Fungicidal preparations from Inula viscosa

Inula viscosa is a perennial plant native to the Mediterranean Basin. Extracts made from the shoots of this plant exhibited a strong fungicidal activity in vitro and in vivo. TLC analyses revealed at least 7 fungicidal compounds. Most are lipophilic. When such extracts were sprayed on the leaf surface of crop plants they effectively controlled downy mildew in grape, cucumber and tobacco; late blight in potato and tomato; gray mold in cucumber and tomato; and, powdery mildew in cucurbits and cereals. Field experiments conducted with grape vine and potato resulted in effective control of Plasmopara viticola and Phytophthora infestans, respectively. The data suggest that Inula viscosa is a useful source of herbal fungicidal preparations for agricultural use.

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A Peptide Found in Human Serum, Derived from the C-Terminus of Albumin, Shows Antifungal Activity In Vitro and In Vivo

Microorganisms ◽

10.3390/microorganisms8101627 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1627

Author(s):

Tecla Ciociola ◽

Pier Paolo Zanello ◽

Tiziana D’Adda ◽

Serena Galati ◽

Stefania Conti ◽

...

Keyword(s):

Antifungal Activity ◽

Human Serum ◽

Fungicidal Activity ◽

Galleria Mellonella ◽

Serum Proteins ◽

Morphological Alterations ◽

C Terminus ◽

Different Sources

The growing problem of antimicrobial resistance highlights the need for alternative strategies to combat infections. From this perspective, there is a considerable interest in natural molecules obtained from different sources, which are shown to be active against microorganisms, either alone or in association with conventional drugs. In this paper, peptides with the same sequence of fragments, found in human serum, derived from physiological proteins, were evaluated for their antifungal activity. A 13-residue peptide, representing the 597–609 fragment within the albumin C-terminus, was proved to exert a fungicidal activity in vitro against pathogenic yeasts and a therapeutic effect in vivo in the experimental model of candidal infection in Galleria mellonella. Studies by confocal microscopy and transmission and scanning electron microscopy demonstrated that the peptide penetrates and accumulates in Candida albicans cells, causing gross morphological alterations in cellular structure. These findings add albumin to the group of proteins, which already includes hemoglobin and antibodies, that could give rise to cryptic antimicrobial fragments, and could suggest their role in anti-infective homeostasis. The study of bioactive fragments from serum proteins could open interesting perspectives for the development of new antimicrobial molecules derived by natural sources.

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In Vitro and In Vivo Antifungal Activity of Sorbicillinoids Produced by Trichoderma longibrachiatum

Journal of Fungi ◽

10.3390/jof7060428 ◽

2021 ◽

Vol 7 (6) ◽

pp. 428

Author(s):

Men Thi Ngo ◽

Minh Van Nguyen ◽

Jae Woo Han ◽

Myung Soo Park ◽

Hun Kim ◽

...

Keyword(s):

Late Blight ◽

Culture Filtrate ◽

Fungal Pathogens ◽

Gray Mold ◽

Trichoderma Longibrachiatum ◽

Chemical Structures ◽

Natural Agents ◽

Blight Disease

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.

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Synergistic Effect of Combined Application of a New Fungicide Fluopimomide with a Biocontrol Agent Bacillus methylotrophicus TA-1 for Management of Gray Mold in Tomato

Plant Disease ◽

10.1094/pdis-01-19-0143-re ◽

2019 ◽

Vol 103 (8) ◽

pp. 1991-1997 ◽

Cited By ~ 3

Author(s):

Xiaoxue Ji ◽

Jingjing Li ◽

Zhen Meng ◽

Shouan Zhang ◽

Bei Dong ◽

...

Keyword(s):

Field Experiments ◽

Biocontrol Agent ◽

Severe Disease ◽

Combined Treatment ◽

Field Trials ◽

Antimicrobial Activities ◽

Gray Mold ◽

Control Efficacy ◽

Bacillus Methylotrophicus

Gray mold caused by Botrytis cinerea can be a severe disease of tomato infecting leaves and fruits of tomato plants. Chemical control is currently the most effective and reliable method; however, application of fungicides has many drawbacks. The combination of biological control agents with newly developed fungicides may be a practicable method to control B. cinerea. Fluopimomide is a newly developed fungicide with a novel mode of action. Bacillus methylotrophicus TA-1, isolated from rhizosphere soil of tomato, is a bacterial strain with a broad spectrum of antimicrobial activities. Little information is currently available about the effect of fluopimomide and its integrated effect on B. cinerea. Therefore, laboratory, pot, and field experiments were carried out to determine the effects of fluopimomide alone and in combination with B. methylotrophicus TA-1 against gray mold on tomato. The in vitro growth of B. methylotrophicus TA-1 was unaffected by 100 mg liter−1 fluopimomide. Inhibition of B. cinerea mycelial growth was significantly increased under combined treatment of fluopimomide and B. methylotrophicus TA-1. In greenhouse experiments, efficacy against gray mold was significantly greater by an integration of fluopimomide and B. methylotrophicus TA-1 than by either alone; control efficacy of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 at 108 colony-forming units (cfu) ml−1 reached 70.16 and 69.32%, respectively, compared with the untreated control. In both field trials during 2017 and 2018, control efficacy was significantly higher for the combination of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 than for either treatment alone. The results from this study indicated that integration of the new fungicide fluopimomide with the biocontrol agent B. methylotrophicus TA-1 synergistically increased control efficacy of the fungicide against gray mold of tomato.

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Combinatorial Synthesis of Novel 1-Sulfonyloxy/acyloxyeugenol Derivatives as Fungicidal Agents

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207324666210813114829 ◽

2021 ◽

Vol 24 ◽

Author(s):

Genqiang Chen ◽

Lina Zhu ◽

Jiaxuan He ◽

Song Zhang ◽

Yuanhao Li ◽

...

Keyword(s):

Fungicidal Activity ◽

High Efficiency ◽

Biological Activities ◽

Phytophthora Capsici ◽

Effective Control ◽

Syzygium Aromaticum ◽

Wide Range ◽

Structural Skeleton ◽

Acyloxy Group

Background: Developing the high-efficiency and low-risk small-molecule green-fungicide is the key to effective control of the plant pathogenic oomycetes. Essential oils play a very important role in novel fungicide discovery for their unique sources and potential target sites. Eugenol, a kind of plant essential oil, was mainly isolated from the unopened and dried flower buds of Syzygium aromaticum of the Myrtaceae family. Due to its unique structural skeleton, eugenol and its derivatives have exhibited a wide range of biological activities. However, study on the synthesis of novel 1-sulfonyloxy/acyloxyeugenol derivatives as fungicidal agents against Phytophthora capsici has not yet been reported. Methods: Twenty-six novel 1-sulfonyloxy/acyloxyeugenol derivatives (3a-p and 5a-j) were prepared and their structures were well characterized by 1H NMR, HRMS, and m.p.. Their fungicidal activity was evaluated against P. capsici by using the mycelial growth rate method. Results: To find novel natural-product-based fungicidal agents to control the plant pathogenic oomycetes, we herein designed and synthesized two series of novel 1-sulfonyloxy/acyloxyeugenol derivatives (3a-p and 5a-j) as fungicidal agents against P. capsici Leonian, in vitro. Results of fungicidal activity revealed that, among all compounds, especially compounds 3a, 3f, and 3n displayed the most potent anti-oomycete activity against P. capsici with EC50 values of 79.05, 75.05, and 70.80, respectively. Conclusion: The results revealed that the anti-oomycete activity of eugenol with the sulfonyloxy group was higher than that with the acyloxy group. It is suggested that the fungicidal activity of eugenol can be improved by introducing the sulfonyloxy group. This will pave the way for further design, structural modification, and to develop eugenol derivatives as fungicidal agents.

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Efficacy of Potential Control Agents Against Rosellinia necatrix and Their Physiological Impact on Avocado

Plant Disease ◽

10.1094/pdis-08-20-1751-re ◽

2021 ◽

Author(s):

Phinda Magagula ◽

Nicky Taylor ◽

Velushka Swart ◽

Noëlani van den Berg

Keyword(s):

Integrated Management ◽

Integrated Approach ◽

Dry Mass ◽

Persea Americana ◽

Effective Control ◽

Rosellinia Necatrix ◽

Potential Control ◽

Greenhouse Trial

Rosellinia necatrix is the causal agent of white root rot (WRR), a fatal disease affecting many woody plants, including avocado (Persea americana). As with other root diseases, an integrated approach is required to control WRR. No fully effective control methods are available, and no chemical or biological agents against R. necatrix have been registered for use on avocado in South Africa. Fluazinam has shown promising results in the greenhouse and field in other countries, including Spain. The current study aimed to investigate the potential of a fumigant, chloropicrin, and biological control agents (B-Rus, Beta-Bak, Mity-Gro, and Trichoderma) against R. necatrix both in vitro and in vivo as compared with fluazinam. In a greenhouse trial, results showed that Trichoderma and B-Rus were as effective as fluazinam at inhibiting R. necatrix in vitro and suppressed WRR symptoms when applied before inoculation with R. necatrix. In contrast, Mity-Gro and Beta-Bak failed to inhibit the pathogen in vitro and in the greenhouse trial, despite application of the products to plants before R. necatrix infection. Fluazinam suppressed WRR symptoms in plants when applied at the early stages of infection, whereas chloropicrin rendered the pathogen nonviable when used as a preplant treatment. Plants treated with Trichoderma, B-Rus, and fluazinam sustained dry mass production and net CO2 assimilation by maintaining the green leaf tissues despite being infected with the pathogen. This study has important implications for the integrated management of WRR.

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Adenine nucleotides and magnesium ions in relation to control of mammalian cerebral-cortex hexokinase

Biochemical Journal ◽

10.1042/bj1120579 ◽

1969 ◽

Vol 112 (5) ◽

pp. 579-586 ◽

Cited By ~ 40

Author(s):

H S Bachelard ◽

P. S. G. Goldfarb

Keyword(s):

Mixed Type ◽

Competitive Inhibition ◽

Adenine Nucleotides ◽

Effective Control ◽

Magnesium Ions ◽

Soluble Enzyme ◽

Kinetics Of ◽

Kinetics Of Inhibition

1. The kinetics of inhibition of brain soluble cytoplasmic hexokinase by ADP were examined in relation to variations in the concentrations of Mg2+ and ATP. The type of inhibition observed was dependent on the Mg2+/ATP ratio. 2. ADP at Mg2+/ATP ratios 2:1 exhibited inhibition of the ‘mixed’ type; at Mg2+/ATP ratios 1:1 the inhibition appeared to be competitive with regard to ATP. 3. Inhibition by free ATP was observed when the Mg2+/ATP ratio was less than 1:1. The inhibition was also of the ‘mixed’ type with respect to MgATP2−. 4. The inhibitions due to ADP and to free ATP were not additive. The results suggested that there may be up to four sites in the soluble enzyme: for glucose, glucose 6-phosphate, ADP and MgATP2−. 5. The ‘free’ non-particulate intracellular Mg2+ concentration was measured and concluded to be about 1·5mm. 6. The concentrations in vivo of Mg2+ and ATP likely to be accessible to a cytoplasmic enzyme are suggested to be below those that yield maximum hexokinase rates in vitro. The enzymic rates were measured at relevant suboptimum concentrations of Mg2+ and ATP in the presence of ADP. Calculations that included non-competitive inhibition due to glucose 6-phosphate (56–65% at 0·25mm) resulted in net rates very similar to the measured rates for overall glycolysis. This system may therefore provide a basis for effective control of cerebral hexokinase.

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Effects of Origanum vulgare essential oil and its two main components, carvacrol and thymol, on the plant pathogen Botrytis cinerea

PeerJ ◽

10.7717/peerj.9626 ◽

2020 ◽

Vol 8 ◽

pp. e9626

Author(s):

Huiyu Hou ◽

Xueying Zhang ◽

Te Zhao ◽

Lin Zhou

Keyword(s):

Antifungal Activity ◽

Essential Oil ◽

Botrytis Cinerea ◽

Spore Germination ◽

Gray Mold ◽

Origanum Vulgare ◽

Mycelium Growth ◽

Main Components

Background Botrytis cinerea causes serious gray mold disease in many plants. This pathogen has developed resistance to many fungicides. Thus, it has become necessary to look for new safe yet effective compounds against B. cinerea. Methods Essential oils (EOs) from 17 plant species were assayed against B. cinerea, of which Origanum vulgare essential oil (OVEO) showed strong antifungal activity, and accordingly its main components were detected by GC/MS. Further study was conducted on the effects of OVEO, carvacrol and thymol in vitro on mycelium growth and spore germination, mycelium morphology, leakages of cytoplasmic contents, mitochondrial injury and accumulation of reactive oxygen species (ROS) of B. cinerea. The control efficacies of OVEO, carvacrol and thymol on tomato gray mold were evaluated in vivo. Results Of all the 17 plant EOs tested, Cinnamomum cassia, Litsea cubeba var. formosana and O. vulgare EOs had the best inhibitory effect on B. cinerea, with 0.5 mg/mL completely inhibiting the mycelium growth of B. cinerea. Twenty-one different compounds of OVEO were identified by gas chromatography–mass spectrometry, and the main chemical components were carvacrol (89.98%), β-caryophyllene (3.34%), thymol (2.39%), α-humulene (1.38%) and 1-methyl-2-propan-2-ylbenzene isopropyl benzene (1.36%). In vitro experiment showed EC50 values of OVEO, carvacrol and thymol were 140.04, 9.09 and 21.32 μg/mL, respectively. Carvacrol and thymol completely inhibited the spore germination of B. cinerea at the concentration of 300 μg/mL while the inhibition rate of OVEO was 80.03%. EC50 of carvacrol and thymol have significantly (P < 0.05) reduced the fresh and dry weight of mycelia. The collapse and damage on B. cinerea mycelia treated with 40 μg/mL of carvacrol and thymol was examined by scanning electron microscope (SEM). Through extracellular conductivity test and fluorescence microscope observation, it was found that carvacrol and thymol led to increase the permeability of target cells, the destruction of mitochondrial membrane and ROS accumulation. In vivo conditions, 1000 μg/mL carvacrol had the best protective and therapeutic effects on tomato gray mold (77.98% and 28.04%, respectively), and the protective effect was significantly higher than that of 400 μg/mL pyrimethanil (43.15%). While the therapeutic and protective effects of 1,000 μg/mL OVEO and thymol were comparable to chemical control. Conclusions OVEO showed moderate antifungal activity, whereas its main components carvacrol and thymol have great application potential as natural fungicides or lead compounds for commercial fungicides in preventing and controlling plant diseases caused by B. cinerea.

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Actinomycete as biocontrol agents against tomato gray mold disease caused by Botrytis cinerea

Kuwait Journal of Science ◽

10.48129/kjs.v48i3.9200 ◽

2021 ◽

Vol 48 (3) ◽

Author(s):

Hind Lahmyed ◽

◽

Rachid Bouharroud ◽

Redouan Qessaoui ◽

Abdelhadi Ajerrar ◽

...

Keyword(s):

Botrytis Cinerea ◽

Extracellular Enzymes ◽

Chitinase Activity ◽

Gray Mold ◽

Antagonistic Activity ◽

Future Research ◽

In Planta ◽

Tomato Fruits

The present work aims to isolate actinomycete bacteria with antagonistic abilities towards Botrytis cinerea, the causal agent of gray mold, from a soil sample collected from the rhizosphere of a healthy tomato grove. In vitro confrontation led to the isolation of 104 actinomycete isolates; fifteen isolates have shown the most significant mortality rate of the mycelial growth of B. cinerea (>50%). Based on the results of this screening, representative strains were selected to verify their in vivo antagonistic activity on tomato fruits; the reduction of B. cinerea has a percentage ranging from 52.38% to 96.19%. Furthermore, the actinomycete isolates were evaluated for their plant growth-promoting (PGP) properties and their ability to produce biocontrol-related extracellular enzymes viz., amylase, protease, cellulase, chitinase, esterases, and lecithinase. Indeed, Ac70 showed high β-1,3-glucanase activity and siderophore production (17U/ml and 43% respectively), and the highest chitinase activity (39μmol/ml) was observed for Ac24. These results indicated that these actinomycetes might potentially control gray mold caused by B. cinerea on tomato fruits. Investigations on enhancing the efficacy and survival of the biocontrol agent in planta and finding out the best formulation are recommended for future research.

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Warburgia ugandensis Leaf and Bark Extracts: An Alternative to Copper as Fungicide against Downy Mildew in Organic Viticulture?

Plants ◽

10.3390/plants10122765 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2765

Author(s):

Christian Kraus ◽

Rada Abou-Ammar ◽

Andreas Schubert ◽

Michael Fischer

Keyword(s):

Heavy Metal ◽

Downy Mildew ◽

Leaf Extract ◽

Plasmopara Viticola ◽

Field Trials ◽

Bark Extract ◽

Leaf Discs ◽

Intensive Use

In organic viticulture, copper-based fungicides are commonly used to suppress Downy Mildew infection, caused by the oomycete Plasmopara viticola. However, the frequent and intensive use of such fungicides leads to accumulation of the heavy metal in soil and nearby waters with adverse effects on the ecosystem. Therefore, alternative, organic fungicides against Downy Mildew are urgently needed to reduce the copper load in vineyards. In this study, the use of Warburgia ugandensis Sprague (Family Canellacea) leaf and bark extracts as potential fungicides against Downy Mildew were evaluated. In vitro (microtiter) and in vivo (leaf discs, seedlings) tests were conducted, as well as field trials to determine the efficacy of the extracts against Downy Mildew. The results revealed an MIC100 of 500 µg/mL for the leaf extract and 5 µg/mL for the bark extract. Furthermore, experiments with leaf discs and seedlings demonstrated a strong protective effect of the extracts for up to 48 h under (semi-) controlled conditions. However, in field trials the efficacy of the extracts distinctly declined, regardless of the extracts’ origin and concentration.

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Evolution from Natural β-Carboline Alkaloids to Obtain 1,2,4,9-tetrahydro-3-thia-9-aza-fluorene Derivatives as Potent Fungicidal Agents against Rhizoctonia solani

International Journal of Molecular Sciences ◽

10.3390/ijms19124044 ◽

2018 ◽

Vol 19 (12) ◽

pp. 4044 ◽

Cited By ~ 1

Author(s):

Junmin Xi ◽

Zhijun Zhang ◽

Qi Zhu ◽

Guohua Zhong

Keyword(s):

Rhizoctonia Solani ◽

Fungicidal Activity ◽

Sheath Blight ◽

Potential Candidate ◽

Oxygen Species ◽

Rice Sheath Blight ◽

Validamycin A ◽

Rice Disease

Rice sheath blight, caused by Rhizoctonia solani, is a globally important rice disease and the increasing resistance of this pathogen highlights the need for new active compounds against rice sheath blight. In this study, natural β-carboline alkaloids were optimized to obtain a series of 1,2,4,9-tetrahydro-3-thia-9-aza-fluorene derivatives and evaluated for their fungicidal activity and mode of action against R. solani. Of these compounds, 18 exhibited significant in vitro fungicidal activity against R. solani, with an EC50 value of 2.35 μg/mL, and was more active than validamycin A. In vivo bioassay also demonstrated that 18 displayed superior protective and curative activities as compared to validamycin A. Mechanistically, 18 not only induced the loss of mitochondrial membrane potential and accumulation of reactive oxygen species, but also interfered with DNA synthesis. Therefore, compound 18 displayed pronounced in vitro and in vivo fungicidal activity against R. solani and could be used as a potential candidate for the control of rice sheath blight.

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