Metabolism of Antifungal Thiochroman-4-ones by <i>Trichoderma viride</i> and <i>Botrytis cinerea</i>

Biotransformation of 6-methylthiochroman-4-one (<b>1</b>) and 6-chlorothiochroman-4-one (<b>2</b>) was performed using <i>Trichoderma viride</i> in order to obtain new derivatives with antifungal properties against the phytopathogen <i>Botrytis cinerea</i>. Two thiochromanone derivatives are described for the first time. Antifungal activity of these compounds was tested against two different strains of <i>Botrytis cinerea</i>; <b>1</b> and <b>2</b> gave 100% inhibition of <i>Bc</i>2100 at 100–250 μg/mL, and <b>3</b> gave a maximal inhibition of 96% of <i>Bc</i>UCA992 at 200 μg/mL. The detoxification mechanism of <b>1</b> and <b>2</b> by <i>B. cinerea</i> was also investigated

Chemically Induced Cryptic Sesquiterpenoids and Expression of Sesquiterpene Cyclases in <i>Botrytis cinerea</i> Revealed New Sporogenic (+)-4-<i>Epi</i>eremophil-9-en-11-ols

The sequencing of the genomes of the B05.10 and T4 strains of the fungus <i>Botrytis cinerea</i> revealed an abundance of novel biosynthetic gene clusters, the majority of which were unexpected on the basis of the previous analyses of the fermentation of these and closely related species. By systematic alteration of easy accessible cultivation parameters, using chemical induction with copper sulfate, we have found a cryptic sesquiterpenoid family with new structures related to eremophil-9-ene, which had the basic structure of the sesquiterpene (+)-5-<i>epi</i>aristolochene ((+)-4-<i>epi</i>eremophil-9-ene). An expression study of the sesquiterpene cyclase genes present in the <i>Botrytis cinerea</i> genome, under culture conditions, is reported. In general, a 3 day delay and a higher <i>BcSTC</i> genes expression were observed when copper (5 ppm) was fed to the fermentation broth. In addition, to the observed effect on the <i>BcBOT2</i> (<i>BcSTC1</i>) gene, involved in the biosynthesis of the botrydial toxin, a higher expression level for <i>BcSTC3</i> and <i>BcSTC4</i> was observed with respect to the control in the strain B05.10. Interestingly, under copper conditions, the <i>BcSTC4</i> gene was the most expressed gene in the <i>Botrytis cinerea</i> UCA992 strain. <i>In vitro</i> evaluation of the biological role of these metabolites indicates that they contributed to the conidial development in <i>B. cinerea</i> and appear to be involved in self-regulation of the production of asexual spores. Furthermore, they promoted the formation of complex appressoria or infection cushions