Click Chemistry Protocol Research Articles

Synthesis of Paracetamol‐Appended Bis 1,2,3‐Triazole Analogues as Anti‐Inflammatory Agents

AbstractParacetamol‐based bis 1,2,3‐triazole analogues were synthesized involving copper‐catalyzed click chemistry protocol. The new compounds were characterized by 1H NMR, 13C NMR, and mass spectral techniques. All the compounds were evaluated for their in vitro anti‐inflammatory properties using diclofenac as standard reference. The compound 6b with chlorine and fluorine functions displayed outstanding activity with IC50 values of 7.34 ± 0.45 µM and 7.84 ± 0.47 µM, respectively. Compound 6g with methyl and fluorine functions displayed best activity with IC50 values of 9.34 ± 0.22 µM and 9.40 ± 0.35 µM, respectively. Compound 6i, 6k, 6f, 6a, 6e, 6h, 6j, and 6l exhibited promising activity with respect to diclofenac. Using PyRx tool, the molecular docking study against crystal structure of COX‐2 proved the binding efficacies with notable binding interactions.

Quinoline-1,2,3-triazole hybrids: Design, synthesis, antimalarial and antimicrobial evaluation

A new library of Quinoline appended 1,2,3-triazole hybrids of biotic interest was synthesized using terminal alkynes containing quinoline moiety, benzyl amine based bromides, sodium azide via click chemistry protocol and were assessed for antimalarial and antimicrobial potential. All of the synthesized triazoles were characterized using different spectral techinques viz. FTIR, 1H NMR,13C NMR and HRMS. Antimalarial activity of the synthesized quinoline-triazole hybrids against the Plasmodium falciparum strain displayed modest to good results. The synthesized compounds also reflected good antimicrobial potential against four bacteria (Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Escherichia coli) and two fungi (Candida albicans, Aspergillus niger). Molecular docking studies and in-silico ADME (Absorption, Distribution, Metabolism and Elimination) analysis were also performed to check the binding and drug-likeliness of the synthesized compounds.

Synthesis of New Chroman-4-one Based 1,2,3-Triazole Analogues as Antioxidant and Anti-Inflammatory Agents.

A library of new chroman-4-one based 1,2,3-triazole analogues were synthesized involving a series of condensation, cyclization, Suzuki coupling and copper catalysed click chemistry protocols. The newly synthesized compounds 8a-l were screened for their invitro antioxidant and anti-inflammatory activities by employing Ascorbic acid and Diclofenac as reference drugs respectively. The compound without any substituent on benzyl ring (8a), compound with -Cl substituent in para position of benzyl ring (8i), and compound with ethoxy substituent in para position of benzyl ring (8k) exhibited potent antioxidant and anti-inflammatory activities with higher percentage of inhibition. To understand their binding affinities, molecular docking study of these three compounds performed against NADPH oxidase with presented outstanding docking scores and promising binding interactions like H-bond and hydrophobic.

Facile Modification of Propiolated Castor Oil via Nucleophilic Thiol‐Yne Click Reactions

AbstractThe combination of modern click protocols and bio‐based building blocks is a great step toward energy‐efficient, and sustainable polymer production. Herein, thiol‐Michael addition (thiol‐yne) reactions from the toolbox of click chemistry protocols are chosen and propiolated castor oil (PCO) is used, a vegetable oil derivative, as the bio‐based building block for the facile functionalization of PCO with various thiols. In addition to the functionalization of PCO, hyperbranched and crosslinked polymers are also prepared. The thiol‐yne click functionalization reactions of the PCO are conducted at room temperature within 5 min and in the presence of an organic catalyst. The yields are found to change between 80% and 99% depending on the type of the thiol compound. The effect of various organic catalysts is investigated, and 1,8‐diazabicyclo(5.4.0)undec‐7‐ene (DBU) is found to be the most effective catalyst for the thiol‐yne modification reactions. The hyperbranched polymer reaches 23.8 kDa (Mw) within 5 min. The findings of this paper open up new horizons for polymer researchers who work in the field of sustainable polymers and click chemistry and the presented idea here is appealing because it offers a potential strategy for fast, reliable, modular, and functional macromolecule preparation from renewable vegetable oils.

Integrated enzyme-linked immunosensor with biofunctionalized ion-selective membranes by pulstrode delivery of substrate

A new principle for electrochemical enzyme immunoassays is proposed where the enzyme substrate is selectively delivered by an electrochemical excitation pulse to the location where the biomolecular interaction takes place. This is achieved by covalent attachment of the capture antibody on the surface of a polymeric ion-selective membrane, which also serves to monitor the enzyme activity over time by open circuit chronopotentiometry. The membrane biofunctionalization was accomplished by using a click chemistry protocol in addition to N-hydroxysuccinimide ester crosslinking and was characterized using confocal microscopy and electrochemical impedance spectroscopy. To demonstrate the principle, a choline-oxidase labelled antibody served as the detection reporter in a sandwich immunoassay for the determination of human lysozyme in saliva in the range of 10–100 μg mL−1 with a detection limit of 0.7 μg mL−1 (3σ). The enzyme-immunocomplex at the sensing surface catalyzes the oxidation of choline, an ion marker to which the membrane is selective and that is released from the membrane by a pulstrode protocol (galvanostatic pulse of 1 s duration and 10 μA magnitude). The enzyme turnover is interrogated by measuring the open circuit potential of the electrode over time after the release pulse. A model based on diffusion and enzyme kinetics is developed to rationalize the sensing principle and to guide the experiments. The results with this integrated immunosensor compare well to that of a conventional enzyme-linked immunoassay.

Exploration of cytotoxic potential and tubulin polymerization inhibition activity of cis-stilbene-1,2,3-triazole congeners.

To scrutinize cis-stilbene based molecules with potential anticancer and tubulin polymerization inhibition activity, a new series of cis-stilbene-1,2,3-triazole congeners was designed and synthesized via a click chemistry protocol. The cytotoxicity of these compounds 9a-j and 10a-j was screened against lung, breast, skin and colorectal cancer cell lines. Based on the results of MTT assay, we further evaluated the selectivity index of the most active compound 9j (IC50 3.25 ± 1.04 μM on HCT-116) by comparing its IC50 value (72.24 ± 1.20 μM) to that of the normal human cell line. Further, to confirm apoptotic cell death, cell morphology and staining studies (AO/EB, DAPI and Annexin V/PI) were carried out. The outcomes of studies showed apoptotic features like change in cell shape, cornering of nuclei, micronuclei formation, fragmented, bright, horseshoe-shaped nuclei, etc. Moreover, active compound 9j displayed G2/M phase cell cycle arrest with significant tubulin polymerization inhibition activity with an IC50 value of 4.51 μM. Additionally, in silico ADMET, molecular docking and molecular dynamic studies of 9j with 3E22 protein proved the binding of the compound at the colchicine binding site of tubulin.

Antioxidant activity of novel 4H- chromene tethered 1,2,3-Triazole Analogues: Synthesis and molecular docking studies

Novel 4H chromene coupled triazole hybrids 8a-l were synthesized through a hassle free multicomponent one pot synthesis and click chemistry protocols. The structures of novel compounds were established by interpretation of 1H NMR, 13C NMR, IR and Mass spectral data. The novel hybrids were screened for their invitro antioxidant activity by employing DPPH and Hydrogen peroxide radical scavenging assays, using Ascorbic acid as standard reference. Novel compounds 8h and 8i exhibited superior radical quenching percentage with IC50 value of 1.29 ± 0.35 and 1.23 ± 0.34 µM respectively, compared to the IC50 value of (1.46 ± 0.52 µM)Ascorbic acid. Compounds 8f, 8j and 8k also demonstrated best IC50 value of 3.02 ± 0.62, 2.45 ± 0.53 and 3.18 ± 0.25 µM in comparison to reference. The molecular docking studies of target compounds against the crystal structure of NADPH oxidase endorsed best docking scores and binding interactions, and are in agreement to experimental data.

Exploiting click-chemistry: backbone post-functionalisation of homoleptic gold(I) 1,2,3-triazole-5-ylidene complexes.

The synthesis of a homoleptic azide-functionalised Au(I) bis-1,2,3-triazole-5-ylidene complex is reported, starting from a backbone-modified 1,2,3-triazolium salt ligand precursor. The incorporated azide handle allows for a straightforward modification of the complex according to click-chemistry protocols without impacting the steric shielding around the metal center, demonstrating the superiority of the presented triazole ligand framework over imidazole based systems. Employing the SPAAC and the CuAAC reactions, post-modification of the complex is facilitated with two model substrates, while retaining very high antiproliferative activity (nanomolar range IC50 values) in A2780 and MCF-7 human cancer cells.

Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells.

Site-specific delivery using functionalized nanocarriers is in high demand in imaging applications of modern clinical research. To improve the imaging capabilities of conventionally used contrast agents and expand the targeting accuracy, functional gadolinium oxide based nanocarriers originated from homogeneous core shells structures (Gd2O3@SiO2@Fe3O4) were developed using a multilayer formation approach. The synthesis and chemical configuration for the covalent binding of macrocyclic chelating agents and estrogen targeting molecules on these nanocarriers were designed by a two-step chemical synthesis method. Initially, SiO2@Fe3O4 structures were prepared and encapsulated with a homogenous thin Gd2O3 overlayer. The exterior surface of the as-prepared carriers offered chemical binding with a breast cancer specific estrogen molecule, covalently grafted through a Click-Chemistry protocol. In the next step, to enhance the diagnostic imaging capabilities of these carriers, thiocyanate-linked chelator molecule, DOTA, was attached to the surface of estrogen bound Gd2O3@SiO2@Fe3O4 using basic reaction conditions. The active amino groups before and after conjugation of estrogen molecules on the surface were quantified using a fluorescamine based approach. Due to the covalent binding of the macrocyclic chelator to the Gd2O3@SiO2@Fe3O4 surface, core shell carriers showed potential radiolabeling efficiency using positron emitter radionuclide, gallium-68 (68Ga). Intracellular uptake of estrogen-conjugated carriers was evaluated with MCF7 breast cancer cell lines using confocal laser scanning microscopy and fluorescent flow cytometry. In addition, in vitro cytotoxicity studies of functional nanocarriers as compared to bare nanoparticles showed reduced toxicity to HEK-293 cells demonstrating the role of surface attached molecules in preventing direct exposure of the Gd2O3 surface to the cells. The as-developed gadolinium based nanocarriers presented excellent capabilities as biocompatible target-specific imaging probes which indicates great potential in the field of dual-mode contrast agents.

Arylopeptoid oligomers functionalised by combinatorial or sequential on-resin click chemistry using a copper(I)-N-heterocyclic carbene catalyst.

An efficient on-resin click chemistry protocol using a stable copper(I)-N-heterocyclic carbene catalyst is developed for post-functionalization of N-alkylated aminomethylbenzamide oligomers (arylopeptoids). The accessibility to a panel of polyfunctionalized N-substituted aromatic oligoamides by solid-phase synthesis is demonstrated using combinatorial and sequential approaches.

Development of a Virus-Like Particle-Based Anti-HER2 Breast Cancer Vaccine.

Simple SummaryVirus-like particles (VLPs) have attracted significant interest as immunotherapy platforms and cancer vaccines for inducing antigen-specific immune responses against tumors. We prepared a human epidermal growth factor receptor-2 (HER2) cancer vaccine, by conjugating the HER2-derived CH401 epitope to the external surface of Physalis mottle virus (PhMV)-like particles via copper-free click chemistry. Another candidate was prepared by loading Toll-like receptor 9 (TLR9) agonists as adjuvant into the interior cavity of PhMV-CH401—although the addition of the adjuvant conferred no additional immune priming. The VLP-based anti-HER2 vaccine candidate was administered subcutaneously, using a prime-boost immunization schedule and BALB/c mice. The vaccine candidate elicited a strong immune response, including high titers of HER2-specific immunoglobulins and increased the toxicity of antisera to DDHER2 tumor cells. DDHER2 tumor challenge studies demonstrated efficacy, as evident from the delayed onset of tumor growth and the prolonged survival of the vaccinated vs. naïve BALB/C mice.To develop a human epidermal growth factor receptor-2 (HER2)-specific cancer vaccine, using a plant virus-like particle (VLP) platform. Copper-free click chemistry and infusion encapsulation protocols were developed to prepare VLPs displaying the HER2-derived CH401 peptide epitope, with and without Toll-like receptor 9 (TLR9) agonists loaded into the interior cavity of the VLPs; Physalis mottle virus (PhMV)-based VLPs were used. After prime-boost immunization of BALB/c mice through subcutaneous administration of the vaccine candidates, sera were collected and analyzed by enzyme-linked immunosorbent assay (ELISA) for the CH401-specific antibodies; Th1 vs. Th2 bias was determined by antibody subtyping and splenocyte assay. Efficacy was assessed by tumor challenge using DDHER2 tumor cells. We successful developed two VLP-based anti-HER2 vaccine candidates—PhMV-CH401 vs. CpG-PhMV-CH401; however, the addition of the CpG adjuvant did not confer additional immune priming. Both VLP-based vaccine candidates elicited a strong immune response, including high titers of HER2-specific immunoglobulins and increased toxicity of antisera to DDHER2 tumor cells. DDHER2 tumor growth was delayed, leading to prolonged survival of the vaccinated vs. naïve BALB/C mice. The PhMV-based anti-HER2 vaccine PhMV-CH401, demonstrated efficacy as an anti-HER2 cancer vaccine. Our studies highlight that VLPs derived from PhMV are a promising platform to develop cancer vaccines.

Receptor-Mediated In Vivo Targeting of Breast Cancer Cells with 17α-Ethynylestradiol-Conjugated Silica-Coated Gold Nanoparticles.

Efficient therapies for breast cancer remain elusive because of the lack of strategies for targeted transport and receptor-mediated uptake of synthetic drug molecules by cancer cells. Conjugation of nanoparticles (NPs) with active targeting ligands enabling selective molecular recognition of antigens expressed on the surface of cancer cells is promising for localization and treatment of malignant cells. In this study, covalent attachment of synthetic estrogen 17α-ethynylestradiol on the silica (SiO2) shell of silica-gold NPs (SiO2@Au) was undertaken to improve the cancer-targeting ability of the nano-biotags. Chemical and structural analysis of the bioconjugates examined in solution (UV-vis and ξ-potential) and solid state (Fourier transform infrared spectroscopy, X-ray diffractometry, and transmission electron microscopy) confirmed the identity of the carrier particles and surface-bound ligands. The mesoporous silica shell served as a reservoir for anticancer drugs (doxorubicin and quercetin) and to facilitate covalent attachment of receptor molecules by click chemistry protocols. The chemoselective recognition between the nanoconjugates and cell membranes was successfully demonstrated by the accumulation of nanoprobes in the tumor tissue of mice with subcutaneous breast cancer, whereas healthy cells were unaffected. The drug release studies showed sustained release kinetics over several weeks. These findings elaborate the exceptional selectivity and potential of estrogen-coated nano-biolabels in efficient diagnosis and detection of breast cancer cells.

Mediating the Fate of Cancer Cell Uptake: Dual-Targeted Magnetic Nanovectors with Biotin and Folate Surface Ligands.

Recognition of folate and biotin surface receptors by dual-functionalized nanoparticles (NPs) is key for site-selective receptor-mediated transport of anticancer drugs to cancer cells. We present here dopamine-capped iron oxide nanoprobes (Fe3O4, 10 ± 2 nm) containing two surface-grafted biologically relevant ligands, namely, folic acid (FA) and biotin (BT). The covalent attachment of both FA and BT on Fe3O4 nanoparticles was achieved by following carbodiimide coupling and click-chemistry protocols. The dual-function Fe3O4 probes were delivered into E-G7 and human HeLa cancer cell lines and tested toward their cellular uptake by immunofluorescence and flow cytometry analysis. Owing to receptor-mediated endocytosis, enhanced accumulation of nanoprobes in cancer cells was successfully monitored by confocal laser microscopy. When compared to dual-function probes, single-functionalized nanoparticles possessing either FA or BT ligands showed significantly reduced uptake in the tested cell lines, underlining the superior interaction potential of dual-purpose probes. A time-dependent receptor-mediated endocytosis of FA-Fe3O4-BT nanovectors was demonstrated by flow cytometry analysis, whereas the unfunctionalized NPs did not show any specificity in terms of uptake. Besides their specific uptake, the surface-functionalized nanoparticles exhibited promising cytotoxicity profiles by demonstrating good viability of more than 95% with analogous cancer cell lines. Our results demonstrate that dual and/or multivariate conjugation of receptor-specific ligands on NPs is highly effective in molecular recognition of surface biomarkers that enhances their potential in anticancer treatment for pretargeting-radio strategies based on biotin/avidin interactions.

Multivalent magnetic nanoaggregates with unified antibacterial activity and selective uptake of heavy metals and organic pollutants

Covalently functionalized magnetite (Fe3O4) nanoaggregates carrying an imidazolium-derivative (1-hexadecyl-3-vinyl imidazolium bromide, HDVI) and L-cysteine (L-Cys) as surface ligands act as bimodal water-treatment particulate agents (HDVI@L-Cys@PAA@Fe3O4) with high antibacterial efficacy and specific surface adsorption properties. For covalent conjugation of HDVI the polyacrylic acid (PAA)-coated magnetite nanocrystals (PAA@Fe3O4) were functionalized with L-cysteine via carbodiimide coupling (L-Cys@PAA@Fe3O4) having terminal -SH groups that were used for thiol-ene click chemistry. The carefully performed series of water-remediation tests with magnetically separable HDVI@L-Cys@PAA@Fe3O4 nanoaggregates demonstrated their high efficiency in the concomitant removal transition metal ions and organic pollutant without losing the antibacterial effect. Time-dependent adsorption experiments showed high degree (>90%) of trapping and removal activity. Antibacterial action of the HDVI@L-Cys@PAA@Fe3O4 nanoaggregates originates from the amphiphilic structure of HDVI groups capable of penetrating the bacterial cell walls. The presence of surface-bound ligands and conversion efficiency of carbodiimide and click chemistry protocol was verified by FT-IR, elemental and thermogravimetric analysis. The phase, composition morphology and surface charge of nanoaggregates were examined by XRD, SEM/TEM and zeta potential studies, respectively. The experimental findings reported here represent a conceptual advancement in the state-of-the-art magnetic beads developed for water purification or remediation purposes. Our results evidently demonstrate that nanoaggregates are highly effective in unifying bactericidal activity against different microorganism with heavy metal and organic pollutant removal properties.

Effect of detection of epigenomic changes in plasma-derived cell-free DNA on multicancer classification.

1539 Background: Epigenomic changes in DNA methylation patterns are more precisely delineated by active demethylation events as marked by 5-hydroxymethylation (5hmC) of cytosine residues. 5hmC appears to be dynamically modulated in tumor tissues and can be employed as a cancer biomarker. Strategies which interrogate 5hmC genome-wide patterns in a liquid biopsy context may provide efficient and precise technology for early cancer screening and detection. In this study we identified genome-wide 5hmC changes in plasma based circulating free DNA (cfDNA) from breast, colorectal, lung, pancreatic and prostate cancer patients versus non-cancer individuals. Methods: cfDNA was isolated from plasma, enriched for the 5hmC fraction using novel click-chemistry protocol for labelling followed by sequencing and alignment to a reference genome to construct features sets of 5hmC patterns. Regularized classification models were constructed to classify cancer samples apart from non-cancer. Results: > 500 non-cancer individuals and > 500 cancer patients across five cancer types (breast, colorectal, lung, pancreas and prostate) were included in this study. About 60% of the cancer samples were early stage disease (I or II). The ability to classify non-cancer versus cancer patients was evaluated by 5-fold cross validation of our trained prediction models. Our models were able to classify all breast cancer with a test auROC of 0.86 while prediction model classification for ER negative samples had an auROC of 0.92. Colorectal performance auROC was 0.9; lung auROC = 0.92, pancreatic auROC = 0.97 and prostate auROC = 0.91. Overall sensitivity range, when allowing 2% false positive, was between 85% and 52%. Further using 5hmC signal in blood we were able to identify several signaling pathways specifically relevant to the biology of the cancers investigated. Conclusions: These findings further demonstrate that 5hmC changes in cfDNA enable non-invasive detection of breast, colorectal, lung pancreatic, and prostate cancers. Further, 5hmC signals enabled the identification of a suite of cancer signaling pathways differentially enriched in cancers versus non-cancers. These data suggest that dynamic changes in tumor cell methylation, detectable through 5-hydroxymethylation, are contained in the circulating blood and signal active disease biology.

Fabrication of chitosan based magnetic nanocomposite by click reaction strategy; evaluation of nanometric and cytotoxic characteristics

Efficient procedure for preparation of the novel magnetic nanobiocomposite (MNbC) was successfully established by employing click chemistry protocol. The resulted structure exhibited valuable characteristics from biological viewpoints. The prepared materials and obtained nanobiocomposite were characterized by means of nuclear magnetic resonance (NMR), fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). To assay the antiproliferative effects of the MNbC; as cancerous cells, Hela, MCF-7 and Saos were evaluated by means of MTT assay and compared with normal fibroblast cell line. Promising antiproliferative effects were observed on both epitheloid and mesenchymal cancer cell lines depending on MNbC concentration and time. To detect the apoptosis-associated changes of cell membranes during the process of apoptosis, Acridine Orange/Ethidium Bromide (AO/EB) dual staining fluorescent technique was incorporated. The studies in this article including all of these specifications represent convincing key findings that make MNbC as an appreciable candidate for further bio-applications.

Novel anticancer and antibacterial organometallic polymer based on ferrocene as a building block and xanthone bioactive scaffolds: Synthesis, characterization, and biological study

Poly(azine ferrocene‐triazole‐xanthone amide) (PAFTXA) was successfully synthesized from azine ferrocene bisacetylene (AFcB) and 2,7‐(N‐2‐azidoacetamide) xanthone (NAzX) by using click chemistry protocol. In this paper, innovative AFcB moiety incorporated in this procedure as a monomer. This monomer was prepared in three steps from ferrocene scaffold, and the synthetic processes were discussed in details. Characterization of the synthesized novel intermediate materials, monomer, and the resulting polymer was performed by nuclear magnetic resonance, Fourier transform infrared, thermal gravimetric analysis, differential scanning calorimetry, and ultraviolet‐visible spectrophotometer. In addition, the in vitro antibacterial activity of the polymer was appraised against Gram‐positive and Gram‐negative bacteria by using minimum inhibitory concentration method. Moreover; antitumoral effects of synthesized polymer were evaluated on Hela, MCF‐7, and Saos cancer cell lines and compared with normal fibroblast cell line by means of 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. Promising antiproliferative effects were detected on both epitheloid and mesenchymal cancer cell lines depending on PAFTXA concentration and time. Survey on its characteristic features revealed the proficiencies of our prepared biomaterial such as its high thermal stability as well as valuable antitumoral and antibacterial capabilities that make it an appreciable candidate for further bioapplications.

Synthesis, Photophysical, Electrochemical Studies, and Antioxidant Properties of Fluorescein‐Linked Glycodendrimers

AbstractFluorescein‐linked glycodendrimers 1, 2, 3, and 4 were synthesized up to the third generation with glucose surface groups and triazole as the bridging unit by using a CuI‐catalyzed click chemistry protocol. All the synthesized glycodendrimers showed comparable antioxidant behavior to that of the standard with ascorbic acid when tested with both the DPPH (1,1‐diphenyl‐2‐picryl hydrazyl) scavenging assay and HO radical scavenging assay methods. Higher generation glycodendrimers exhibited superior antioxidant activity than the lower generation glycodendrimers owing to the presence of a greater number of triazole units and multivalent glucose units. The fluorescence and UV absorption intensity increases with the increase in dendrimer generation. All the dendrimers 1–4 showed reduction peaks with negative potentials in their cyclic voltammograms.

The application of a novel, cell permeable activity-based probe for the detection of cysteine cathepsins

Cysteine cathepsins, such as cathepsin S (CTSS), are implicated in the pathology of a wide range of diseases and are of potential utility as diagnostic and prognostic biomarkers. In previous work, we demonstrated the potency and efficiency of a biotinylated diazomethylketone (DMK)-based activity-based probe (ABP), biotin-PEG-LVG-DMK, for disclosure of recombinant CTSS and CTSS in cell lysates. However, the limited cell permeability of both the biotin and spacer groups restricted detection of CTSS to cell lysates. The synthesis and characterisation of a cell permeable ABP to report on intracellular CTSS activity is reported. The ABP, Z-PraVG-DMK, a modified peptidyl diazomethylketone, was based on the N-terminus of human cystatin motif (Leu-Val-Gly). The leucine residue was substituted for the alkyne-bearing proparcylglycine to facilitate conjugation of an azide-tagged reporter group using click chemistry, following irreversible inhibition of CTSS. When incubated with viable Human Embryonic Kidney 293 cells, Z-PraVG-DMK permitted disclosure of CTSS activity following cell lysis and rhodamine azide conjugation, by employing standard click chemistry protocols. Furthermore, the fluorescent tag facilitated direct detection of CTSS using in-gel fluorescent scanning, obviating the necessity for downstream biotin-streptavidin conjugation and detection procedures.

ChemInform Abstract: One‐Pot Synthesis of New Triazole—Imidazo[2,1‐b][1,3,4]thiadiazole Hybrids via Click Chemistry and Evaluation of Their Antitubercular Activity.

AbstractTitle compounds (III) are synthesized via one‐pot click chemistry protocol.