High Fungicidal Activity Research Articles

Multifunctional Nanocomposites Synthesized By Solid-Phase Method with High Photocatalytic, Antibacterial, and Fungicidal Activity

An easily scalable technology was developed for the solid-state synthesis of multifunctional hybrid Ag3PO4/AgCl nanocomposites. This innovative approach relies on solution-free (dry) mechanical activation, implemented through successive ion-exchange reactions in a planetary ball mill. The nanosized hybrid structure of the synthesized Ag3PO4/AgCl nanocomposites was substantiated through the utilization of XRD, SEM, TEM, DSC, and UV-visible spectroscopy methods. The investigation also unveiled a synergistic effect between Ag3PO4 and AgCl.The Ag3PO4/AgCl nanocomposites with a ratio of 75:25 mas. % exhibited the highest and most stable photocatalytic activity under visible light irradiation (λ≥400 nm). The rate constant for the photocatalytic degradation of Methylene Blue (10 mg/L) was found to be two times greater than that observed with Ag3PO4 nanoparticles and four times faster than for AgCl nanoparticles, as illustrated in Figure 1. "In addition, the synthesized nanocomposites remained stable after five cycles of the photocatalytic process, with their activity remaining almost unchanged.Furthermore, the antimicrobial and fungicidal efficacy of these nanocomposites was assessed using Staphylococcus aureus, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Erwinia amylovora test strains. The results of the microbiological tests revealed, that almost all prepared materials were able to suppress pathogenic microorganisms. The conducted study identified these nanocomposites as promising candidates for further detailed and targeted studies concerning their interaction with specific microorganisms. Figure - 1. (a) Visible spectrum changes of MB during its photodegradation by the Ag3PO4/AgCl -75/25 composite. (b) Photocatalytic degradation profiles of MB over AgCl, Ag3PO4 and Ag3PO4/AgCl catalysts under visible light irradiation. (c) Graphs for determining the kinetics of decomposition of MS under the influence of different catalysts. (d) Photodegradation stability of MB using the Ag3PO4/AgCl – 75/25 catalyst.AcknowledgmentsThis research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan, grant number АР13068426. Figure 1

Preparation of salicylic acid nano-protectant with dual synergistic mechanism: High direct fungicidal activity and plant defence toward cotton Verticillium wilt

Nanomaterials exhibit a wide range of potential applications in agricultural field. Here we construct a series of nano-protectants based on one model plant elicitor salicylic acid (SA) and six types of nanomaterials, including mesoporous silica nanosphere (MSN), mesoporous Fe3O4 nanosphere (Fe3O4), carbon quantum dot (CQD), polylactic acid-glycolic acid copolymer (PLGA), star polycation (SPc) and hydrophilic and lipophilic diblock polymer (HLDP), and explore the best nanomaterial for plant disease control. Our results demonstrate that the HLDP-SA nano-protectant displays the best control effects on cotton Verticillium wilt caused by one of the most notorious soil-borne fungi (Verticillium dahliae). The HLDP self-assembles with SA via electrostatic interaction into HLDP-SA nano-protectant, which changes the morphology of SA from needle-like particles to spherical particles. The loading efficiency of HLDP toward SA is calculated to be 49.28%, and the plant uptake of HLDP-loaded SA significantly increases by 3–4 times. HLDP-SA nano-protectant can suppress the spore germination of V991 strain with the spore germination rate of merely 2%, and its colony diameter is significantly decreased by 64.9%. Our transcriptome data demonstrate that the HLDP-SA nano-protectant accelerates the delivery and translocation of exogenous substances into V. dahliae, which exhibits the highest direct fungicidal activity via inhibiting the metabolism and weakening the pathogenicity. Meanwhile, its enhanced plant uptake with better adhesion performance on leaves amplifies the plant defense induced by SA via accelerating the biosynthesis of plant secondary metabolites, such as SA, abscisic acid (ABA) and gossypol. This study provides a powerful nanomaterial with dual synergistic mechanism for designing nano-protectant with high fungicidal activity and amplified plant defense.

Fleagrass (Adenosma buchneroides Bonati) Acts as a Fungicide Against Candida albicans by Damaging Its Cell Wall.

Fleagrass, a herb known for its pleasant aroma, is widely used as a mosquito repellent, antibacterial agent, and for treating colds, reducing swelling, and alleviating pain. The antifungal effects of the essential oils of fleagrass and carvacrol against Candida albicans were investigated by evaluating the growth and the mycelial and biofilm development of C. albicans. Transmission electron microscopy was used to evaluate the integrity of the cell membrane and cell wall of C. albicans. Fleagrass exhibited high fungicidal activity against C. albicans at concentrations of 0.5% v/v (via the Ras1/cAMP/PKA pathway). Furthermore, transmission electron microscopy revealed damage to the cell wall and membrane after treatment with the essential oil, which was further confirmed by the increased levels of β-1,3-glucan and chitin in the cell wall. This study showed that fleagrass exerts good fungicidal and hyphal growth inhibition activity against C. albicans by disrupting its cell wall, and thus, fleagrass may be a potential antifungal drug.

Synthesis, fungicidal activity and molecular docking of novel pyrazole-carboxamides bearing a branched alkyl ether moiety

Succinate dehydrogenase inhibitors are essential fungicides used in agriculture. To explore new pyrazole-carboxamides with high fungicidal activity, a series of N-substitutedphenyl-3-di/trifluoromethyl-1-methyl-1H-pyrazole-4-carboxamides bearing a branched alkyl ether moiety were designed and synthesized. The in vitro bioassay indicated that some target compounds displayed appreciable fungicidal activity. For example, compounds 5d and 5e showed high efficacy against S. sclerotiorum with EC50 values of 3.26 and 1.52 μg/mL respectively, and also exhibited excellent efficacy against R. solani with EC50 values of 0.27 and 0.06 μg/mL respectively, which were comparable or superior to penflufen. The further in vivo bioassay on cucumber leaves demonstrated that 5e provided strong protective activity of 94.3 % against S. sclerotiorum at 100 μg/mL, comparable to penflufen (99.1 %). Cytotoxicity assessment against human renal cell lines (239A cell) revealed that 5e had low cytotoxicity within the median effective concentrations. Docking study of 5e with succinate dehydrogenase illustrated that R-5e formed one hydrogen bond and two π-π stacking interactions with amino acid residues of target enzyme, while S-5e formed only one π-π stacking interaction with amino acid residue. This study provides a valuable reference for the design of new succinate dehydrogenase inhibitor.

Advantageous properties of a new fungicide, isofetamid.

The fungicidal properties of a new fungicide, isofetamid, were examined to assess its antifungal spectrum, mode of action, and effects on the infection process of Botrytis cinerea. Additionally, we investigated its fungicidal activity against isolates of B. cinerea resistant to existing fungicides. In mycelial growth inhibition tests, isofetamid exhibited excellent fungicidal activity against ascomycetes but showed no activity against basidiomycetes and oomycetes. Respiratory enzyme assay using mitochondria revealed that isofetamid inhibited succinate dehydrogenase activity prepared from B. cinerea and other ascomycetes fungi used in the study. On the other hand, the activity of mitochondria prepared from Pythium, potato and rat were not inhibited. Isofetamid inhibited also many stages of the infection processes in B. cinerea. Furthermore, it exhibited high fungicidal activity against B. cinerea isolates that were resistant to existing fungicides.

Design, Synthesis, Antifungal Activity, and Molecular Docking Studies of Novel Chiral Isoxazoline-Benzofuran-Sulfonamide Derivatives.

Succinate dehydrogenase (SDH) is one of the most important molecular targets for the development of novel fungicides. With the emerging problem of resistance in plant fungal pathogens, novel compounds with high fungicidal activity need to be developed, but the study of chiral pesticides for the inhibition of highly destructive plant pathogens has been rarely reported in recent years. Therefore, a series of novel chiral isoxazoline-benzofuran-sulfonamide derivatives were designed to investigate potential novel antifungal molecules. The chiral target compound 3a was cultured as a single crystal and confirmed using X-ray diffraction. All the target compounds were tested for antifungal activity, and compounds 3c, 3i, 3s, and 3r were found to have significant antifungal effects against S. sclerotiorum with EC50 values of 0.42 mg/L, 0.33 mg/L, 0.37 mg/L, and 0.40 mg/L, respectively, which were superior to the commercial fungicide fluopyram (EC50 = 0.47 mg/L). The IC50 value of compound 3i against the SDH of S. sclerotiorum was 0.63 mg/mL, which was further demonstrated by enzyme activity assays. Scanning electron microscopy showed that 3i had a significant inhibitory effect on S. sclerotiorum. In addition, the fluorescence quenching analysis assay indicated that compound 3i had a similar effect with the positive control fluopyram. Molecular docking exhibited that target compounds with chiral configuration had better affinity than racemic configuration, and 3i possessed stronger action than fluopyram, which was in keeping with the in vitro test results. These results would provide a basis and reference for the development of novel chiral fungicides.

Piperidinium surfactants functionalized with carbamate fragment: Aggregation, antimicrobial activity and cytotoxicity

The biomimetic nature of supramolecular systems, the structural similarity of synthetic surfactants to biomolecules (lipids, proteins), provide them with high membranotropy, the ability to overcome biological barriers, and affinity towards biosubstances. Despite rather high toxicity cationic surfactants are of importance as antimicrobial agents, gene nanocarriers and mitochondria targeted ligands. To minimize this limitation, cationic amphiphilic matrix undergoes modification with various functional groups. In this work, new piperidinium cationic surfactants containing one or two carbamate fragments were prepared; their aggregation behavior was systematically studied by tensiometery, spectrophotometry and fluorimetry. The presence of a carbamate fragment leads to a 2–3-fold decrease in critical micelle concentration and to a significant increase in solubilization capacity compared to unsubstituted analogue. Evaluation of the antimicrobial effect showed that all compounds exhibit high bactericidal and fungicidal activity against a wide range of pathogenic microorganisms, including their resistant forms. Importantly, the introducing carbamate moiety allows of decreasing hemolytic activity of cationic surfactants. The data obtained make it possible to recommend carbamate piperidinium surfactants as effective biocompatible and biodegradable nanocontainers for hydrophobic probes with high antimicrobial effect and moderate hemolytic activity.

INTERRELATION OF BIOLOGICAL ACTIVITY AND CALCULATED PARAMETERS OF NITRILSILANES AND NITRILSILOXANES

The processes of oil production, transport, refining are time-bound, which is fraught with sludge and storage, which is the cause of microbiological corrosion. The geometric, electronic and energy parameters of previously synthesized organosilicon nitriles and the manifestation of their antimicrobial activity are studied, and some regularities of their physicochemical properties are established. It was found that heteroatomic compounds containing silicon atoms in their composition have a high and effective fungicidal activity, inhibiting the growth of fungi and plants, as well as minimal toxicity. It has been established that the effect of the studied compounds can last up to several weeks, in contrast to the currently used drugs of biological action during the storage and transportation of petroleum oils. The results of the physicochemical parameters of a number of nitrilesilanes and nitrilesiloxanes calculated by the DFT method with the B3LYP/6-31G(d,p) functional are presented. The studied compounds are highly reactive, and in this work the biological activities of a number of organosilicon nitriles have been experimentally established. Based on the calculated and experimental data obtained, the relationship between the energies of the boundary molecular orbitals (depending on the electronic structure) and the antimicrobial properties of the presented nitrile silanes and nitrile siloxanes were established. It has been shown that a number of studied organosilicon compounds, especially nitrile siloxanes, are superior in bactericidal activity to the biocide sodium pentachlorophenolate. When compiling a 3D function graph, the average deviation of the results of mathematical calculations from the results of a biological experiment was a maximum of 23%. It has been established that the most effective of the given compounds of a number of organosilicon nitrile silanes and nitrile siloxanes can be widely used in industry and can be recommended as biocidal additives for lubricating oils and other lubricating and cutting fluids and materials.

Synthesis of azole derivatives of 1,2,3-dithiazole-5-imines and study of their fungicidal

A three-stage method was proposed for the synthesis of new 4-[4-(2-azolylethyl)piperazine-1-yl]- N -aryl-5 H 1,2,3-dithiazole-5-imines. This approach includes the reaction of Appel salt with anilines to produce 1,2,3-dithiazole-5-imines, which were converted into 4-[(4-chloroethyl)piperazine-1-yl]-5 H -1,2,3-dithiazole-5-imines, alkylating azoles at the final stage. The high fungicidal activity of target compounds and intermediate 4-chloro N -aryl-1,2,3-dithiazole-5-imines was shown in vitro tests versus six species of phytopathogenic fungi.

Synthesis of Azole Derivatives of 1,2,3-Dithiazole-5-imines and Study of Their Fungicidal

A three-stage method was proposed for the synthesis of new 4-[4-(2-azolylethyl)piperazine-1-yl]-N-aryl-5H-1,2,3-dithiazole-5-imines. This approach includes the reaction of Appel salt with anilines to produce 1,2,3-dithiazole-5-imines, which were converted into 4-[(4-chloroethyl)piperazine-1-yl]-5H-1,2,3-dithiazole-5-imines, alkylating azoles at the final stage. The high fungicidal activity of target compounds and intermediate 4-chloro-N-aryl-1,2,3-dithiazole-5-imines was shown in vitro tests versus six species of phytopathogenic fungi.

Study of some N,S,O – containing organic compounds as additives preventing microbiological damage of cutting fluids

The article is dedicated to the study of synthesized N,S,O – containing organic compounds as additives – biocides that prevent microbiological damage to the emulsion cutting fluid. Tests were carried out in accordance with ГОСТ 9.085-78. As microorganisms were taken Pseudomonas aerudinosa and Mycobakterium laktiocolium as bacteria, Aspergillus niger and Caetonium globosum as fungi. The results of the performed tests showed that the studied compounds do not suppress microbes, i.e. do not have bactericidal properties. However, all the studied compounds, while exhibiting fungicidal properties, effectively suppress fungi and are superior in these properties to Azin-4 biocide. Compounds with the highest fungicidal activity were identified.

Cu(II), Ni(II) and Co(II) Complexes of Malonic Acid Dihydrazide with Bis-BrSalicylhydrazone

New complexes of Cu(II), Ni(II), and Co(II) with N1,N3-bis(5-bromo-2-hydroxybenzylidene)-malonohydrazide (LH4) have been synthesized. It was shown that, in the synthesized Cu(II) and Co(II) complexes with the LH4 ligand, coordination occurs according to the Schiff base type, while in the Ni(II) complex the oxygen atom of the amide (hydrazide) group in the enol form and the nitrogen atom of the azomethine group take part in the coordination groups. Based on the data of IR, electron spectroscopy, EPR, thermogravimetry and elemental analysis of the obtained complexes, the octahedral coordination of Cu(II) ions and the binuclear structure of the complexes are assumed. It was established that all obtained compounds have high bactericidal and fungicidal activity. After, the activities of the studied ligand and its metal complexes against various cancer proteins including breast, colon, and lung cancer were compared.

Discovery of triphenylphosphonium (TPP)-conjugated N-(1,1'-biphenyl)-2-yl aliphatic amides as excellent fungicidal candidates.

Succinate dehydrogenase inhibitors (SDHIs) are the fastest growing agricultural fungicides at present, but their rapidly growing resistance is a serious problem for their application. Previously, we screened out a fungicidal lead compound CBUA-TPP (1) through triphenylphosphonium (TPP)-driven mitochondrial-targeting strategy. The targeting led to the rapid accumulation of 1 in mitochondria and the saturation inhibition of complex II in a short time, resulting in electron leakage and the explosion of reactive oxygen species (ROS). However, the contribution of biphenyl-2-amines to the activity of these compounds and their structure-activity relationship are still unknown. Two series of CBUA-TPP (1) analogues (series 2 and 3) were designed and synthesized. The bioassay results indicated that series 2 compounds generally showed much higher fungicidal activities than series 3, suggesting the crucial contribution of the biarylamine module in these targeted molecules and the pyridinyl substitution of phenyl is unfavorable to their activities. Interestingly, these two series of compounds displayed almost opposite substituent effects. Several compounds showed excellent fungicidal activities in vitro, among which compound 2-1 exhibited excellent field control efficacy on potato late blight. By optimizing the lead compound, the contribution of biarylamine in CBUA-TPP (1) analogs to the fungicidal activity is clarified. Several compounds, represented by 2-1, have great potential as fungicide candidates. They exhibit high and broad-spectrum fungicidal activities and are highly effective against common pathogenic fungi infecting vegetables and fruits both in vitro and field control. It not only provided a new choice for controlling these diseases, but its low resistance tendency also provided a better scheme for resistance management. © 2023 Society of Chemical Industry.

SPECIES OF THE Rhododendron l. GENUS ON THE COAST OF ADJARA AND THE ANTIMICROBIAL ACTIVITY OF THEIR LEAF EXTRACTS AGAINST PHYTOPATHOGENS

Based on the Institute of Phytopathology and Biodiversity of Batumi Shota Rustaveli State University, studied the antimicrobial action of the extracts obtained from the leaves of the species: Rhododendron japonicum, Rhododendron arborescens, Rhododendron brachycarpum, Rhododendron macrosepalum, Rhododendron dalavayi, on the example of fungicidal and fungistatic actions. The experiments were mainly conducted during periods of active vegetation.  It has been determined: extracts obtained from Rhododendron dalavayi and Rhododendron brachycarpum are characterized by very high antimicrobial action. The highest fungicidal activity was observed in the case of dilution of ethanol extract 1:1, 1:2, in the case of fairly high dilutions of 1:4and 1:8, in the rest of the cases there was a clearly expressed fungistatic activity; in the case of aqueous extracts (tinctures), high fungicidal action was detected in relation with fungi Phytophtora infestans, Alternaria alternata, Alternaria   solani, Pestalotia theae, Fusarium moniliforme, whereas fungistatic – in relation with the fungi Trichothecium roseum, Pestalotia  coryli,  Fusarium moniliforme. The rest of the species of Rhododendron under study are characterized by weakly expressed fungistatic activity.  The high antimicrobial activity of the extracts of the leaves of Rhododendron dalavayi and Rhododendron brachycarpum is of interest for the purpose of practical use.

SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF N-(4-METHOXYPHENYL)ACETAMIDE AND N-PHENYLACETAMIDE DERIVATIVES

Particular attention in the cultivation of industrial and agricultural crops is paid to the fight against pathogenic fungi, which not only lead to significant yield losses, but they are also dangerous to humans. The aim of this work is the synthesis of biologically active compounds in the series of aromatic dithiocarbamic acids based on N-(4-methoxyphenyl)acetamide and N-phenylacetamide and the study of their antifungal and antibacterial activities. Results and discussion. Biologically active aromatic sodium dithiocarbamates were synthesized by the reaction of amines (N-(4-methoxyphenyl)acetamide and N-phenylacetamide) with carbon disulfide in the presence of NaOH in ethanol at a temperature of 25°C in 78 and 85% yields. Thioanhydrides were synthesized by the acylation of sodium acetyl(4-methoxyphenyl)carbamodithioate and sodium acetyl(phenyl)carbamodithioate with acid chlorides (benzoic, 3,4-dimethoxybenzoic, 2-bromobenzoic, and 4-nitrobenzoic) in chloroform at a temperature of 25°C. The corresponding derivatives of aromatic thioanhydrides of dithiocarbamic acids were obtained in 49-88% yields. The structure of the synthesized compounds was established on the basis of elemental analysis data, IR spectra, 1Н and 13С NMR spectroscopy. Antifungal and bactericidal properties of the synthesized compounds were studied against phytopathogenic fungi and Fusarium oxysporum and Pectobacterium carotovorum bacteria. Conclusion. According to the test results, it was revealed that sodium acetyl(4-methoxyphenyl)carbamodithioate at a concentration of 0.4% has a high fungicidal activity and completely inhibits the growth of the Fusarium oxysporum phytopathogen. The maximum zone of inhibition (18 mm) of Pectobacterium carotovorum bacteria was at a concentration of 0.4%.

SEARCH FOR THE THERAPEUTIC POTENTIAL OF BIOLOGICALLY ACTIVE SUBSTANCES CONTAINED IN CONIFEROUS PLANTS

The paper presents scientific information about the problems in the search for therapeutic potential in coniferous plants widely used in folk medicine. Samples of coniferous plants growing in the mountain forests of the Western Altai in the eastern part of Kazakhstan were selected for the experiment: Baltic pine (Pinus sylvestris L.), European spruce (Picea abies L.), Siberian fir (Abies sibírica), Siberian pine (Pinus sibirica DuTour), and common juniper (Juniperus communis L.). During the study, the phytochemical composition of the components of P. sylvestris L. essential oils was determined by the indicators of sesquiterpenic fraction (69.76%), terpenoids (20.0%), and monoterpenes (5.51%). Using modern methods of studying biological activity (antimicrobial, antifungal, and anthelmintic), the authors established the presence of biological activity in the extracts of selected coniferous plants. In all coniferous plants, bactericidal activity was manifested in water decoctions, where biological preparations of Siberian fir and Baltic pine were more active. The oil extracts showed less bactericidal activity. Among them, extracts of Siberian pine and juniper were inactive, and the extract of European spruce was more active in its native form and 1:2 dilution. Among plants with a complete absence of bactericidal activity against the Candida parapsilosis opportunistic yeast, Siberian fir should be named. In other coniferous plants (European spruce, Baltic pine, juniper), bactericidal activity was detected only in oil solutions in a dilution of 1:2, and oil extract of Siberian pine in a dilution of 1:8 had a suppressive effect. Water/alcohol tincture of Siberian fir was found to have high fungicidal activity against Aspergillusniger, which continued to influence the growth of the micromycete at a dilution of 1:64 during the observation period. The presence of antiparasitic properties was observed in some plant extracts of coniferous forest plants. The best results were noted in alcohol tinctures of Baltic pine, juniper, and Siberian pine.

Synthesis and Evaluation on the Fungicidal Activity of S-Alkyl Substituted Thioglycolurils

A series of S-alkyl substituted thioglycolurils was prepared through the alkylation of corresponding thioglycolurils with halogenoalkanes and tested for their fungicidal activity against six phytopathogenic fungi from different taxonomic classes: Venturia inaequalis, Rhizoctonia solani, Fusarium oxysporum, Fusarium moniliforme, Bipolaris sorokiniana, and Sclerotinia sclerotiorum, and two pathogenic yeasts: Candida albicans and Cryptococcus neoformans var. grubii. A number of S-alkyl substituted thioglycolurils exhibited high activity against Venturia inaequalis and Rhizoctonia solani (85-100% mycelium growth inhibition), and moderate activity against other phytopathogens. S-Ethyl substituted thioglycolurils possessed a high activity against Candida albicans. Additionally, the hemolytic and cytotoxic properties of promising derivatives were determined using human red blood cells and human embryonic kidney cells, respectively. Two S-ethyl derivatives possessed both low cytotoxicity against normal human cells and high fungicidal activity against Candida albicans.

Lenzites betulina базидиальді саңырауқұлағының микробқа қарсы белсенділігін арттыруда оңтайлы өсіру жағдайларын таңдау

In recent decades, more and more attention has been paid to the study of various compounds isolated from higher basidial fungi. The analysis of the taxonomic species composition of fungi of the genus basidiomycetes causing white rot on birch is carried out. During the study of cultural - morphological and molecular - genetic properties, it was found that the culture of fungi belongs to the species Lenzites betulina. To increase the ability of the isolated fungus to synthesize antimicrobial compounds, the composition of the nutrient medium (the ratio of carbon and peptone) was modified, the optimal temperature (28 ° C) and pH medium (7.5-8.0) were selected. Antagonistic properties between the test cultures of S.marcescens, E. coli, S.aureus, C. albicans and the culture of Lenzites betulina fungi were also studied. The study showed that the greatest antibiotic effect of Lenzites betulina fungi was exerted on the culture of С.albicans yeast and E.coli bacteria. Thus, it was found that fungi of the Lenzites betulina species exhibit high bactericidal and fungicidal activity to opportunistic yeast and bacterial cultures.

Synthesis and Pesticidal Activity of New Niacinamide Derivatives Containing a Flexible, Chiral Chain

Natural products are a source for pesticide or drug discovery. In order to discover lead compounds with high fungicidal or herbicidal activity, new niacinamide derivatives derived from the natural product niacinamide, containing chiral flexible chains, were designed and synthesized. Their structures were confirmed by 1H NMR, 13C NMR and HRMS analysis. The fungicidal and herbicidal activities of these compounds were tested. The fungicidal activity results demonstrated that the compound (S)-2-(2-chloronicotinamido)propyl-2-methylbenzoate (3i) exhibited good fungicidal activity (92.3% inhibition) against the plant pathogen Botryosphaeria berengriana at 50 μg/mL and with an EC50 of 6.68 ± 0.72 μg/mL, which is the same as the positive control (fluxapyroxad). Compound 3i was not phytotoxic and could therefore be used as a fungicide on crops. Structure-activity relationships (SAR) were studied by molecular docking simulations with the succinate dehydrogenase of the fungal mitochondrial respiratory chain.

A New Method of Preparing Aurone by Marine Actinomycetes and Its Potential Application in Agricultural Fungicides.

A strain of marine actinomycetes was isolated from an intertidal zone and identified as Streptomyces cinereoruber. Through the fermentation of this strain, a compound with fungicidal activity was extracted and purified. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR) data, the metabolite was determined to be an aurone. The toxicity of the aurone toward four kinds of tumor cells-SH-SY5Y, HepG2, A549, and HeLa cells-was verified by the MTT method, delivering IC50 values of 41.81, 47.19, 63.95, and 51.92 μg/mL, respectively. Greenhouse bioassay showed that the aurone exhibited a high fungicidal activity against powder mildew (Botrytis cinerea), cucurbits powder mildew (Sphaerotheca fuliginea (Schlecht ex Ff.) Poll), and rice blast (Pyricularia oryzae).