Reappraisal of causing white tip disease of Canada thistle as a new species, , sp. nov., and bioactivity of its major metabolites.

Bioherbicides are expected to be a supplement to integrated pest management, assisting in the control of problematic weed species. For instance, bioherbicides (Phoma and BioPhoma) were recently registered in Canada and the USA for the control of some perennial dicotyledonous weeds in lawns. These products are based on strains of the fungus (syn.

Structure-Activity Relationships of Natural C-9-Methyl-Substituted 10-Membered Lactones and Their Semisynthetic Derivatives.

Fungal 10-membered lactones (TMLs), such as stagonolide A, herbarumin I, pinolidoxin, and putaminoxin, are promising candidates for the development of nature-derived herbicides. The aim of this study was to analyze the structure-activity relationships (SAR) of C-9-methyl-substituted TMLs with a multitarget bioassay approach to reveal compounds with useful (phytotoxic, entomotoxic, antimicrobial) or undesirable (cytotoxic) bioactivities. A new TML, stagonolide L (), along with five known compounds (stagonolides D () and E (), curvulides A () and B/B (,), and pyrenolide C ()), were purified from cultures of the phytopathogenic fungus , and five semisynthetic derivatives of and (-) were obtained.

Natural ten-membered lactones: sources, structural diversity, biological activity, and intriguing future.

Covering: 2012 to 2022Ten-membered lactones (TMLs) are an interesting and diverse group of natural polyketides that are abundant in fungi and, to a lesser extent, in bacteria, marine organisms, and insects. TMLs are known for their ability to exhibit a wide spectrum of biological activity, including phytotoxic, cytotoxic, antifungal, antibacterial, and others. However, the random discovery of these compounds by scientific groups with various interests worldwide has resulted in patchy information about their distribution among different organisms and their biological activity.

Effects of Phytotoxic Nonenolides, Stagonolide A and Herbarumin I, on Physiological and Biochemical Processes in Leaves and Roots of Sensitive Plants.

Phytotoxic macrolides attract attention as prototypes of new herbicides. However, their mechanisms of action (MOA) on plants have not yet been elucidated. This study addresses the effects of two ten-membered lactones, stagonolide A (STA) and herbarumin I (HBI) produced by the fungus , on , and .

Structure-Activity Relationship of Phytotoxic Natural 10-Membered Lactones and Their Semisynthetic Derivatives.

Ten-membered lactones (nonenolides) demonstrate phytotoxic, antimicrobial, and fungicidal activity promising for the development of natural product-derived pesticides. The fungus is able to produce phytotoxic stagonolides A (), J (), K () and herbarumin I () with high yield. The aim of this study was to create a set of structurally related nonenolides and to reveal the structural features that affect their biological activity.

Entomotoxic Activity of the Extracts from the Fungus, and Its Major Metabolite, Tenuazonic Acid.

The study of fungal antibiotics in their competitive interactions with arthropods may lead to the development of novel biorational insecticides. Extracts of MFP253011 obtained using various methods showed a wide range of biological activities, including entomotoxic properties. Analysis of their composition and bioactivity allowed us to reveal several known mycotoxins and unidentified compounds that may be involved in the entomotoxic activity of the extracts.

Effect of Adjuvants on Herbicidal Activity and Selectivity of Three Phytotoxins Produced by the Fungus, .

The use of many fungal phytotoxins as natural herbicides is still limited because they cannot penetrate leaf cuticle without injury and a little is known on their selectivity. In order to assess the herbicidal potential of phytotoxic 10-membered lactones (stagonolide A, stagonolide K, and herbarumin I), the selection of adjuvants, the evaluation of selectivity of the toxins and the efficacy of their formulations were performed. Among four adjuvants tested, Hasten™ (0.

Isolation and Bioactivity of Secondary Metabolites from Solid Culture of the Fungus, .

The fungus, is considered to be a potential agent for the biocontrol of perennial sowthistle (). A new chlorinated xanthone, methyl 8-hydroxy-3-methyl-4-chloro-9-oxo-9-xanthene-1-carboxylate () and a new benzophenone derivative, 5-chloromoniliphenone (), were isolated together with eleven structurally related compounds (-) from the solid culture of the fungus, which is used for the production of bioherbicidal inoculum of . Their structures were determined by spectroscopic (mostly by NMR and MS) methods.

Stagonolides J and K and Stagochromene A, Two New Natural Substituted Nonenolides and a New Disubstituted Chromene-4,5-dione Isolated from S-47 Proposed for the Biocontrol of .

Two new natural 10-membered macrolides (, ) and one chromene-4,5-dione derivative (), named stagonolides J and K and stagochromene A, respectively, were isolated from the phytopathogenic fungus S-47, together with two known compounds, stagonolide A () and herbarumin I (). Stagonolides J and K and stagochromene A were characterized as (5,7*,8*,9*)-7,8-dihydroxy-9-propyl-5-nonen-9-olide, (5,7,9)-7-hydroxy-9-propyl-5-nonen-9-olide, and (2*,3*)-3-hydroxy-2-propyltetrahydro-2-chromene-4,5(3,4a)-dione, respectively, by spectroscopic (mostly by NMR and ESIMS) data. Compounds - showed different rates of phytotoxic activity on punctured leaf discs of .

Biological evaluation and determination of the absolute configuration of chloromonilicin, a strong antimicrobial metabolite isolated from Alternaria sonchi.

Chloromonilicin was isolated for the first time from Alternaria sonchi, a mycoherbicide proposed for the control of the noxious weed Sonchus arvensis. The already known alternethanoxins A and B and the three recently isolated phytotoxic polycyclic ethanones named alternethanoxins C-E were also isolated from the same source. Chloromonilicin was identified by spectroscopic data (essentially one-dimensional NMR, 2-dimensional NMR and high-resolution ESI-MS) and its structure was confirmed by single X-ray analysis, which also allowed the assignment of the absolute configuration.

Alternethanoxins C-E, Further Polycyclic Ethanones Produced by Alternaria sonchi, a Potential Mycoherbicide for Sonchus arvensis Biocontrol.

Three new polycyclic ethanones, named alternethanoxins C-E, were isolated together with the well-known and closely related alternethanoxins A and B, from the solid culture of Alternaria sonchi, a fungal pathogen proposed for perennial sowthistle (Sonchus arvensis L.) biocontrol. Alternethanoxins C-E were characterized by spectroscopic methods (essentially NMR and HRESI MS) as 2'-dihydroxymethyl-2,5,6,6'-tetrahydroxy-3'-methoxy-biphenyl-3-carboxylic acid methyl ester, 1,4,6,9,10-pentahydroxy-7-methoxy-6H-benzo[c]chromene-2-carboxylic acid methyl ester, and 7,9-dihydroxy-2-methoxy-9H-4,8-dioxa-cyclopenta[def]phenanthrene-5-carboxylic acid methyl ester.