Aigialomycins A-E, new resorcylic macrolides from the marine mangrove fungus Aigialus parvus

Aigialomycins A-E (2-6), new 14-membered resorcylic macrolides, were isolated together with a known hypothemycin (1) from the mangrove fungus, Aigialus parvus BCC 5311. Structures of these compounds, including absolute configuration, were elucidated by spectroscopic methods, chemical conversions, and X-ray crystallographic analysis. Hypothemycin and aigialomycin D (5) exhibited in vitro antimalarial activity with IC50 values of 2.2 and 6.6 mug/mL, respectively, while other analogues were inactive. Cytotoxicities of these compounds were also evaluated.