Employing dereplication and gradient 1D NMR methods to rapidly characterize sponge-derived sesterterpenes.

The sesterterpene constituents of two Indo-Pacific sponges were investigated and rapidly characterized using aggressive dereplication methods along with gradient 1D NMR techniques. Lendenfeldia frondosa yielded three sesterterpenes: 12beta,16beta,22-trihydroxy-24alpha-methylscalar-25beta,24alpha-olide (1), the 24 epimer of a known compound; 12beta,22-dihydroxy-24-methylscalar-17-en-24,25-olide (2), a known compound; and 22-hydroxy-24-methylsedn-16-en-24-one-12beta,25beta-olide (3), a new compound. A Hyrtios sp. sponge yielded known 12alpha-acetoxy-16beta-hydroxyscalarolbutenolide (5).