Dendrillic Acids A and B: Nitrogenous, Rearranged Spongian Nor-Diterpenes from a sp. Marine Sponge.

Two nitrogenous rearranged spongian nor-diterpenoids, dendrillic acids A and B, were isolated from a marine sponge sp. (order: Dendroceratida; family: Darwinellidae). The structures of the metabolites were elucidated on the basis of spectroscopic analysis as well as density functional theory prediction of NMR chemical shifts and application of the DP4+ algorithm.

Synthesis, Characterization, and Bioactivity of the Lichen Pigments Pulvinamide, Rhizocarpic Acid, and Epanorin and Congeners.

The lichen natural products pulvinamide, rhizocarpic acid, and epanorin have been synthesized and characterized spectroscopically and by X-ray crystallography. The syntheses, by ring-opening of pulvinic acid dilactone (PAD), may well be biomimetic, given the well-known occurrence of PAD in lichen. The enantiomers, -rhizocarpic acid and -epanorin, and corresponding carboxylic acids, norrhizocarpic acid and norepanorin, were similarly prepared.