Search Results (330)

Fused 1,2,5-chalcogenadiazoles are often used as biologically active compounds and organic optovoltaic materials. [1,2,5]Thiadiazolo[3,4-b]pyrazines are much less studied due to difficulties in their preparation. In this communication, [1,2,5]thiadiazolo[3,4-b]pyrazine-5,6(4H,7H)-dione, a key precursor for the synthesis of 5,6-dihalo-[1,2,5]thiadiazolo[3,4-b]pyrazines, was prepared via condensation of 1,2,5-thiadiazole-3,4-diamine with oxalic acid or oxalyl chloride. The structure of the newly synthesized compound was established by elemental analysis, high-resolution mass spectrometry, ¹H and ¹³C NMR, IR spectroscopy, and mass spectrometry. Full article

Photodynamic therapy is a non-invasive treatment strategy for various types of cancer, based on the use of light to activate a photosensitizer which triggers processes leading to cell death. Given the increasing interest in the development of mitochondria-targeted photosensitizers, in this study we synthesized two novel thiadiazol-substituted porphyrins, 5,10,15,20-tetra(2,1,3-benzothiadiazol-5-yl) porphyrin (C1) and 5,10,15,20-tetra(1,2,3-thiadiazol-4-yl) porphyrin (C2), designed to target mitochondria in cancer cells thanks to the azole residues present in their structure. The two porphyrinic compounds were characterized in terms of structural and photophysical properties, revealing high yields of singlet oxygen production. Their interaction with biological structures was analyzed in a triple-negative human breast carcinoma cell line (MDA-MB-231), either as free compounds or delivered via mitochondriotropic liposome formulations. Both newly synthesized porphyrins entered MDA-MB-231 cells, with compound C2 demonstrating more efficient localization in the cytoplasm and in mitochondria. Dark and phototoxicity tests were also performed: both compounds proved to be effective phototoxic agents, with C2 showing the highest activity, making it a promising photosensitizer for mitochondria-targeted photodynamic therapy. Full article

A reliable synthesis of C5-unsubstituted 1,3,4-thiadiazole-2-thiolates is described that avoids potentially explosive or laborious steps. This work presents a reliable method for preparing the starting material dithioformate from carbon disulfide and potassium or sodium tri-sec-butylhydroborates for the preparation of the mesoionic title compounds with potassium hydrazinecarbodithioates. New 1,3,4-thiadiazole-2-thiolates are presented, and missing structural analysis data of known derivatives are added (1D- and 2D-NMR, HR-ESI-MS, IR). Full article

The image analysis of plants provides an opportunity to measure changes in growth and physiology quantitatively, and non-destructively, over time providing significant advantages over traditional methods of assessment which often rely on qualitative and subjective measures to distinguish between different treatments or genotypes in an experiment. Image analysis techniques are commonly deployed for the analysis of plants in the field or glasshouse, but few studies have demonstrated the use of image analysis to phenotype plants grown under aseptic conditions in culture media. Lolium × hybridum Hausskn ‘Shogun’ plants were germinated in vitro and cultured on media containing combinations of thidiazuron [1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea] (TDZ), N6-benzylaminopurine (BA) and gibberellic acid (GA3) or on phytohormone-free control media. RGB images were taken of the plants throughout the experiment and morphological image analysis techniques were used to quantify changes in plant development. A novel approach to quantitatively measure ’greenness‘ in plants using the CIELAB colour model (L*a*b) colour space from RGB images was developed. This methodology could be utilised to develop improved in vitro growth protocols for Lolium and grass species with similar morphology. Full article

The World Health Organization has recently underlined the increasing global burden of cancer, with a particularly alarming impact on underserved populations. In recent years, 1,3,4-thiadiazole has emerged as a versatile pharmacophore to obtain bioactive compounds. The pharmacological properties of this ring are primarily attributed to its role as a bioisostere of pyrimidine, the core structure of three nucleic bases. This structural feature endows 1,3,4-thiadiazole derivatives with the ability to interfere with DNA replication processes. Additionally, the mesoionic behavior of this heterocycle gives it important properties, such as the ability to cross biological membranes and interact with target proteins. Noteworthy, in analogy to the other sulfur heterocycles, the presence of C-S σ* orbitals, conferring small regions of low electron density on the sulfur atom, makes interaction with the target easier. This review focuses on the most promising anticancer agents with 1,3,4-thiadiazole structure reported in the past five years, providing information that may be useful to medicinal chemists who intend to develop new anticancer derivatives. Full article

The toxicity of hazardous dyes like rhodamine B and heavy metal ions like lead warrants the need for wastewater remediation. We describe here the functionalization of cobalt-doped iron oxide (Co_0.1Fe_2.9O₄) magnetic nanoparticles (MNPs) with citrate moieties for the effective sequestration of rhodamine B dye and lead ions from contaminated water. Citrate-functionalized MNPs are prepared using a co-precipitation technique. For the uncoated MNPs, the hydrodynamic diameter and zeta potential are found to be 21 nm and ~45 ± 3.1 mV, respectively. The hydrodynamic diameters are found to increase to ~51, ~59, and ~68 nm for the MNPs functionalized with ~20, ~40, and ~60 mg/mL of citrate, respectively, whereas the corresponding zeta potentials are found to be ~−27.95 ± 3.5 mV, ~−32.5 ± 3.6 mV, and ~−33.9 ± 3.5 mV, respectively. The chemisorption of the citrate moieties over the MNPs cause the zeta potential to be negative, a phenomenon which is further verified from the citrate-specific absorption bands in the Fourier transform infrared (FTIR) spectra of the surface-functionalized MNPs. UV-visible spectrophotometry is employed to probe the MNP-aided elimination of rhodamine B dye and lead ions from aqueous media, where the absorption bands at ~554 nm and ~375 nm (for lead (II)-5-dimercapto-1,3,4-thiadiazole chelate) are utilized for quantitative analyses. These citrate-functionalized nanoparticles are found to successfully remove the toxic rhodamine B dye and lead ions from water, with removal efficiencies of ~93.7 ± 2.6% and ~90 ± 2.4%, respectively. The unbound -COO⁻ functional groups of the citrate-functionalized MNPs electrostatically interact with the cationic rhodamine B dye or lead (II) ions, thereby leading to the adsorption onto the surface-functionalized MNPs and the subsequent magnetic-field-assisted removal. The experimental findings show the efficacy of the citrate-functionalized cobalt-doped iron oxide MNPs for the sequestration of dye pollutants and lead ions from contaminated water. Full article

The SARS-CoV-2 proteases M^pro and PL^pro are critical targets for antiviral drug development for the treatment of COVID-19. The 1,2,4-thiadiazole functional group is an inhibitor of cysteine proteases, such as papain and cathepsins. This chemical moiety is also present in ceftaroline fosamil (CF), an FDA-approved fifth-generation cephalosporin antibiotic. This study investigates the interactions between CF, its primary metabolites (M1 is dephosphorylated CF and M2 is an opened β-lactam ring) and derivatives (protonated M1H and M2H), and its open 1,2,4-thiadiazole rings derivatives (open-M1H and open-M2H) with SARS-CoV-2 proteases and evaluates CF’s effects on in vitro viral replication. In silico analyses (molecular docking and molecular dynamics (MD) simulations) demonstrated that CF and its metabolites are potential inhibitors of PL^pro and M^pro. Docking analysis indicated that the majority of the ligands were more stable with M^pro than PL^pro; however, in vitro biochemical analysis indicated PL^pro as the preferred target for CF. CF inhibited viral replication in the human Calu-3 cell model at submicromolar concentrations when added to cell culture medium at 12 h. Our results suggest that CF should be evaluated as a potential repurposing agent for COVID-19, considering not only viral proteases but also other viral targets and relevant cellular pathways. Additionally, the reactivity of sulfur in the 1,2,4-thiadiazole moiety warrants further exploration for the development of viral protease inhibitors. Full article

Background/objectives: Schistosomiasis is caused by flatworms of the genus Schistosoma, for which mollusks of the genus Biomphalaria are intermediate hosts. Niclosamide (NCL) is a molluscicide recommended by the World Health Organization (WHO) for control of Biomphalaria. Although effective, it is expensive and environmentally toxic, which raises concerns regarding its widespread use. As a result, we explored new synthetic substances as alternative strategies for controlling Biomphalaria glabrata. We evaluated the molluscicidal activity of 2-(1H-py-razol-1-yl)-1,3,4-thiadiazole and 2-(4,5-dihydro-1H-pyrazol-1-yl)-1,3,4-thiadiazole derivatives against B. glabrata snails and embryos, as well as Schistosoma cercariae (infective larvae). Methods: Adult and young snails were added to 24-well plates containing 20 synthetic compounds from the PDAN series for initial screening over 96 h at a concentration of 100 ppm. Water and NCL (2 ppm) were used as the negative and positive controls, respectively. Active compounds in the adult B. glabrata assay were selected for the tests vs. embryos and cercariae. Results: In the initial screen, only PDAN 52 (63 ± 4%) and 79 (12 ± 3%) showed molluscicidal activity at a concentration of 100 ppm up to 48 h. Consequently, we selected only PDAN 52. The LC₅₀ value found in the tests on embryos after 24 h of treatment was 20 ± 2 ppm and, after 48 h, it was 4 ± 0.5 ppm. Against cercariae, we measured an LC₅₀ value of 68 ± 5 ppm after 4 h of treatment. PDAN 52 did not induce marked toxicity against a second mollusk, Physella acuta, after 48 h of exposure. Conclusions: We highlight the promising molluscicidal activity of PDAN 52 against different developmental stages of the mollusk, B. glabrata, as well the infective larvae of Schistosoma mansoni. Full article

The use of plant protection products (PPPs) is the main method of controlling Cercospora leaf spot (CLS), as it constitutes a cheap and effective approach that is easy for farmers to follow. Unfortunately, it is widely recognized that the use of PPPs poses a risk not only to the environment but also to human health. The urgent need for sustainable development, recommended by the European Union and expressed in the “Farm to Fork Strategy”, includes a serious restriction on the use of PPPs. This strategy assumes a 50% reduction in the use of PPPs by 2030. These efforts have driven the exploration of innovative and effective plant protection strategies utilizing new active compounds. The examined substance, N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), is a novel amide derivative of benzothiadiazole with the ability to induce systemic acquired resistance (SAR). This work presents a series of experiments conducted in the process of determining the appropriate technology for BTHWA use and proving its effectiveness in controlling CLS in sugar beet cultivation. It has been demonstrated that the application of treatments using BTHWA or BTHWA combined with a fungicide in a reduced number of treatments had the same effect on the reduction of plant infection with C. beticola and obtained root and technological sugar yields the same as those that resulted from the use of a full fungicidal treatment. The results provide grounds for reducing the use of fungicides by showing that the same effects can be attained by combining or replacing them with BTHWA. Full article

There is currently a growing interest in imino derivatives of compounds such as thiadiazoles and other groups of compounds whose extended π-electron systems enhance their photophysical properties. These compounds also show low toxicity and strong antifungal activity, making them effective against fungal pathogens in crops. For the above reasons, in the first part of the paper, the structure of the selected analogs was considered, and detailed spectroscopic analyses were conducted focusing on the excited state intramolecular proton transfer (ESIPT) process taking place in the same. Measurements were taken in terms of absorption spectroscopy and electron fluorescence, synchronous spectra, and fluorescence lifetimes, as well as calculations of fluorescence quantum efficiency in selected solvents and concentrations. In the spectral observations, the ESIPT process was manifested in several solvents as very distinct dual fluorescence. Moreover, in selected molecules, this phenomenon was strongly related to molecular aggregation, which was associated with not very efficient but nonetheless visible fluorescence of the AIE (Aggregation-Induced Emission) type. In the second part of the paper, a detailed preliminary study is presented exploring the microbiological properties of selected imino-1,3,4-thiadiazole derivatives in the context of their potential applicability as inhibitors affecting the development and growth of some of the most important fungal pathogens attacking cereal crops and posing an increasing threat to modern agriculture. Overall, the research presented in this article provides a detailed, experimental analysis of the spectroscopic properties of selected imino-thiadiazoles and points to their potential use as novel and effective solutions capable of limiting the growth and development of fungal pathogens in cereals. Full article

The present study aims to create spiro-N-(4-sulfamoyl-phenyl)-1,3,4-thiadiazole-2-carboxamide derivatives with anticancer activities. The in vitro anticancer evaluation showed that only the novel spiro-acenaphthylene tethered-[1,3,4]-thiadiazole (compound 1) exhibited significant anticancer efficacy as a selective inhibitor of tumor-associated isoforms of carbonic anhydrase. Compound 1 demonstrated considerable efficacy against the renal RXF393, colon HT29, and melanoma LOX IMVI cancer cell lines, with IC₅₀ values of 7.01 ± 0.39, 24.3 ± 1.29, and 9.55 ± 0.51 µM, respectively. In comparison, doxorubicin exhibited IC₅₀ values of 13.54 ± 0.82, 13.50 ± 0.71, and 6.08 ± 0.32 µM for the corresponding cell lines. Importantly, compound 1 exhibited lower toxicity to the normal WI 38 cell line than doxorubicin, with IC₅₀ values of 46.20 ± 2.59 and 18.13 ± 0.93 µM, respectively, indicating greater selectivity of the target compound compared to the standard anticancer agent doxorubicin. Also, mechanistic experiments demonstrated that compound 1 exhibits inhibitory activity against human carbonic anhydrase hCA IX and XII, with IC₅₀ values of 0.477 ± 0.03 and 1.933 ± 0.11 μM, respectively, indicating enhanced selectivity for cancer-associated isoforms over cytosolic isoforms hCA I and II, with IC₅₀ values of 7.353 ± 0.36 and 12.560 ± 0.74 μM, respectively. Cell cycle studies revealed that compound 1 caused G1 phase arrest in RXF393 cells, and apoptosis experiments verified a substantial induction of apoptosis with significant levels of early and late apoptosis, as well as necrosis (11.69%, 19.78%, and 3.66%, respectively), comparable to those induced by the conventional cytotoxic agent doxorubicin, at 9.91%, 23.37%, and 6.16%, respectively. Molecular docking experiments confirmed the strong binding affinity of compound 1 to the active sites of hCA IX and XII, highlighting significant interactions with zinc-binding groups and hydrophobic residues. These findings underscore the target compound’s potential as a viable anticancer agent via targeting CA. Full article

MDM2 and MDM4 are major negative regulators of tumor suppressor p53. Beyond regulating p53, MDM2 possesses p53-independent activity in promoting cell cycle progression and tumorigenesis via its RING domain ubiquitin E3 ligase activity. MDM2 and MDM4 form heterodimer polyubiquitin E3 ligases via their RING domain interaction. Inhibitors disrupting p53 interaction with MDM2/MDM4 are in clinical trials in patients bearing wild-type p53 cancers. However, these inhibitors are not designed to work for p53-null/mutant cancer cells. Owing to the importance of the E3 ligase of MDM2 in its p53-independent oncogenic activity, inhibitors targeting the E3 ligase activity of MDM2-MDM4 are desirable for p53-mutant cancer cells. Here, we report the development of such inhibitors with pro-apoptotic activity in p53-null leukemic cells. Among analogues of MDM2-MDM4 E3 ligase inhibitors, we initially identified MMRi36 as a potent pro-apoptotic compound in p53-null leukemic cells with acquired drug resistance. MMRi36 acts as an activator of MDM2-MDM4 E3 ligase by stabilizing MDM2-MDM4 heterodimers and promotes MDM2/MDM4 degradation in cells. Interestingly, replacement of the sulfur in 1,3,4-thiadiazole MMRi36 with a carbon led to identification of pyrazole MMRi36C that dissociates the MDM2-MDM4 RING heterodimers, inhibits the E3 ligase activity of the complex, and induces p53 protein accumulation, but retains the p53-independent pro-apoptotic activity. A brief SAR study identified a fluorine derivative of MMRi36C with improved pro-apoptotic activity. This study discovered a novel class of compound that targets MDM2-MDM4 ubiquitin E3 ligase activity for apoptosis induction in p53-mutant cancer cells. Full article

Outdoor bronze statues are constantly exposed to weather conditions and reactive compounds in the atmosphere that can interact with their surfaces. To avoid these interactions, a commonly used method is the application of coatings with corrosion inhibitors. However, a significant limitation of these inhibitors is their gradual loss over time. In this study, we aimed to improve the durability of 5-ethyl-1,3,4-thiadiazol-2-amine (AEDTA), the inhibitor chosen to formulate new acrylic coatings for outdoor bronzes. Methyl-β-cyclodextrin (Me-β-CD) was selected to host the inhibitor due to the capability of cyclodextrins to form complexes incorporating small organic molecules. The complexes of Me-β-CD and AEDTA were prepared and the inclusion of AEDTA was proved by Fourier-transform infrared spectroscopy, X-ray diffraction and nuclear magnetic resonance spectroscopy. Then, acrylic coatings were prepared at different concentrations of the Me-β-CD/AEDTA system. They were thermally aged and monitored every 24 h. To evaluate the volatilization of the corrosion inhibitor, solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) and thermal desorption-GC/MS (TD-GC/MS) analyses were performed during the first 72 h. The results were compared to those of pure AEDTA films and Incralac^®. The outcomes showed that Me-β-CD/AEDTA complexes are promising candidates for developing coatings with improved stability and longer retention of AEDTA. Full article

Melanoma is a malignant neoplasm of melanocytes in the skin, and its occurrence is increasing annually. Plant-based products contain active compounds with low toxicity and are accessible alternatives for melanoma cancer treatment. The biotechnology approach for obtaining plant-based products provides continuity and allows the high-yield production of phytochemically uniform biomass. The callus biomass of Eryngium planum L. and Lychnis flos-cuculi L. was induced on Murashige and Skoog (MS) medium supplemented with growth regulators. A combination of 3.0 mg/L of 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 0.3 mg/L of 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea—(thidiazuron) was used to obtain E. planum callus. Meanwhile, the callus of L. flos-cuculi was cultivated on MS medium with 2.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Methanolic extracts (EpME and LFcME), including 40% MeOH fractions (Ep40MF and LFc40MF) and 80% MeOH fractions (Ep80MF and LFc80MF), of E. planum and L. flos-cuculi cell biomass were prepared. Their cytotoxicity activity was assessed in human fibroblast cells (MRC-5) and human melanoma cells (MeWo) by direct cell counting and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Qualitative analyses using thin-layer chromatography and UPLC-HRMS/MS chromatograms showed the presence of phenolic acids and saponins within the extracts and fractions of both cell biomasses. LFc80MF and Ep80MF showed the strongest toxicity against the MeWo cell line, with IC₅₀ values of 47 ± 0.5 and 52 ± 4 μg/mL after 72 h of treatment. EpME and LFcME had IC₅₀ values of 103 ± 4 and 147 ± 4 µg/mL, respectively. On the other hand, Ep40MF and LFc40MF were less toxic against the MeWo cell line compared to the extracts and 80% MeOH fractions, with IC₅₀ values of 145 ± 10 and 172 ± 7 µg/mL. This study suggests that the obtained extracts and fractions of E. planum and L. flos-cuculi cell biomass potentially possess significant cytotoxic activity against MeWo cells, which work in a time and dose-dependent manner. Although the extracts and 80% MeOH fractions were more potent, the 40% MeOH was shown to be more selective against the MeWo than the control MRC-5 cells. Full article

The aim of this study was to examine lettuce using different concentrations of the biostimulator N-methyl-N-methoxyamide-7-carboxybenzo(1.2.3)thiadiazole (BTHWA), a new benzothiadiazole derivative. Different concentrations of BTHWA during watering and spraying were applied to lettuce. Chlorophyll fluorescence, gas exchange, thermal images, and plant parameter data were used to study physiological process and the growth of lettuce. Chlorophyll fluorescence data showed a strong effect after the first BTHWA application to lettuce. After three applications, the plants were harvested and data were recorded. Similarly, in the second experiment, gas exchange and thermal images were recorded after the first treatment of BTHWA. Our findings showed improved chlorophyll efficiency after the first BTHWA application, and no adverse effects were recorded on the overall photochemistry at any concentration. Regarding growth parameters, spraying BTHWA reduced the fresh weight but decreased the damage index. A lower watering concentration (0.066 mg/L) applied three times did not cause any damage to plants and fresh weight, even after repeated applications. Infrared thermal images showed BTHWA application also significantly affected plant temperature. Gas exchange data revealed that sprayed plants exhibited higher transpiration rates, stomatal conductance, and photosynthetic rates when compared to watered and control plants. This study suggests that application of a low dose of BTHWA is safe to use in agriculture practices in lettuce without compromising its growth and yield. Full article