Synthesis and antioxidant activity of 3-(Pyridin-2-ylmethyl)-1,3-thiazinan(thiazolidin)-4-ones

Catalytic One-pot Solvent Free Synthesis, Biological Activity, and Docking Study of New Series of 1, 3-thiazolidine-4-one Derivatives Derived from 2- (P-tolyl) Benzoxazol-5-amine

OBJECTIVE

In this study, a simple triethylammonium salt of phosphoric acid (triethylammonium dihydrogen phosphate) (4) in the liquid state was utilized as an inexpensive, efficient one-pot three components, solvent-free synthesis of thiazolidine-4-one derivatives, with good to excellent yields. Techniques such as FT-IR, 1H-NMR, 13C-NMR, 13C-NMR-DEPT-135, and MS. were used for the structural elucidation. The high biotic efficiency of the newly obtained compounds was confirmed by in vitro antimicrobial action against Gram-positive (S. Aureus), Gram-negative bacteria (P. Aeruginosa and E. Coli) and antifungal activity (C. Albicans) via microplate titer dilution technique. Finally, a molecular docking study was performed with a resolved crystal structure of S. Aureus D-alanine alanyl carrier protein ligase (PDB ID: 7VHV). This investigation aimed to synthesize a new series of thiazolidine-4-one derivatives combined with benzoxazole moiety.

MATERIAL AND METHODS

Ionic liquid assistance one-pot solvent-free synthesis method used to synthesize a new series of thiazolidine-4-one derivative 10(a-e).

RESULTS

Structural identification of new synthesis and biological evaluation via techniques of (IR, 1H-NMR, 13C-NMR, 13C-NMR-DEPT-135, and MS).

CONCLUSION

Ionic liquid is utilized as an inexpensive, efficient one-pot three-component solvent-free synthesis of thiazolidine-4-one derivatives with good to excellent yields. Most of the synthesized compounds showed high biological and anti-fungal activity, in line with the docking study against mentioned microorganism and crystal structure of PDB (ID: 7VHV), respectively.

Recent advances in synthetic strategies and SAR of thiazolidin-4-one containing molecules in cancer therapeutics

Cancer is one of the life-threatening diseases accountable for millions of demises globally. The inadequate effectiveness of the existing chemotherapy and its harmful effects has resulted in the necessity of developing innovative anticancer agents. Thiazolidin-4-one scaffold is among the most important chemical skeletons that illustrate anticancer activity. Thiazolidin-4-one derivatives have been the subject of extensive research and current scientific literature reveals that these compounds have shown significant anticancer activities. This manuscript is an earnest attempt to review novel thiazolidin-4-one derivatives demonstrating considerable potential as anticancer agents along with a brief discussion of medicinal chemistry-related aspects of these compounds and structural activity relationship studies in order to develop possible multi-target enzyme inhibitors. Most recently, various synthetic strategies have been developed by researchers to get various thiazolidin-4-one derivatives. In this review, the authors highlight the various synthetic, green, and nanomaterial-based synthesis routes of thiazolidin-4-ones as well as their role in anticancer activity by inhibition of various enzymes and cell lines. The detailed description of the existing modern standards in the field presented in this article may be interesting and beneficial to the scientists for further exploration of these heterocyclic compounds as possible anticancer agents.

Novel quinoline/thiazinan-4-one hybrids; design, synthesis, and molecular docking studies as potential anti-bacterial candidates against MRSA

In an attempt to develop effective and safe antibacterial agents, we synthesized novel thiazinanones by combining the quinolone scaffold and the 1,3-thiazinan-4-one group by reaction between ((4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarbothioamides and 2,3-diphenylcycloprop-2-enone in refluxing ethanol in the presence of triethyl amine as a catalyst. The structure of the synthesized compounds was characterized by spectral data and elemental analysis, IR, MS, ¹H and ¹³C NMR spectroscopy which showed two doublet signals for CH-5 and CH-6 and four sharp singlets for the protons of thiazinane NH, CH[double bond, length as m-dash]N, quinolone NH and OH, respectively. Also, the ¹³C NMR spectrum clearly showed the presence of two quaternary carbon atoms which were assigned to thiazinanone-C-5 and C-6. All the 1,3-thiazinan-4-one/quinolone hybrids were screened for antibacterial activity. Compounds 7a, 7e and 7g showed broad spectrum antibacterial activity against most of the tested strains either G +ve or G -ve. Compound 7e is the most potent antibacterial agent against MRSA with the minimum inhibitory concentration against MRSA found to be 48 μg mL^-1 compared to the drug ciprofloxacin (96 μg mL^-1). Additionally, a molecular docking study was performed to understand the molecular interaction and binding mode of the compounds on the active site of S. aureus Murb protein. In silico docking assisted data strongly correlated with the experimental approach of antibacterial activity against MRSA.

Effect of Thiazolidin-4-one Against Lipopolysaccharide-Induced Oxidative Damage, and Alterations in Adenine Nucleotide Hydrolysis and Acetylcholinesterase Activity in Cultured Astrocytes

Astrocytes play multiple important roles in brain physiology. However, depending on the stimuli, astrocytes may exacerbate inflammatory reactions, contributing to the development and progression of neurological diseases. Therefore, therapies targeting astrocytes represent a promising area for the development of new brain drugs. Thiazolidinones are heterocyclic compounds that have a sulfur and nitrogen atom and a carbonyl group in the ring and represent a class of compounds of great scientific interest due to their pharmacological properties. The aim of this study was to investigate the effect of 3-(3-(diethylamino)propyl)-2-(4-(methylthio)phenyl)thiazolidin-4-one (DS27) on cell proliferation and morphology, oxidative stress parameters, activity of the enzymes ectonucleotidases and acetylcholinesterase (AChE) and interleukin 6 (IL-6) levels in primary astrocyte cultures treated with lipopolysaccharide (LPS), to model neuroinflammation. The astrocyte culture was exposed to LPS (10 μg/ml) for 3 h and subsequently treated with compound DS27 for 24 and 48 h (concentrations ranging to 10-100 μM). LPS induced an increase in astrocyte proliferation, AChE activity, IL-6 levels, oxidative damage, ATP and ADP and a reduction in AMP hydrolysis in rat primary astrocyte cultures. DS27 treatment was effective in reversing these alterations induced by LPS. Our findings demonstrated that DS27 is able to modulate cholinergic and purinergic signaling, redox status, and the levels of pro-inflammatory cytokines in LPS-induced astrocyte damage. These glioprotective effects of DS27 may be very important for improving neuroinflammation, which is associated with many brain diseases.

Amino Acid Conjugates of Aminothiazole and Aminopyridine as Potential Anticancer Agents: Synthesis, Molecular Docking and in vitro Evaluation

PURPOSE

The development of resistance to available anticancer drugs is increasingly becoming a major challenge and new chemical entities could be unveiled to compensate this therapeutic failure. The current study demonstrated the synthesis of 2-aminothiazole [S3(a-d) and S5(a-d)] and 2-aminopyridine [S4(a-d) and S6(a-d)] derivatives that can target multiple cellular networks implicated in cancer development.

METHODS

Biological assays were performed to investigate the antioxidant and anticancer potential of synthesized compounds. Redox imbalance and oxidative stress are hallmarks of cancer, therefore, synthesized compounds were preliminarily screened for their antioxidant activity using DPPH assay, and further five derivatives S3b, S3c, S4c, S5b, and S6c, with significant antioxidant potential, were selected for investigation of in vitro anticancer potential. The cytotoxic activities were evaluated against the parent (A2780) and cisplatin-resistant (A2780CISR) ovarian cancer cell lines. Further, Molecular docking studies of active compounds were performed to determine binding affinities.

RESULTS

Results revealed that S3c, S5b, and S6c displayed promising inhibition in cisplatin-resistant cell lines in comparison to parent cells in terms of both resistance factor (RF) and IC50 values. Moreover, S3c proved to be most active compound in both parent and resistant cell lines with IC50 values 15.57 µM and 11.52 µM respectively. Our docking studies demonstrated that compounds S3c, S5b, and S6c exhibited significant binding affinity with multiple protein targets of the signaling cascade.

CONCLUSION

Anticancer activities of compounds S3c, S5b, and S6c in cisplatin-resistant cell lines suggested that these ligands may contribute as lead compounds for the development of new anticancer drugs.

Chemistry of Substituted Thiazinanes and Their Derivatives

Thiazinanes and its isomeric forms represent one of the most important heterocyclic compounds, and their derivatives represented a highly potent drug in disease treatment such as, 1,1-dioxido-1,2-thiazinan-1,6-naphthyridine, which has been shown to have anti-HIV activity by a mechanism that should work as anti-AIDS treatment, while (Z)-methyl 3-(naphthalen-1-ylimino)- 2-thia-4-azaspiro[5 5]undecane-4-carbodithioate showed analgesic activity, cephradine was used as antibiotic and chlormezanone was utilized as anticoagulants. All publications were interested in the chemistry of thiazine (partially or fully unsaturated heterocyclic six-membered ring containing nitrogen and sulfur), but no one was dealing with thiazinane itself which encouraged us to shed new light on these interesting heterocycles. This review was focused on the synthetic approaches of thiazinane derivatives and their chemical reactivity.

Synthesis of thiazolidin-4-ones and thiazinan-4-ones from 1-(2-aminoethyl)pyrrolidine as acetylcholinesterase inhibitors

The present study describes the synthesis of a novel series of thiazolidin-4-one and thiazinan-4-one using 1-(2-aminoethyl)pyrrolidine as amine precursor. All compounds were synthesised by one-pot three component cyclocondensation reaction from the amine, a substituted benzaldehyde and a mercaptocarboxylic acid. The compounds were obtained in moderate to good yields and were identified and characterised by ¹H, ¹³C, 2 D NMR and GC/MS techniques. The compounds also were screened for their in vitro acetylcholinesterase (AChE) activity in hippocampus and cerebral cortex on Wistar rats. The six most potent compounds have been investigated for their cytotoxicity by cell viability assay of astrocyte primary culture, an important cell of central nervous system. We highlighted two compounds (6a and 6k) that had the lowest IC₅₀ in hippocampus (5.20 and 4.46 µM) and cerebral cortex (7.40 and 6.83 µM). These preliminary and important results could be considered a starting point for the development of new AChE inhibitory agents.

Convenient diastereoselective synthesis of annulated 3-substituted-(5S*,6S*,Z)-2-(2-(2,4-dinitrophenyl)hydrazono)-5,6-diphenyl-1,3-thiazinan-4-ones

Racemic 2-(2,4-dinitrophenyl)hydrazono)-5,6-diphenyl-1,3-thiazinan-4-ones and (Z)-N'-(2,4-dinitrophenyl)-2,3-diphenylacrylohydrazide were formed during the diastereoselective reaction between 4-substituted 1-(2,4-dinitrophenyl)thiosemicarbazides and 2,3-diphenylcycloprop-2-enone under refluxing ethanol. The structures of the synthesized compounds were confirmed by single-crystal X-ray analyses.

2-Aryl-3-(2-morpholinoethyl)thiazolidin-4-ones: Synthesis, anti-inflammatory in vivo, cytotoxicity in vitro and molecular docking studies

Seven new 4-thiazolidinones bearing the morpholino moiety were easily synthesized by one-pot reactions of 4-(2-aminoethyl)morpholine (2-morpholinoethylamine), arenealdehydes and mercaptoacetic acid refluxing toluene for 19 h with moderate to good yields (45-97%). These novel compounds were fully identified and characterized by NMR spectroscopy and mass spectrometry. Thiazolidin-4-ones in vivo anti-inflammatory activities were determined using a croton oil-induced ear edema model of inflammation in BALB C mice. The best results were found for compounds 4c (49.20 mmol/kg), 4d (49.20 mmol/kg) and 4f (52.48 mmol/kg), which showed the ability to decrease the ear edema in mice by 50%, 48% and 54%, respectively, when compared to the standard drug indomethacin. In addition, the in vitro cytotoxicity activity of thiazolidin-4-ones against Vero cells was also performed and four compounds (4a, 4c, 4d and 4f) showed no toxic effect at 500 μg/mL. A docking simulation of compounds into the 1Q4G (COX-1) and 4PH9 (COX-2) enzymes binding site was conducted. This preliminary result will guide us in for further studies to improve the anti-inflammatory activity.

Crystal structures of 3-(2H-1,3-benzodioxol-5-ylmethyl)-2-(m- and p-nitrophenyl)-1,3-thiazolidin-4-ones: different roles of the oxygen atoms

The crystal structures of two isomeric 3-(2H-1,3-benzodioxol-5-ylmethyl)-2-(aryl)-1,3-thiazolidin-4-one compounds (1: aryl=4-O2NC6H4; 2: aryl=3-O2NC6H4) are reported. In both these nonplanar, compounds, the carbonyl oxygen is involved in intramolecular C–H···O hydrogen bonds. However, there are significant differences in the sets of intermolecular interactions, in particular the roles of the oxygen atoms, exhibited by the two compounds. Thus in 1, a dioxolyl oxygen and the two nitro group oxygen atoms are each involved in different chain forming C–H···O intermolecular hydrogen bonds, while the carbonyl oxygen atom is not involved in any intermolecular interaction. In 2, the dioxolyl oxygen atom is involved in the formation of centrosymmetric dimers, the carbonyl oxygen in three different C–H···O hydrogen bonds and the nitro group oxygens in two N–O···π(aryl) interactions. Compound 2 exhibits also C–H···π(phenyl), π(phenyl)···π(phenyl) and π(benzodioxolyl)···π(benzodioxolyl) interactions, while in 1 only the latter interaction is present. Compound 1 crystallizes in the monoclinic space group, P21/a with Z=4, while compound 2 crystallizes in the triclinic space group, P1̅, with Z=2.

Facile synthesis of new N-sulfonamidyl-4-thiazolidinone derivatives and their biological evaluation

A one-pot three-component facile synthesis of N-sulfonamidyl-4-thiazolidinone derivatives using a [HDBU][HSO₄] reusable ionic liquid was carried out, together with an investigation into their antifungal and antioxidant properties and a molecular docking study.