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

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