Search Results (16)

Maize (Zea mays L.) is a major economic crop highly susceptible to Colletotrichum graminicola, the causal agent of anthracnose leaf blight, which causes substantial annual yield losses. This fungal pathogen employs numerous effectors to manipulate plant immunity, yet the functions of many secreted proteins during biphasic infection remain poorly characterized. In this study, we identified CgMas2, a candidate secreted protein in C. graminicola and a homolog of Magnaporthe oryzae MoMas2. Deletion of CgMAS2 in the wild-type strain CgM2 did not affect fungal vegetative growth or conidial morphology but significantly impaired virulence on maize leaves. Leaf sheath infection assays revealed that CgMas2 is required for biotrophic invasive hyphal growth, as the mutant showed defective spreading of invasive hyphae to adjacent cells. Subcellular localization analysis indicated that CgMas2 localizes to the cytoplasm of conidia and to the primary infection hyphae. Furthermore, DAB staining demonstrated that disrupt of CgMAS2 leads to host reactive oxygen species (ROS) accumulation. Comparative transcriptome analysis of maize infected with ΔCgmas2 versus CgM2 revealed enrichment of GO terms related to peroxisome and defense response, along with up-regulation of benzoxazinoid biosynthesis genes (benzoxazinone biosynthesis 3, 4 and 5) at 60 h post-inoculation (hpi). Conversely, six ethylene-responsive transcription factors (ERF2, ERF3, ERF56, ERF112, ERF115 and ERF118) involved in ethylene signaling pathways were down-regulated at 96 hpi. These expression patterns were validated by RT-qPCR. Collectively, our results demonstrate that CgMas2 not only promotes invasive hyphal growth during the biotrophic stage but may also modulate phytohormone signaling and defense compound biosynthesis during the necrotrophic phase of infection. Full article

Glycogen phosphorylase (GP) is a key enzyme of glycogen catabolism, so it is significant to discover a new GP inhibitor. A series of benzoxazepinone derivatives were identified as glycogen phosphorylase (GP) inhibitors with potent activity. These compounds exhibited strong inhibitory effects. Among them, compound 8g (IC₅₀ = 0.62 ± 0.16 μM) showed significant inhibitory activity against rabbit muscle glycogen phosphorylase a (GPa). Its inhibition of glycogen degradation in HL-7702 cells was three times greater than that of PSN-357. Molecular docking studies revealed that the binding conformation of compound 8g with PYGL allowed the benzoxazinone moiety to form stable hydrogen-bond networks and hydrophobic interactions, which may explain its excellent activity. Full article

Northern corn leaf blight (NCLB), caused by Setosphaeria turcica (S. turcica), is one of the devastating foliar diseases of maize (Zea mays) in maize-producing regions globally. Previous research has predominantly centered on elucidating the infection strategy and process of the pathogen, but the molecular mechanism of maize response to the pathogen is still largely unknown. In this study, we employed transcriptomics technology to comprehensively analyze alterations in RNA expression profiles within maize leaves at critical time points (hours post-infestation, 24 hpi, and 72 hpi) during S. turcica infection. Our study identified 7196 differentially expressed genes (DEGs) involved in the maize leaf response to S. turcica infection compared to the control (CK at 0 hpi). Functional analysis revealed that these DEGs were enriched in multiple metabolic pathways. Notably, genes associated with “benzoxazinone biosynthesis”, “tetracyclic pyrrole biosynthesis”, and “photosynthesis” were all down-regulated. In contrast, DEGs related to “phenol metabolism” and “phenylpropanoid metabolism” were significantly upregulated. Moreover, the genes belonging to the NAC, MYB-related, HB, and WRKY transcription factor families were also significantly enriched among the DEGs. The expression levels of six randomly selected DEGs were validated using qRT-PCR, confirming the accuracy of the RNA-Seq findings. This study delves into the functional genes and metabolic pathways closely associated with maize’s response to S. turcica infection, providing foundational data for a deeper understanding of the molecular mechanisms underlying the interaction between S. turcica and maize. Full article

Wheat dwarf bunt is a damaging disease caused by Tilletia controversa Kühn (TCK). Once the disease infects wheat, it is difficult to control and will significantly reduce wheat output and quality. RNA sequencing and whole genome re-sequencing were used to search for potential TCK resistance genes in Yili 053 (sensitive variety) and Zhongmai 175 (moderately resistant variety) in the mid-filling, late-filling, and maturity stages. The transcriptomic analysis revealed 11 potential disease resistance genes. An association analysis of the findings from re-sequencing found nine genes with single nucleotide polymorphism mutations. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that three up-regulated genes were involved in the synthesis of benzoxazinone and tryptophan metabolism. Additionally, quantitative real-time polymerase chain reaction confirmed the RNA sequencing results. The results revealed novel TCK resistance genes and provide a theoretical basis for researching the function of resistance genes and molecular breeding. Full article

Eight different compounds inspired by benzoxazinones were synthesized in one simple step with easy purification. These compounds have a sulfur atom instead of the oxygen atom present in benzoxazinones. Furthermore, a new derivative obtained by a Rutkauskas–Beresnevicius reaction was synthesized. These compounds were evaluated in vitro to assess their phytotoxicity in plant cells by the elongation of wheat coleoptiles. The novel compounds showed higher inhibition than benzoxazinones and the positive control, especially at higher concentrations (1000 and 300 μM). Benzoxazinones have been described as histidine deacetylase inhibitors and we therefore evaluated the effect of 1.4-benzothiazinones and 1.4-benzoxathianones against HDA6, one of the most important enzymes of the family, in silico by molecular docking and molecular dynamics. In vitro studies against Echinochloa crus-galli, Lolium rigidum and Portulaca oleracea weeds gave interesting results against the growth of the roots for both monocots and dicots. Specifically, the inhibition was more pronounced against dicots, as in the case of common purslane, whose inhibition at a concentration of 1000 μM was similar to that of the classical herbicide employed as a positive control. Higher inhibition was obtained when an aliphatic group was present in the C2 position of 1.4-benzothiazinones. Full article

Eleven 3-amino-2-methyl-quinazolin-4(3H)-ones have been synthesized, in good to excellent yields, via their corresponding benzoxazinones using an efficient tandem microwave-assisted green process. Representative acetamides have been thermally derived from their functional free 3-amino group, whereas for the synthesis of various arylamides, a novel green microwave-assisted protocol has been developed, which involved the attack of hydrazides on benzoxazinones. Eight out of the eleven 3-amino-2-methyl-quinazolin-4(3H)-ones were found photo-active towards plasmid DNA under UVB, and four under UVA irradiation. Amongst all acetamides, only the 6-nitro derivative retained activity both under UVB and UVA irradiation, whereas the 6-bromo-substituted one was active only under UVB. 3-arylamido-6-bromo derivatives exhibited dramatically decreased photo-activity; however, all 3-arylamido-6-nitro compounds developed extraordinary activity, even at concentrations as low as 1μM, which was enhanced compared to their parent 3-amino-2-methyl-6-nitro-quinazolinone. Molecular docking studies were indicative of satisfactory binding to DNA and correlated to the presented photo-activity. Since quinazolinones are known “privileged” pharmacophores for anticancer and antimicrobial activities, the present study gives information on turning “on” and “off” photosensitization on various derivatives which are often used as synthones for drug development, when chromophores and auxochromes are incorporated or being functionalized. Thus, certain compounds may lead to the development of novel photo-chemo or photodynamic therapeutics. Full article

We developed particle swarm optimization-based support vector regression (PSVR) and ordinary linear regression (OLR) models for estimating the refractive index (n) and energy gap (E) of a polyvinyl alcohol composite. The n-PSVR model, which can estimate the refractive index of a polyvinyl alcohol composite using the energy gap as a descriptor, performed better than the n-OLR model in terms of root mean square error (RMSE) and mean absolute error (MAE) metrics. The E-PSVR model, which can predict the energy gap of a polyvinyl alcohol composite using its refractive index descriptor, outperformed the E-OLR model, which uses similar descriptor based on several performance measuring metrics. The n-PSVR and E-PSVR models were used to investigate the influences of sodium-based dysprosium oxide and benzoxazinone derivatives on the energy gaps of a polyvinyl alcohol polymer composite. The results agreed well with the measured values. The models had low mean absolute percentage errors after validation with external data. The precision demonstrated by these predictive models will enhance the tailoring of the optical properties of polyvinyl alcohol composites for the desired applications. Costs and experimental difficulties will be reduced. Full article

The KOH-promoted chemodivergent benzannulation of ortho-fluorobenzamides with 2-propyn-1-ol can afford either 1,4-benzoxazepin-5(4H)-ones or 1,3-benzoxazin-4(4H)-ones in good yields with high selectivity, depending greatly upon the use of solvents. In the case of using DMSO, the intermolecular benzannulation produced seven-membered benzo-fused heterocycles of 1,4-benzoxazepin-5(4H)-ones, whereas in MeCN, the six-membered benzo-fused heterocycles of 1,3-benzoxazin-4(4H)-ones were formed. The KOH-promoted benzannulation proceeded most probably through the C–F nucleophilic substitution of ortho-fluorobenzamides with 2-propyn-1-ol to give the intermediate of ortho-[(2-propynyl)oxy]benzamide, which underwent the intramolecular hydroamidation in a different manner to afford either seven- or six-membered benzo-fused heterocycles. Full article

In this work, a novel 7-hydroxybenzoxazinone-based fluorescent probe (PBD) for the selective sensing of biothiols is reported. Upon treatment with biothiols, PBD shows a strong fluorescence enhancement (up to 70-fold) and a large Stokes shift (155 nm). Meanwhile, this probe exhibits high resistance to interference from other amino acids and competing species. PBD features good linearity ranges with a low detection limit of 14.5 nM for glutathione (GSH), 17.5 nM for cysteine (Cys), and 80.0 nM for homocysteine (Hcy), respectively. Finally, the potential utility of this probe for biothiol sensing in living HeLa cells is demonstrated. Full article

Initial conditions disclosed for the Passerini-Smiles reaction are associated with a lack of efficiency that has prevented chemists from using it since its discovery. We wish to report herein our thorough study in the development of new experimental conditions for this coupling between electron-poor phenols, isocyanides, and carbonyl derivatives. These new conditions have been applied to several synthetic strategies towards benzoxazinones. Full article

Herpes simplex virus infections have been described in the medical literature for centuries, yet the the drugs available nowadays for therapy are largely ineffective and low oral bioavailability plays an important role on the inefficacy of the treatments. Additionally, the details of the inhibition of Herpes Virus type 1 are still not fully understood. Studies have shown that several viruses encode one or more proteases required for the production new infectious virions. This study presents an analysis of the interactions between HSV-1 protease and benzoxazinone derivatives through a combination of structure-activity relationships, comparative modeling and molecular docking studies. The structure activity relationship results showed an important contribution of hydrophobic and polarizable groups and limitations for bulky groups in specific positions. Two Herpes Virus type 1 protease models were constructed and compared to achieve the best model which was obtained by MODELLER. Molecular docking results pointed to an important interaction between the most potent benzoxazinone derivative and Ser129, consistent with previous mechanistic data. Moreover, we also observed hydrophobic interactions that may play an important role in the stabilization of inhibitors in the active site. Finally, we performed druglikeness and drugscore studies of the most potent derivatives and the drugs currently used against Herpes virus. Full article

The three-dimensional quantitative structure–activity relationship (3D-QSAR) and pharmacophore identification studies on 28 substituted benzoxazinone derivatives as antiplatelet agents have been carried out. Multiple linear regression (MLR) method was applied for QSAR model development considering training and test set approaches with various feature selection methods. Stepwise (SW), simulated annealing (SA) and genetic algorithm (GA) were applied to derive QSAR models which were further validated for statistical significance and predictive ability by internal and external validation. The results of pharmacophore identification studies showed that hydrogen bond accepters, aromatic and hydrophobic, are the important features for antiplatelet activity. The selected best 3D kNN-MFA model A has a training set of 23 molecules and test set of 5 molecules with validation (q²) and cross validation (pred_r²) values 0.9739 and 0.8217, respectively. Additionally, the selected best 3D QSAR (MLR) model B has a training set of 23 molecules and test set of 5 molecules with validation (r²) and cross validation (pred_r²) values of 0.9435 and 0.7663, respectively, and four descriptors at the grid points S_123, E_407, E_311 and H_605. The information rendered by 3D-QSAR models may lead to a better understanding and designing of novel potent antiplatelet molecules. Full article

The behavior of 2-ethoxy-(4H)-3,1-benzoxazin-4-one (1) towards nitrogen nucleo-philes, e.g. ethanolamine, aromatic amines (namely: p-toluidine, p-anisidine, p-hydroxyaniline, o-hydroxyaniline, o-bromoaniline, o-phenylenediamine, p-phenylene- diamine, o-tolidinediamine) p-aminobenzoic acid, glucosamine hydrochloride, 2-amino- nicotinic acid, 1-naphthalenesulfonic acid hydrazide, n-decanoic acid hydrazide, benzoic acid hydrazide, semicarbazide, aminoacids (e.g. D,L-alanine, L-asparagine, L-arginine) and derivatives of 2-aminothiodiazole has been investigated. The behavior of the benzoxazinone towards a selected sulfur nucleophile, L-cysteine, has also been discussed. Formation of an amidine salt as a reaction intermediate has been assumed. The effect of solvent in some reactions has been elucidated. The structures of all the novel quinazoline and quinazolinone derivatives, obtained by heterocyclic ring opening and ring closure were inferred by the IR, MS as well as ¹H-NMR spectral analysis. Moreover, the antimicrobial potential of some of the new synthesized derivatives has been evaluated. Full article

A new method has been designed to prepare the known benzoxazinone derivative 2-(N-phthaloylmethyl)-4H-3,1-benzoxazin-4-one (4). The acyl chloride derivative N-phthaloylglycine reacts with anthranilic acid in chloroform, in the presence of triethylamine, to give an intermediate that is then reacted with cyanuric chloride, used as a cyclization agent, to produce the benzoxazinone derivative. Full article