Phoslactomycins from <i>Streptomyces</i> sp. MLA1839 and Their Biological Activities

Phoslactomycins H (<b>1</b>) and I (<b>2</b>), two new members of the phoslactomycin class of chemistry, were isolated from <i>Streptomyces</i> sp. MLA1839 on the basis of their antifungal activities. Their structures were elucidated using extensive NMR spectroscopy and mass spectrometry. Phoslactomycin H (<b>1</b>) featured a rare and unprecedented <i>N</i>,<i>N</i>-dimethylamine substitution at C-4 and existed as a hydroxy acid rather than the more common lactone. Herein, we report the structure of these compounds and their biological activities

Alveolarides: Antifungal Peptides from <i>Microascus alveolaris</i> Active against Phytopathogenic Fungi

Three novel cyclodepsipeptides, alveolarides A (<b>1</b>), B (<b>2</b>), and C (<b>3</b>), each possessing the rare 2,3-dihydroxy-4-methyltetradecanoic acid unit and a β-phenylalanine amino acid residue, along with the known peptide scopularide were isolated and identified from the culture broth of <i>Microascus alveolaris</i> strain PF1466. The pure compounds were evaluated for biological activity, and alveolaride A (<b>1</b>) provided strong <i>in vitro</i> activity against the plant pathogens <i>Pyricularia oryzae</i>, <i>Zymoseptoria tritici</i>, and <i>Ustilago maydis</i>. Moderate activity of alveolaride A was observed under <i>in planta</i> conditions against <i>Z. tritici</i>, <i>Puccinia triticina</i>, and <i>Phakopsora pachyrhizi</i>. Structures of <b>1</b>, <b>2</b>, and <b>3</b> were determined by detailed analysis of NMR (1D and 2D) and mass spectrometry data. The partial absolute configuration of alveolaride A (<b>1</b>) was established