4-Aryl-1,2,3-triazole: A Novel Template for a Reversible Methionine Aminopeptidase 2 Inhibitor, Optimized To Inhibit Angiogenesis in Vivo

Current Trends in Sirtuin Activator and Inhibitor Development

Sirtuins are NAD+-dependent protein deacylases and key metabolic regulators, coupling the cellular energy state with selective lysine deacylation to regulate many downstream cellular processes. Humans encode seven sirtuin isoforms (Sirt1-7) with diverse subcellular localization and deacylase targets. Sirtuins are considered protective anti-aging proteins since increased sirtuin activity is canonically associated with lifespan extension and decreased activity with developing aging-related diseases. However, sirtuins can also assume detrimental cellular roles where increased activity contributes to pathophysiology. Modulation of sirtuin activity by activators and inhibitors thus holds substantial potential for defining the cellular roles of sirtuins in health and disease and developing therapeutics. Instead of being comprehensive, this review discusses the well-characterized sirtuin activators and inhibitors available to date, particularly those with demonstrated selectivity, potency, and cellular activity. This review also provides recommendations regarding the best-in-class sirtuin activators and inhibitors for practical research as sirtuin modulator discovery and refinement evolve.

A mild protocol for efficient preparation of functional molecules containing triazole

The construction of a class of novel triazole molecules containing sulfonyl fluoride functionalities was achieved through Cu-catalyzed click chemistry in good to excellent yields. The sulfonyl fluoride moieties were cleaved completely under base conditions to produce N-unsubstituted triazoles quantitatively, which provides a strategy to combine SuFEx click chemistry with Cu-catalyzed click chemistry ingeniously.

I2/DMSO-mediated oxidative C-C and C-heteroatom bond formation: a sustainable approach to chemical synthesis

The I2/DMSO pair has emerged as a versatile, efficient, practical, and eco-friendly catalyst system, playing a significant role as a mild oxidative system, and thus employed as a good alternative to metal catalysts in synthetic chemistry. Presently, I2/DMSO is a thriving catalytic system that is used in preparing C-C and C-X (X = O/S/N/Se/Cl/Br) bonds, resulting in the formation of various bioactive molecules. Many processes utilize this system, including in situ glyoxal synthesis by diverse sp, sp2, and sp3 functionalities via iodination and subsequent Kornblum oxidation. Focusing on oxidation processes, this study examines the synergistic effect of dimethyl sulfoxide (DMSO) and molecular iodine in improving synthetic techniques. We provide a comprehensive overview of the research progress on the I2/DMSO catalytic system for the formation of C-C and C-heteroatom bonds from 2018 to the present. Additionally, the future prospects of this research field are discussed.

Azide-free cyclization reaction access to 4-aryl-NH-1,2,3-triazoles: P-toluenesulfonyl hydrazide and sulfamic acid as nitrogen sources

An iodine-mediated cyclization has been developed to 4-aryl-NH-1,2,3-triazoles, with p-toluenesulfonyl hydrazide and sulfamic acid used as nitrogen sources. Sulfamic acid plays a crucial role in this reaction by both acting as a substrate and providing an acidic environment. This reaction offers a metal- and azide-free strategy to access NH-1,2,3-triazoles.

Synthesis of 1,2,3-triazole-fused N-heterocycles from N-alkynyl hydroxyisoindolinones and sodium azide via the Huisgen reaction

An efficient methodology for the synthesis of dihydro[1,2,3]triazolo-pyrimidoisoindolones and dihydro[1,2,3]triazolo-diazepinoisoindolones has been developed using the Huisgen reaction from sodium azide and alkyne substituted amido alcohols in moderate to good yields. The reaction involves the in situ generation of the N-acyliminium ion intermediate, which undergoes a nucleophilic attack by the azide ion, followed by a [3 + 2]-intramolecular azide-alkyne cycloaddition reaction. Importantly, the reaction proceeds without the involvement of any transition metal catalyst. This methodology can be further utilized for the synthesis of dihydro[1,2,3]triazolo-pyrimidoisoindolthiones via thionation of amides.

Synthesis, Structural Investigations, DNA/BSA Interactions, Molecular Docking Studies, and Anticancer Activity of a New 1,4-Disubstituted 1,2,3-Triazole Derivative

We report herein a new 1,2,3-triazole derivative, namely, 4-((1-(3,4-dichlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-hydroxybenzaldehyde, which was synthesized by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The structure of the compound was analyzed using Fourier transform infrared spectroscopy (FTIR), 1H NMR, 13C NMR, UV-vis, and elemental analyses. Moreover, X-ray crystallography studies demonstrated that the compound adapted a monoclinic crystal system with the P21/c space group. The dominant interactions formed in the crystal packing were found to be hydrogen bonding and van der Waals interactions according to Hirshfeld surface (HS) analysis. The volume of the crystal voids and the percentage of free spaces in the unit cell were calculated as 152.10 Å3 and 9.80%, respectively. The evaluation of energy frameworks showed that stabilization of the compound was dominated by dispersion energy contributions. Both in vitro and in silico investigations on the DNA/bovine serum albumin (BSA) binding activity of the compound showed that the CT-DNA binding activity of the compound was mediated via intercalation and BSA binding activity was mediated via both polar and hydrophobic interactions. The anticancer activity of the compound was also tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using human cell lines including MDA-MB-231, LNCaP, Caco-2, and HEK-293. The compound exhibited more cytotoxic activity than cisplatin and etoposide on Caco-2 cancer cell lines with an IC50 value of 16.63 ± 0.27 μM after 48 h. Annexin V suggests the induction of cell death by apoptosis. Compound 3 significantly increased the loss of mitochondrial membrane potential (MMP) levels in Caco-2 cells, and the reactive oxygen species (ROS) assay proved that compound 3 could induce apoptosis by ROS generation.

Copper-Mediated Intramolecular Interrupted CuAAC Selanylation

We, herein, describe a copper-mediated domino CuAAC intramolecular selanylation for the synthesis of unprecedented fused benzo[4,5][1,3]selenazolo[3,2-c][1,2,3]triazoles from 1,2-bis(2-azidoaryl)diselenides and terminal alkynes under microwave irradiation. This is the seminal method for the synthesis of these fused heterocycles, and it proceeds under mild conditions, tolerates several functional groups, and can be carried out using environmentally benign solvents such as dimethyl carbonate. This transformation has been successfully extended to TMS-protected alkynes and to bioactive alkynes. A plausible reaction mechanism is proposed based on several control experiments and previous reports.

Exploration of 1,2,3-triazole linked benzenesulfonamide derivatives as isoform selective inhibitors of human carbonic anhydrase

A novel series of 1,2,3-triazole benzenesulfonamide substituted 1,3-dioxoisoindolin-5-carboxylate (7a-l) inhibitors of human α-carbonic anhydrase (hCA) was designed using a tail approach. The design method relies on the hybridization of a benzenesulfonamide moiety with a tail of 1,3-dioxoisoindoline-5-carboxylate and a zinc-binding group on a 1,2,3-triazole scaffold. Among the synthesized analogues, 2‑iodophenyl (7f, K_I of 105.00 nM and S_I of 2.98) and 2‑naphthyl (7h, K_I of 32.11 nM and S_I of 3.48) analogues (over off-target hCA I) and phenyl (7a, K_I of 50.13 nM and S_I of 2.74) and 2,6‑dimethylphenyl (7d, K_I of 50.60 nM and S_I of 3.35) analogues (over off-target hCA II) exhibited a remarkable selectivity for tumor isoforms hCA IX and XII, respectively. Meanwhile, analogue 7a displayed a potent inhibitory effect against the tumor-associated isoform hCA IX (K_I of 18.29 nM) compared with the reference drug acetazolamide (AAZ, K_I of 437.20 nM), and analogue 7h showed higher potency (K_I of 9.22 nM) than AAZ (K_I of 338.90 nM) against another tumor-associated isoform hCA XII. However, adding the lipophilic large naphthyl tail to the 1,3-dioxoisoindolin-5-carboxylate analogues increased both the hCA inhibitory and selective activities against the target isoform, hCA XII. Additionally, these analogues (7a-l) showed IC₅₀ values against the human lung (A549) adenocarcinoma cancer cell line ranging from 129.71 to 352.26 μM. The results of the molecular docking study suggested that the sulfonamide moiety fits snugly into the hCAs active sites and interacts with the Zn²⁺ ion. At the same time, the tail extension engages in various hydrophilic and hydrophobic interactions with the nearby amino acids, which affects the potency and selectivity of the hybrids.

Novel indazole skeleton derivatives containing 1,2,3-triazole as potential anti-prostate cancer drugs

In this study, a novel batch of indazole containing 1,2,3-triazole agents were designed and synthesized. The antiproliferative activity of target compounds in four human cancer cells, PC-3 (human prostate cancer cell), MCF-7 (human breast cancer cell), HepG-2 (human hepatoma cell) and MGC-803 (human gastric cancer cell), was evaluated by thiazole blue (MTT). In the antiproliferative activity screening, we were surprised to find that most compounds have specific cytotoxicity to PC-3 cancer cells. In particular, 9a has an IC₅₀ value of 4.42 ± 0.06 μmol/L against PC-3 cell. Cloning experiments showed that 9a could inhibit the formation of PC-3 cancer cell clone in a dose-dependent manner. Through cell cycle arrest experiment, we found that compound 9a can block the cell cycle in G2/M phase and inhibit cell proliferation. Finally, by evaluating the safety of compound 9a, we noticed that it showed fairly good safety both in vivo and in vitro. Overall, based on the biological activity evaluation and safety, analogue 9a can be viewed as a potential lead compound for further development of novel anti-prostate cancer drug.

Copper-Catalyzed Azide-Alkyne Cycloaddition of Hydrazoic Acid Formed In Situ from Sodium Azide Affords 4-Monosubstituted-1,2,3-Triazoles

We report a copper-catalyzed cycloaddition of hydrogen azide (hydrazoic acid, HN3) with terminal alkynes to form 4-substituted-1H-1,2,3-triazoles in a sustainable manner. Hydrazoic acid was formed in situ from sodium azide under acidic conditions to react with terminal alkynes in a copper-catalyzed reaction. Using polydentate N-donor chelating ligands and mild organic acids, the reactions were realized to proceed at room temperature under aerobic conditions in a methanol-water mixture and with 5 mol % catalyst loadings to afford 4-substituted-1,2,3-triazoles in high yields. This method is amenable on a wide range of alkyne substrates, including unprotected peptides, showing diverse functional group tolerance. It is applicable for late-stage functionalization synthetic strategies, as demonstrated in the synthesis of the triazole analogue of losartan. The preparation of orthogonally protected azahistidine from Fmoc-l-propargylglycine was realized on a gram scale. The hazardous nature of hydrazoic acid has been diminished as it forms in situ in <6% concentrations at which it is safe to handle. Reactions of distilled solutions of hydrazoic acid indicated its role as a reactive species in the copper-catalyzed reaction.

Developments in the Application of 1,2,3-Triazoles in Cancer Treatment

BACKGROUND

The impact of cancer on modern society cannot be emphasized enough in terms of both economic and human costs. Cancer treatments are known, unfortunately, for their side effects - frequently numerous and severe. Drug resistance is another issue medical professionals have to tackle when dealing with neoplastic illnesses. Cancer rates are rising worldwide due to various factors - low-quality nutrition, air and water pollution, tobacco use, etc. For those and many other reasons, drug discovery in the field of oncology is a top priority in modern medical science.

OBJECTIVE

To present the reader with the latest in cancer drug discovery with regard to 1,2,3-triazole- containing molecules in a clear, concise way so as to make the present review a useful tool for researchers.

METHODS

Available information present on the role of 1,2,3-triazoles in cancer treatment was collected. Data was collected from scientific literature, as well as from patents.

RESULTS

A vast number of triazole-containing molecules with antiproliferative properties have been proposed, synthesized and tested for anticancer activity both in vitro and in vivo. The substances vary greatly when considering molecular structure, proposed mechanisms of action and affected cancer cell types.

CONCLUSION

Triazole-containing molecules with anticancer activity are being widely synthesized and extensively tested. They vary significantly in terms of both structure and mechanism of action. The methods for their preparation and administration are well established and with proven reproducibility. These facts suggest that triazoles may play an important role in the discovery of novel antiproliferative medications with improved effectiveness and safety profile.

Selective inhibition of Helicobacter pylori methionine aminopeptidase by azaindole hydroxamic acid derivatives: Design, synthesis, in vitro biochemical and structural studies

Methionine aminopeptidases (MetAPs) are an important class of enzymes that work co-translationally for the removal of initiator methionine. Chemical inhibition or gene knockdown is lethal to the microbes suggesting that they can be used as antibiotic targets. However, sequence and structural similarity between the microbial and host MetAPs has been a challenge in the identification of selective inhibitors. In this study, we have analyzed several thousands of MetAP sequences and established a pattern of variation in the S1 pocket of the enzyme. Based on this knowledge, we have designed a library of 17 azaindole based hydroxamic acid derivatives which selectively inhibited the MetAP from H. pylori compared to the human counterpart. Structural studies provided the molecular basis for the selectivity.

Intercepting the Banert cascade with nucleophilic fluorine: direct access to α-fluorinated NH-1,2,3-triazoles

The treatment of propargylic azides with silver(i) fluoride in acetonitrile was found to yield α-fluorinated NH-1,2,3-triazoles via the Banert cascade. The reaction was regioselective and the products result from an initial [3,3] rearrangement. The reaction is demonstrated on >15 examples with yields ranging from 37% to 86%.

Synthesis, Anticancer Activity on Prostate Cancer Cell Lines and Molecular Modeling Studies of Flurbiprofen-Thioether Derivatives as Potential Target of MetAP (Type II)

BACKGROUND

Prostate cancer is still one of the serious causes of mortality and morbidity in men. Despite recent advances in anticancer therapy, there is a still need of novel agents with more efficacy and specificity in the treatment of prostate cancer. Because of its function on angiogenesis and overexpression in the prostate cancer, methionine aminopeptidase-2 (MetAP-2) has been a potential target for novel drug design recently.

OBJECTIVE

A novel series of Flurbiprofen derivatives N-(substituted)-2-(2-(2-fluoro-[1,1'- biphenyl]-4-il)propanoyl)hydrazinocarbothioamide (3a-c), 4-substituted-3-(1-(2-fluoro-[1,1'-biphenyl]- 4-yl)ethyl)-1H-1,2,4-triazole-5(4H)-thione (4a-d), 3-(substitutedthio)-4-(substituted-phenyl)- 5-(1-(2-fluoro-[1,1'-biphenyl]-4-yl)ethyl)-4H-1,2,4-triazole (5a-y) were synthesized. The purpose of the research was to evaluate these derivatives against MetAP-2 in vitro and in silico to obtain novel specific and effective anticancer agents against prostate cancer.

METHODS

The chemical structures and purities of the compounds were defined by spectral methods (1H-NMR, 13C-NMR, HR-MS and FT-IR) and elemental analysis. Anticancer activities of the compounds were evaluated in vitro by using MTS method against PC-3 and DU-143 (androgenindependent human prostate cancer cell lines) and LNCaP (androgen-sensitive human prostate adenocarcinoma) prostate cancer cell lines. Cisplatin was used as a positive sensitivity reference standard.

RESULTS

Compounds 5b and 5u; 3c, 5b and 5y; 4d and 5o showed the most potent biological activity against PC3 cancer cell line (IC50= 27.1 μM, and 5.12 μM, respectively), DU-145 cancer cell line (IC50= 11.55 μM, 6.9 μM and 9.54 μM, respectively) and LNCaP cancer cell line (IC50= 11.45 μM and 26.91 μM, respectively). Some compounds were evaluated for their apoptotic caspases protein expression (EGFR/PI3K/AKT pathway) by Western blot analysis in androgen independent- PC3 cells. BAX, caspase 9, caspsase 3 and anti-apoptotic BcL-2 mRNA levels of some compounds were also investigated. In addition, molecular modeling studies of the compounds on MetAP-2 enzyme active site were evaluated in order to get insight into binding mode and energy.

CONCLUSION

A series of Flurbiprofen-thioether derivatives were synthesized. This study presented that some of the synthesized compounds have remarkable anticancer and apoptotic activities against prostate cancer cells. Also, molecular modeling studies exhibited that there is a correlation between molecular modeling and anticancer activity results.

Quantum mechanical investigations of base-catalyzed cycloaddition reaction between phenylacetylene and azidobenzene

In this study, the mechanism for both the Huisgen 1,3-dipolar cycloaddition and the base-catalyzed cycloaddition reactions between phenylacetylene and azidobenzene has been investigated with density functional theory, namely at the M06-2X/6-31G(d) computational level. Later, the reaction has been modeled with a representative simple alkyne and a simple azide to concentrate solely on how the difference bases affect the mechanism of the reaction between phenylacetylene and azidobenzene as charged components. In this study, another mechanism of this reaction with uncharged components has been proposed to compare the calculated thermodynamic and kinetic properties for charged and uncharged systems. The calculated activation barrier differences between the catalyzed and the uncatalyzed reactions are consistent with the faster and the regioselective synthesis of the triazole product in the presence of solvents. The calculated barrier of the rate-determining step in the base-catalyzed mechanism with the uncharged system is lower than that with charged systems. Finally, the reaction leading to final product formation in uncharged system is more spontaneous than that in the charged system, and the same applies to the total reaction in the presence of solvents.

Silver Mediated Banert Cascade with Carbon Nucleophiles

The Banert cascade of propargylic azides can be promoted by simple silver salts, and the triazafulvene intermediate can be intercepted by carbon nucleophiles. Various indoles (>25 examples, up to 92% yield) and electron-rich heterocycles were effective. The Mayr nucleophilicity parameter (N) was found to correlate to the reaction efficiency, which enabled the formation of C_sp³-C_sp² and C_sp³-C_sp³ bonds under otherwise identical conditions from structurally dissimilar nucleophiles.

Potential inhibitors of methionine aminopeptidase type II identified via structure-based pharmacophore modeling

Methionine aminopeptidase (MetAP2) is a metal-containing enzyme that removes initiator methionine from the N-terminus of a newly synthesized protein. Inhibition of the enzyme is crucial in diminishing cancer growth and metastasis. Fumagillin-a natural irreversible inhibitor of MetAP2-and its derivatives are used as potent MetAP2 inhibitors. However, because of their adverse effects, none of them has progressed to clinical studies. In search for potential reversible inhibitors, we built structure-based pharmacophore models using the crystal structure of MetAP2 complexed with fumagillin (PDB ID: 1BOA). The pharmacophore models were validated using Gunner-Henry scoring method. The best pharmacophore consisting of 1 H-bond donor, 1 H-bond acceptor, and 3 hydrophobic features was used to conduct pharmacophore-based virtual screening of ZINC15 database against MetAP2. The top 10 compounds with pharmacophore fit values > 3.00 were selected for further analysis. These compounds were subjected to absorption, distribution, metabolism, elimination, and toxicity (ADMET) prediction and found to have druglike properties. Furthermore, molecular docking calculations was performed on these hits using AutoDock4 to predict their binding mode and binding energy. Three diverse compounds: ZINC000014903160, ZINC000040174591, and ZINC000409110720 with respective binding energy/docking scores of - 9.22, - 9.21, and -817 kcal/mol, were submitted to 100 ns (MD) simulations using Nanoscale MD (NAMD) software. The compounds showed stable binding mode over time. Therefore, they may serve as a scaffold for further computational and experimental optimization toward the design of more potent and safer MetAP2 inhibitors.

Synthesis of 1,4-Biphenyl-triazole Derivatives as Possible 17β-HSD1 Inhibitors: An in Silico Study

Triazoles occupy an important position in medicinal chemistry because of their various biological activities. The structural features of 1,2,3-triazoles enable them to act as a bioisostere of different functional groups such as amide, ester, carboxylic acid, and heterocycle, being capable of forming hydrogen bonds and π-π interactions or coordinate metal ions with biological targets. In this work, the synthesis of 1,2,3-triazole derivatives via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is reported. Overexpression of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) is often found in breast cancer cells. Molecular similarity and docking analysis were used to evaluate the potential inhibitory activity of 1,2,3-triazoles synthesized over 17β-HSD1 for the treatment of mammary tumors. Our in silico analysis shows that compounds 4c, 4d, 4f, 4g, and 4j are good molecular scaffold candidates as 17β-HSD1 inhibitors.

Organocatalytic enone-azide [3 + 2]-cycloaddition: synthesis of functionally rich C/N-double vinyl 1,2,3-triazoles

An enolate-mediated organocatalytic [3 + 2]-cycloaddition of enones with less reactive vinyl/alkyl/aryl azides is reported at room temperature for short reaction times. The metal-free amine-mediated catalytic conditions of this [3 + 2]-cycloaddition allowed us to synthesize a collection of C/N-double vinyl-1,2,3-triazoles and C-vinyl-1,2,3-triazoles through functionalized enones as quality azidophiles with various azides. It is an efficient catalytic [3 + 2]-cycloaddition for the synthesis of biologically important fully decorated C/N-double vinyl-1,2,3-triazoles with excellent outcomes with reference to the reaction rate, selectivity, operation simplicity, substrate scope, yields, and synthetic applications as demonstrated in the paper. Herein, we illustrated the importance of enolate reactivity with azides compared to enamines by correlation with previous enamine-mediated click reactions in the reaction mechanism section.

Bimetallic Cu/Pd-catalyzed three-component azide-alkyne cycloaddition/isocyanide insertion: synthesis of fully decorated tricyclic triazoles

The construction of fully decorated 1,2,3-triazole-fused 5-, 6- and 7-membered rings has been disclosed via a bimetallic relay-catalyzed cascade process combining azide-alkyne cycloaddition, C(sp2)-H functionalization of intermediary 1,2,3-triazoles and isocyanide insertion. The salient features of this methodology include simple starting materials, reduced synthetic steps, good substrate scope and high efficiency.

Metal-Free Cascade [4 + 1] Cyclization Access to 4-Aryl-NH-1,2,3-triazoles from N-Tosylhydrazones and Sodium Azide

A molecular iodine-mediated coupling cyclization reaction for the synthesis of 4-aryl-NH-1,2,3-triazoles has been developed from N-tosylhydrazones and sodium azide. This metal-free cascade [4 + 1] cyclization reaction could rapidly synthesize valuable compounds via a sequential C-N and N-N bond formation. Mechanistic studies demostrate that the nitrogen atoms of the 1,2,3-triazoles are not entirely from sodium azide.

An Efficient Approach to Phosphorylated Isoindoline Fused with Triazoles via Zn-Catalyzed Cascade Cyclization of 2-Propynol Benzyl Azides and Diarylphosphine Oxides

An efficient approach for the synthesis of phosphorylated isoindoline fused with triazoles via Zn(OTf)₂-catalyzed cascade cyclization of easily prepared ortho-propynol benzyl azides and diarylphosphine oxides is developed. The transformation occurred smoothly in moderate to excellent yields and tolerated various propargylic alcohol substrates.

Synthesis of Tris-Heterocycles via a Cascade IMCR/Aza Diels-Alder + CuAAC Strategy

6-Triazolylmethyl-pyrrolo[3,4-b]pyridin-5-one tris-heterocycles were synthesized in 43-57% overall yields. The two-stage synthesis involved a cascade process (Ugi-3CR/aza Diels-Alder/N-acylation/aromatization) followed by a copper-assisted alkyne-azide [3+2] cycloaddition (CuAAC). This efficient and convergent strategy proceeded via complex terminal alkynes functionalized with a fused bis-heterocycle at the α-position. The final products are ideal candidates for SAR studies as they possess two privileged scaffolds in medicinal chemistry: 4-substituted or 1,4-substituted 1H-1,2,3-triazoles and pyrrolo[3,4-b]pyridin-5-ones.

Evaluation of the in vitro and in vivo antileishmanial activity of a chloroquinolin derivative against Leishmania species capable of causing tegumentary and visceral leishmaniasis

The treatment against leishmaniasis presents problems, since the currently used drugs are toxic and/or have high costs. In addition, parasite resistance has increased. As a consequence, in this study, a chloroquinolin derivative, namely 7-chloro-N,N-dimethylquinolin-4-amine or GF1059, was in vitro and in vivo tested against Leishmania parasites. Experiments were performed to evaluate in vitro antileishmanial activity and cytotoxicity, as well as the treatment of infected macrophages and the inhibition of infection using pre-treated parasites. This study also investigated the GF1059 mechanism of action in L. amazonensis. Results showed that the compound was highly effective against L. infantum and L. amazonensis, presenting a selectivity index of 154.6 and 86.4, respectively, against promastigotes and of 137.6 and 74.3, respectively, against amastigotes. GF1059 was also effective in the treatment of infected macrophages and inhibited the infection of these cells when parasites were pre-incubated with it. The molecule also induced changes in the parasites' mitochondrial membrane potential and cell integrity, and caused an increase in the reactive oxygen species production in L. amazonensis. Experiments performed in BALB/c mice, which had been previously infected with L. amazonensis promastigotes, and thus treated with GF1059, showed that these animals presented significant reductions in the parasite load when the infected tissue, spleen, liver, and draining lymph node were evaluated. GF1059-treated mice presented both lower parasitism and low levels of enzymatic markers, as compared to those receiving amphotericin B, which was used as control. In conclusion, data suggested that GF1059 can be considered a possible therapeutic target to be tested against leishmaniasis.

Targeting Metalloenzymes for Therapeutic Intervention

Metalloenzymes are central to a wide range of essential biological activities, including nucleic acid modification, protein degradation, and many others. The role of metalloenzymes in these processes also makes them central for the progression of many diseases and, as such, makes metalloenzymes attractive targets for therapeutic intervention. Increasing awareness of the role metalloenzymes play in disease and their importance as a class of targets has amplified interest in the development of new strategies to develop inhibitors and ultimately useful drugs. In this Review, we provide a broad overview of several drug discovery efforts focused on metalloenzymes and attempt to map out the current landscape of high-value metalloenzyme targets.

Reaction engineering and photophysical studies of fully enriched C-vinyl-1,2,3-triazoles

A library of fluorogenic C-vinyl-1,2,3-triazoles were synthesized in very good yields with excellent selectivity by using an organocatalytic formal [3 + 2]-cycloaddition. One of the coumarin-triazoles 4ba has shown excellent fluorescence properties (λ_em = 533 nm).

Regioselective Synthesis of N2-Alkylated-1,2,3 Triazoles and N1-Alkylated Benzotriazoles: Cu2S as a Recyclable Nanocatalyst for Oxidative Amination of N, N-Dimethylbenzylamines

Copper chalcogenide nanoparticles (Cu₂S) synthesized for the first time from a single-source precursor, CuSPh, act as highly efficient and reusable heterogeneous catalyst for regioselective amination of N, N-dimethylbenzylamines with various azoles. The reaction involves N-H/C-H cross-dehydrogenative coupling (CDC) and demonstrates wide functional group tolerance. It provides highly selective access to N¹-alkylated benzotriazoles, N²-alkylated 1,2,3-triazoles and 4-phenyl-1,2,3-triazoles, and N-alkylated carbazoles in 70-89% yields under solvent-free conditions. The Cu₂S nanocatalyst has been characterized by PXRD, XPS, SEM-EDX, and HR-TEM analysis. Mechanistic studies suggest that the reaction follows a radical pathway and involves an iminium ion intermediate.

Novel 1,2,3‐Triazole‐Functionalized 1,2‐Benzothiazine 1,1‐Dioxide Derivatives: Regioselective Synthesis, Biological Evaluation and Docking Studies

A series of novel 1,2‐benzothiazine‐1,1‐dioxide derivatives (Z)‐3‐hydroxy‐1‐(4‐hydroxy‐2‐methyl‐1,1‐dioxido‐2H‐benzo[e][1, 2]thiazin‐3‐yl)‐3‐phenyl substituted prop‐2‐en‐1‐one (6 a‐d) were synthesized starting from sodium salt of saccharin 1 in series of steps via 3‐acetyl‐2‐methyl‐1,1‐dioxido‐2H‐benzo[e][1, 2]thiazin‐4‐yl substituted benzoates (5 a‐d). Compound 6 e was obtained alternately from 1‐(4‐Hydroxy‐2‐methyl‐1,1‐dioxo‐1,2‐dihydro‐1λ6‐benzo[e][1, 2]thiazin‐3‐yl)‐ethanone (4). Compounds 6 a‐e were further reacted with aromatic azides to form (4‐hydroxy‐2‐methyl‐1,1‐dioxido‐2H‐benzo[e][1, 2]thiazin‐3‐yl)(1‐substitutedphenyl)‐5‐ substituted pheny or methyl‐1H‐1,2,3‐triazol‐4‐yl)methanone derivatives (7 a‐o) by regioselective cyclization. All the compounds were evaluated for anti‐inflammatory and anti‐cancer activities. Compounds 5 a‐b, 6 a‐b, 7 a, 7 c‐d, 7 i and 7 k‐l which showed significant anti‐inflammatory activity at micro molar concentration have been identified. Also screened for cytotoxic activity against four human cancer cells and one normal cell such as prostate cancer (PC‐3), breast adenocarcinoma (MDA‐MB‐231), liver hepatocellular carcinoma (Hep G2), cervical cancer (HeLa) and normal umbilical vein endothelial cell (HUVEC). Compounds 6 a, 7 g, 7 h and 7 k have been identified as promising candidates. Further, anti‐inflammatory activity is also validated by docking studies and compounds 5 a, 5 b and 7 d found to show good interactions when docked with IL‐1β signaling complex.