Other smaller peaks with similar UV to 1 were observed more evidently in the scaled-up cultures (Fig. ). Among them, 4 is a non-polar burnettiene of a molecular weight of 462 and with a polyene UV with a bathochromic shift of ~20 nm compared to the other burnettienes (Fig. ). However, 4 was prone to degradation and the quantity isolated was insufficient for structure elucidation.