Chemistry and Biology of Ustiloxin Analogs as Mycotoxins.

Ustiloxin analogs, including ustiloxins and phomopsins, are a group of cyclopeptide mycotoxins produced by fungi. They are a 13-membered macrocyclic ring and an ether linkage between tyrosine and isoleucine as the core structure. They are ribosomally synthesized and post-translationally modified peptides.

Ustisorbicillinols G and H, Two New Antibacterial Sorbicillinoids from the Albino Strain LN02 of Rice False Smut Fungus .

(anamorph: ), the causal fungal pathogen of rice false smut, has been found to produce various secondary metabolites. The albino strain LN02 is a natural albino phenotype mutant of due to its inability to produce ustilaginoidins. The fermentation of LN02 was performed in solid rice medium to obtain fungal cultures, which were chemically investigated.

Detoxification of Ustiloxin A Through Oxidative Deamination and Decarboxylation by Endophytic Fungus .

Ustiloxins are a group of cyclopeptide mycotoxins produced by rice false smut pathogen (anamorph: ) which seriously threaten the safety production of rice and the health of humans and livestock. Ustiloxin A, accounting for 60% of the total ustiloxins, is the main toxic component. Biotransformation, a process of modifying the functional groups of compounds by means of regio- or stereo-specific reactions catalyzed by the enzymes produced by organisms, has been considered as an efficient way to detoxify mycotoxins.

Regulation of Histone Acetylation Modification on Biosynthesis of Secondary Metabolites in Fungi.

The histone acetylation modification is a conservative post-translational epigenetic regulation in fungi. It includes acetylation and deacetylation at the lysine residues of histone, which are catalyzed by histone acetyltransferase (HAT) and deacetylase (HDAC), respectively. The histone acetylation modification plays crucial roles in fungal growth and development, environmental stress response, secondary metabolite (SM) biosynthesis, and pathogenicity.

Involvement of LaeA and Velvet Proteins in Regulating the Production of Mycotoxins and Other Fungal Secondary Metabolites.

Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an -adenosylmethionine binding site and displays methyltransferase activity.

Phytotoxic Isocassadiene-Type Diterpenoids from Tomato Fusarium Crown and Root Rot Pathogen f. sp. .

Fusarium crown and root rot (FCRR) has emerged as a highly destructive soil-borne disease, posing a significant threat to the safe cultivation of tomatoes in recent years. The pathogen of tomato FCRR is f. sp.

Rosellichalasins A-H, cytotoxic cytochalasans from the endophytic fungus Rosellinia sp. Glinf021.

Eight new cytochalasans rosellichalasins A-H (1-8), as well as two new shunt metabolites rosellinins A (9) and B (10) before intramolecular Diels-Alder cycloaddition reaction in cytochalasan biosynthesis, along with nine known cytochalsans (11-19) were isolated from the endophytic fungus Rosellinia sp. Glinf021, which was derived from the medicinal plant Glycyrrhiza inflata. Their structures were characterized by extensive analysis of 1D and 2D NMR as well as HRESIMS spectra and quantum chemical ECD calculations.

Diphenyl ethers from endophytic fungus Rhexocercosporidium sp. Dzf14 and their antibacterial activity by affecting homeostasis of cell membranes.

Background: Phytopathogenic bacteria cause severe losses to crops every year. The management of crop bacterial diseases with chemical agents has been considered as the main strategy. In order to cope with the bactericide resistance made by the pathogens, new antibacterials need to be continuously developed.

Activation of Ustilaginoidin Biosynthesis Gene in Albino Strain LN02 Influences Development, Stress Responses, and Inhibition of Rice Seed Germination.

(anamorph: ) is the pathogen of rice false smut (RFS), which is a destructive rice fungal disease. The albino strain LN02 is a natural white-phenotype mutant of due to its incapability to produce toxic ustilaginoidins. In this study, three strains including the normal strain P1, albino strain LN02, and complemented strain -1 of the LN02 strain were employed to investigate the activation of the ustilaginoidin biosynthesis gene in the albino strain LN02 to influence sporulation, conidia germination, pigment production, stress responses, and the inhibition of rice seed germination.

Rosellosides A and B, two phenyloxazole glycosides from -derived fungus sp. Glinf021.

Two new chlorinated phenyloxazole glycosides, named rosellosides A () and B (), were isolated from the endophytic fungus sp. Glinf021, which was derived from the medicinal plant (Leguminosae). Both compounds were rare chlorinated polyketide glycosides bearing an oxazole moiety.

A Genome-Wide Comparison of Rice False Smut Fungus Albino Strain LN02 Reveals the Genetic Diversity of Secondary Metabolites and the Cause of Albinism.

Rice false smut (RFS) caused by (anamorph: ) has become one of the most destructive fungal diseases to decrease the yield and quality of rice grains. An albino strain LN02 was isolated from the white RFS balls collected in the Liaoning Province of China in 2019. The strain LN02 was considered as a natural albino mutant of by analyzing its phenotypes, internal transcribed spacer (ITS) conserved sequence, and biosynthesis gene clusters (BGCs) for secondary metabolites.

Effects of Carbon, Nitrogen, Ambient pH and Light on Mycelial Growth, Sporulation, Sorbicillinoid Biosynthesis and Related Gene Expression in .

Sorbicillinoids are a class of hexaketide metabolites produced by (teleomorph: ), an important fungal pathogen that causes a devastating rice disease. In this study, we investigated the effects of environmental factors, including carbon and nitrogen sources, ambient pH and light exposure, on mycelial growth, sporulation, as well as the accumulation of sorbicillinoids, and the expression of related genes involved in sorbicillinoid biosynthesis. It was found that the environmental factors had great influences on mycelial growth and sporulation of .

Recent Advances in Search of Bioactive Secondary Metabolites from Fungi Triggered by Chemical Epigenetic Modifiers.

Genomic analysis has demonstrated that many fungi possess essential gene clusters for the production of previously unobserved secondary metabolites; however, these genes are normally reduced or silenced under most conditions. These cryptic biosynthetic gene clusters have become treasures of new bioactive secondary metabolites. The induction of these biosynthetic gene clusters under stress or special conditions can improve the titers of known compounds or the production of novel compounds.

and Involved in Sorbicillinoid Biosynthesis Contribute to Fungal Development, Stress Response and Phytotoxicity in .

(teleomorph: ) is an important fungal pathogen that causes a devastating rice disease. It can produce mycotoxins including sorbicillinoids. The biosynthesis and biological functions of sorbicillinoids have not been reported in .

Recent Advances in Sorbicillinoids from Fungi and Their Bioactivities (Covering 2016-2021).

Sorbicillinoids are a family of hexaketide metabolites with a characteristic sorbyl side chain residue. Sixty-nine sorbicillinoids from fungi, newly identified from 2016 to 2021, are summarized in this review, including their structures and bioactivities. They are classified into monomeric, dimeric, trimeric, and hybrid sorbicillinoids according to their basic structural features, with the main groups comprising both monomeric and dimeric sorbicillinoids.

Phytotoxic Secondary Metabolites from Fungi.

Fungal phytotoxic secondary metabolites are poisonous substances to plants produced by fungi through naturally occurring biochemical reactions. These metabolites exhibit a high level of diversity in their properties, such as structures, phytotoxic activities, and modes of toxicity. They are mainly isolated from phytopathogenic fungal species in the genera of , , , , , and .