Design, synthesis, in silico studies, in vivo and in vitro assessment of pyridones and thiazolidinones as anti-inflammatory, antipyretic and ulcerogenic hits

Ammar Y, A. Abu Ali O, Ragab A, Mahfoz AM, Abusaif MS. Fluorinated indeno-quinoxaline bearing thiazole moieties as hypoglycaemic agents targeting α-amylase, and α-glucosidase: synthesis, molecular docking, and ADMET studies

Inhibition of α-glucosidase and α-amylase are key tactics for managing blood glucose levels. Currently, stronger, and more accessible inhibitors are needed to treat diabetes. Indeno[1,2-b] quinoxalines-carrying thiazole hybrids 1-17 were created and described using NMR. All analogues were tested for hypoglycaemic effect against STZ-induced diabetes in mice. Compounds 4, 6, 8, and 16 were the most potent among the synthesised analogues. These hybrids were examined for their effects on plasma insulin, urea, creatinine, GSH, MDA, ALT, AST, and total cholesterol. Moreover, these compounds were tested against α-glucosidase and α-amylase enzymes in vitro. The four hybrids 4, 6, 8, and 16 represented moderate to potent activity with IC50 values 0.982 ± 0.04, to 10.19 ± 0.21 for α-glucosidase inhibition and 17.58 ± 0.74 to 121.6 ± 5.14 μM for α-amylase inhibition when compared to the standard medication acarbose with IC50=0.316 ± 0.02 μM for α-glucosidase inhibition and 31.56 ± 1.33 μM for α-amylase inhibition. Docking studies as well as in silico ADMT were done.

The role of current synthetic and possible plant and marine phytochemical compounds in the treatment of acne

Acne is a long-standing skin condition characterized by plugged hair follicles due to the accumulation of dead skin cells, sebum, and Propionibacterium acnes (P. acnes) bacteria, causing inflammation, and the formation of pimples or lesions. Acne was recognized in the ancient times by the ancient Egyptians, Greeks, and Romans. Since ancient times, folk medicine from different cultures have comprised herbal and natural products for the treatment of acne. Current acne medications include antibiotics, keratolytics, corticosteroids, in addition to hormonal therapy for women. However, these conventional drugs can cause some serious side effects. And therefore, seeking new safe treatment options from natural sources is essential. Plants can be a potential source of medicinal phytochemicals which can be pharmacologically active as antibacterial, antioxidant, anti-inflammatory, keratolytic and sebum-reducing. Organic acids, obtained from natural sources, are commonly used as keratolytics in dermatology and cosmetology. Most of the promising phytochemicals in acne treatment belong to terpenes, terpenoids, flavonoids, alkaloids, phenolic compounds, saponins, tannins, and essential oils. These can be extracted from leaves, bark, roots, rhizomes, seeds, and fruits of plants and may be incorporated in different dosage forms to facilitate their penetration through the skin. Additionally, medicinal compounds from marine sources can also contribute to acne treatment. This review will discuss the pathogenesis, types and consequences of acne, side effects of conventional treatment, current possible treatment options from natural sources obtained from research and folk medicine and possible applied dosage forms.

New thiazole, thiophene and 2-pyridone compounds incorporating dimethylaniline moiety: synthesis, cytotoxicity, ADME and molecular docking studies

Various sets of thiazole, thiophene, and 2-pyridone ring structures containing a dimethylaniline component were synthesized. Substituted thiazoles 2-3 and thiophenes 5-7 were produced by reacting thiocarbamoyl compound 4 with α-halogenated reagents in different basic conditions. Also, a series of 2-pyridone derivatives 9a-f substituted with dimethylaniline was synthesized through Michael addition of malononitrile to α,β-unsaturated nitrile derivatives 8a-f. The synthesized products were structurally proven by spectroscopic methods such as IR, 1H NMR, 13C NMR, and MS data. Furthermore, the anti-cancer efficacy of the compounds was assessed using the MTT assay on two cell lines: hepatocellular carcinoma (HepG-2) and breast cancer (MDA-MB-231). The results showed the highest growth inhibition for derivatives 2, 6, 7, and 9c, which were further examined for their IC50 values. The IC50 for compound 2 showed equipotent activity (IC50 = 1.2 µM) against the HepG-2 cell line compared to Doxorubicin (IC50 = 1.1 µM). Compounds 2, 6, 7 and 9c showed very good ADME assessments for further drug administration. Moreover, the PASS theoretical prediction for the compounds showed high antimitotic and antineoplastic activities for compounds 2, 6, 7, and 9c, as well as potent inhibition activity for the insulysin enzyme (IDE). Molecular docking stimulations were performed on CDK1/CyclinB1/CKS2 (PDB ID: 4y72) and BPTI (PDB ID: 2ra3). When docked into (PDB ID: 4y72), all of the tested compounds showed considerable inhibition, and the 2-pyridone derivative 9d had the maximum binding affinity (- 8.1223 kcal/mol). While thiophene derivative 6 offered the maximum binding affinity (- 7.5094 kcal/mol) when docked into (PDB ID: 2ra3).

Interception of Epoxide ring to quorum sensing system in Enterococcus faecalis and Staphylococcus aureus

Quorum sensing inhibitor (QSI) has been attracting attention as anti-virulence agent which disarms pathogens of their virulence rather than killing them. QSI marking cyclic peptide-mediated QS in Gram-positive bacteria is an effective tool to overcome the crisis of antibiotic-dependent chemotherapy due to the emergence of drug resistance strain, e.g., methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Enterococci (VRE). From a semi-large-scale screening thus far carried out, two Epoxide compounds, Ambuic acid and Synerazol, have been found to efficiently block agr and fsr QS systems, suggesting that the Epoxide group is involved in the mode of action of these QSIs. To address this notion, known natural Epoxide compounds, Cerulenin and Fosfomycin were examined for QSI activity for the agr and fsr systems in addition to in silico and SAR studies. As a result, most of investigated Epoxide containing antibiotics correlatively interfere with QSI activity for the agr and fsr systems under sublethal concentrations.

Aminopyridone-linked benzimidazoles: a fragment-based drug design for the development of CDK9 inhibitors

Aim: A fragment-based design and synthesis of three novel series of aminopyridone-linked benzimidazoles as potential anticancer candidates with significant CDK9 inhibition was implemented. Materials & methods: All synthesized compounds were submitted to National Cancer Institute, 60 cell lines and seven-dose cytotoxicity toward three cancer cells. Results: Compounds 2, 4a, 4c, 4d, 6a and 8a exhibited significant cytotoxicity and selectivity with IC50 range of 7.61-57.75 μM. Regarding the mechanism either in vitro or in silico, 4a, 6a and 8a displayed potent CDK9 inhibition with IC50 value of 0.424-8.461 μM. Compound 6a arrested the cell cycle at S phase and induced apoptosis in MCF-7 cells. Conclusion: Compound 6a is a promising CDK9 inhibitor that warrants additional research for cancer treatment.

Thiocarbohydrazone and Chalcone-Derived 3,4-Dihydropyrimidinethione as Lipid Peroxidation and Soybean Lipoxygenase Inhibitors

The potential of the 4,6-diphenyl-3,4-dihydropyrimidine-2(1H)-thione (abbreviated as KKII5) and (E)-N'-benzylidenehydrazinecarbothiohydrazide (abbreviated as DKI5) compounds as possible drug leads is investigated. KKII5 and DKI5 are synthesized in high yield of up to 97%. Their structure, binding in the active site of the LOX-1 enzyme, and their toxicity are studied via joint experimental and computational methodologies. Specifically, the structure assignment and conformational analysis were achieved by applying homonuclear and heteronuclear 2D nuclear magnetic resonance (NMR) spectroscopy (2D-COSY, 2D-NOESY, 2D-HSQC, and 2D-HMBC) and density functional theory (DFT). The obtained DFT lowest energy conformers were in agreement with the NOE correlations observed in the 2D-NOESY spectra. Additionally, docking and molecular dynamics simulations were performed to discover their ability to bind and remain stabile in the active site of the LOX-1 enzyme. These in silico experiments and DFT calculations indicated favorable binding for the enzyme under study. The strongest binding energy, -9.60 kcal/mol, was observed for dihydropyrimidinethione KKII5 in the active site of LOX-1. ADMET calculations showed that the two molecules lack major toxicities and could serve as possible drug leads. The redox potential of the active center of LOX-1 with the binding molecules was calculated via DFT methodology. The results showed a significantly smaller energy attachment of 2.8 eV with KKII5 binding in comparison to DKI5. Thus, KKII5 enhanced the ability of the active center to receive electrons compared to DKI5. This is related to the stronger binding interaction of KKII5 relative to that of DK15 to LOX-1. The two very potent LOX-1 inhibitors exerted IC₅₀ 19 μΜ (KKII5) and 22.5 μΜ (DKI5). Furthermore, they both strongly inhibit lipid peroxidation, namely, 98% for KKII5 and 94% for DKI5.

Parsing structural fragments of thiazolidin-4-one based α-amylase inhibitors: A combined approach employing in vitro colorimetric screening and GA-MLR based QSAR modelling supported by molecular docking, molecular dynamics simulation and ADMET studies

α-Amylase (EC.3.2.1.1) is a ubiquitous digestive endoamylase. The abrupt rise in blood glucose levels due to the hydrolysis of carbohydrates by α-amylase at a faster rate is one of the main reasons for type 2 diabetes. The inhibitors prevent the action of digestive enzymes, slowing the digestion of carbs and eventually assisting in the management of postprandial hyperglycemia. In the course of developing α-amylase inhibitors, we have screened 2-aryliminothiazolidin-4-one based analogs for their in vitro α-amylase inhibitory potential and employed various in silico approaches for the detailed exploration of the bioactivity. The DNSA bioassay revealed that compounds 5c, 5e, 5h, 5j, 5m, 5o and 5t were more potent than the reference drug (IC₆₀ value = 22.94 ± 0.24 μg mL^-1). The derivative 5o with -NO₂ group at both the rings was the most potent analog with an IC₆₀ value of 19.67 ± 0.20 μg mL^-1 whereas derivative 5a with unsubstituted aromatic rings showed poor inhibitory potential with an IC₆₀ value of 33.40 ± 0.15 μg mL^-1. The reliable QSAR models were developed using the QSARINS software. The high value of R²_ext = 0.9632 for model IM-9 showed that the built model can be applied to predict the α-amylase inhibitory activity of the untested molecules. A consensus modelling approach was also employed to test the reliability and robustness of the developed QSAR models. Molecular docking and molecular dynamics were employed to validate the bioassay results by studying the conformational changes and interaction mechanisms. A step further, these compounds also exhibited good ADMET characteristics and bioavailability when tested for in silico pharmacokinetics prediction parameters.

Novel fluorinated pyrazole-based heterocycles scaffold: cytotoxicity, in silico studies and molecular modelling targeting double mutant EGFR L858R/T790M as antiproliferative and apoptotic agents

Hepatocellular carcinoma (HCC), also known as hepatoma, is the most prevalent type of primary liver cancer. It begins in the hepatocytes, the liver’s major cell type. Cancer that began in another region of the body but has spread to the liver is known as secondary cancer of life; several still unmet demands for better, less toxic therapy to treat this malignant tumor. Several novel pyrazolo[1,5-a]pyrimidine derivatives were synthesized as part of our goal to develop promising anticancer drugs. All the synthesized hybrids have been screened for their cytotoxicity effect against three cancer cell lines which are; HepG-2, HCT-116, and MCF-7. The liver cancer cells were found to be the most sensitive to the effect of the new molecules. A subsequent set of in vitro biological evaluation studies has been conducted on the most promising derivatives to identify their effect on such a cancer type. In HepG-2 cells, four derivatives (8a, 8b, 10c, and 11b) demonstrated good anticancer activity. The most efficacious compounds were 8b and 10c, which had IC50 values of 2.36 ± 0.14 and 1.14 ± 0.063 μM, respectively, higher than the reference medication Imatinib. The latter’s putative molecular effect has been investigated further by looking at its influence on the cell cycle, EGFR, and specific apoptotic and anti-apoptotic markers in HepG-2 cells. These findings indicated that 8b and 10c could trigger apoptosis by upregulating BAX and caspase-3 and cell cycle at the Pre-G1 and G2-M stages. The compounds 8b and 10c showed high potency for EGFR with IC50 equal to 0.098 and 0.079 μM, respectively. Compound 10c had the most effective inhibitory activity for EGFR L858R-TK with IC50 (36.79 nM). Additionally, in silico ADMET and docking studies were done for the most active hits, representing good results.

Graphical Abstract

Bioactive 2-pyridone-containing heterocycle syntheses using multicomponent reactions

2-Pyridone-containing heterocycles are considered privileged scaffolds in drug discovery due to their behavior as hydrogen bond donors and/or acceptors and nonpeptidic mimics, and remarkable physicochemical properties such as metabolic stability, solubility in water, and lipophilicity. This review provides a comprehensive overview of multicomponent reactions (MCRs) for the synthesis of 2-pyridone-containing heterocycles. In particular, it covers the articles published from 1999 to date related to anticancer, antibacterial, antifungal, anti-inflammatory, α-glucosidase inhibitor, and cardiotonic activities of 2-pyridone-containing heterocycles obtained exclusively by an MCR. The discussion focuses on bioactivity data, synthetic approaches, plausible reaction mechanisms, and molecular docking simulations to facilitate comparison and underscore the applications of the 2-pyridone motif in drug discovery and medicinal chemistry. We also present our conclusions and outlook for the future.