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

Mycoleptodiscins A and B, Cytotoxic Alkaloids from the Endophytic Fungus <i>Mycoleptodiscus</i> sp. F0194

Two novel reddish-orange alkaloids, mycoleptodiscin A (<b>1</b>) and mycoleptodiscin B (<b>2</b>), were isolated from liquid cultures of the endophytic fungus <i>Mycoleptodiscus</i> sp. that had been isolated from <i>Desmotes incomparabilis</i> in Panama. Elucidation of their structures was accomplished using 1D and 2D NMR spectroscopy in combination with IR spectroscopic and MS data. These compounds are indole-terpenes with a new skeleton uncommon in nature. Mycoleptodiscin B (<b>2</b>) was active in inhibiting the growth of cancer cell lines with IC₅₀ values in the range 0.60–0.78 μM