New sesquicillins, insecticidal antibiotics produced by Albophoma sp. FKI-1778

Four new antibiotics, sesquicillins B to E were isolated from the culture broth of Albophoma sp. FKI-1778 together with known sesquicillin (sesquicillin A in this paper). The structures of sesquicillins were elucidated by spectroscopic studies including various NMR experiments. All sesquicillins have a common pyrano-diterpene skeleton. Sesquicillins showed moderate inhibitory activity against the growth of Artemia salina (brine shrimps) and Jurkat cells.