Antimicrobial metabolites from a novel halophilic actinomycete <i>Nocardiopsis terrae</i> YIM 90022

<div><p>A quinoline alkaloid <b>1</b> and five known compounds (<b>2</b>–<b>6</b>) were isolated from a novel halophilic actinomycete <i>Nocardiopsis terrae</i> YIM 90022, and their structures were determined by spectroscopic studies as 4-oxo-1,4-dihydroquinoline-3-carboxamide (<b>1</b>), <i>p</i>-hydroxybenzoic acid (<b>2</b>), <i>N</i>-acetyl-anthranilic acid (<b>3</b>), indoly-3-carboxylic acid (<b>4</b>), cyclo(Trp-Gly) (<b>5</b>) and cyclo(Leu-Ala) (<b>6</b>). Compound <b>1</b> was isolated from natural resources for the first time. Compounds <b>1</b> and <b>3</b> showed antimicrobial activities against some plant pathogens.</p></div

A new natural nucleotide and other antibacterial metabolites from an endophytic <i>Nocardia</i> sp.

<div><p>Nine compounds were isolated from <i>Nocardia</i> sp. YIM 64630, and their structures were elucidated as 5′-<i>O</i>-acetyl-2′-deoxyuridine (<b>1</b>), 22<i>E</i>,24<i>R</i>-5α,6α-epoxyergosta-8(14),22-diene-3β,7α-diol (<b>2</b>), 22<i>E</i>,24<i>R</i>-5α,6α-epoxyergosta-8,22-diene-3β,7α-diol (<b>3</b>), 22<i>E</i>,24<i>R</i>-ergosta-7,22-diene-3β,5α,6β-triol (<b>4</b>), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (<b>5</b>), 4′,5,6-trihydroxy-7-methoxyisoflavone (<b>6</b>), 2,4,4′-trihydroxy-deoxybenzoin (<b>7</b>), methyl [4-hydroxyphenyl]acetate (<b>8</b>) and daidzein by extensive spectroscopic analyses. Compound <b>1</b> was isolated from natural resources for the first time. The antimicrobial and antioxidant activities of compounds <b>1</b>–<b>8</b> were investigated.</p></div

A new cyclic tetrapeptide from an endophytic <i>Streptomyces</i> sp. YIM67005

<div><p>One new cyclic tetrapeptide, cyclo(l-Tyr-l-Pro-l-Phe-<i>trans</i>-4-hydroxy-l-Pro) (<b>1</b>), together with two known cyclodipeptides, cyclo(l-Phe-<i>trans</i>-4-hydroxy-l-Pro) (<b>2</b>) and cyclo(l-Val-l-Tyr) (<b>3</b>), were isolated from the fermentation broth of <i>Streptomyces</i> sp. YIM67005 associated with <i>Inula cappa</i> DC. The planar structure of compound <b>1</b> was determined on the basis of spectroscopic techniques, while the absolute configurations of the amino acid residues were determined by the application of the advanced Marfey method. The cytotoxicity and antimicrobial activity of compound <b>1</b> were investigated.</p></div

A new polyoxygenated farnesylcyclohexenone from Fungus <i>Penicillium</i> sp.

<div><p>A new polyoxygenated farnesylcyclohexenone, peniginsengin A (<b>1</b>), was isolated from the fermentation of <i>Penicillium</i> sp. YIM PH30003, an endophytic fungus associated with <i>Panax notoginseng</i> (Burk.) F. H. Chen. The structure was assigned based on a combination of 1 D and 2 D NMR and mass spectral data. The cytotoxicity and antimicrobial activities of compound <b>1</b> were investigated.</p></div

The antifungal metabolites obtained from the rhizospheric <i>Aspergillus</i> sp. YIM PH30001 against pathogenic fungi of <i>Panax notoginseng</i>

<div><p>Eight anthraquinones (<b>1–8</b>), three xanthones (<b>11–13</b>) and two phenols (<b>9–10</b>) were isolated from <i>Aspergillus</i> sp. associated with <i>Panax notoginseng</i>, and their structures were determined as ziganein-1-methyl ether (<b>1</b>), 8-<i>O</i>-methylchrysophanol <b>(2</b>), averythrin (<b>3</b>), averufin (<b>4</b>), 8-<i>O</i>-methyl averufin (<b>5</b>), versicolorin B (<b>6</b>), averantin (<b>7</b>), methyl-averantin (<b>8</b>), arugosin C (<b>9</b>), diorcinol (<b>10</b>), sterigmatocystin (<b>11</b>), demethylsterigmatocystin (<b>12</b>) and dihydrosterigmatocystin (<b>13</b>) by spectroscopic analyses. Compounds <b>1</b>, <b>2</b> and<b> 5</b> were the novel isolates from genus <i>Aspergillus</i>. Compounds <b>3</b>, <b>6</b> and<b> 7</b> exhibited antifungal activity against <i>Fusarium</i><i>solani</i>, pathogenic fungus of <i>P. notoginseng</i>, with minimum inhibitory concentrations (MICs) of 16<b>–</b>32 μg/mL, and compounds <b>1</b>, <b>3</b>, <b>4</b>, <b>7</b> and <b>9</b> showed antibacterial activity against <i>Bacillus</i><i>subtilis</i> with MICs of 64–128 μg/mL, 16–32 μg/mL, 8–16 μg/mL, 16–32 μg/mL and 64–128 μg/mL, respectively. The metabolites showed the potential value in the research of antifungal agents, especially in searching for a biocontrol of diseases of <i>P. notoginseng</i>. The preliminary structure–activity relationships have been discussed for some of the compounds.</p></div

Anti-phytopathogen, multi-target acetylcholinesterase inhibitory and antioxidant activities of metabolites from endophytic <i>Chaetomium globosum</i>

<p>Fourteen metabolites with various structure types were isolated from endophytic <i>Chaetomium globosum</i>. Five compounds were separated from genus <i>Chaetomium</i> for the first time. Some compounds exhibited remarkable inhibition against phytopathogenic fungi causing root rot of <i>Panax notoginseng.</i> Compounds <b>1</b>–<b>5</b> had significant DPPH-free radical-scavenging activity. Compounds <b>3</b> and <b>5</b> indicated significant inhibitions against the acetylcholinesterase (AChE). From preliminary structure–activity relationship, it was found that the oxygenic five-membered ring of <b>3</b> and <b>5</b> was crucial in the anti<b>-</b>AChE activity. These structures provide new templates for the potential treatment and management of plant diseases and Alzheimer disease.</p