On the Biosynthesis of Tenuazonic Acid in Alternaria tenuis.

Gatenbeck, Sten; Sierankiewicz, Julian; Enzell, Curt R.; Hoeven, Marcel G. van der; Swahn, Carl‐Gunnar

doi:10.3891/acta.chem.scand.27-1825

Cited by 23 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tenuazonic acid is a potent mycotoxin belonging to the 3-acylpyrrolidine-2,4-diones family of tetramic acid analogs (Weidenbörner, 2001 ). It is biosynthesized from L-isoleucine in Alternaria tenuis (Gatenbeck and Sierankiewicz, 1973 ). In previous studies, tenuazonic acid showed antibacterial, antiviral and antitumor activities (Miller et al, 1963 ; Gitterman, 1965 ).…”

Section: Discussionmentioning

confidence: 99%

An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products

et al. 2015

View full text Add to dashboard Cite

Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.

show abstract

Section: Discussionmentioning

confidence: 99%

An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In Alternaria tenuis TA is biosynthesized from L-isoleucine (Gatenbeck & Sieranki, 1973;Stickings & Townsend, 1961).…”

Section: Introductionmentioning

confidence: 99%

Quantification of the Alternaria mycotoxin tenuazonic acid in beer

et al. 2010

View full text Add to dashboard Cite

“…In addition to the insufficient toxicological data not much is known about biosynthesis and regulation of the mycotoxins either. Hypothetical biosynthesis pathways for AOH/AME and TA have been suggested ([Gatenbeck and Hermodsson 1965]; [Gatenbeck and Sierankiewicz 1973]; [Hiltunen and Söderhäll 1992]; [Light 1970]; [Stinson 1985]) but the genes are not known. Environmental factors have a great impact on Alternaria toxin production.…”

Section: Introductionmentioning

confidence: 99%

Influence of pH and carbon to nitrogen ratio on mycotoxin production by Alternaria alternata in submerged cultivation

et al. 2012

View full text Add to dashboard Cite

Production of the Alternaria mycotoxins alternariol (AOH), alternariol monomethylether (AME) and tenuazonic acid (TA) by Alternaria alternata DSM 12633 was influenced by pH and carbon to nitrogen (C:N) ratio of the growth medium both in shaking flasks and bioreactor cultivation. The impact of medium pH on mycotoxin production was studied in the range of pH 3.5 - 8. pH values above 5.5 led to a decreased mycotoxin production or inhibited mycotoxin formation completely whereas an acidic pH in the range of 4.0-4.5 was optimal for mycotoxin production. The influence of the C:N ratio was evaluated over the range of 24 to 96. Glucose was used as carbon source and its concentration was altered while nitrogen concentration was kept constant. Growth kinetics and mycotoxin production parameters were studied depending on different C:N ratios. With increasing initial glucose concentration fungal biomass did increase but the maximum specific growth rate was not influenced. The optimal initial C:N ratio for attaining highest mycotoxin concentrations was 72. A higher C:N ratio did not further enhance mycotoxin production.

show abstract

On the Biosynthesis of Tenuazonic Acid in Alternaria tenuis.

Cited by 23 publications

References 0 publications

An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products

An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products

Quantification of the Alternaria mycotoxin tenuazonic acid in beer

Influence of pH and carbon to nitrogen ratio on mycotoxin production by Alternaria alternata in submerged cultivation

Contact Info

Product

Resources

About