Design, Synthesis, Antibacterial Activity, Antiviral Activity, and Mechanism of Myricetin Derivatives Containing a Quinazolinone Moiety

Synthesis and Antifungal Activity of Chalcone Derivatives Containing 1,3,4-Thiadiazole

24 chalcone derivatives containing 1,3,4-thiadiazole were synthesized. The results of bioactivity tests indicated that some of the target compounds exhibited superior antifungal activities in vitro. Notably, the EC50 value of D4 was 14.4 μg/mL against Phomopsis sp, which was significantly better than that of azoxystrobin (32.2 μg/mL) and fluopyram (54.2 μg/mL). The in vivo protective activity of D4 against Phomopsis sp on kiwifruit (71.2 %) was significantly superior to azoxystrobin (62.8 %) at 200 μg/mL. The in vivo protective activities of D4 were 74.4 and 57.6 % against Rhizoctonia solani on rice leaf sheaths and rice leaves, respectively, which were slightly better than those of azoxystrobin (72.1 and 49.2 %) at 200 μg/mL. Scanning electron microscopy (SEM) results showed that the mycelial surface collapsed, contracted and grew abnormally after D4 treatment. Finally, the results were further verified by in vivo antifungal assay, fluorescence microscopy (FM) observation, determination of relative conductivity, membrane lipid peroxidation degree assay, and determination of cytoplasmic content leakage. Molecular docking results suggested that D4 could be a potential SDHI.

Design, Synthesis, Bioactivity, and Tentative Exploration of Action Mode for Benzyl Ester-Containing Derivatives

The active splicing strategy has witnessed improvement in bioactivity and antifungal spectra in pesticide discovery. Herein, a series of simple-structured molecules (Y1-Y53) containing chloro-substituted benzyl esters were designed using the above strategy. The structure-activity relationship (SAR) analysis demonstrated that the fatty acid fragment-structured esters were more effective than those containing an aromatic acid moiety or naphthenic acid part. Compounds Y36 and Y41, which featured a thiazole-4-acid moiety and trifluoromethyl aliphatic acid part, respectively, exhibited excellent in vivo curative activity (89.4%, 100 mg/L Y36) and in vitro fungicidal activity (EC50 = 0.708 mg/L, Y41) against Botrytis cinerea. Determination of antifungal spectra and analysis of scanning electron microscopy (SEM), membrane permeability, cell peroxidation, ergosterol content, oxalic acid pathways, and enzymatic assays were performed separately here. Compound Y41 is cost effective due to its simple structure and shows promise as a disease control candidate. In addition, Y41 might act on a novel target through a new pathway that disrupts the cell membrane integrity by inducing cell peroxidation.

Design, synthesis and antiviral activity of indole derivatives containing quinoline moiety

A series of indole derivatives containing quinoline structures were designed and synthesized. The synthesized compounds were characterized by NMR and HRMS. And W14 was performed by single crystal X-ray diffraction experiments. The antiviral activity studies showed that some of the target compounds possessed significant activity against tobacco mosaic virus (TMV). In particular, W20 had significant activity. The results of in vivo anti-TMV activity assay showed that W20 possessed the best curative and protective activities with EC50 values of 84.4 and 65.7 μg/mL, which were better than ningnanmycin (NNM) 205.1 and 162.0 μg/mL, respectively. The results of Microscale thermophoresis (MST) showed that W20 had a strong binding affinity for the tobacco mosaic virus coat protein (TMV-CP) with a dissociation constant (Kd) of 0.00519 μmol/L, which was superior to that of NNM (1. 65320 μmol/L). The molecular docking studies were in accordance with the experimental results. In addition, the determination of malondialdehyde (MDA) content in tobacco leaves showed that W20 improved the disease resistance of tobacco. Overall, this study shows that indole derivatives containing quinoline can be used as new antiviral agents for plant viruses for further research.

PharmaRedefine: A database server for repurposing drugs against pathogenic bacteria

Pathogenic bacteria represent a formidable threat to human health, necessitating substantial resources for prevention and treatment. With the escalating concern regarding antibiotic resistance, there is a pressing need for innovative approaches to combat these pathogens. Repurposing existing drugs offers a promising solution. Our present work hypothesizes that proteins harboring ligand-binding pockets with similar chemical environments may be able to bind the same drug. To facilitate this drug-repurposing strategy against pathogenic bacteria, we introduce an online server, PharmaRedefine. Leveraging a combination of sequence and structure alignment and protein pocket similarity analysis, this platform enables the prediction of potential targets in representative bacteria for specific FDA-approved drugs. This novel approach holds tremendous potential for drug repositioning that effectively combat infections caused by pathogenic bacteria. PharmaRedefine is freely available at http://guolab.mpu.edu.mo/pharmredefine.

Recent Advances and Outlook of Benzopyran Derivatives in the Discovery of Agricultural Chemicals

Scaffold structures, new mechanisms of action, and targets present enormous challenges in the discovery of novel pesticides. The discovery of new scaffolds is the basis for the continuous development of modern agrochemicals. Identification of a good scaffold such as triazole, carbamate, methoxy acrylate, pyrazolamide, pyrido-pyrimidinone mesoionic, and bisamide often leads to the development of a new series of pesticides. In addition, pesticides with the same target, including the inhibitors of succinate dehydrogenase (SDH), oxysterol-binding-protein, and p-hydroxyphenyl pyruvate dioxygenase (HPPD), may have the same or similar scaffold structure. Recent years have witnessed significant progress in the discovery of new pesticides using natural products as scaffolds or bridges. In recent years, there have been increasing reports on the application of natural benzopyran compounds in the discovery of new pesticides, especially osthole and coumarin. A systematic and comprehensive review of benzopyran active compounds in the discovery of new agricultural chemicals is helpful to promote the discussion and development of benzopyran active compounds. Therefore, this work systematically reviewed the research and application of benzopyran derivatives in the discovery of agricultural chemicals, summarized the antiviral, herbicidal, antibacterial, fungicidal, insecticidal, nematicidal and acaricidal activities of benzopyran active compounds, and discussed the structural-activity relationship and mechanism of action. In addition, some active fragments were recommended to further optimize the chemical structure of benzopyran active compounds based on reference information.

Heterocycles-Containing HDAC Inhibitors Active in Cancer: An Overview of the Last Fifteen Years

Cancer is one of the primary causes of mortality worldwide. Despite nowadays are numerous therapeutic treatments to fight tumor progression, it is still challenging to completely overcome it. It is known that Histone Deacetylases (HDACs), epigenetic enzymes that remove acetyl groups from lysines on histone's tails, are overexpressed in various types of cancer, and their inhibition represents a valid therapeutic strategy. To date, some HDAC inhibitors have achieved FDA approval. Nevertheless, several other potential drug candidates have been developed. This review aims primarily to be comprehensive of the studies done so far regarding HDAC inhibitors bearing heterocyclic rings since their therapeutic potential is well known and has gained increasing interest in recent years. Hence, inserting heterocyclic moieties in the HDAC-inhibiting scaffold can be a valuable strategy to provide potent and/or selective compounds. Here, in addition to summarizing the properties of novel heterocyclic HDAC inhibiting compounds, we also provide ideas for developing new, more potent, and selective compounds for treating cancer.

Flavonol Derivatives Containing a Quinazolinone Moiety: Design, Synthesis, and Antiviral Activity

A series of flavonol derivatives containing quinazolinone were designed and synthesized, and their antiviral activities against tobacco mosaic virus (TMV) were evaluated. The results of the half maximal effective concentration (EC50 ) test against TMV showed that the EC50 value of curative activity of K5 was 139.6 μg/mL, which was better than that of the commercial drug ningnanmycin (NNM) 296.0 μg/mL, and the EC50 value of protective activity of K5 was 120.6 μg/mL, which was superior to that of NNM 207.0 μg/mL. The interaction of K5 with TMV coat protein (TMV-CP) was investigated using microscale thermophoresis (MST) and molecular docking and the results showed that K5 can combine with TMV-CP more strongly to TMV-CP than that NNM can. Furthermore, the assay measuring malondialdehyde (MDA) content indicated that K5 had the ability to improve the disease resistance of tobacco. Hence, this study offers strong evidence that flavonol derivatives have potential as novel antiviral agents.

Myricetin-based fluorescence probes with AIE and ESIPT properties for detection of hydrazine in the environment and fingerprinting

BACKGROUND

Hydrazine (N2H4) is a highly toxic and versatile chemical raw material, which poses a serious threat to the environment and human health when used in large quantities. However, the traditional methods for the detection of N2H4 have the disadvantages of time-consuming, complicated operation and expensive instruments. In contrast, fluorescence probes have many advantages, such as simple operation, high sensitivity, good selectivity, and fast response time. Therefore, there is an urgent need for a fluorescence probe that can rapidly and accurately detect the presence of N2H4 and monitor the changes in its concentration.

RESULTS

For this purpose, we designed and synthesized a series of myricetin fluorescence probes 3-(substituent group)-5,7-dimethoxy-4-oxo-2-(3,4,5-trimethoxy. phenyl)-4H-chromen-4-one (Myr-R) for N2H4 detection. In the presence of N2H4, the probe 5,7-dimethoxy-3-(2,3,4,5,6-pentafluorobenzoate)-2-(3,4,5-trimethoxyphen-yl). -4H-chr-omen-4-one (Myr-3) shows significant fluorescence changes, double emission properties and a large Stokes shift (183 nm), and exhibits high selectivity and sensitivity to N2H4 (The detection limit is 93 nM). Importantly, the qualitative and quantitative analysis of N2H4 in water, soil, and air can be accomplished using fluorescence, smartphone, and UV lamps coupled with Myr-3. In addition, Myr-3 can be used for monitoring and imaging intracellular N2H4. Meanwhile, the fluorophore 3-hydroxy-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-benzopyran-4-one (Myr-Me) was applied to fingerprinting of different substrate materials due to the fact that it exhibits strong yellow fluorescence emission in the solid state and shows excellent contrast and high resolution.

SIGNIFICANCE

The probe Myr-3 is not only able to rapidly detect N2H4 in complex environments, but also can be used for imaging intracellular N2H4. In addition, the fluorophore Myr-Me can be used as an effective imaging agent for visual fingerprinting. These properties enable the probe Myr-3 and the fluorophore Myr-Me for a wide range of potential applications in related fields.

Visible light-mediated synthesis of quinazolinones from benzyl bromides and 2-aminobenzamides without using any photocatalyst or additive

This paper reports a novel method for the visible-light-mediated synthesis of quinazolinones from the reaction of benzyl bromides with 2-aminobenzamides. The reaction proceeded efficiently at room temperature upon irradiation with an 18 W blue light-emitting diode in air without photocatalysts or additives. By varying the solvent type, substrate molar ratio, and reaction time, the optimal reaction conditions, including the use of methanol solvent, room temperature, and reaction time of 28 h, were identified. Under these conditions, various quinazolinones were obtained using 18 substrates, with the highest yield of 93%. To determine the industrial value of the proposed method, a scale-up reaction was performed and 80% product yield was achieved. Mechanistic studies revealed that the reaction likely proceeded via a radical pathway and that the hydrogen bromide by-product generated during the first step of the reaction of benzyl bromide with 2-aminobenzamide promoted the subsequent step.

Design, Synthesis and Antitumor Activity of Quercetin Derivatives Containing a Quinoline Moiety

Quercetin is a flavonoid with significant biological and pharmacological activity. In this paper, quercetin was modified at the 3-OH position. Rutin was used as a raw material. We used methyl protection, Williamson etherification reactions, and then substitution reactions to prepare 15 novel quercetin derivatives containing a quinoline moiety. All these complexes were characterized by 1H NMR, 13C NMR, IR and HRMS. Of these, compound 3e (IC50 = 6.722 μmol·L-1) had a better inhibitory effect on human liver cancer (HepG-2) than DDP (Cisplatin) (IC50 = 26.981 μmol·L-1). The mechanism of the action experiment showed that compound 3e could induce cell apoptosis.

Design, synthesis, and bioactivity studies of chalcone derivatives containing [1,2,4]-triazole-[4,3-a]-pyridine

In this study, 30 chalcone derivatives containing [1,2,4]-triazole-[4,3-a]-pyridine were designed and synthesized. The results of antibacterial activity showed that EC50 values of N26 against Xoo, Pcb was 36.41, 38.53 μg/mL, respectively, which were better than those of thiodiazole copper, whose EC50 values were 60.62, 106.75 μg/mL, respectively. The bacterial inhibitory activity of N26 against Xoo was verified by SEM. Antibacterial mechanism between N26 and Xoo was preliminarily explored, the experimental results showed that when the drug concentration was 100 mg/L, N26 had a good cell membrane permeability of Xoo, and it can inhibit the production of EPS content and extracellular enzyme content to disrupt the integrity of the Xoo biofilms achieving the effect of inhibiting Xoo. At 200 mg/L, N26 can protect and inhibit the lesions of post-harvested potatoes in vivo. The activities of N1-N30 against TMV were determined with half leaf dry spot method. The EC50 values of the curative and protective activity of N22 was 77.64 and 81.55 μg/mL, respectively, which were superior to those of NNM (294.27, 175.88 μg/mL, respectively). MST experiments demonstrated that N22 (Kd = 0.0076 ± 0.0007 μmol/L) had a stronger binding ability with TMV-CP, which was much higher than that of NNM (Kd = 0.7372 ± 0.2138 μmol/L). Molecular docking results showed that N22 had a significantly higher affinity with TMV-CP than NNM.

Myricetin Attenuates Ethylene Glycol-Induced Nephrolithiasis in Rats via Mitigating Oxidative Stress and Inflammatory Markers

Urolithiasis or nephrolithiasis is a condition of kidney stone formation and is considered a painful disease of the urinary tract system. In this work, we planned to discover the therapeutic roles of myricetin on the ethylene glycol (EG)-induced nephrolithiasis in rats. The experimental rats were treated with 0.75% of EG through drinking water for 4 weeks to initiate the nephrolithiasis and subsequently treated with 25 and 50 mg/kg of myricetin. The body weight and urine volume were measured regularly. After the sacrification of rats, the samples were collected, and serum and urinary biomarkers such as creatinine, urea, Ca2 + ion, and BUN, OPN, oxalate, and citrate levels were determined using assay kits. These biomarkers, the MDA level and CAT, SOD, and GPx activities, were assessed in the kidney tissue homogenates. The IL-6, IL-1β, and TNF-α levels were also quantified using respective kits. The histopathological analysis was done on the kidney tissues. Myricetin treatment did not show major changes in the body weight and kidney weight in the EG-induced rats. The treatment with 25 and 50 mg/kg of myricetin considerably reduced the urea, creatinine, BUN, Ca2 + ion, and oxalate and increased the citrate content in serum and urine samples of EG-induced rats. Further, myricetin depleted the inflammatory cytokines and MDA levels and elevated the CAT, SOD, and GPx activities in the renal tissues. The activities of ALT, AST, ALP, GGT, and LDH were also reduced by the myricetin. Furthermore, the myricetin upheld the histoarchitecture of the kidneys. The outcomes of this investigation propose that myricetin is effective in EG-induced urolithiasis probably because of its antioxidant, anti-inflammatory, and renoprotective activities. In addition, further studies are still required to verify the precise therapeutic mechanism of myricetin.

Design, Synthesis of Novel 1,2,3-Triazole Pendent Quinazolinones and Their Cytotoxicity against MCF-7 Cell Line

A library of 6-(((1-(substitutedphenyl)-1H-1,2,3-triazol-4-yl)methyl) amino)-3-methylquinazolin-4(3H)-one analogues synthesized from Isatin precursor through a series of nitration, reduction, hydrolysis, cyclization and click reaction. The structures of compounds were characterized by spectral data including IR, 1 H-NMR, 13 C NMR and Mass. The novel quinazolinone - 1,2,3-triazoles were screened for their cytotoxicity against the human breast adenocarcinoma cell lines MCF-7 by MTT assay. 4-Isopropyl and 2-bromo substituted analogues executed high activity against MCF-7 cell line with IC50 value of 10.16±0.07 μM and 11.23±0.20 μM compared to the Doxorubicin whose IC50 value is 10.81±0.03 μM. The activity of remaining compounds is good to moderate. Further, the molecular docking studies against the crystal structure of Epidermal Growth Factor Receptor delivered the best binding energies and the interactions such as H-bond and hydrophobic are inevitable. The predicted pharmacokinetic properties results showed that these compounds have more drug likeness properties.

Mur ligase F as a new target for the flavonoids quercitrin, myricetin, and (-)-epicatechin

MurC, D, E, and F are ATP-dependent ligases involved in the stepwise assembly of the tetrapeptide stem of forming peptidoglycan. As highly conserved targets found exclusively in bacterial cells, they are of significant interest for antibacterial drug discovery. In this study, we employed a computer-aided molecular design approach to identify potential inhibitors of MurF. A biochemical inhibition assay was conducted, screening twenty-four flavonoids and related compounds against MurC-F, resulting in the identification of quercitrin, myricetin, and (-)-epicatechin as MurF inhibitors with IC50 values of 143 µM, 139 µM, and 92 µM, respectively. Notably, (-)-epicatechin demonstrated mixed type inhibition with ATP and uncompetitive inhibition with D-Ala-D-Ala dipeptide and UM3DAP substrates. Furthermore, in silico analysis using Sitemap and subsequent docking analysis using Glide revealed two plausible binding sites for (-)-epicatechin. The study also investigated the crucial structural features required for activity, with a particular focus on the substitution pattern and hydroxyl group positions, which were found to be important for the activity. The study highlights the significance of computational approaches in targeting essential enzymes involved in bacterial peptidoglycan synthesis.

Myricetin: a potential plant-derived anticancer bioactive compound-an updated overview

The globe is currently confronting a global fight against the deadliest cancer sickness. Chemotherapy, hormonal therapy, surgery, and radiation therapy are among cancer treatment options. Still, these treatments can induce patient side effects, including recurrence, multidrug resistance, fever, and weakness. As a result, the scientific community is always working on natural phytochemical substances. Numerous phytochemical compounds, including taxol analogues, vinca alkaloids such as vincristine and vinblastine, and podophyllotoxin analogues, are currently undergoing testing and have shown promising results against a number of the deadliest diseases, as well as considerable advantages due to their safety and low cost. According to research, secondary plant metabolites such as myricetin, a flavonoid in berries, herbs, and walnuts, have emerged as valuable bio-agents for cancer prevention. Myricetin and its derivatives have antiinflammatory, anticancer, apoptosis-inducing, and anticarcinogenic properties and can prevent cancer cell proliferation. Multiple studies have found that myricetin has anticancer characteristics in various malignancies, including colon, breast, prostate, bladder, and pancreatic cancers. Current knowledge of the anticancer effects of myricetin reveals its promise as a potentially bioactive chemical produced from plants for the prevention and treatment of cancer. This review aimed to study the numerous bioactivities, mode of action, and modification of several cellular processes that myricetin possesses to impede the spread of cancer cells. This review also addresses the challenges and future prospects of using myricetin as a anticancer drug.

Environmentally Friendly Approach to the Synthesis of 3-[Benzylideneamino]-2-methylquinazolin-4(3H)-one Derivatives and Calculation of Their Toxicity

Application of deep eutectic solvents in synthesis of different heterocyclic compounds was proven very efficient. These solvents are a new generation of green solvents showing excellent potential for different purposes, where they are used as environmentally acceptable substitute for toxic and volatile organic solvents. This research describes their application in the synthesis of series of quinazolinone Schiff bases in combination with microwave, ultrasound-assisted and mechanochemical methods. First, a model reaction was performed in 20 different deep eutectic solvents to find the best solvent and then reaction conditions (solvent, temperature and reaction time) were optimized for each method. Afterwards, 40 different quinazolinone derivatives were synthesized in choline chloride/malonic acid (1 : 1) DES by each method and compared by their yields. Here we show that deep eutectic solvents can be very efficient in the synthesis of quinazolinone derivatives as an excellent substitution for volatile organic solvents. With green chemistry approach in mind, we have also performed a calculation on compounds' toxicity and solubility, showing that most of them possess toxic and mutagenic properties with low water solubility.

Synthesis and Biological Activity of Myricetin Derivatives Containing Pyrazole Piperazine Amide

In this paper, a series of derivatives were synthesized by introducing the pharmacophore pyrazole ring and piperazine ring into the structure of the natural product myricetin through an amide bond. The structures were determined using carbon spectrum and hydrogen spectrum high-resolution mass spectrometry. Biological activities of those compounds against bacteria, including Xac (Xanthomonas axonopodis pv. Citri), Psa (Pseudomonas syringae pv. Actinidiae) and Xoo (Xanthomonas oryzae pv. Oryzae) were tested. Notably, D6 exhibited significant bioactivity against Xoo with an EC₅₀ value of 18.8 μg/mL, which was higher than the control drugs thiadiazole-copper (EC₅₀ = 52.9 μg/mL) and bismerthiazol (EC₅₀ = 69.1 μg/mL). Furthermore, the target compounds were assessed for their antifungal activity against ten plant pathogenic fungi. Among them, D1 displayed excellent inhibitory activity against Phomopsis sp. with an EC₅₀ value of 16.9 μg/mL, outperforming the control agents azoxystrobin (EC₅₀ = 50.7 μg/mL) and fluopyram (EC₅₀ = 71.8 μg/mL). In vitro tests demonstrated that D1 possessed curative (60.6%) and protective (74.9%) effects on postharvest kiwifruit. To investigate the active mechanism of D1, its impact on SDH activity was evaluated based on its structural features and further confirmed through molecular docking. Subsequently, the malondialdehyde content of D1-treated fungi was measured, revealing that D1 could increase malondialdehyde levels, thereby causing damage to the cell membrane. Additionally, the EC₅₀ value of D16 on P. capsici was 11.3 μg/mL, which was superior to the control drug azoxystrobin (EC₅₀ = 35.1 μg/mL), and the scanning electron microscopy results indicated that the surface of drug-treated mycelium was ruffled, and growth was significantly affected.

Design and Synthesis of Antifungal Candidates Containing Triazole Scaffold from Natural Rosin against Valsa mali for Crop Protection

Two series of dehydroabietyl-1,2,4-triazole-4-Schiff-based derivatives were synthesized from rosin to control plant fungal diseases. In vitro evaluation and screening of the antifungal activity were performed using Valsa mali, Colletotrichum orbiculare, Fusarium graminearum, Sclerotinia sclerotiorum, and Gaeumannomyces graminis. Compound 3f showed excellent fungicidal activity against V. mali (EC₅₀ = 0.537 μg/mL), which was significantly more effective than the positive control fluconazole (EC₅₀ = 4.707 μg/mL). Compound 3f also had a considerable protective effect against V. mali (61.57%-92.16%), which was slightly lower than that of fluconazole (85.17-100%) at 25-100 μg/mL. Through physiological and biochemical analyses, the preliminary mode of action of compound 3f against V. mali was explored. Ultrastructural observation of mycelia showed that compound 3f hindered the growth of the mycelium and destroyed the ultrastructure of V. mali seriously. Conductivity analysis and laser scanning confocal microscope staining showed that compound 3f changed cell-membrane permeability and caused accumulation of reactive oxygen species. The enzyme activity results showed that compound 3f significantly inhibited the activity of CYP51 (59.70%), SOD (76.9%), and CAT (67.86%). Molecular docking identified strong interaction energy between compound 3f and crystal structures of CYP51 (-11.18 kcal/mol), SOD (-9.25 kcal/mol), and CAT (-8.79 kcal/mol). These results provide guidance for the discovery of natural product-based antifungal pesticide candidates.

Design, Synthesis and Bioactivity of Novel Pyrimidine Sulfonate Esters Containing Thioether Moiety

Pesticides play an important role in crop disease and pest control. However, their irrational use leads to the emergence of drug resistance. Therefore, it is necessary to search for new pesticide-lead compounds with new structures. We designed and synthesized 33 novel pyrimidine derivatives containing sulfonate groups and evaluated their antibacterial and insecticidal activities. Results: Most of the synthesized compounds showed good antibacterial activity against Xanthomonas oryzae pv. Oryzae (Xoo), Xanthomonas axonopodis pv. Citri (Xac), Pseudomonas syringae pv. actinidiae (Psa) and Ralstonia solanacearum (Rs), and certain insecticidal activity. A₅, A₃₁ and A₃₃ showed strong antibacterial activity against Xoo, with EC₅₀ values of 4.24, 6.77 and 9.35 μg/mL, respectively. Compounds A₁, A₃, A₅ and A₃₃ showed remarkable activity against Xac (EC₅₀ was 79.02, 82.28, 70.80 and 44.11 μg/mL, respectively). In addition, A₅ could significantly improve the defense enzyme (superoxide dismutase, peroxidase, phenylalanine ammonia-lyase and catalase) activity of plants against pathogens and thus improve the disease resistance of plants. Moreover, a few compounds also showed good insecticidal activity against Plutella xylostella and Myzus persicae. The results of this study provide insight into the development of new broad-spectrum pesticides.

Design, synthesis and bioactivity of myricetin derivatives for control of fungal disease and tobacco mosaic virus disease

A series of myricetin derivatives containing isoxazole were designed and synthesized. All the synthesized compounds were characterized by NMR and HRMS. In terms of antifungal activity, Y3 had a good inhibitory effect on Sclerotinia sclerotiorum (Ss), and the median effective concentration (EC₅₀) value was 13.24 μg mL^-1, which was better than azoxystrobin (23.04 μg mL^-1) and kresoxim-methyl (46.35 μg mL^-1). Release of cellular contents and cell membrane permeability experiments further revealed that Y3 causes the destruction of the cell membrane of the hyphae, which in turn plays an inhibitory role. The anti-tobacco mosaic virus (TMV) activity in vivo showed that Y18 had the best curative and protective activities, with EC₅₀ values of 286.6 and 210.1 μg mL^-1 respectively, the effect was better than ningnanmycin. Microscale thermophoresis (MST) data showed that Y18 had a strong binding affinity with tobacco mosaic virus coat protein (TMV-CP), with a dissociation constant (K _d) value of 0.855 μM, which was better than ningnanmycin (2.244 μM). Further molecular docking revealed that Y18 interacts with multiple key amino acid residues of TMV-CP, which may hinder the self-assembly of TMV particles. Overall, after the introduction of isoxazole on the structure of myricetin, its anti-Ss and anti-TMV activities have been significantly improved, which can be further studied.

Current and future outlook of loaded components in hydrogel composites for the treatment of chronic diabetic ulcers

Due to recalcitrant microangiopathy and chronic infection, traditional treatments do not easily produce satisfactory results for chronic diabetic ulcers. In recent years, due to the advantages of high biocompatibility and modifiability, an increasing number of hydrogel materials have been applied to the treatment of chronic wounds in diabetic patients. Research on composite hydrogels has received increasing attention since loading different components can greatly increase the ability of composite hydrogels to treat chronic diabetic wounds. This review summarizes and details a variety of newly loaded components currently used in hydrogel composites for the treatment of chronic diabetic ulcers, such as polymer/polysaccharides/organic chemicals, stem cells/exosomes/progenitor cells, chelating agents/metal ions, plant extracts, proteins (cytokines/peptides/enzymes) and nucleoside products, and medicines/drugs, to help researchers understand the characteristics of these components in the treatment of diabetic chronic wounds. This review also discusses a number of components that have not yet been applied but have the potential to be loaded into hydrogels, all of which play roles in the biomedical field and may become important loading components in the future. This review provides a "loading component shelf" for researchers of composite hydrogels and a theoretical basis for the future construction of "all-in-one" hydrogels.

Design, Synthesis and Antifungal Activity of Novel 1,4-Pentadiene-3-one Containing Quinazolinone

Twenty 1,4-pentadiene-3-one derivatives containing quinazolinone (W1-W20) were designed and synthesized. The bioactivity test results showed that some compounds had antifungal activities in vitro. W12 showed excellent bioactivity against Sclerotinia sclerotiorum (S. sclerotiorum) and Phomopsis sp., with EC₅₀ values of 0.70 and 3.84 μg/mL, which are higher than those of the control drug azoxystrobin at 8.15 and 17.25 μg/mL. In vivo activity tests were carried out on oilseed rape and kiwifruit. The protective effect of W12 on oilseed rape infected with S. sclerotiorum (91.7 and 87.3%) was better than that of azoxystrobin (90.2 and 79.8%) at 100 and 50 μg/mL, respectively, and the protective effect on kiwifruit infected with Phomopsis sp. (96.2%) was better than that of azoxystrobin (94.6%) at 200 μg/mL. Scanning electron microscopy results showed the hyphae of S. sclerotiorum treated with compound W12 abnormally collapsed and shriveled, inhibiting the growth of mycelium and, thus, laying the inhibiting effect on S. sclerotiorum. The results of the mechanism research showed that the action of W12 changed the mycelial morphology of S. sclerotiorum, affected the permeability of cells, increased the leakage of cytoplasm and allowed the cell membrane to break down. This study shows that 1,4-pentadiene-3-one derivatives containing quinazolinone have good effects on plant fungi and the potential for becoming new fungicides.

Recent Achievements in Antiviral Agent Development for Plant Protection

Plant virus disease is the second most prevalent plant diseases and can cause extensive loss in global agricultural economy. Extensive work has been carried out on the development of novel antiplant virus agents for preventing and treating plant virus diseases. In this review, we summarize the achievements of the research and development of new antiviral agents in the recent five years and provide our own perspective on the future development in this highly active research field.

Novel 1,3,4-oxadiazole sulfonate/carboxylate flavonoid derivatives: synthesis and biological activity

BACKGROUND

With the long-term use of traditional bactericides and antiviral agents, drug resistance has become increasingly prominent, resulting in impaired crop growth and yields. Based on this, the introduction of small molecular active groups into natural products has become the direction of research for green pesticides.

RESULTS

In this study, novel 1,3,4-oxadiazole sulfonate/carboxylate flavonoid derivatives were explored. Among them, D4 exhibited good inhibitory effects on plant bacteria. It is worth mentioning that D4 (15 μg ml^-1 ) exhibited an excellent median effective concentration (EC₅₀ ) value against Xanthomonas oryzae pv. oryzae (Xoo), which was better than bismerthiazol (73 μg ml^-1 ) and thiodiazole copper (100 μg ml^-1 ). The EC₅₀ for D4 was much lower than the two positive controls (bismerthiazol, thiodiazole copper), making D4 more potent in this assay of bacterial growth inhibition. In addition, mechanism research using scanning electron microscopy revealed that D4 could cause deformation or rupture of the cell membranes of Xoo and Pseudomonas syringae pv. actinidiae. Moreover, D4 exhibited the best EC₅₀ for in vivo curative (132 μg ml^-1 ) and protective (101 μg ml^-1 ) activities against tobacco mosaic virus, which were more effective than ningnanmycin. Microscale thermophoresis data suggested that D4 [dissociation constant (K_d ) = 0.038 ± 0.011 μmol L^-1 ] exhibited a stronger binding capacity than the control agent ningnanmycin (K_d = 4.707 ± 2.176 μmol L^-1 ).

CONCLUSION

The biological activity data and mode of action demonstrated that D4 had the best antibacterial and antiviral effects. Compound D4 discovered in the current work may be a very promising agricultural drug. © 2022 Society of Chemical Industry.

Evaluation of the Abilities of Three Kinds of Copper-Based Nanoparticles to Control Kiwifruit Bacterial Canker

Kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae reduces kiwifruit crop yield and quality, leading to economic losses. Unfortunately, few agents for its control are available. We prepared three kinds of copper-based nanoparticles and applied them to control kiwifruit bacterial canker. The successful synthesis of Cu(OH)2 nanowires, Cu3(PO4)2 nanosheets, and Cu4(OH)6Cl2 nanoparticles were confirmed by transmission and scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The minimum bactericidal concentrations (MBCs) of the three nanoparticles were 1.56 μg/mL, which exceeded that of the commercial agent thiodiazole copper (MBC > 100 μg/mL). The imaging results indicate that the nanoparticles could interact with bacterial surfaces and kill bacteria by inducing reactive oxygen species’ accumulation and disrupting cell walls. The protective activities of Cu(OH)2 nanowires and Cu3(PO4)2 nanosheets were 59.8% and 63.2%, respectively, similar to thiodiazole copper (64.4%) and better than the Cu4(OH)6Cl2 nanoparticles (40.2%). The therapeutic activity of Cu4(OH)6Cl2 nanoparticles (67.1%) bested that of Cu(OH)2 nanowires (43.9%), Cu3(PO4)2 nanosheets (56.1%), and thiodiazole copper (53.7%). Their therapeutic and protective activities for control of kiwifruit bacterial canker differed in vivo, which was related to their sizes and morphologies. This study suggests these copper-based nanoparticles as alternatives to conventional bactericides for controlling kiwifruit diseases.

Synthesis and Bioactivity of Novel Sulfonate Scaffold-Containing Pyrazolecarbamide Derivatives as Antifungal and Antiviral Agents

Novel pyrazolecarbamide derivatives bearing a sulfonate fragment were synthesized to identify potential antifungal and antiviral agents. All the structures of the key intermediates and target compounds were confirmed by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). The single-crystal X-ray diffraction of the compound T22 showed that pyrazole carbamide is a sulfonate. The in vitro antifungal activities of the target compounds against Colletotrichum camelliae, Pestalotiopsis theae, Gibberella zeae, and Rhizoctonia solani were evaluated at 50 μg/ml. Among the four pathogens, the target compounds exhibited the highest antifungal activity against Rhizoctonia solani. The compound T24 (EC₅₀ = 0.45 mg/L) had higher antifungal activity than the commercial fungicide hymexazol (EC₅₀ = 10.49 mg/L) against R. solani, almost similar to bixafen (EC₅₀ = 0.25 mg/L). Additionally, the target compounds exhibited protective effects in vivo against TMV. Thus, this study reveals that pyrazolecarbamide derivatives bearing a sulfonate fragment exhibit potential antifungal and antiviral activities.

Quinazoline Based HDAC Dual Inhibitors as Potential Anti-Cancer Agents

Cancer is the most devastating disease and second leading cause of death around the world. Despite scientific advancements in the diagnosis and treatment of cancer which can include targeted therapy, chemotherapy, endocrine therapy, immunotherapy, radiotherapy and surgery in some cases, cancer cells appear to outsmart and evade almost any method of treatment by developing drug resistance. Quinazolines are the most versatile, ubiquitous and privileged nitrogen bearing heterocyclic compounds with a wide array of biological and pharmacological applications. Most of the anti-cancer agents featuring quinazoline pharmacophore have shown promising therapeutic activity. Therefore, extensive research is underway to explore the potential of these privileged scaffolds. In this context, a molecular hybridization approach to develop hybrid drugs has become a popular tool in the field of drug discovery, especially after witnessing the successful results during the past decade. Histone deacetylases (HDACs) have emerged as an important anti-cancer target in the recent years given its role in cellular growth, gene regulation, and metabolism. Dual inhibitors, especially based on HDAC in particular, have become the center stage of current cancer drug development. Given the growing significance of dual HDAC inhibitors, in this review, we intend to compile the development of quinazoline based HDAC dual inhibitors as anti-cancer agents.

1,3,4-Oxadiazole Contained Sesquiterpene Derivatives: Synthesis and Microbiocidal Activity for Plant Disease

A series of 1,3,4-oxadiazole contained sesquiterpene derivatives were synthesized, and the activity of the target compounds against Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac), and tobacco mosaic virus (TMV) were evaluated. The biological activity results showed that the EC₅₀ values of compounds H4, H8, H11, H12, H14, H16, and H19 for Xac inhibitory activity were 33.3, 42.7, 56.1, 74.5, 37.8, 43.8, and 38.4 μg/ml, respectively. Compounds H4, H8, H15, H19, H22, and H23 had inhibitory effects on Xoo, with EC₅₀ values of 51.0, 43.3, 43.4, 50.5, 74.6, and 51.4 μg/ml, respectively. In particular, the curative and protective activities of compound H8 against Xoo in vivo were 51.9 and 49.3%, respectively. In addition, the EC₅₀ values of the inactivation activity of compounds H4, H5, H9, H10, and H16 against TMV were 69.6, 58.9, 69.4, 43.9, and 60.5 μg/ml, respectively. The results of molecular docking indicated that compound H10 exhibited a strong affinity for TMV-coat protein, with a binding energy of −8.88 kcal/mol. It may inhibit the self-assembly and replication of TMV particles and have an anti-TMV effect, which supports its potential usefulness as an antiviral agent.

Myricetin (3,3',4',5,5',7-Hexahydroxyflavone) Prevents 5-Fluorouracil-Induced Cardiotoxicity

5-Fluorouracil (5-FU) is a strong anti-cancer drug used to manage numerous cancers. Cardiotoxicity, renal toxicity, and liver toxicity are some of the adverse effects which confine its clinical use to some extent. 5-FU-induced organ injuries are associated with redox imbalance, inflammation, and damage to heart functioning, particularly in the present study. Myricetin is an abundant flavonoid, commonly extracted from berries and herbs having anti-oxidative and anti-cancer activities. We planned the current work to explore the beneficial effects of myricetin against 5-FU-induced cardiac injury in Wistar rats through a biochemical and histological approach. Prophylactic myricetin treatment at two doses (25 and 50 mg/kg) was given to rats orally for 21 days against cardiac injury induced by a single injection of 5-FU (150 mg/kg b.wt.) given on the 20th day intraperitoneally. The 5-FU injection induced oxidative stress, inflammation, and extensive cardiac damage. Nevertheless, myricetin alleviated markers of inflammation, apoptosis, cardiac toxicity, oxidative stress, and upregulated anti-oxidative machinery. The histology of heart further supports our biochemical findings mitigated by the prophylactic treatment of myricetin. Henceforth, myricetin mitigates 5-FU-induced cardiac damage by modulating oxidative stress, inflammation, and cardiac-specific markers, as found in the present study.

Design and synthesis of novel quinazolinone–chalcone hybrids as potential apoptotic candidates targeting caspase-3 and PARP-1: in vitro, molecular docking, and SAR studies

Novel quinazolinone–chalcone hybrids as potential apoptotic candidates targeting caspase-3 and PARP-1.