A Simple Work-Up-free, Solvent-free Approach to Novel Amino Acid Linked 1,4-Disubstituted 1,2,3-Triazoles as Potent Antituberculosis Agents

Pyrano[2,3-c]pyrazole fused spirooxindole-linked 1,2,3-triazoles as antioxidant agents: Exploring their utility in the development of antidiabetic drugs via inhibition of α-amylase and DPP4 activity

Environment-benign, multicomponent synthetic methodologies are vital in modern pharmaceutical research and facilitates multi-targeted drug development via synergistic approach. Herein, we reported green and efficient synthesis of pyrano[2,3-c]pyrazole fused spirooxindole linked 1,2,3-triazoles using a tea waste supported copper catalyst (TWCu). The synthetic approach involves a one-pot, five-component reaction using N-propargylated isatin, hydrazine hydrate, ethyl acetoacetate, malononitrile/ethyl cyanoacetate and aryl azides as model substrates. Mechanistically, the reaction was found to proceed via in situ pyrazolone formation followed by Knoevenagel condensation, azide alkyne cycloaddition and Michael's addition reactions. The molecules were developed using structure-based drug design. The primary goal is to identifying anti-oxidant molecules with potential ability to modulate α-amylase and DPP4 (dipeptidyl-peptidase 4) activity. The anti-oxidant analysis, as determined via DPPH, suggested that the synthesized compounds, A6 and A10 possessed excellent anti-oxidant potential compared to butylated hydroxytoluene (BHT). In contrast, compounds A3, A5, A8, A9, A13, A15, and A18 were found to possess comparable anti-oxidant potential. Among these, A3 and A13 possessed potential α-amylase inhibitory activity compared to the acarbose, and A3 further emerged as dual inhibitors of both DPP4 and α-amylase with anti-oxidant potential. The relationship of functionalities on their anti-oxidant and enzymatic inhibition was explored in context to their SAR that was further corroborated using in silico techniques and enzyme kinetics.

Microwave-induced one-pot synthesis of 3-imidazolyl indole clubbed 1,2,3-triazole hybrids as antiproliferative agents and density functional theory study

Herein, we outline a highly efficient PEG-4000-mediated one-pot three-component reaction for the synthesis of 3-imidazolyl indole clubbed 1,2,3-triazole derivatives (5a-r) at up to 96% yield as antiproliferative agents. This three-component protocol offers the advantages of an environmentally benign reaction, excellent yield, quick response time, and operational simplicity triggered by the copper catalyst under microwave irradiation. All the synthesized compounds were tested for antiproliferative activity against six human solid tumor cell lines, that is, A549 and SW1573 (nonsmall cell lung), HBL100 and T-47D (breast), HeLa (cervix), and WiDr (colon). Among them, six compounds, 5g-j, 5m, and 5p, demonstrated effective antiproliferative action with GI50 values under 10 μM. Furthermore, density functional theory (DFT) calculations were performed for all the synthesized molecules through geometry optimizations, frontier molecular orbital approach, and molecular electrostatic potential (MESP). The theoretical DFT calculation was performed using the DFT/B3LYP/6-31+G (d,p) basis set. Moreover, the biological reactivity of all the representative synthesized molecules was compared with the theoretically calculated quantum chemical descriptors and MESP 3D plots. We also investigated the drug-likeness characteristic and absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction. In general, our approach enables environmentally friendly access to 3-imidazolyl indole clubbed 1,2,3-triazole derivatives as prospective antiproliferative agents.

Recent advances in triazoles as tyrosinase inhibitors

The tyrosinase enzyme, which is widely found in microorganisms, animals and plants, has a significant position in melanogenesis, plays an important role in undesirable browning of fruits and vegetables, antibiotic resistance, skin pigment formation, sclerotization of cuticle, neurodegeneration, etc. Therefore, with the wide potential application fields of tyrosinase in food, agriculture, cosmetics and pharmaceutical industries, which has become the target enzyme for the development of therapeutic agents such as antibrowning, anticancer, antibacterial, skin whitening, insecticides, etc., a large number of synthetic tyrosinase inhibitors have been widely reported in recent years. The triazole ring, which has a broad spectrum of biological action, is of increasing interest in the synthesis of new tyrosinase inhibitors. In this review, tyrosinase inhibition effects, structure-activity relationships, enzyme inhibition kinetics and mechanisms of action of 1,2,3- or 1,2,4-triazole derivatives were investigated. The data gathered is anticipated to supply rational guidance and an influential strategy for the development of novel, potent and safe tyrosinase inhibitors for better practical application in the future.

Diversity-oriented synthesis of 1H-1,2,3-triazole tethered pyrazolo[5,1-b]quinazoline hybrids as antimicrobial agents

A straightforward and high yielding synthetic approach is employed to synthesize the novel 1H-1,2,3-triazole tethered pyrazolo[5,1-b]quinazoline hybrids 7(a-t) as new antimicrobial agents with two pharmacophore in the effective two step synthesis. The first step is the four component one-pot synthesis of highly functionalized pyrazolo[5,1-b]quinazolines 5(a-j) catalysed by TBAB, with the advantages of an environmentally benign reaction, high yielding, quick reaction time, and operational simplicity. In the subsequent stage, CuSO4/NaAsc system was employed to synthesize the 1H-1,2,3-triazole tethered pyrazolo[1,5-b]quinazoline hybrids as 1H-1,2,3-triazoles are the structures of great diversity and importance in diverse therapeutics containing numerous biological activities. The antimicrobial activity of all the synthesized hybrid compounds have been preliminary tested using the broth dilution technique against two gram-positive and two gram-negative bacterial strains as well as two fungal strains. In comparison to standard drugs, the majority of compounds exhibited good to moderate activity. Among the all the compounds, 7a (MIC 18.54 μM) against Pseudomonas aeruginosa, 7j (MIC 89.76 μM) against Bacillus subtilis as well as Rhizopus oryzae and 7t (MIC 84.88 μM) against Aspergillus parasiticus have remarkable antimicrobial potency as compared to standard drug.

Treatments of Mycobacterium tuberculosis and Toxoplasma gondii with Selenium Nanoparticles

Toxoplasma gondii and Mycobacterium tuberculosis are pathogens that are harmful to humans. When these diseases interact in humans, the result is typically fatal to the public health. Several investigations on the relationship between M. tuberculosis and T. gondii infections have found that there is a strong correlation between them with each infection having a reciprocal effect on the other. TB may contribute to the reactivation of innate toxoplasmosis or enhance susceptibility to a new infection, and toxoplasma co-infection may worsen the severity of pulmonary tuberculosis. As a consequence, there is an earnest and urgent necessity to generate novel therapeutics that can subdue these challenges. Selenium nanostructures' compelling properties have been shown to be a successful treatment for Mycobacterium TB and Toxoplasma gondii. Despite the fact that selenium (Se) offers many health advantages for people, it also has a narrow therapeutic window; therefore, consuming too much of either inorganic or organic compounds based on selenium can be hazardous. Compared to both inorganic and organic Se, Se nanoparticles (SeNPs) are less hazardous. They are biocompatible and excellent in selectively targeting specific cells. As a consequence, this review conducted a summary of the efficacy of biogenic Se NPs in the treatment of tuberculosis (TB) and toxoplasmosis. Mycobacterium tuberculosis, Toxoplasma gondii, and their co-infection were all briefly described.

Insights into development of Decaprenyl-phosphoryl-β-D-ribose 2'-epimerase (DprE1) inhibitors as antitubercular agents: A state of the art review

Mycobacterium tuberculosis is a causative agent for the world threatening infectious disease known as tuberculosis. M. tuberculosis is also referred as Koch's bacillus as it was first defined by Robert Koch in 1821. In the entire history of M. tuberculosis infection, several different targets were identified and explored with a hope of effective therapeutic treatment against tuberculosis. Drug-resistant tuberculosis is the major obstacle for researchers and letting them fail continuously to discover new drug candidates. Among the numerous antitubercular targets, Decaprenyl-phosphoryl-β-D-ribose-2'-epimerase (DprE1) is novel target identified in the year 2009. The present article portrays insights of DprE1 enzyme in all the aspects i.e., identification, structural elucidation to designing strategies and synthesis of potential drug candidates to combat resistant strains. Along with the synthesis and biological activity of novel compounds, structure-activity relationship (SAR) data is given to help medicinal chemists and researchers working in this area for the development of new inhibitors to fight against M. tuberculosis. DprE1 is new ray of hope for antitubercular treatment. No single drug candidate (DprE1 inhibitor) has passed clinical trial yet and hence it nullifies the risk of development of resistance or mutations at specific residues. Researchers working in this area have to design and come up with new potent candidates with less dose, no toxicity to combat this deadly infection. This review emphasized on year wise systematic development and progress of DprE1 inhibitors.

Design and Synthesis of Quinazolinone-Triazole Hybrids as Potent Anti-Tubercular Agents

A straightforward and convenient methodology has been developed for the reaction of 2-aminobenzamide and carbonyls affording 2,3-dihydroquinazolin-4(1H)-ones using aqueous solution of [C12Py][FeCl3Br]. The developed methodology was applied for the synthesis of 25 quinazolinone-triazole hybrids followed by evaluation of their in vitro anti-tubercular (TB) activity. The results revealed that 8 quinazolinone-triazole hybrids displayed promising activity having MIC values of 0.78-12.5 μg/mL. The compound 3if with MIC 0.78 μg/mL was found to be the lead nominee among the series, better than Ethambutol, a first line anti-TB drug and comparable with Rifampicin. The active compounds with MIC values ≤ 6.25 μg/mL were subjected to in vitro cytotoxicity and found nontoxic. In drug-drug interaction, compounds 3ia and 3ii interacted synergistically with all the three anti-TB drugs, INH, RFM, and EMB. Other 3 compounds interacted either in synergistic or additive manners. Important information on the binding interaction of the target compounds with the active sites of 1DQY Antigen 85C from Mycobacterium tuberculosis and Enoyl acyl carrier protein reductase (InhA) enzymes was obtained from molecular docking studies. Screening of the drug-likeness properties and bioactivity score indicates that synthesized molecules could be projected as potential drug candidates. Based on the current study, quinazolinone-triazole hybrids framework can be useful in drug development for TB.

Designing a new basic ionic liquid [DHIM][OH] as a task specific bifunctional catalyst for facile microwave assisted metal free synthesis of 5-amino-1,2,3-triazoles

A green protocol for the synthesis of a series of 5-amino-1,2,3-triazoles from benzyl cyanide and phenyl azide derivatives catalyzed by the novel bifunctional ionic liquid [DHIM][OH] under microwave irradiation has been developed.