Stereochemical features of sesquiterpene metabolites as a distinctive trait of red seaweeds in the genus Laurencia

Red seaweeds in the genus Laurencia may be classified into four lineages according to the stereochemical features of their metabolites, i.e. the known obtusane (like obtusol (+)-1), isoobtusane (like isoobtusol (+)-2) and rogiolane (like rogiolol (-)-3) and - structurally revised and renamed here - cartilagineane chamigrene sesquiterpenes (like cartilagineol 10), in a vision that encompasses also biogenetic descendants, like cuparane sesquiterpenes, and fits ideas of historical contingency. (C) 1997 Elsevier Science Ltd.