Evaluation of quinoxaline derivatives as potential ergosterol biosynthesis inhibitors: design, synthesis, ADMET, molecular docking studies, and antifungal activities

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.

Synthesis of quinoxalines and assessment of their inhibitory effects against human non-small-cell lung cancer cells

Twenty-six quinoxalin derivatives were synthesized to assess their biological activities against human non-small-cell lung cancer cells (A549 cells). Compound 4b (IC50 = 11.98 ± 2.59 μM) and compound 4m (IC50 = 9.32 ± 1.56 μM) possess anticancer activity comparable to 5-fluorouracil (clinical anticancer drug) (IC50 = 4.89 ± 0.20 μM). Western blot tests further confirmed that compound 4m effectively induced apoptosis of A549 cells through mitochondrial- and caspase-3-dependent pathways. The introduction of bromo groups instead of nitro groups into the quinoxaline skeleton has been shown to provide better inhibition against lung cancer cells in this article. This modification in the molecular structure could enhance the biological activity and effectiveness of quinoxaline derivatives in the design and synthesis of anticancer drugs, making bromo-substituted quinoxalines a promising avenue for further research and development in anticancer therapeutics.

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.

Recent Methods for the Synthesis of Quinoxaline Derivatives and their Biological Activities

Quinoxaline derivatives have been incorporated into numerous marketed drugs used for the treatment of various diseases. Examples include glecaprevir (Mavyret), voxilaprevir (Vosevi), Balversa (L01EX16) (erdafitinib), carbadox, XK469R (NSC698215), and becampanel (AMP397). These quinoxaline derivatives exhibit a diverse range of pharmacological activities, including antibacterial, antitubercular, antiviral, anti-HIV, anti-inflammatory, antifungal, anticancer, antiproliferative, antitumor, kinase inhibition, antimicrobial, antioxidant, and analgesic effects. Recognizing the significance of these bioactive quinoxaline derivatives, researchers have dedicated their efforts to developing various synthetic methods for their production. This review aimed to compile the most recent findings on the synthesis and biological properties of quinoxaline derivatives from 2015 to 2023.

Update on fungal lipid biosynthesis inhibitors as antifungal agents

Fungal diseases today represent a world-wide problem. Poor hygiene and decreased immunity are the main reasons behind the manifestation of this disease. After COVID-19, an increase in the rate of fungal infection has been observed in different countries. Different classes of antifungal agents, such as polyenes, azoles, echinocandins, and anti-metabolites, as well as their combinations, are currently employed to treat fungal diseases; these drugs are effective but can cause some side effects and toxicities. Therefore, the identification and development of newer antifungal agents is a current need. The fungal cell comprises many lipids, such as ergosterol, phospholipids, and sphingolipids. Ergosterol is a sterol lipid that is only found in fungal cells. Various pathways synthesize all these lipids, and the activities of multiple enzymes govern these pathways. Inhibiting these enzymes will ultimately impede the lipid synthesis pathway, and this phenomenon could be a potential antifungal therapy. This review will discuss various lipid synthesis pathways and multiple antifungal agents identified as having fungal lipid synthesis inhibition activity. This review will identify novel compounds that can inhibit fungal lipid synthesis, permitting researchers to direct further deep pharmacological investigation and help develop drug delivery systems for such compounds.

New pyrrole derivatives as DNA gyrase and 14α-demethylase inhibitors: Design, synthesis, antimicrobial evaluation, and molecular docking

An efficient one-pot reaction utilizing readily available chemical reagents was used to prepare novel 2-amino-1,5-diaryl-1H-pyrrole-3-carbonitrile derivatives and the structures of these compounds were validated by spectroscopic data and elemental analyses. All the synthetic compounds were evaluated for their antimicrobial activities (MZI assay). The tested compounds proved high activities on Staphylococcus aureus (Gram-positive bacteria) and Candida albicans (Pathogenic fungi). However, they did not show any activity on Escherichia coli (Gram-negative bacteria). The most effective compounds in MZI assay 7c, 9a, 9b, 11a, and 11b were selected to determine their MIC on S. aureus and C. albicans. Furthermore, DNA gyrase and 14-α demethylase inhibitory assays were performed to study the inhibitory activities of 7c, 9a, 9b, 11a, and 11b. The results illustrated that compound 9b was the most DNA gyrase inhibitor (IC50 of 0.0236 ± 0.45 µM, which was 1.3- fold higher than gentamicin reference IC50 values of 0.0323 ± 0.81 µM). In addition, compound 9b demonstrated the highest 14-α demethylase inhibitory effect with IC50 of 0.0013 ± 0.02 µM, compared to ketoconazole (IC50 of 0.0008 ± 0.03 µM) and fluconazole (IC50 of 0.00073 ± 0.01 µM), as antifungal reference drugs. Lastly, docking studies were performed to rationalize the dual inhibitory activities of the highly active compounds on both DNA gyrase and 14-α demethylase enzymes.

Design and Synthesis of 2-(4-Bromophenyl)Quinoline-4-Carbohydrazide Derivatives via Molecular Hybridization as Novel Microbial DNA-Gyrase Inhibitors

Microbial DNA gyrase is regarded as an outstanding microbial target. Hence, 15 new quinoline derivatives (5-14) were designed and synthesized. The antimicrobial activity of the afforded compounds was pursued via in vitro approaches. The investigated compounds displayed eligible MIC values, particularly against G-positive Staphylococcus aureus species. Consequently, an S. aureus DNA gyrase supercoiling assay was performed, using ciprofloxacin as a reference control. Obviously, compounds 6b and 10 unveiled IC₅₀ values of 33.64 and 8.45 μM, respectively. Alongside, ciprofloxacin exhibited an IC₅₀ value of 3.80 μM. Furthermore, a significant docking binding score was encountered by compound 6b (-7.73 kcal/mol), surpassing ciprofloxacin (-7.29 kcal/mol). Additionally, both compounds 6b and 10 revealed high GIT absorption without passing the blood brain barrier. Finally, the conducted structure-activity relationship study assured the usefulness of the hydrazine moiety as a molecular hybrid for activity either in cyclic or opened form.

A New Species Agrocybe striatipes, also a Newly Commercially Cultivated Mushroom with Highly Nutritional and Healthy Values

The species of Agrocybe (Strophariaceae, Agaricales, Agaricomycetes) are saprophytic and widely distributed in temperate regions. In this study, a new species named Agrocybe striatipes from China is described, which has been successfully cultivated in China recently. The phenotypic characteristics examination and molecular phylogenetic analyses using multilocus data (ITS and nrLSU) both support it as a new species in the genus Agrocybe. Moreover, nutritional ingredient analysis showed that the fruiting body of A. striatipes was rich in seventeen amino acids, including eight essential amino acids, in addition to high levels of calcium (78.5 mg/kg) and vitamin D (44.1 μg/100g). The following analysis of the heavy metal contents of the fruiting bodies show that it does not contain lead, cadmium, arsenic, mercury, and other heavy metal elements. In the crude extract of the mushroom, the nutrients in the aqueous phase are amino acids and oligosaccharides, and the active substances in the ethyl acetate layer are sterols, which have a variety of pharmacological effects. In conclusion, A. striatipes is not only a new species but also has highly application values as a cultivated edible mushroom in nutrition and health.

Synthesis, Biological Evaluation, and Molecular Modeling Studies of New 1,3,4-Thiadiazole Derivatives as Potent Antimicrobial Agents

In this work, the synthesis, characterization, and biological activities of a new series of 1,3,4-thiadiazole derivatives were investigated. The structures of final compounds were identified using ¹ H-NMR, ¹³ C-NMR, elemental analysis, and HRMS. All the new synthesized compounds were then screened for their antimicrobial activity against four types of pathogenic bacteria and one fungal strain, by application of the MIC assays, using Ampicilin, Gentamycin, Vancomycin, and Fluconazole as standards. Among the compounds, the MIC values of 4 and 8 μg/mL of the compounds 3f and 3g, respectively, are remarkable and indicate that these compounds are good candidates for antifungal activity. The docking experiments were used to identify the binding forms of produced ligands with sterol 14-demethylase to acquire insight into relevant proteins. The MD performed about 100 ns simulations to validate selected compounds' theoretical studies. Finally, using density functional theory (DFT) to predict reactivity, the chemical characteristics and quantum factors of synthesized compounds were computed. These results were then correlated with the experimental data. Furthermore, computational estimation was performed to predict the ADME properties of the most active compound 3f.

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.

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