Kahukuenes, new diterpenoids from the marine alga Laurencia majuscula

Kahukuenes A [4] and B [5], new diterpenoids possessing an unprecedented prenylated chamigrene structure as part of a decalin ring, were isolated from the Hawaiian marine alga Laurencia majuscula. Spectroscopic methods, including extensive 1D and 2D nmr studies, were used to establish the structure and relative stereochemistry of these two secondary metabolites.