Aspergilasines A-D: Four Merocytochalasans with New Carbon Skeletons from Aspergillus flavipes QCS12

Aspergilasines A-D (1-4), four rnerocytochalasans with new skeletons, were isolated from the liquid culture broth of Aspergillits flavipe QCS12. Aspergilasine A (1) possesses a uniquely caged pentacyclo [7.2,0.1(4,11).0(2,7).0(5,,10)] dodecane skeleton With an unexpected cyclobutane ring that fotmed by the fusion of two epicoccine moieties via two [3 + 2] cycloadditions. Aspergilasies B-D (2-4) are key bioSyhthetic intermediates of epicochalasine B that fit well with our previous biosynthetic proposal.