Benzopyran derivatives from endophytic <i>Daldinia eschscholzii</i> JC-15 in <i>Dendrobium chrysotoxum</i> and their bioactivities

<p>Five new benzopyran derivatives (<b>2</b>–<b>6</b>) and a new natural product (<b>1</b>) were isolated from endophytic <i>Daldinia eschscholzii</i> in <i>Dendrobium chrysotoxum</i> and determined as (R)-2,3-dihydro-2,5-dihydroxy-2-methylchromen-4-one (<b>1</b>), (2R, 4S)-2,3-dihydro-2-methyl-benzopyran-4,5-diol (<b>2</b>), (R)-3-methoxyl-1-(2,6-dihydroxy phenyl)-butan-1-one (<b>3</b>), 7-O-α-d-ribosyl-5-hydroxy-2-methyl-4H-chromen-4-one (<b>4</b>), 7-O-α-d-ribosyl-2,3-dihydro-5-hydroxy-2-methyl-chromen-4-one (<b>5</b>), daldinium A (<b>6</b>). These compounds were evaluated for their antimicrobial activity, anti-acetylcholinesterase, nitric oxide inhibition, anticoagulant, photodynamic antimicrobial activities and glucose uptake of adipocytes. Some compounds showed photoactive antimicrobial activities and glucose uptake stimulating activities.</p

Phytotoxic, antibacterial, and antioxidant activities of mycotoxins and other metabolites from <i>Trichoderma</i> sp.

<p>A new natural mycotoxin was isolated from the fermentation broth of <i>Trichoderma</i> sp. Jing-8 and the structure was determined as alternariol 1′-hydroxy-9-methyl ether (<b>1</b>), together with twelve known compounds. The structures were elucidated on the basis of their 1D, 2D NMR spectra and mass spectrometric data. Compounds <b>1</b>, <b>8</b> and <b>9</b> indicated inhibitions against germination of the seeds of cabbage with MICs < 3 μg/mL. The compound <b>1</b> showed the antibacterial activity against <i>Bacillus subtilis</i> and <i>Staphylococcus aureus</i> with MICs at 64 μg/mL. Compound <b>1</b> and <b>3</b> showed significant DPPH radical-scavenging activities with IC₅₀ at 12 μg/mL, respectively. The OH at C-1′ in compound <b>1</b> decreased the cytotoxicity of these mycotoxins. A primary structure–activity relationship about the alternariol derivatives was discussed. Compounds <b>2</b>–<b>7</b> and <b>8</b> were the first time to be isolated from the <i>Trichoderma</i>.</p

Phytotoxic, antibacterial, and antioxidant activities of mycotoxins and other metabolites from <i>Trichoderma</i> sp.

<p>A new natural mycotoxin was isolated from the fermentation broth of <i>Trichoderma</i> sp. Jing-8 and the structure was determined as alternariol 1′-hydroxy-9-methyl ether (<b>1</b>), together with twelve known compounds. The structures were elucidated on the basis of their 1D, 2D NMR spectra and mass spectrometric data. Compounds <b>1</b>, <b>8</b> and <b>9</b> indicated inhibitions against germination of the seeds of cabbage with MICs < 3 μg/mL. The compound <b>1</b> showed the antibacterial activity against <i>Bacillus subtilis</i> and <i>Staphylococcus aureus</i> with MICs at 64 μg/mL. Compound <b>1</b> and <b>3</b> showed significant DPPH radical-scavenging activities with IC₅₀ at 12 μg/mL, respectively. The OH at C-1′ in compound <b>1</b> decreased the cytotoxicity of these mycotoxins. A primary structure–activity relationship about the alternariol derivatives was discussed. Compounds <b>2</b>–<b>7</b> and <b>8</b> were the first time to be isolated from the <i>Trichoderma</i>.</p