1-Phenyl-1H- and 2-phenyl-2H-1,2,3-triazol derivatives: design, synthesis and inhibitory effect on alpha-glycosidases

Kinetics and molecular modeling studies on the inhibition mechanism of GH13 α-glycosidases by small molecule ligands

Alpha-glucosidase inhibitors play an important role in Diabetes Mellitus (DM) treatment since they prevent postprandial hyperglycemia. The Glycoside Hydrolase family 13 (GH13) is the major family of enzymes acting on substrates containing α-glucoside linkages, such as maltose and amylose/amylopectin chains in starch. Previously, our group identified glycoconjugate 1H-1,2,3-triazoles (GCTs) inhibiting two GH13 α-glycosidases: yeast maltase (MAL12) and porcine pancreatic amylase (PPA). Here, we combined kinetic studies and computational methods on nine GCTs to characterize their inhibitory mechanism. They all behaved as reversible inhibitors, and kinetic models encompassed noncompetitive and various mechanisms of mixed-type inhibition for both enzymes. Most potent inhibitors displayed Ki values of 30 μM for MAL12 (GPESB16) and 37 μM for PPA (GPESB15). Molecular dynamics and docking simulations indicated that on MAL12, GPESB15 and GPESB16 bind in a cavity adjacent to the active site, while on the PPA, GPESB15 was predicted to bind at the entrance of the catalytic site. Notably, despite its putative location within the active site, the binding of GPESB15 does not obstruct the substrate's access to the cleavage site. Our study contributes to paving the way for developing novel therapeutic strategies for managing DM-2 through GH13 α-glycosidases inhibition.

Steroid-triazole conjugates: A brief overview of synthesis and their application as anticancer agents

Steroids are biomolecules that play pivotal roles in various physiological and drug discovery processes. Abundant research has been fuelled towards steroid-heterocycles conjugates over the last few decades as potential therapeutic agents against various diseases especially as anticancer agents. In this context various steroid-triazole conjugates have been synthesized and studied for their anticancer potential against various cancer cell lines. A thorough search of the literatures revealed that a concise review pertaining the present topic is not compiled. Therefore, in thus review we summarize the synthesis, anticancer activity against various cancer cell lines and structure activity relationship (SAR) of various steroid-triazole conjugates. This review can lay down the path towards the development of various steroid-heterocycles conjugates with lesser side effects and profound efficacy.

Synthesis and evaluation of triazole congeners of nitro-benzothiazinones potentially active against drug resistant Mycobacterium tuberculosis demonstrating bactericidal efficacy

With growing concerns regarding target residue mutation hovering over established anti-TB pharmacophores, it is imperative to have reserve chemotypes at our disposal to curb unrestrained spread of tuberculosis. In this context, we herein present the synthesis and bio-evaluation of a library of new nitrobenzothiazinone (BTZ) congeners comprising 2-mercapto/amino-benzothiazinone tethered 1,2,3-triazole hybrids as antitubercular agents. In preliminary screening, 10 out of 37 compounds displayed substantial in vitro potency against Mtb H37Rv (MIC 0.5-8 μg mL^-1). Structural optimization of the initial hit 5o (MIC 0.5 μg mL^-1) led to identification of linker variants 9a, 9b, 9c, and 9d exhibiting potent anti-TB activity (MIC 0.03-0.12 μg mL^-1). When tested against Vero cells to determine their selectivity index (SI), these compounds displayed no appreciable cytotoxicity (SI >80). Further studies on activity against drug resistant (DR) Mtb indicated these compounds to be equally potent (MIC 0.03-0.25 μg mL^-1). The in silico covalent docking study suggested a similar polar interaction to that of PBTZ169 with an additional and contrasting side chain interaction at the active site of Mtb DprE1 target protein. Further, the time kill kinetic study found compounds 9a and 9d to be demonstrating bactericidal efficacy, completely eliminating bacilli in 7 days at 10× MIC. The most promising compound 9d, considering its potent anti-TB activity (MIC 0.06 μg mL^-1 against drug susceptible Mtb and MIC 0.06-0.25 μg mL^-1 against DR Mtb) along with a broad therapeutic index (SI >640) demonstrating a comparable concentration dependent bactericidal efficacy to that of RIF, holds a significant edge to be translated into a potent anti-Mtb agent.

1-(4-Nitrophenyl)-1H-1,2,3-Triazole-4-carbaldehyde: Scalable Synthesis and Its Use in the Preparation of 1-Alkyl-4-Formyl-1,2,3-triazoles

1,2,3-Triazole-4-carbaldehydes are useful synthetic intermediates which may play an important role in the discovery of novel applications of the 1,2,3-triazole moiety. In this work, a one-step multigram scale synthesis of 4-formyl-1-(4-nitrophenyl)-1H-1,2,3-triazole (FNPT) as a preferred reagent for the synthesis of 1-alkyl-4-formyltriazoles is described, making use of the commercially available 3-dimethylaminoacrolein and 4-nitrophenyl azide. Next, the earlier reported reaction of FNPT with alkylamines is further explored, and for hexylamine, the one-pot sequential cycloaddition and Cornforth rearrangement is demonstrated. In addition, a useful protocol for the in situ diazotization of 4-nitroaniline is provided. This facilitated the complete hydrolysis of rearranged 4-iminomethyl-1,2,3-triazoles and allowed for the recycling of 4-nitrophenyl azide.

From Glycals to Nitrogen Heterocycles and Carbocycles via "Cleavage-Intramolecular Recombination Strategy"

Glycals (carbohydrate enol-ethers) have enjoyed profound applications in organic synthesis for more than a century. They not only serve as versatile glycosyl donors or as substrates for Ferrier rearrangement, but also find extensive synthetic applications especially as a "chiral pool" for accomplishing the synthesis of a variety of natural and biologically important compounds. As cyclic enol ethers, they demonstrate high reactivity and are among the most and variously transformable monosaccharide derivatives. The uniqueness of the reactivity of glycals is that they can be synthetically tuned to get a library of derivatives through stereo- and regioselective introduction of a variety of functional groups at C1, C2, C3 as well as C4 carbons of the sugar. We have developed a practical approach for stereoselective mono- and diamination of glycals and over the years utilized these scaffolds for the synthesis of a variety of biologically important nitrogen heterocycles and carbocycles through a "Diversity Oriented Approach". Our synthetic strategy in this direction mainly relied on the cleavage of ring O-C bond of the sugar followed by an "intramolecular recombination" reaction. Utilizing this strategy, we have accomplished the synthesis of several biologically important natural products, their analogues and related unnatural derivatives. Examples of such compounds reported from our group include polyhydroxypyrrolidines, DMDP, anisomycin, steviamine, pochonicine, conduramines, bulgecinine, aminocyclitols, azepanes, 4-hydroxy-D-proline, azanucleosides and their analogues. A personal account highlighting these syntheses is presented here.

Structural optimization, synthesis and in vitro synergistic anticancer activities of combinations of new N3-substituted dihydropyrimidine calcium channel blockers with cisplatin and etoposide

T-type calcium channels are considered potential drug targets to combat cancer. Combining T-type calcium channel blockers with conventional chemotherapy drugs represents a promising strategy towards successful cancer treatment. From this perspective, we report in this study the design and synthesis of a novel series of N3-sustituted dihydropyrimidines (DHPMs) as anticancer adjuvants to cisplatin (Cis) and etoposide (Eto). Full spectral characterization of the new compounds was done using FT-IR, ¹H NMR, ¹³C NMR, and HRMS. Structure elucidation was confirmed by 2D NMR ¹H-H COSY, HSQC and NOESY experiments. Novel derivatives were tested for their Ca²⁺ channel blocking activity by employing the whole cell patch-clamp technique. Results demonstrated that most compounds were potential T-type calcium channel blockers with the triazole-based C12 and C13 being the most selective agents against Ca_V3.2 channel. Further electrophysiological studies demonstrated that C12 and C13 inhibited Ca_V3.2 currents with respective affinity of 2.26 and 1.27 µM, and induced 5 mV hyperpolarizing shifts in the half-inactivation potential. Subsequently, C12 and C13 were evaluated for their anticancer activities alone and in combination with Cis and Eto against A549 and MDA-MB 231 cancer cells. Interestingly, both compounds exhibited potential anticancer effects with IC₅₀ values < 5 µM. Combination studies revealed that both compounds had synergistic effects (combination index CI < 1) on Cis and Eto through induction of apoptosis (p53 activation and up-regulation of BAX and p21 gene expression). Importantly, in silico physicochemical and ADMET assessment of both compounds revealed their potential drug-like properties with decreased risk of cardiac toxicity. Hence, C12 and C13 are promising anticancer adjuvants through inhibition of Ca_V3.2 T-type calcium channels, thereby serving as eminent leads for further modification.

A Fine-Tuned Lipophilicity/Hydrophilicity Ratio Governs Antibacterial Potency and Selectivity of Bifurcated Halogen Bond-Forming NBTIs

Herein, we report the design of a focused library of novel bacterial topoisomerase inhibitors (NBTIs) based on innovative mainly monocyclic right-hand side fragments active against DNA gyrase and Topo IV. They exhibit a very potent and wide range of antibacterial activity, even against some of the most concerning hard-to-treat pathogens for which new antibacterials are urgently needed, as reported by the WHO and CDC. NBTIs enzyme activity and whole cell potency seems to depend on the fine-tuned lipophilicity/hydrophilicity ratio that governs the permeability of those compounds through the bacterial membranes. Lipophilicity of NBTIs is apparently optimal for passing through the membrane of Gram-positive bacteria, but the higher, although not excessive lipophilicity and suitable hydrophilicity seems to determine the passage through Gram-negative bacterial membranes. However, due to the considerable hERG inhibition, which is still at least two orders of magnitude away from MICs, continued optimization is required to realize their full potential.

Triazole analogues as potential pharmacological agents: a brief review

Background

A large number of studies have recently reported that, because of their significant biological and pharmacological properties, heterocyclic compounds and their derivatives have attracted a strong interest in medicinal chemistry. The triazole nucleus is one of the most important heterocycles which has a feature of natural products as well as medicinal agents. Heterocyclic nitrogen is abundantly present in most medicinal compounds. The derivatization of triazole ring is based on the phenomenon of bio-isosteres in which substituted the oxygen atom of oxadiazole nucleus with nitrogen triazole analogue.

Main text

This review focuses on recent synthetic procedure of triazole moiety, which comprises of various pharmacological activities such as antimicrobial, anticonvulsant, anti-inflammatory, analgesic, antitubercular, anthelmintic, antioxidant, antimalarial, antiviral, etc..

Conclusion

This review highlights the current status of triazole compounds as different multi-target pharmacological activities. From the literature survey, triazole is the most widely used compound in different potential activities.

Biological Evaluation of Selected 1,2,3-triazole Derivatives as Antibacterial and Antibiofilm Agents

BACKGROUND

Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses.

METHODS

Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05).

RESULTS

Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound.

CONCLUSION

Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

Bioactive 1,2,3-Triazoles: An Account on their Synthesis, Structural Diversity and Biological Applications

The triazole heterocycle is a privileged scaffold in medicinal chemistry, since its structure is present in a large number of biologically active molecules, including several drugs currently in the market. Due to their vast applications, a wide variety of methods are described for their preparation, such as the 1,3-dipolar cycloaddition and processes involving diazo compounds and diazo transfer reactions. Considering the significant number of contributions from our research group to this chemistry in recent decades, in this account we discuss both the development of new methods for the synthesis of 1,2,3-triazoles and the preparation of new triazole-functionalized biologically active molecules using classical approaches.

Plasmodium falciparum Knockout for the GPCR-Like PfSR25 Receptor Displays Greater Susceptibility to 1,2,3-Triazole Compounds That Block Malaria Parasite Development

The search for new compounds with antimalarial activity is urgent, as resistance to ones in the classical drug, has already been described in more than one continent. Compounds derived from 1,2,3-triazoles are effective against parasites and bacteria. Here, we evaluated the potential antimalarial activity against the human malaria parasite Plasmodium falciparum in a culture of fifty-four triazole compounds derived from 1H-and 2H-1,2,3-triazole. We identified thirty-one compounds with potential antimalarial activity at concentrations in the micromolar order (µM) and IC₅₀ values ranging from 2.80 µM (9) to 29.27 µM (21). Then, we selected some of these compounds to perform the same tests on the PfSR25- strain (knockout for P. falciparum G-protein coupled receptor-like, SR25). Our experiences with the PfSR25- strain showed that both compounds with higher antimalarial activity for the 3D7 strain and those with less activity resulted in lower IC₅₀ values for the knockout strain. The cytotoxicity of the compounds was evaluated in human renal embryonic cells (HEK 293), using MTT assays. This demonstrated that the compounds with the highest activity (9, 13, 19, 22, 24, 29), showed no toxicity at the tested concentrations.

Hybrid molecules based on fullerene C60 and 5Z,9Z-dienoic acids: Synthesis and cytotoxic activity

The present research project details synthesis of new hybrid methanofullerenes based on acetylene and triazole esters of malonic acid containing 5Z,9Z-dienoic acids and fullerene C₆₀ under Bingel-Hirsch conditions, including study of the cytotoxic activity with respect to Jurkat, K562, U937 and HL60 tumor cell lines. Hybrid methanofullerenes containing acetylenic fragments, unlike triazole substituents, were found to exhibit higher cytotoxicity, but are characterized by lower selectivity of action in relation to healthy cells.

Synthesis and screening of (E)-3-(2-benzylidenehydrazinyl)-5,6-diphenyl-1,2,4-triazine analogs as novel dual inhibitors of α-amylase and α-glucosidase

(E)-3-(2-Benzylidenehydrazinyl)-5,6-diphenyl-1,2,4-triazines analogs 1-27 were synthesized by multi-step reaction scheme and subjected to in vitro inhibitory screening against α-amylase and α-glucosidase enzymes. Out of these twenty-seven synthetic analogs, ten compounds 14-17, 19, and 21-25 are structurally new. All compounds exhibited good to moderate inhibitory potential in terms of IC₅₀ values ranging (IC₅₀ = 13.02 ± 0.04-46.90 ± 0.05 µM) and (IC₅₀ = 13.09 ± 0.08-46.44 ± 0.24 µM) in comparison to standard acarbose (IC₅₀ = 12.94 ± 0.27 µM and 10.95 ± 0.08 µM), for α-amylase and α-glucosidase, respectively. Structure-activity relationship indicated that analogs with halogen substitution(s) were found more active as compared to compounds bearing other substituents. Kinetic studies on most active α-amylase and α-glucosidase inhibitors 5, 7, 9, 15, 24, and 27, suggested non-competitive and competitive types of inhibition mechanism for α-amylase and α-glucosidase, respectively. Molecular docking studies predicted the good protein-ligand interaction (PLI) profile with key interactions such as arene-arene, H-<, <-<, and <-H etc., against the corresponding targets.

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.

Hypoglycaemic activity of Bauhinia holophylla through GSK3-β inhibition and glycogenesis activation

CONTEXT

Bauhinia L. species, including Bauhinia holophylla (Bong.) Steud. (Fabaceae), have traditionally been used to treat diabetes. Bauhinia is a complex botanical genus, and the indiscriminate use of the diverse Bauhinia species is reflected in the experimental divergence of their medicinal potential.

OBJECTIVE

The hypoglycaemic and hypolipidaemic effects, molecular mechanism of action and phytochemical properties of an authentic extract of B. holophylla leaves were evaluated.

MATERIALS AND METHODS

A phytochemical study of a 70% EtOH extract was performed using FIA-ESI-IT-MS/MSn and HPLC-PAD-ESI-IT-MS. The extract (200 or 400 mg/kg b.w.) was administered for 14 days to streptozotocin-induced diabetic Swiss mice. Glucose tolerance and insulin sensitivity, blood parameters, gene and protein expression, and the in vivo and in vitro inhibition of intestinal glucosidases were assessed.

RESULTS

HPLC-PAD-ESI-IT-MS analysis identified flavonoid derivatives of quercetin, myricetin, luteolin and kaempferol. Treatment with 400 mg/kg of the extract reduced blood glucose (269.0 ± 32.4 mg/dL vs. 468.0 ± 32.2 mg/dL for diabetic animals), improved glucose tolerance, decreased cholesterol and triglyceride levels, and increased the mRNA expression of proteins involved in glucogenesis in the liver and muscle, such as PI3-K/Akt, GS, GSK3-β (ser-9), AMPK and Glut4. The activity of intestinal maltase was inhibited in vitro (IC50: 43.0 µg/mL for the extract compared to 516.4 µg/mL for acarbose) and in vivo.

DISCUSSION AND CONCLUSIONS

Treatment with B. holophylla was associated with a marked hypoglycaemic effect through the stimulation of glycogenesis and inhibition of gluconeogenesis and intestinal glucose absorption, without increasing basal insulinaemia.

Design, Synthesis and Antiplasmodial Evaluation of Sulfoximine-triazole Hybrids as Potential Antimalarial Prototypes

Background:

Malaria, caused by the deadly Plasmodium falciparum strain, claims the lives of millions of people annually. The emergence of drug-resistant strains of P. falciparum to the artemisinin-based combination therapy (ACT), the last line of defense against malaria, is worrisome and urges for the development of new chemo-types with a new mode of action. In the search of new antimalarial agents, hybrids of triazoles and other known antimalarial drugs have been reported to possess better activity than either of the parent compounds administered individually. Despite their better activity, no hybrid antimalarial drugs have been developed so far.

Objective:

In the hope of developing new antimalarial prototypes, we propose the design, synthesis and antimalarial evaluation of novel sulfoximine-triazole hybrids owing to their interesting biological and physiological properties.

Methods:

The sulfoximine part of the hybrid will be synthesized via imidation of the corresponding sulfoxide. Propargylation of the NH moiety of the sulfoximine followed by copper-catalyzed click chemistry with benzyl azide was envisaged to provide the target sulfoximine-triazole hybrids.

Results:

Five novel sulfoximine-triazole hybrids possessing various substituents on the sulfoximine moiety have been successfully synthesized and evaluated for their antiplasmodial and cytotoxicity activities. The results revealed that the co-presence of the sulfoximine and triazole moieties along with a lipophilic alkyl substituent on the sulfur atom impart significant activity.

Conclusion:

Sulfoximine-triazole hybrids could be used as a prototype for the synthesis of new derivatives with better antiplasmodial activities.

Strategies Towards the Synthesis of N2-Substituted 1,2,3-Triazoles

The chemistry of 1,2,3-triazoles gained much attention since the discovery of the copper catalyzed Alkyne-azide cycloaddition (CuAAC) reaction which delivers exclusively the 1,4-regioisomer in high yields. On the other hand there is still no universal methodology capable of delivering the N2 substituted regioisomer. The unique properties of these N2-substituted 1,2,3-triazoles have stimulated synthetic efforts on the developments of methodologies capable of delivering it in high yield and selectivity. These efforts are the subject of the presented review.

Design, synthesis and glycosidase inhibition studies of novel triazole fused iminocyclitol-δ-lactams

Synthesis of novel triazole fused iminocyclitol-δ-lactams, from tri-O-benzyl-d-glucal, involving intermolecular [3 + 2]cycloaddition and intramolecular lactamisation reactions as key steps is described.

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).

Design and Synthesis of Novel Dehydroepiandrosterone Analogues as Potent Antiproliferative Agents

The aim of the present study was to determine the cytotoxic effects of a series of novel dehydroepiandrosterone derivatives containing triazole at the C₁₆ position on human cancer cells. The cancer cells used in the present study were A549, Hela, HepG-2, BEL7402, MCF-7, and HCT116. Several of the synthesised compounds exhibited potent antiproliferative effects. The most promising compound was (E)-3-hydroxy-16-((1-(4-iodophenyl)-1H-1,2,3-triazole-4-yl)methylene)-10,13-dimet-hyl-1,3,4,7,8,9,10,11,12,13,15,16-dodecahydro-2H-cyclopenta[a]phenanthren-17(14)-one (compound 2n), which showed considerably high antiproliferative activity in the HepG-2 cell line, with an IC₅₀ value of 9.10 µM, and considerably high activity against the MCF-7 cell line, with an IC₅₀ value of 9.18 µM. Flow cytometry assays demonstrated that compound 2n exerted antiproliferative effects by arresting cells in the G2 phase of the cell cycle and inducing apoptosis.

Searching for new drugs for Chagas diseases: triazole analogs display high in vitro activity against Trypanosoma cruzi and low toxicity toward mammalian cells

Chagas disease is one of the most relevant endemic diseases in Latin America caused by the flagellate protozoan Trypanosoma cruzi. Nifurtimox and benzonidazole are the drugs used in the treatment of this disease, but they commonly are toxic and present severe side effects. New effective molecules, without collateral effects, has promoted the investigation to develop new lead compounds with to advance for clinical trials. Previously, 3-nitro-1H-1,2,4-triazole-based amines and 1,2,3-triazoles demonstrated significant trypanocidal activity against T. cruzi. In this paper, we synthesized a new series of 92 examples of 1,2,3-triazoles. Six compounds exhibited antiparasitic activity, 14, 25, 27, 31 and 40, 43 and were effective against epimastigotes of two strains of T. cruzi (Y and Dm28-C) and 25, 27 and 31 exhibited trypanocidal activity similar to benzonidazole. Notably, the compound 25 compared to benzonidazole increase the toxicity against T. cruzi, with no apparent toxicity to the cell line of mice macrophages or primary mice peritoneal macrophages. As results, we calculated selectivity indexes up to 2000 to 25 and 31 in both T. cruzi strains. Derivative 14 caused a trypanostatic effect because it did not damage external epimastigote membrane. Triazoles 40 and 43 impaired parasites viability using a pathway not dependent on ROS production.

Iminosugars Spiro-Linked with Morpholine-Fused 1,2,3-Triazole: Synthesis, Conformational Analysis, Glycosidase Inhibitory Activity, Antifungal Assay, and Docking Studies

Synthesis of iminosugars 1, 2, 3a, and 4a and N-alkyl (ethyl, butyl, hexyl, octyl, decyl, and dodecyl) derivatives 3b-g and 4b-g spiro-linked with morpholine-fused 1,2,3-triazole is described. Conformation of the piperidine ring in each spiro-iminosugar was evaluated by ¹H NMR spectroscopy, and conformational change in N-alkylated compounds 4b-g with respect to parent spiro-iminosugar 4a is supported by density functional theory calculations. Out of 16 new spiro-iminosugars, the spiro-iminosugars 3a (IC₅₀ = 0.075 μM) and 4a (IC₅₀ = 0.036 μM) were found to be more potent inhibitors of α-glucosidase than the marketed drug miglitol (IC₅₀ = 0.100 μM). In addition, 3a (minimum inhibition concentration (MIC) = 0.85 μM) and 4a (MIC = 0.025 μM) showed more potent antifungal activity against Candida albicans than antifungal drug amphotericin b (MIC = 1.25 μM). In few cases, the N-alkyl derivatives showed increase of α-glucosidase inhibition and enhancement of antifungal activity compare to the respective parent iminosugar. The biological activities were further substantiated by molecular docking studies.

Tandem synthesis of 1-formyl-1,2,3-triazoles

A tandem method for preparing 4-formyl-1,2,3-triazoles via a two-step one-pot acetal cleavage/CuAAC reaction was developed. Using this method, 4-formyl-1,2,3-triazole analogs with both electron-withdrawing and electron-donating substituents were prepared in good yield and purity. Expansion of this method to a three-step tandem reaction that incorporates an additional step of azide substitution was also successful, circumventing the need for organic azide isolation. This one-pot method, noteworthy in its simplicity and mild conditions, utilizes practical, readily available reactants and relies on protic solvent to promote acid-catalyzed acetal cleavage.

Synthesis and biological evaluation of novel 1,2,3-triazole derivatives as anti-tubercular agents

A library of seventeen novel 1,2,3-triazole derivatives were efficiently synthesized in excellent yields by the popular 'click chemistry' approach and evaluated in vitro for their anti-tubercular activity against Mycobacterium tuberculosis H37Ra (ATCC 25177 strain). Among the series, six compounds exhibited significant activity with minimum inhibitory concentration (MIC) values ranging from 3.12 to 0.78μg/mL and along with no significant cytotoxicity against MBMDMQs (mouse bone marrow derived macrophages). Molecular docking of the target compounds into the active site of DprE1 (Decaprenylphosphoryl-β-d-ribose-2'-epimerase) enzyme revealed noteworthy information on the plausible binding interactions.

K. N, Kayarmar R, S. K. P, R MS. Design, synthesis and characterization of new 1,2,3-triazolyl pyrazole derivatives as potential antimicrobial agents via a Vilsmeier–Haack reaction approach

A new series of 1,2,3-triazolyl pyrazole derivatives were synthesisedviaa Vilsmeier–Haack reaction approach and screened for theirin vitroanti-bacterial, anti-fungal and anti-oxidant activities.

Investigation of cobalt(iii)-triazole systems as prototypes for hypoxia-activated drug delivery

A novel cobalt(iii)-triazole system was developed for hypoxia-activated drug delivery with an [O₂]-dependent reduction to cobalt(ii) followed by ligand dissociation.

Synthesis and antifungal activity of 1,2,3-triazole phenylhydrazone derivatives

A series of 1,2,3-triazole phenylhydrazone derivatives were designed and synthesized as antifungal agents. Their structures were determined based on (1)H-NMR spectroscopy, MS, elemental analysis and X-ray single-crystal diffraction. The antifungal activities were evaluated against four phytopathogenic fungi including Rhizoctonia solani, Sclerotinia sclerotiorum, Fusarium graminearum and Phytophthora capsici, by the mycelium growth inhibition method in vitro. Compound 5p exhibited significant anti-phytopathogenic activity, with the EC50 values of 0.18, 2.28, 1.01, and 1.85 μg mL(-1), respectively. In vivo testing demonstrated that 5p was effective in the control of rice sheath blight, rape sclerotinia rot and fusarium head blight. A 3D-QSAR model was built for a systematic SAR profile to explore more potent 1,2,3-triazole phenylhydrazone analogs as novel fungicides.