Discovery of Novel Antioomycete Metabolites from the Marine-Derived Fungus .

In our screening program for natural products that are effective in controlling plant diseases, we found that the culture filtrate of SFC20160907-M11 effectively suppressed the development of tomato late blight disease caused by . Using a bioassay-guided fractionation of antioomycete activity, 12 active compounds (-) were obtained from an ethyl acetate extract of the culture filtrate. Chemical structures of five new compounds - were determined by the extensive analyses of nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS), and circular dichroism (CD) data.

Edeine B produced by reduces the virulence of a plant pathogenic fungus by inhibiting mitochondrial respiration.

Plant pathogenic fungi cause serious diseases, which result in the loss of crop yields and reduce the quality of crops worldwide. To counteract the escalating risks of chemical fungicides, interest in biological control agents to manage plant diseases has significantly increased. In this study, we comprehensively screened microbial culture filtrates using a yeast screening system to find microbes exhibiting respiratory inhibition activity.

Sulfur metabolism-mediated fungal glutathione biosynthesis is essential for oxidative stress resistance and pathogenicity in the plant pathogenic fungus .

is a destructive fungal pathogen that causes Fusarium head blight (FHB) on a wide range of cereal crops. To control fungal diseases, it is essential to comprehend the pathogenic mechanisms that enable fungi to overcome host defenses during infection. Pathogens require an oxidative stress response to overcome host-derived oxidative stress.

Biocontrol potential of HK235 producing antifungal-related peptide chitinocin.

is a necrotrophic fungal pathogen with an extremely broad host range, causing significant economic losses in agricultural production. In this study, we discovered a culture filtrate of bacterial strain HK235, which was identified as , exhibiting high levels of antifungal activity against . From the HK235 culture filtrate, we isolated a new antimicrobial peptide molecule designated as chitinocin based on activity-guided fractionation followed by characterization of the amino acid composition and spectroscopic analyses.

Phenyl Ethers from the Marine-Derived Fungus and Their Antimicrobial Activity Against Plant Pathogenic Fungi and Bacteria.

Marine fungi produce various secondary metabolites with unique chemical structures and diverse biological activities. In the continuing search for new antifungal agents from fungi isolated from marine environments, the culture filtrate of a fungus SFC20160407-M11 exhibited the potential to control plant diseases caused by fungi. From the culture filtrate of SFC20160407-M11, a total of seven compounds were isolated and identified by activity-guided column chromatography and spectroscopic analysis: violaceol I (), violaceol II (), diorcinol (), versinol (), orcinol (), orsellinic acid (), and sydowiol C ().

Curvicollide D, a new modified γ-lactone from the culture broth of Albifimbria verrucaria and its antifungal activity against plant pathogenic fungi.

In our screening program for new antifungal active compounds, a new modified γ-lactone curvicollide D (1) together with five known trichothecenes (2-6) were isolated from the culture filtrate of fungus Albifimbria verrucaria based on the in vitro antifungal assay. The chemical structure of new compound 1 was elucidated by NMR and HR-MS spectroscopic analyses, and the relative configurations of 1 were deduced from NOE experiments and coupling constant analysis. Compound 1 exhibited moderate antifungal activities against plant pathogenic fungi Botrytis cinerea, Colletotrichum coccodes, and Magnaporthe oryzae with MIC value in a range of 100-200 µg ml.

Characterization of Alternaria porri causing onion purple blotch and its antifungal compound magnolol identified from Caryodaphnopsis baviensis.

Alternaria porri (Ellis) Clf. causes purple blotch disease on Allium plants which results in the reduction of crop yields and quality. In this study, to efficiently find natural antifungal compounds against A.

Biocontrol Potential of Species Producing Antimicrobial Metabolites.

Microbial metabolites have been recognized as an important source for the discovery of new antifungal agents because of their diverse chemical structures with novel modes of action. In the course of our screening for new antifungal agents from microbes, we found that culture filtrates of two fungal species SFC20200425-M11 and SFC20200425-M27 have the potentials to reduce the development of fungal plant diseases such as tomato late blight and wheat leaf rust. From these two spp.

Clerodane Diterpenoids Identified from Showing Antifungal Activity against Plant Pathogens.

In the search for new natural resources showing plant disease control effects, we found that the methanol extract of suppressed fungal disease development in plants. To identify the bioactive substances, the methanol extract of was extracted by organic solvents, and consequently, four new 2-oxo-clerodane diterpenes (), a new 4(3 → 2)--clerodane diterpene (), together with ten known compounds () were isolated and identified from the extracts. Of the new compounds, compound showed a broad spectrum of antifungal activity with moderated minimum inhibitory concentration (MIC) values in a range of 50-100 μg/mL against tested fungal pathogens.

Plant Disease Control Efficacy of and Its Antifungal Compounds.

Plants contain a number of bioactive compounds that exhibit antimicrobial activity, which can be recognized as an important source of agrochemicals for plant disease control. In searching for natural alternatives to synthetic fungicides, we found that a methanol extract of the plant species suppressed the disease development of rice blast caused by . Through a series of chromatography procedures in combination with activity-guided fractionation, we isolated and identified a total of eleven compounds including four labdane-type diterpenes (-), six isopimarane-type diterpenes (-), and one sesquiterpene ().

Genome Sequence of Brevibacillus brevis HK544, an Antimicrobial Bacterium Isolated from Soil in Daejeon, South Korea.

The Brevibacillus brevis HK544 strain, which was isolated from soil, exhibited antimicrobial activity against plant pathogens such as Botrytis cinerea, Phytophthora infestans, and Erwinia amylovora. Here, we report the draft genome sequence of the B. brevis HK544 strain, which consists of one circular chromosome of 6,486,246 bp with a GC content of 47.

In Vitro and In Vivo Antifungal Activity of Sorbicillinoids Produced by .

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of 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 (), and a new natural compound, 2',3'-dihydro-epoxysorbicillinol (), together with 11 known compounds (-), were obtained from the solvent extracts.

The Antifungal Test: An Efficient Screening Tool for the Discovery of Microbial Metabolites with Respiratory Inhibitory Activity.

Valuable natural compounds produced by a variety of microorganisms can be used as lead molecules for development of new agrochemicals. Furthermore, high-throughput screening systems with specific modes of action can increase the probability of discovery of new fungicides. In the current study, a rapid assay tested with various microbes was developed to determine the degree of respiratory inhibition of in two different liquid media, YG (containing a fermentable carbon source) and NFYG (containing a non-fermentable carbon source).

Transcription Factor PdeR Is Involved in Fungal Development, Metabolic Change, and Pathogenesis of Gray Mold .

The necrotrophic fungus releases extracellular enzymes that facilitate its penetration into a host. This study functionally characterized the gene of , which is predicted to encode a Zn(II)Cys zinc finger transcription factor. To investigate the role of , deleted and complemented strains of in were generated, which were designated as Δ and PdeRc, respectively.

Discovery of New Triterpenoid Saponins Isolated from with Antifungal Activity against Rice Blast Fungus .

While searching for new antifungal compounds, we revealed that a methanol extract of plant species has a potent antifungal activity against rice blast fungus . To identify the antifungal substances, the methanol extract of was extracted by organic solvents, and consequently, six active compounds were isolated from the -butanol layer. The isolated compounds were five new acylated triterpenoid saponins including maejaposide I (), maejaposides C-1, C-2, and C-3 (-), and maejaposide A-1 (), along with a known one, maejaposide A ().

Antimicrobial aromatic polyketides: a review of their antimicrobial properties and potential use in plant disease control.

Aromatic polyketides are secondary metabolites widely found in bacteria, fungi, and plants, which are well-known for their diverse chemical structures and biological functions. The structural diversity of aromatic polyketides arises from a series of enzymatic modifications of the linear poly-β-ketone intermediates during biosynthesis. Their versatile bioactivities are exemplified by reports of their use as antibacterials, antifungals, antivirals, and antiparasitics.

Identification of novel compounds, oleanane- and ursane-type triterpene glycosides, from Trevesia palmata: their biocontrol activity against phytopathogenic fungi.

Plants contain a number of bioactive compounds that exhibit antimicrobial activity, which can be recognized as an important source of agrochemicals for plant disease control. As part of our search for new antimicrobial agents from natural sources, we found that a crude methanol extract of Trevesia palmata exhibited a promising antifungal activity against phytopathogenic fungi, such as Magnaporthe oryzae and Botrytis cinerea. Furthermore, based on activity-guided fractionation, we isolated five antifungal compounds from the methanol extract of T.

Crinipellins A and I, Two Diterpenoids from the Basidiomycete Fungus , as Potential Natural Fungicides.

In the course of screening for microbes with antifungal activity, we found that the culture filtrate of the IUM00035 isolate exhibited strong antifungal activity against and . Based on the phylogenetic analysis with the ITS region, the IUM00035 isolate was identified as . To identify antifungal compounds from the IUM00035 isolate, the culture filtrate of the isolate was partitioned with ethyl acetate and -butanol and, consequently, two active compounds were isolated from the ethyl acetate extract.

Nematicidal and Plant Growth-Promoting Activity of HK169: Genome Analysis Provides Insight into Its Biological Activities.

In the course of screening for microbes with nematicidal activity, we found that HK169 displayed promising nematicidal activity against the root-knot nematode , along with plant growth-promoting properties. Soil drenching of a culture of HK169 reduced gall formation by 66% while also increasing root and shoot weights by 251% and 160%, respectively, compared with an untreated control. The cell-free culture filtrate of the HK169 culture killed all juveniles of within 48 h.

The chejuenolide biosynthetic gene cluster harboring an iterative trans-AT PKS system in Hahella chejuensis strain MB-1084.

Hahella chejuensis MB-1084 is a Gram-negative marine bacterial strain that produces unusual 17-membered carbocyclic tetraenes, chejuenolide A and B. Two fosmid clones responsible for chejuenolide production were identified from the genomic DNA library of the MB-1084 strain. Systematic inactivation of the open reading frames (ORFs) in the sequenced region defines the boundaries of the chejuenolide (che) biosynthetic gene cluster (24.

In vivo assessment of plant extracts for control of plant diseases: A sesquiterpene ketolactone isolated from Curcuma zedoaria suppresses wheat leaf rust.

As an alternative to synthetic pesticides, natural materials such as plant extracts and microbes have been considered to control plant diseases. In this study, methanol extracts of 120 plants were explored for in vivo antifungal activity against Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia triticina, and Blumeria graminis f. sp.

In Vivo Disease Control Efficacy of Isoquinoline Alkaloids Isolated from against Wheat Leaf Rust and Pepper Anthracnose.

Phytochemicals have been considered as alternatives for synthetic fungicides because of their biodegradability and low toxicity. In this study, we found that the methanolic extract of suppressed the development of plant diseases caused by and . As the antifungal substance, three isoquinoline alkaloids (dehydrocorydaline, stylopine, and corydaline) were isolated from .

Antibacterial activity of tannins isolated from Sapium baccatum extract and use for control of tomato bacterial wilt.

In the search for new antibacterial agents from natural sources, we revealed that a crude methanol extract of Sapium baccatum was highly active against Ralstonia solanacearum, a causal agent of a serious disease called bacterial wilt of tomato. The bioassay-guided fractionation of this extract resulted in the isolation of seven known active compounds, including gallic acid, methyl gallate, corilagin, tercatain, chebulagic acid, chebulinic acid, and quercetin 3-O-α-L-arabinopyranoside. Their chemical structures were determined by electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy.