characterized using attenuated total reflectance infrared (IR-ATR) spectroscopy, thermogravimetric analysis (TG), and UV-Vis diffuse reflectance spectroscopy. Their electrical properties were investigated using solid-state impedance spectroscopy (IS). The crystal and molecular structure of the complex [Cu₂(L²)₂(MeOH)₃]∙MeOH was determined by single-crystal X-ray diffraction (SCXRD). This study underscores the pivotal role of ligand modifications in modulating the functional properties of coordination complexes, offering valuable insights for the advancement of materials chemistry. Full article

Research in the field of metallodrugs is continually increasing. However, it is often limited by the poor solubility in water of the metal complexes. To try to overcome this problem, the two new ligands bis-(sodium 3-methoxy-5-sulfonate-salicylaldehyde)thiocarbohydrazone (bis-TCH, Na₂H₄L¹) and bis-(sodium 3-methoxy-5-sulfonate-salicylaldehyde)carbohydrazone (bis-CH, Na₂H₄L²) were synthesized and characterized, both achieving high solubility in water. The speciation of the ligands and their coordinating behaviour towards the biologically relevant Cu(II) and Zn(II) ions were studied spectroscopically and potentiometrically, determining the pK_as of the ligands and the formation constants of the complex species. The monometallic and bimetallic Cu(II) and Zn(II) complexes were isolated, and the single-crystal X-ray structure of [Cu₂(NaHL¹)(H₂O)₇]^.3.5H₂O was discussed. Finally, preliminary studies of the in vitro cytotoxic properties of the new compounds were started on normal (Hs27) and cancer (U937) cell lines. bis-TCH was able to induce a growth inhibition effect between 40% and 45% in both cell lines; bis-CH did not produce a reduction in cell viability in Hs27 cells but revealed mild antiproliferative activity after 72 h of treatment in U937 cancer cells (GI₅₀ = 46.5 ± 4.94 μg/mL). Coordination of the Cu(II) ions increased the toxicity of the compounds, while, in contrast, Zn(II) complexes were not cytotoxic. Full article

Two distinct intracellular pathogens, namely Mycobacterium tuberculosis (Mtb) and Toxoplasma gondii (Tg), cause major public health problems worldwide. In addition, serious and challenging health problems of co-infections of Tg with Mtb have been recorded, especially in developing countries. Due to this fact, as well as the frequent cases of resistance to the current drugs, novel anti-infectious therapeutics, especially those with dual (anti-Tg and anti-Mtb) modes of action, are needed. To address this issue, we explored the anti-Tg potential of thiazolidinedione-based (TZD-based) hybrid molecules with proven anti-Mtb potency. Several TZD hybrids with pyridine-4-carbohydrazone (PCH) or thiosemicarbazone (TSC) structural scaffolds were more effective and more selective than sulfadiazine (SDZ) and trimethoprim (TRI). Furthermore, all of these molecules were more selective than pyrimethamine (PYR). Further studies for the most potent TZD-TSC hybrids 7, 8 and 10 and TZD-PCH hybrid molecule 2 proved that these compounds are non-cytotoxic, non-genotoxic and non-hemolytic. Moreover, they could cross the blood–brain barrier (BBB), which is a critical factor linked with ideal anti-Tg drug development. Finally, since a possible link between Tg infection and the risk of glioblastoma has recently been reported, the cytotoxic potential of TZD hybrids against human glioblastoma cells was also evaluated. TZD-PCH hybrid molecule 2 was found to be the most effective, with an IC₅₀ of 19.36 ± 1.13 µg/mL against T98G cells. Full article

We describe the design and synthesis of two isatin-tethered quinolines series (Q6a–h and Q8a–h), in connection with our research interest in developing novel isatin-bearing anti-tubercular candidates. In a previous study, a series of small molecules bearing a quinoline-3-carbohydrazone moiety was developed as anti-tubercular agents, and compound IV disclosed the highest potency with MIC value equal to 6.24 µg/mL. In the current work, we adopted the bioisosteric replacement approach to replace the 3,4,5-trimethoxy-benzylidene moiety in the lead compound IV with the isatin motif, a privileged scaffold in the TB drug discovery, to furnish the first series of target molecules Q6a–h. Thereafter, the isatin motif was N-substituted with either a methyl or benzyl group to furnish the second series Q8a–h. All of the designed quinoilne-isatin conjugates Q6a–h and Q8a–h were synthesized and then biologically assessed for anti-tubercular actions towards drug-susceptible, MDR, and XDR strains. Superiorly, the N-benzyl-bearing compound Q8b possessed the best activities against the examined M. tuberculosis strains with MICs equal 0.06, 0.24, and 1.95 µg/mL, respectively. Full article

Cyclization of acyclic C-glycoside derivatives 1a,b to 2a,b as the major isomers, and 4a,b as the minor isomers were carried out. The isopropylidene derivatives 3a,b were prepared, as well as the hydrazide derivative 6, which was condensed with a variety of aldehydes to give hydrazones 7a–e which were also prepared from the compounds 12a–e. Acetylation of 7a,d gave the corresponding acetyl derivatives 8a,d, respectively. In addition, the dicarbonyl compound 9 was prepared in the hydrate form, which reacted with a number of aroylhydrazines to give the corresponding bisaroyl-hydrazones 10a–d, which were cyclized into 1,3,4-oxadiazoles 11a–d. Furthermore, two of the prepared compounds were examined to show the ability to activate MAO-B. In addition a number of prepared compounds showed antibacterial and antiviral activities. Full article