Design, synthesis, molecular docking and DFT studies on novel melatonin and isatin based azole derivatives

Current advancements and future perspectives of 1,2,3-triazoles to target lanosterol 14α-demethylase (CYP51), a cytochrome P450 enzyme: A computational approach

Antifungal resistance has become a significant challenge, necessitating the development of novel antifungal agents. Resistance often arises from prolonged and widespread use of existing treatments, leading to mutations in fungal enzymes that reduce drug efficacy. Amongst various scaffolds, 1,2,3-triazoles have emerged as antifungal agents due to their ability to bind effectively to fungal enzymes. This review examines the binding interactions of 1,2,3-triazoles with lanosterol 14α-demethylase (CYP51), an enzyme in Candida albicans (PDB IDs:5TZ1and5V5Z), highlighting their potential in fighting resistance. The CYP51 family is a captivating topic to investigate the structural and functional roles of P450 and makes for a key medical focus. It is one of crucial step in biosynthesis of sterol in eukaryotes. Antifungals mostly work on CYP51 and could also be used to treat protozoan diseases in the future. 1,2,3-Triazoles exert their antifungal effects by inhibiting the CYP51 enzyme, which is crucial for ergosterol synthesis in fungal cell membranes thereby leading to disruption of membrane integrity and ultimately leads to death of fungal cell. In silico studies like molecular docking and molecular dynamics (MD) simulations, reveal that these compounds establish strong interactions (e.g., π-π, π-alkyl, CH, hydrogen bonding, and Van der Waals interactions) with active site residues, stabilizing the ligand-enzyme complex. This review of virtual screening assays shows the adaptability of the 1,2,3-triazole scaffold and its widespread use in core antifungal compounds, making it a key pharmacophore for new lead development against resistant fungal species.

Synthesis and DNA binding studies of novel triazine-isatin hybrids: experimental and computational insights

DNA binding is a crucial determinant in developing novel anticancer agents, as it plays a key role in the mechanism of action for many chemotherapeutic drugs. In this study, a series of novel s-triazine-isatin hybrids (7a-f) was synthesized, and their binding interactions with salmon sperm DNA (SS-DNA) were investigated under physiological conditions (pH 7.4) using UV-vis absorption spectroscopy. The experimental findings demonstrated strong DNA-binding affinity through absorption and intensity shifts via groove-binding modes with SS-DNA. The binding constants (K b) of synthesized hybrids with SS-DNA calculated from the Benesi-Hildebrand plot, ranged from 104 to 105 M-1, with compound 7f exhibiting the highest binding constant (9.51 × 105 M-1) at 298 K, surpassing the reference cabozantinib. The Gibbs free energy change in the binding interaction of 7f, was found to be ΔG = -34.1 kJ mol-1 indicating a spontaneous binding process. The molecular docking results supported experimental findings with a docking score of -10.3 kcal mol-1 for 7f, highlighting hydrophobic and hydrogen bonding interactions within the AT-rich region of DNA grooves. In addition, DFT and in silico studies provided insights into the charge density of structures and drug-likeness, hence the s-triazine-isatin hybrid core holds promise as a potential therapeutic agent.

Mps1-Targeted Molecular Design of Melatonin for Broad-Spectrum Antifungal Agent Discovery

Melatonin, a multifunctional class of natural products, has demonstrated antifungal activity, making it a promising candidate for developing antifungal agents. The mitogen-activated protein kinase (Mps1) within fungal pathogens has a target inhibitory effect of melatonin in fungi. We use a virtual screening strategy to design melatonin derivatives based on the melatonin-Mps1 targeting model. Of these, a multiflorane-substitution compound M-12 emerges as a potent antifungal agent, exhibiting broad-spectrum efficacy against eight phytopathogenic fungal species, and effectively reduces the severity of tomato gray mold, Fusarium head blight in wheat, Sclerotinia stem rot in rape, and peach brown rot. M-12 half-maximal effective concentration values (5.50 μM against Botrytis cinerea, 5.21 μM against Fusarium graminearum, 10.6 μM against Rhizoctonia solani, and 9.02 μM against Sclerotinia sclerotiorum) are better than those of commercial broad-spectrum fungicide azoxystrobin (55.0, 23.2, 46.5, and 17.7 μM, respectively). Antifungal activity of enantiomer (S)-M-12 (5.02 μM) is significantly greater than its (R)-enantiomer (23.6 μM) against B. cinerea. Molecular docking and transcriptome analysis reveal that M-12 achieves its antifungal effects by inhibiting Mps1 kinase, thereby suppressing fungal growth and virulence.

Novel isatin-triazole based thiosemicarbazones as potential anticancer agents: synthesis, DFT and molecular docking studies

Thiosemicarbazones of isatin have been found to exhibit versatile bioactivities. In this study, two distinct types of isatin-triazole hybrids 3a and 3b were accessed via copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC), together with their mono and bis-thiosemicarbazone derivatives 4a-h and 5a-h. In addition to the characterization by physical, spectral and analytical data, a DFT study was carried out to obtain the optimized geometries of all thiosemicarbazones. The global reactivity values showed that among the synthesized derivatives, 4c, 4g and 5c having nitro substituents are the most soft compounds, with compound 5c having the highest electronegativity and electrophilicity index values among the synthesized series, thus possessing strong binding ability with biomolecules. Molecular docking studies were performed to explore the inhibitory ability of the selected compounds against the active sites of the anticancer protein of phosphoinositide 3-kinase (PI3K). Among the synthesized derivatives, 4-nitro substituted bisthiosemicarbazone 5c showed the highest binding energy of -10.3 kcal mol-1. These findings demonstrated that compound 5c could be used as a favored anticancer scaffold via the mechanism of inhibition against the PI3K signaling pathways.

A Comprehensive Review of the Diverse Spectrum Activity of 1,2,3-Triazole-linked Isatin Hybrids

Heterocyclic compounds containing 1,2,3-triazole and isatin as core structures have emerged as promising drug candidates due to their diverse biological activities such as anti-cancer, antifungal, antimicrobial, antitumor, anti-epileptic, antiviral, and more. The presence of 1,2,3-triazoles and isatin heterocycles in these hybrids, both individually known for their medicinal significance, has increasingly piqued the interest of drug discovery researchers, as they seek to delve deeper into their extensive pharmacological potential for enhancing therapeutic efficacy. Moreover, these hybrid compounds are synthetically accessible using readily available materials. Therefore, there is a pressing need to provide a comprehensive overview of the existing knowledge in this field, offering valuable insights to readers and paving the way for the discovery of novel 1,2,3-triazole-linked isatin hybrids with therapeutic potential.