Discovery and optimization of 2,3-diaryl-1,3-thiazolidin-4-one-based derivatives as potent and selective cytotoxic agents with anti-inflammatory activity

Review of Recent Advances in Thiazolidin-4-One Derivatives as Promising Antitubercular Agents (2021-Present)

Tuberculosis (TB) remains one of the leading causes of mortality worldwide, exacerbated by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis strains. In the pursuit of novel therapeutic strategies, thiazolidin-4-one derivatives have gained significant attention due to their structural diversity and broad-spectrum biological activities. This review provides a comprehensive summary of recent advances (2021-present) in the synthesis, structure-activity relationship (SAR), and mechanisms of action of thiazolidin-4-one derivatives as promising antitubercular agents. A detailed discussion of synthetic pathways is presented, including classical and multi-component reactions leading to various subclasses such as thiazolidine-2,4-diones, rhodanines, and pseudothiohydantoins. The SAR analysis highlights key functional groups that enhance antimycobacterial activity, such as halogen substitutions and heterocyclic linkers, while molecular docking and in vitro studies elucidate interactions with key Mtb targets including InhA, MmpL3, and DNA gyrase. Several compounds demonstrate potent inhibitory effects with MIC values lower than or comparable to first-line TB drugs, alongside favorable cytotoxicity profiles. These findings underscore the potential of thiazolidin-4-one scaffolds as a valuable platform for the development of next-generation antitubercular therapeutics.

3-(3-(diethylamino)propyl)-2-(4-(methylthio)phenyl)thiazolidin-4-one Attenuates Scopolamine-induced Cognitive Impairment in Rats: Insights Into Neuroprotective Effects

Alzheimer's Disease (AD) is characterized by memory decline, dysregulation in cholinergic and purinergic signaling, neuroinflammation, and oxidative stress. Current treatments are limited, highlighting the need for new compounds to prevent or delay AD progression. Thiazolidinones have emerged as promising candidates due to their antioxidant, anti-inflammatory, and anticholinesterase properties. The aim of this study was to evaluate the effects of 3-(3-(diethylamino)propyl)-2-(4-(methylthio)phenyl)thiazolidin-4-one (DS27) in a rat model of scopolamine-induced memory deficits. Male rats were divided into groups: I - Control, II - Scopolamine (SCO) (1 mg/kg), III - SCO and DS27 (5 mg/kg), IV - SCO and DS27 (10 mg/kg), V - SCO and donepezil (5 mg/kg). The animals were treated orally with DS27 or donepezil for seven days. On the 8th day, they underwent the open field test and inhibitory avoidance training, followed by intraperitoneal administration SCO. Twenty-four hours later, an inhibitory avoidance test was conducted. Acetylcholinesterase (AChE) activity, oxidative stress, and inflammatory and purinergic parameters were analyzed in the cerebral cortex, hippocampus, cerebrospinal fluid, serum, lymphocytes, and liver. DS27 prevented memory deficits, alterations in AChE activity, and oxidative damage induced by SCO in brain structures. Additionally, DS27 prevented SCO-induced decrease in IL-10 levels, and increase in IL-6, and TNF-α expression in the cerebral cortex, and normalized ATP and ADP hydrolysis in cerebrospinal fluid and lymphocytes. DS27 did not induce oxidative stress in the liver or alter serum biochemical parameters. These findings suggest that DS27 has significant neuroprotective properties and could be a promising alternative for treating neurodegenerative diseases like AD.

Covalent small-molecule inhibitors of SARS-CoV-2 Mpro: Insights into their design, classification, biological activity, and binding interactions

Since 2020, many compounds have been investigated for their potential use in the treatment of SARS-CoV-2 infection. Among these agents, a huge number of natural products and FDA-approved drugs have been evaluated as potential therapeutics for SARS-CoV-2 using virtual screening and docking studies. However, the identification of the molecular targets involved in viral replication led to the development of rationally designed anti-SARS-CoV-2 agents. Among these targets, the main protease (Mpro) is one of the key enzymes needed in the replication of the virus. The data gleaned from the crystal structures of SARS-CoV-2 Mpro complexes with small-molecule covalent inhibitors has been used in the design and discovery of many highly potent and broad-spectrum Mpro inhibitors. The current review focuses mainly on the covalent type of SARS-CoV-2 Mpro inhibitors. The design, chemistry, and classification of these inhibitors were also in focus. The biological activity of these inhibitors, including their inhibitory activities against Mpro, their antiviral activities, and the SAR studies, were discussed. The review also describes the potential mechanism of the interaction between these inhibitors and the catalytic Cys145 residue in Mpro. Moreover, the binding modes and key binding interactions of these covalent inhibitors were also illustrated. The covalent inhibitors discussed in this review were of diverse chemical nature and origin. Their antiviral activity was mediated mainly by the inhibition of SARS-CoV-2 Mpro, with IC50 values in the micromolar to the nanomolar range. Many of these inhibitors exhibited broad-spectrum inhibitory activity against the Mpro enzymes of other coronaviruses (SARS-CoV-1 and MERS-CoV). The dual inhibition of the Mpro and PLpro enzymes of SARS-CoV-2 could also provide higher therapeutic benefits than Mpro inhibition. Despite the approval of nirmatrelvir by the FDA, many mutations in the Mpro enzyme of SARS-CoV-2 have been reported. Although some of these mutations did not affect the potency of nirmatrelvir, there is an urgent need to develop a second generation of Mpro inhibitors. We hope that the data summarized in this review could help researchers in the design of a new potent generation of SARS-CoV-2 Mpro inhibitors.

New Diaryl-1,2,4-triazolo[3,4-a]pyrimidine Hybrids as Selective COX-2/sEH Dual Inhibitors with Potent Analgesic/Anti-inflammatory and Cardioprotective Properties

COX-2-selective drugs were withdrawn from the market just a few years after their development due to cardiovascular side effects. As a result, developing a selective COX-2 inhibitor as an anti-inflammatory agent with cardioprotective characteristics has become a prominent objective in medicinal chemistry. New 15 diaryl-1,2,4-triazolo[3,4-a]pyrimidine hybrids 8a-o were synthesized and investigated in vitro as dual COX-2/sEH inhibitors. Compounds 8b, 8m, and 8o have the highest potency and selectivity as COX-2 inhibitors (IC50 = 15.20, 11.60, and 10.50 μM, respectively; selectivity index (COX-1/COX-2) = 13, 20, and 25, respectively), compared to celecoxib (COX-2; IC50 = 42 μM; SI = 8). The 5-LOX inhibitory activity of compounds 8b, 8m, and 8o was further examined in vitro. Compounds 8m and 8o, the most effective COX-2 selective inhibitors, demonstrated stronger 5-LOX inhibitory action than the reference quercetin, with IC50 values of 2.90 and 3.05 μM, respectively. Additionally, compounds 8b, 8m, and 8o were the most potent dual COX-2/sEH inhibitors, with IC50 values against sEH of 3.20, 2.95, and 2.20 nM, respectively, and were equivalent to AUDA (IC50 = 1.2 nM). In vivo investigations also demonstrated that these compounds were the most efficacious as analgesic/anti-inflammatory derivatives with a high cardioprotective profile against cardiac biomarkers and inflammatory cytokines. The docking data analysis inquiry helped better understand the binding mechanisms of the most active hybrids within the COX-2 active site and supported their COX-2 selectivity. Compounds 8b, 8m, and 8o exhibited a similar orientation to rofecoxib and celecoxib, with a larger proclivity to enter the selectivity side pocket than the reference compounds.

Design and synthesis of new dihydropyrimidine/sulphonamide hybrids as promising anti-inflammatory agents via dual mPGES-1/5-LOX inhibition

A novel series of dihydropyrimidine/sulphonamide hybrids 3a-j with anti-inflammatory properties have been developed and tested as dual mPGES-1/5-LOX inhibitors. In vitro assay, results showed that compounds 3c, 3e, 3h, and 3j were the most effective dual inhibitors of mPGES-1 and 5-LOX activities. Compound 3j was the most potent dual inhibitor with IC50 values of 0.92 µM and 1.98 µM, respectively. In vivo, anti-inflammatory studies demonstrated that compounds 3c, 3e, 3h, and 3e had considerable anti-inflammatory activity, with EI% ranging from 29% to 71%. Compounds 3e and 3j were equivalent to celecoxib after the first hour but exhibited stronger anti-inflammatory effects than celecoxib after the third and fifth hours. Moreover, compounds 3e and 3j significantly reduced the levels of pro-inflammatory cytokines (PGE2, TNF-α, and IL-6) with gastrointestinal safety profiles. Molecular docking simulations explored the most potent derivatives' binding affinities and interaction patterns within mPGES-1 and 5-LOX active sites. This study disclosed that compound 3j is a promising anti-inflammatory lead with dual mPGES-1/5-LOX inhibition that deserves further preclinical investigation.