Synthesis and antinociceptive-antimicrobial activities of some new amide derivatives of 3,5-di/-and 1,3,5-trimethylpyrazoles

Characterization of a broad-spectrum antifungal strain, Streptomyces graminearus STR-1, against Magnaporthe oryzae

Fungal diseases such as the devastating rice blast pose severe threats to crop production worldwide. Biological control of crop diseases caused by fungal pathogens is an environment-friendly approach for safeguarding crop production. But the insufficient availability of microbial agents effective against various fungal diseases has hampered the development of green production in crops. In this study, we identified a broad-spectrum antifungal bacterium, Streptomyces graminearus STR-1, showing antagonistic activity to diverse fungal pathogens including Magnaporthe oryzae, Rhizoctonia solani, Fusarium graminearum, Ustilaginoidea virens, and Bipolaris maydis. Its antifungal activity was relatively stable and less affected by temperature and pH. Evaluation of the biocontrol activity of STR-1 revealed that STR-1 prevented and controlled rice blast disease via eliciting plant immunity and suppressing fungal infection-structure development. STR-1 broth extract inhibited spore germination, likely through inhibiting protein synthesis. Combining LC-MS and chromatography analysis of the antimicrobial compounds purified from STR-1 broth extract, together with decoding STR-1 genomic sequence, we identified 4-oxo-4-[(1-phenylethyl)amino]but-2-enoic acid, 1,3,5-Trimethylpyrazole and SMA-1 as the potential main STR-1 secondary metabolites associated with its antifungal effects. This study suggests that bacterial strain STR-1 could be used for identifying highly effective and broad-spectrum secondary metabolites for containing rice blast and other crop diseases. The application of the active compounds offers a promising measure to tackle fungal disease.

Protective Effect of Pyrus ussuriensis Maxim. Extract against Ethanol-Induced Gastritis in Rats

Pyrus ussuriensis Maxim (Korean pear) has been used for hundreds of years as a traditional herbal medicine for asthma, cough, and atopic dermatitis in Korea and China. Although it was originally shown to possess anti-inflammatory, antioxidant, and antiatopic properties, its gastroprotective effects have not been investigated. In the present study, we evaluated the protective effects of Pyrus ussuriensis Maxim extract (PUE) against ethanol-induced gastritis in rats. The bioactive compound profile of PUE was determined by gas chromatography mass spectroscopy (GC-MS) and high-performance liquid chromatography (HPLC). The gastroprotection of PUE at different doses (250 and 500 mg/kg body weight) prior to ethanol ingestion was evaluated using an in vivo gastritis rat model. Several endpoints were evaluated, including gastric mucosal lesions, cellular degeneration, intracellular damage, and immunohistochemical localization of leucocyte common antigen. The gastric mucosal injury and ulcer score were determined by evaluating the inflamed gastric mucosa and by histological examination. To identify the mechanisms of gastroprotection by PUE, antisecretory action and plasma prostaglandin E₂ (PGE₂), gastric mucosal cyclic adenosine monophosphate (cAMP), and histamine levels were measured. PUE exhibited significant antioxidant effects with IC₅₀ values of 56.18 and 22.49 µg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′- azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) inhibition (%), respectively. In addition, GC/MS and HPLC analyses revealed several bioactive compounds of PUE. Pretreatment with PUE significantly (p < 0.05) decreased the ulcer index by preventing gastric mucosal lesions, erosion, and cellular degeneration. An immunohistochemical analysis revealed that PUE markedly attenuated leucocyte infiltration in a dose-dependent manner. The enhancement of PGE₂ levels and attenuation of cAMP levels along with the inhibition of histamine release following PUE pretreatment was associated with the cytoprotective and healing effects of PUE. In contrast, the downregulation of the H⁺/K⁺ ATPase pathway as well as muscarinic receptor (M₃R) and histamine receptor (H₂R) inhibition was also involved in the gastroprotective effects of PUE; however, the expression of cholecystokinin-2 receptors (CCK₂R) was unchanged. Finally, no signs of toxicity were observed following PUE treatment. Based on our results, we conclude that PUE represents an effective therapeutic option to reduce the risk of gastritis and warrants further study.

Design, synthesis and biological evaluation of some new 2-Pyrazoline derivatives as potential anticancer agents

A new series of N-(4-(1-Phenyl-5-aryl-4,5-dihydro-1H-pyrazol-3-yl)phenyl)-4-substitutedbenzamide derivatives were designed and synthesized from new chalcone derivatives. All newly synthesized compounds were determined by using IR, ¹H-NMR, ¹³C-NMR spectroscopic methods, elemental analysis and evaluated for their in vitro antiproliferative activities on HeLa, MCF-7, MKN-45 cancer cell lines and NIH-3T3 cell line using MTT assay. Expression of Bax and Bcl-2 proteins was detected by Western-blot analysis and caspase-3 enzyme activity was measured. Notably, compounds 1f and 2f showed a significant cytotoxic effect in all three cancer cells and did not display cytotoxicity on NIH-3T3 normal cells. (IC₅₀ = 26.66 ± 2.73 μM on HeLa, IC₅₀ = 9.41 ± 2.19 μM on MCF-7, IC₅₀ = 5.17 ± 3.54 μM on MKN-45 for 1f. IC₅₀ = 17.96 ± 3.34 μM on HeLa, IC₅₀ = 0.69 ± 0.13 μM on MCF-7, IC₅₀ = 0.88 ± 0.16 μM on MKN-45 for 2f.) Moreover, 1f and 2f upregulated protein expression level of Bax and downregulated protein expression level of Bcl-2 in cells. Similarly, caspase-3 activity was increased in cells via 1f and 2f. It can be concluded that 1f and 2f activated apoptosis by inducing mitochondrial apoptotic proteins in HeLa, MCF-7, MKN-45. This could be potentially new anti-cancer derivatives and used to contribute to new therapeutic development.

New pyrazolyl-dibenzo[b,e][1,4]diazepinones: room temperature one-pot synthesis and biological evaluation

Several new (5-aryloxy-pyrazolyl)- and (5-aryl/olefin-sulfanyl-pyrazolyl)-dibenzo[b,e] [1,4] diazepinone scaffolds have been synthesized, by assembling 5-substituted 3-methyl-1-phenyl-pyrazole-4-carbaldehydes of varied nature with different cyclic diketones and aromatic diamines successfully in the presence of indium chloride in acetonitrile, at room temperature. Desired products are excellent in the purity and isolated without chromatography. All new structures are confirmed, on the basis of single-crystal X-ray diffraction data of representative 29e. Compounds reported in the present work revealed good antioxidant, antimicrobial and antiproliferative activities with promising FRAP (ferric reducing antioxidant power), bacterial resistance and human solid tumor cell growth inhibitory values, respectively. Compounds 25c and 29e, overall, registered good to moderate activity against A549 (lung), HeLa (cervix), SW1573 (lung) T-47D (breast) and WiDr (colon) cell lines, with GI₅₀ values in the 2.6-5.1 μM and 1.8-7.5 μM ranges, respectively. Molecular docking was carried out to elucidate the binding modes of the compounds (25c, 29e) to topoisomerase I and II.