Biologically Active Metabolites from Fungi, 5. Palmarumycins C₁–C₁₆ from Coniothyrium sp.: Isolation, Structure Elucidation, and Biological Activity

Twelve new spiro acetal metabolites, the palmarumycins C 1 –C 8 , ( 1–8 ), C 11 ( 11 ), C 12 ( 12 ), C 15 ( 15 ), C 16 ( 16 ), and three known representatives ( 10, 13, 14 ) of this new class of antibiotics were isolated from Coniothyrium sp. The compounds show antibacterial, antifungal and herbicidal activity at concentrations of 10 −6 –10 −4 mol/l. The structures of palmarumycin C 2 ( 2 ), palmarumycin C 3 ( 3 ), and palmarumycin C 5 ( 5 ) were confirmed by X‐ray structure analysis.