A new 20-membered macrolide produced by a marine-derived Micromonospora strain.

A new 20-membered macrolide named as levantilide C was isolated from the Micromonospora strain FIM07-0019 recovered from shallow coastal waters near the island of Chiloe, Chile. The chemical structure of levantilide C was elucidated on the basis of one- and two-dimensional NMR analysis. Two known indole derivatives were also isolated from this strain. Levantilide C exhibited moderate antiproliferative activity against several tumour cell lines.