Cembranoid constituents from an Australian collection of the soft coral Sinularia flexibilis

Abstract

Two new cembranoid lactones have been isolated from Barrier Reef collections of Sinularia flexibilis. Other metabolites include four previously reported macrocyclic diterprenes. The structure and relative configuration of flexibilide (4), C₂₀H₃₀O₄, was determined by single- crystal X-ray diffraction methods. The colourless crystals are orthorhombic, space group P2₁2₁2₁, a 10.682, b 30.404, c 5.779 Ǻ, Z 4.