A perspective on environmentally benign protocols of thiazole synthesis

Network pharmacology analysis of Plumbago zeylanica to identify the therapeutic targets and molecular mechanisms involved in ameliorating hemorrhoids

Plumbago zeylanica is an important plant used in the Ayurvedic system of medicine for the treatment of hemorrhoids or piles. Despite its clinical uses, its molecular mechanism, for ameliorating hemorrhoids is not yet explored. Hence, the present study evaluated the plausible molecular mechanisms of P. zeylanica in the treatment of hemorrhoids using network pharmacology and other in silico analysis. Network pharmacology was carried out by protein, GO, and KEGG enrichment analysis. Further ADME/T, molecular docking and dynamics studies of the resultant bioactive compounds of P. zeylanica with the regulated proteins were evaluated. Results of the network pharmacology analysis revealed that the key pathways and plausible molecular mechanisms involved in the treatment effects of P. zeylanica on hemorrhoids are cell migration, proliferation, motility, and apoptosis which are synchronized by cancer, focal adhesion, and by signalling relaxin, Rap1, and calcium pathways which indicates the involvement of angiogenesis and vasodilation which are the characteristic features of hemorrhoids. Further, the molecular docking and dynamics studies revealed that the bio active ingredients of P. zeylanica strongly bind with the key target proteins in the ambiance of hemorrhoids. Hence, the study revealed the mechanism of P. zeylanica in ameliorating hemorrhoids.Communicated by Ramaswamy H. Sarma.

Inhibiting brushite crystal growth: molecular docking exploration of Enhydra fluctuans phytoconstituents and their interaction with human serum albumin

In our preliminary in vitro studies, the Enhydra fluctuans extract demonstrated inhibition of calcium phosphate (brushite) crystals. Human serum albumin (HSA) is known to act as a promoter of brushite crystal growth. Therefore, the present study aims to explore the molecular mechanisms involved in brushite crystal nephrolithiasis by conducting molecular docking of phytoconstituents from E. fluctuans with HSA. Molecular docking is conducted on 35 phytoconstituents of E. fluctuans against HSA, and the top five compounds are further analyzed using Induced Fit Docking (IFD) and Molecular Mechanics-Generalized Born Surface Area (MM-GBSA) methods. Molecular dynamics simulations for 50 ns are performed to assess the stability of the protein-ligand complexes. Additionally, in silico physicochemical; absorption, distribution, metabolism, excretion, and toxicity (ADME/T); and pharmacophore modeling studies are conducted. The binding pocket analysis identifies potential binding sites on HSA, and molecular docking reveals Baicalein-7-o-glucoside as the top-performing compound with a strong binding affinity. IFD and MM-GBSA support the stability of the complex. Molecular dynamics simulations indicate stable interactions over the 50 ns period. In silico ADME/T studies suggest that the top five phytoconstituents exhibit drug-like properties with satisfactory pharmacokinetic profiles. Pharmacophore modeling generates a three-point hypothesis, and its validation indicates suitability for the HSA-Baicalein-7-O-glucoside complex. The findings from the current computational investigations indicate that polyphenolic phytoconstituents of E. fluctuans containing the 5,6-dihydroxy chromone ring, such as Baicalein-7-O-diglucoside, may modulate the activity of HSA (PDB ID: 1E7H), potentially inhibiting the process of crystallization.

Microwave-Assisted One-Pot Telescoped Synthesis of 2-Amino-1,3-thiazoles, Selenazoles, Imidazo[1,2-a]pyridines, and Other Heterocycles from Alcohols

Primary and secondary alcohols have been converted into 2-amino-1,3-thiazoles under microwave irradiation, employing trichloroisocyanuric acid (TCCA) as a dual oxidant and chlorine source, TEMPO as a co-oxidant, and thiourea. Secondary alcohols underwent a single-stage, one-pot conversion process, while primary alcohols required a two-stage, one-pot procedure. Both transformations were completed within minutes (25-45 min). The versatility of this protocol extends to the synthesis of other heterocycles, including 1,3-selenazoles, 2-aminoimidazoles, imidazo[1,2-a]pyridines, quinoxalines, and hydrazino thiazoles by replacing thiourea with the appropriate surrogates.

Synthesis of Novel Aminothiazole Derivatives as Promising Antiviral, Antioxidant and Antibacterial Candidates

It is well-known that thiazole derivatives are usually found in lead structures, which demonstrate a wide range of pharmacological effects. The aim of this research was to explore the antiviral, antioxidant, and antibacterial activities of novel, substituted thiazole compounds and to find potential agents that could have biological activities in one single biomolecule. A series of novel aminothiazoles were synthesized, and their biological activity was characterized. The obtained results were compared with those of the standard antiviral, antioxidant, antibacterial and anticancer agents. The compound bearing 4-cianophenyl substituent in the thiazole ring demonstrated the highest cytotoxic properties by decreasing the A549 viability to 87.2%. The compound bearing 4-trifluoromethylphenyl substituent in the thiazole ring showed significant antiviral activity against the PR8 influenza A strain, which was comparable to the oseltamivir and amantadine. Novel compounds with 4-chlorophenyl, 4-trifluoromethylphenyl, phenyl, 4-fluorophenyl, and 4-cianophenyl substituents in the thiazole ring demonstrated antioxidant activity by DPPH, reducing power, FRAP methods, and antibacterial activity against Escherichia coli and Bacillus subtilis bacteria. These data demonstrate that substituted aminothiazole derivatives are promising scaffolds for further optimization and development of new compounds with potential influenza A-targeted antiviral activity. Study results could demonstrate that structure optimization of novel aminothiazole compounds may be useful in the prevention of reactive oxygen species and developing new specifically targeted antioxidant and antibacterial agents.

Thiocyanatoarylation of Methyl Vinyl Ketone under Meerwein Conditions for the Synthesis of 2-Aminothiazole-Based Heterocyclic Systems

4-Aryl-3-thiocyanatobutan-2-ones were prepared by Meerwein reactions from methyl vinyl ketone and aryldiazonium salts under copper(II) catalysis in 35-75% yields. α-Thiocyanato ketones regioselectively react with 1-methyl-3-aminopyrazole forming N-(3-pyrazolyl)-substituted 2-aminothiazoles in 80-91% yields. An ester group in position 3 of the pyrazole induced a regioselective ring-closure reaction followed by an intramolecular cyclization, which gave first representatives of a new heterocyclic system, pyrazolo[4,3-e]thiazolo[3,2-a]pyrimidine, in 74-93% yields. In addition, the preparations of 5-benzyl-4-methylthiazol-2-ones in 84-93% yields are described.

Thiazole-Based Thiosemicarbazones: Synthesis, Cytotoxicity Evaluation and Molecular Docking Study

INTRODUCTION

Hybrid drug design has developed as a prime method for the development of novel anticancer therapies that can theoretically solve much of the pharmacokinetic disadvantages of traditional anticancer drugs. Thus a number of studies have indicated that thiazole-thiophene hybrids and their bis derivatives have important anticancer activity. Mammalian Rab7b protein is a member of the Rab GTPase protein family that controls the trafficking from endosomes to the TGN. Alteration in the Rab7b expression is implicated in differentiation of malignant cells, causing cancer.

METHODS

1-(4-Methyl-2-(2-(1-(thiophen-2-yl) ethylidene) hydrazinyl) thiazol-5-yl) ethanone was used as building block for synthesis of novel series of 5-(1-(2-(thiazol-2-yl) hydrazono) ethyl) thiazole derivatives. The bioactivities of the synthesized compounds were evaluated with respect to their antitumor activities against MCF-7 tumor cells using MTT assay. Computer-aided docking protocol was performed to study the possible molecular interactions between the newly synthetic thiazole compounds and the active binding site of the target protein Rab7b. Moreover, the in silico prediction of adsorption, distribution, metabolism, excretion (ADME) and toxicity (T) properties of synthesized compounds were carried out using admetSAR tool.

RESULTS

The results obtained showed that derivatives 9 and 11b have promising activity (IC50 = 14.6 ± 0.8 and 28.3 ± 1.5 µM, respectively) compared to Cisplatin (IC50 = 13.6 ± 0.9 µM). The molecular docking analysis reveals that the synthesized compounds are predicted to be fit into the binding site of the target Rab7b. In summary, the synthetic thiazole compounds 1-17 could be used as potent inhibitors as anticancer drugs.

CONCLUSION

Promising anticancer activity of compounds 9 and 11 compared with cisplatin reference drug suggests that these ligands may contribute as lead compounds in search of new anticancer agents to combat chemo-resistance.