A laurane sesquiterpene and rearranged derivatives from the Chinese red alga Laurencia okamurai Yamada

One new laurane sesquiterpenoid, 3 beta-hydroxyaplysin (2), and two novel rearranged sesquiterpenes, laurokamurenes A (3) and B (4), together with three known related compounds, 3 alpha-hydroxydebromoaplysin (1), debromoaplysin (6), and laurinterol (7), have been isolated from the Chinese red alga Laurencia okamurai. Their structures, including relative stereochemistry, were determined on the basis of detailed interpretation of 2D NMR spectra and comparison with related known compounds.